Program for 2015 IEEE International Symposium on Medical Measurements and Applications
Thursday, May 7
Thursday, May 7, 09:30 - 10:15
Room 1 (Salone d'Onore)
Thursday, May 7, 10:15 - 10:30
Welcome - Opening session
Room 1 (Salone d'Onore)
Thursday, May 7, 10:30 - 11:00
Carlo Gulotta - "Measurements based on the forced oscillation technique (FOT) for asthma assessment & management"Room 1 (Salone d'Onore)
Thursday, May 7, 11:00 - 12:40
T1.1: Biosignal processing I
Room 1 (Salone d'Onore)
Chairs: Voicu Groza (University of Ottawa, Canada), Anna Maria Lucia Lanzolla (Polytechnic of Bari, Italy)
- 11:00 Gaussian Mixture Modeling for Statistical Analysis of Features of High-Resolution CT Images of Diffuse Pulmonary Diseases
- This paper presents results of statistical analysis of fractal and texture features obtained from images of diffuse pulmonary diseases (DPDs). The features were extracted from preprocessed regions of interest (ROIs) selected from high-resolution computed tomography images. The ROIs represent five different patterns of DPDs and normal lung tissues. A Gaussian mixture model (GMM) was constructed for each feature, including all patterns. For each GMM, the six classes were identified and compared with the radiological classification of the corresponding ROIs. In 78.5% of the features, the GMM provides, for at least one class, a correct classification of at least 60%. The GMM approach facilitates detailed statistical analysis of the characteristics of each feature and assists in the development of classification strategies.
- 11:20 Using Deconvolution to Determine the Sphincter Strength Distribution Around the Urethra
- Urethral Pressure Profilometry (UPP) is a tool in the diagnosis of urinary incontinence. The pressure profile along the urethra is measured by a special catheter in order to assess the contraction strength of the sphincter muscle. However, the diagnostic value of pressure profilometry is limited. We seek to increase the diagnostic value by providing a detailed spatial reconstruction of the pressure profile on the outside surface of the urethra. We use deconvolution in order to solve the inverse problem of determining the pressure distribution on the outside of a tube from measured data on the inside. Therefore, we propose a parametric Point-Spread-Function (PSF) and optimize its parameters using a Finite-Element (FE) model. Simulation results verifying accuracy and robustness of this method conclude this work.
- 11:40 Spatio-Temporal Video Processing for Respiratory Rate Estimation
- In this paper, we present a wire-free, low-cost video processing-based technique for respiratory rate (RR) estimation. The proposed method blends together two recently presented techniques, with the purpose of emphasizing small movements, such as respiratory movements possibly present in a video stream, in order to detect them. Initially, the system performs a spatial decomposition of the video frames in a pyramidal representation, in which each layer contains different spatial details. The levels are then pixel-wise temporally filtered with an infinite impulse response (IIR) filter, purposely designed to extract components having a periodicity compatible with the respiratory rate. Afterwards a single motion signal is extracted from each level. Finally, the extracted signals are jointly analyzed according to the maximum likelihood (ML) criterion in order to estimate the respiratory rate. The parameters extracted by our algorithm show a good agreement with those indicated by a gold-standard polysomnographic system. Therefore, our results, although preliminary, are encouraging and show that the respiratory rate can be reliably measured and monitored by a low-cost, wire-free, video processing-based system.
- 12:00 Combining Graph Analysis and Recurrence Plot on fMRI Data
- In this work we investigate on the nonlinear properties of the brain networks using Graph Analysis and Cross Recurrence Plot. The nonlinear dynamics of the brain is analyzed using time series coming from fMRI data. Two groups of human subjects, one affected by schizophrenia and healthy controls, are imaged during the completion of a working memory task. To examine the spatio-temporal properties of the BOLD signal, nonlinear recurrence properties are extracted from the time series of the most relevant voxels, using the cross recurrence plots and the corresponding measures. Then, a graph is build using such measures as a weight value between different brain regions (the nodes). The purpose of the paper is to give a description of the most relevant functional areas activated during the task and to capture the differences between the groups. Results are promising, since the methodology is still to be fully developed and explored.
- 12:20 Automated Hippocampus Segmentation with the Channeler Ant Model: results on different datasets
- The hippocampus segmentation in Magnetic Resonance (MRI) scans is a relevant issue for the diagnosis of many pathologies. The present work describes a fully automated method for the hippocampal segmentation and discusses the results obtained on three datasets provided by different institutions and referring to different pathologies that involve hippocampus anatomy. The algorithm is based on an extension of the Channeler Ant Model, a powerful non linear segmentation tool belonging to the family of ant colony-based models, whose application to medical image processing already provided some promising results in the analysis of CT and PET scans. In this application, thanks to a modified pheromone deposition rule, both the grey matter intensity and the expected average hippocampus shape are taken into account. The results on the three available datasets, obtained from the comparison to manual segmentations by different subjects and protocols, show an average Dice Index in the 0.72 − 0.79 range, depending on the analysed dataset.
T2.1: Imaging and communication I
Room 2 (Stanza dello Zodiaco)
Chair: Sergio Rapuano (University of Sannio, Italy)
- 11:00 Measurements of Change in Thermal Images Due to Applied Pressure
- Thermal imaging is of value to medical professionals because of its low risk and non-invasive properties. While thermal imaging has been explored in the area of pressure ulcers, many relevant papers address existing pressure ulcers and few address the prevention of pressure ulcers. This paper aims to examine the potential of thermal imaging in the prevention of pressure ulcers by extracting temperature-based and region-based measurements from thermal images and quantifying thermal patterns. A subject was asked to press on a pressure sensor mat at two specified intensities, and a series of thermal images were taken before and after to track thermal behaviour. These images were subjected to standard image processing techniques before temperature specific contour and area measurements were extracted as well as region specific intensity and weighted centroid measurements. Results indicated that the contour and area measurements were able to capture the temperature pattern of the whole hand, while the intensity measurements were able to indicate region specific thermal patterns. These results suggest that the extraction of measurements from a series of thermal images can capture and quantify visually identifiable thermal patterns of the hand over time. These findings will be expanded upon in future work by further examining different measurements, sharper images, different equipment and the involvement of elderly patients. While future collection of patient data is expected to yield different thermal patterns, this paper has demonstrated recognition and quantification of a pattern, regardless of the pattern itself.
- 11:20 Detection of Necrotizing Enterocolitis in Newborns using Abdominal Thermal Signature Analysis
- In this paper we present a novel approach to early diagnosis of Necrotizing Entercolitis in premature newborns. In particular, using an infrared thermal camera, thermal image of newborn abdomen is acquired. Image processing and spatial segmentation are then used to retrieve thermal signature which is represented by a sample distribution of values from an 8-bit grey level color palette. First order statistical features are then extracted from thermal signature and are used into a classifier. Preliminary results are encouraging and show the potential use of the proposed approach for classification between healthy and sick newborns.
- 11:40 Digital Chest Tomosynthesis: the Main Steps to a Computer Assisted Lung Diagnostic System
- In this paper, we present the main parts of a com¬plete lung diagnostic system using digital tomosynthesis, and the first results obtained analyzing real tomosynthesis (DTS) images. In a DTS system first coronal image slices are reconstructed from projections using iterative and MITS reconstruction algorithms. Nodule detection is based on 2D image processing on the sepa-rated slice images, and a joint further analysis of the 2D results. We propose efficient, domain-specific filters for the enhancement and classification of bright, rounded structures. Also we develop a vessel enhancing algorithm based on strain energy filters. Ves¬sel enhancement is required because most of the false positive fin-dings come from nodule-like vessel shadows in the images. To reduce false positive findings SVM-based classifiers are applied, where features obtained from the vessel enhancement module are used as inputs. The system was evaluated on the first DTS scans, obtained from our experimental DTS system. The database con-tains ~2000 nodule candidates. 97% of nodules could be detected, while producing on average 31 false positives per scan.
- 12:00 Preliminary Test of a Prototype of Microwave Axial Tomograph for Medical Applications
- An existing prototype of microwave imaging tomograph, previously designed by the present Authors for NDT applications, has been adapted in order to deal with biomedical targets. The developed system allows collecting multi-view multifrequency data. An efficient inversion procedure is used to retrieve the distributions of the dielectric properties from the measured field samples. Some numerical simulations aimed at validating the proposed system and preliminary measurement results obtained by using a breast phantom are presented in this paper.
- 12:20 AvanTomography: A Compact Module for Positron Emission Mammography
- In AvanTomography project, a compact, high performance module was developed for axial positron emission mammography, which can be integrated with X-ray mammography. With its Axial PET configuration, AvanTomography can achieve a uniform spatial resolution. Compact design of the module enables a cost and space efficient system for breast screening. Various configurations, plate or full ring, can be achieved by using multiple modules, allowing the screening of axillary and mammary regions with a single scanner position. In this project, a 6-module system was constructed and tested with a 22Na point source. Energy calibration was performed. Performance characteristics such as detection efficiency and energy resolution were measured.
T3.1: Special Session: Non-invasive assessment of the neuromuscular system
Room 3 (Stanza della Caccia)
Chairs: Marco Knaflitz (Politecnico di Torino, Italy), Filippo Molinari (Politecnico di Torino, Italy)
- 11:00 Gait Feature Analysis of Polyneuropathy Patients
- Polyneuropathy (PNP) and aging both bring changes to the walking pattern of elderly people. However, the identification methods of PNP from gait patterns were not sufficiently investigated from a technical perspective. In this study an automated classification method was developed to discriminate the neuropathic gait from both young healthy and old healthy gait using artificial neural network (ANN). A robust markerless gait detection system was employed and experiments were conducted in normal clinical conditions on 10 young, 10 old and 10 neuropathy patients. Four types of gait features, namely temporal features, kinematic joint trajectories in time domain, the Fourier transform of joint angles in frequency domain, and the symmetry indexes, were extracted. One-way analysis of variance (ANOVA) was employed as a statistical analysis tool and feature selection method. Each type of features and the selected features obtained from ANOVA were served as the input of a two-layer-feed-forward neural network separately. A two-fold cross validation method with enhanced generalization was utilized to evaluate the accuracy of classification. The ground truth information for the result validation was provided by the medical experts involved in the study. The outcome of individual feature set showed that the kinematic features in time domain reached the highest classification accuracies of 94.2%, 94.8% and 94.8% for three classes, while the symmetric features yielded the lowest. Combining two sets of features can improve the performance slightly and the best performance was achieved by using the selected significant features with accuracies of 96.2%, 97.0% and 96.9% respectively.
- 11:20 Dynamic Posturography:pertubed equilibruim assessment on healthy adult subjects
- Posturography is a fundamental tool to investigate the systems involved in the postural control either in static and in dynamic conditions. In the present paper we decided, by using sinusoidal perturbations of base support in medio-lateral direction, to analyze the equilibrium parameters widely used in posture control studies, Compensatory Postural Adjustments (CPAs), and Anticipatory Postural Adjustments (APAs) in the perspective of defining a range of equilibrium parameters for healthy adult subjects. Fourteen subjects (9 males and 5 females) with no experience of the experimental procedure participated to the experiments. Sine and step movements of base support were imposed through a 3-DOF (Degrees Of Freedom) robot and both standard and here proposed novel indices were calculated for the evaluation of equilibrium performance. The results suggest that the length of the Center Of Pressure (COP) trajectory is proportional to the frequency of the oscillations of the platform in the sine perturbation trials, while the COP range of motion in x and y directions is not influenced. Moreover, we found the absence of asymmetries in the healthy subjects when they performed the session with step perturbations.
- 11:40 Non-Invasive Assessment of Neuromuscular Disorders by 7 Tesla Magnetic Resonance Imaging and Spectroscopy: Dedicated Radio-Frequency Coil Development
- Magnetic Resonance Imaging (MRI) and spectroscopy (MRS) of the muscle is a valuable tool in the diagnosis and monitoring of Neuromuscular Disorders (NMD). New Ultra-High Field (UHF) 7T MRI systems, with their enhanced Signal-to-Noise Ratio (SNR), may offer increased image quality in terms of spatial resolution as well as shorter scanning time compared to lower field systems. In the study of NMD the new features provided by UHF MR may allow the use of functional techniques to improve biochemical and physiological information of skeletal muscle correlated to the pathogenesis and progression of the muscle involvement. This study reports the recent achievements on muscle imaging and spectroscopy obtained at the first and unique Italian 7T MR scanner available at the IMAGO7 Foundation in Pisa. Dedicated radio-frequency coils for proton imaging and phosphorous spectroscopy have been designed, developed and validated in vivo, and are now ready for clinical research studies.
- 12:00 A Non-Invasive Method for a Quantitative Evaluation of Muscle Involvement in MRI of Neuromuscular Diseases
- The work here described has been carried out in the framework of a research topic devoted to the study of NeuroMuscular Diseases (NMD) by Magnetic Resonance Imaging (MRI) as reliable and non invasive instrument for diagnosis and follow up. The evaluation of the images is now only visual, while standardization procedures and quantitative methods could be very useful instruments to optimize the diagnostic performances. We propose a new method to evaluate the fat infiltration in tissues developed and retrospectively applied to images of the human leg. Through a muscle segmentation algorithm on structural T1-weighted magnetic resonance images (MRIs), the estimated non-muscle percentage (eNMP) in the segmented muscle area has been evaluated in healthy subjects as a reference value. A semi-automated procedure allows extending the algorithm to MRIs of NMD patients. A strong correlation has been demonstrated between this index and the disease severity. The final aim is to obtain a quantitative evaluation of fat infiltration percentage and to relate it to the grade of muscle impairment in subjects affected by Neuro-Muscular Diseases (NMD).
- 12:20 Low cost inkjet printing for the fast prototyping of surface EMG detection systems
- In the last years, printing techniques have been developed for the realization of electronic circuits using functional inks. In this field inkjet printing technology has a number of attractive features and received a lot of interest with the development of specifically designed functional inks, including conductive inks based on silver nanoparticles or organic polymers. Some works in literature investigated the use of inkjet printing technique for the development of electrophysiological sensors. The aim of this work was to explore the potentialities of low cost inkjet printing for the prototyping of high-density electrode arrays for the detection of surface electromyographic signal (sEMG). A low cost inkjet system for the printing of conductive tracks based on standard office printer has been setup and tested for the prototyping of sEMG detection systems. The setup allowed the printing of high density bi-dimensional electrode arrays. The sEMG detection systems have been tested on the abductor pollicis muscle and biceps brachii muscle during isometric and dynamic contractions. The detected signals show a good quality and a stable contact without movement artifacts. The proposed system offers the possibility to design and print electrode arrays with different electrode patterns in a few minutes. This characteristic allows developing sEMG detection systems that can be adapted to the anatomy of the muscles under investigation in a short time.
Thursday, May 7, 12:40 - 14:10
Room: Sala delle Colonne
Thursday, May 7, 14:10 - 15:50
T1.2: Sensors for medical systems / Sensor fusion and calibration
Room 1 (Salone d'Onore)
Chairs: Simone Corbellini (Politecnico di Torino, Italy), Bruce Wallace (Carleton University, Canada)
- 14:10 A 7T double-tuned (1H/31P) microstrip surface RF coil for the Imago7 MR scanner
- Ultra-High Field (UHF) (4-9.4T) Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) are valuable tools in the diagnosis and monitoring of many diseases thanks to the enhanced Signal-to-Noise Ratio (SNR) and/or spectral/spatial resolution. However, such UHF MR applications require the development and optimization of specially designed Radio Frequency (RF) coils. In this study we report the design, construction, workbench and MR testing of a novel 7 T double-tuned (1H/31P) RF surface coil made with microstrip technology. The RF coil is suitable for MRI and MRS human studies of the lower limbs and also of the human head. The double-tuned RF coil was tested at the IMAGO7 Foundation in Pisa (Italy). Ex vivo MR 1H images and 31P spectra obtained with a large size calf veal sample showed an excellent SNR within about 50 mm cm from the RF surface coil. It is believed that the combined 7T MR 1H/31P will provide benefits in performing clinical follow-up of muscular disorders in young and aging patients. The proposed design can be easily extended to the detection of the 1H and other low-gamma nuclei, such as 7Li, 11B, 13C, 17O, 23Na.
- 14:30 Big Data Analytics to Identify Deceleration Characteristics of an Older Driver
- This paper presents the analysis of all driving by a single (female) older diver over a one year period from the Candrive project. Data analytics techniques have been applied to this unique big data set that includes 1Hz sampled Global Positioning System (GPS) and Geographic Information System (GIS) data and includes the analysis of 1562 trips covering 13,425 km. The driver is known to have stable general, cognitive and physical health through clinical testing at the start and end of the 1 year period. The paper specifically explores the deceleration habits of the driver by locating all deceleration events over the period with a net velocity drop of 4km/hr or more resulting in 24,794 events being identified. The paper finds that the mean and minimum acceleration values for the events, both have two phases where the acceleration values increase with the size of the velocity drop (-0.252 and -0.0593 hr.m/km.s2 respectively) until the drop exceeds 27.5km/hr and then the second phase has a much lower slope (-0.027 and -0.0053 hr.m/km.s2 respectively). Subsets of the deceleration events such as posted speed limit on road and decelerations ending with a stopped vehicle exhibit the same two phase relationship. The two phases and their transition are attributes of the deceleration habits for the driver that may potentially be used to distinguish between drivers of a vehicle.
- 14:50 Temperature monitoring during laser ablation by FBG sensors encapsulated within a metallic needle: experiments on healthy swine tissue
- Monitoring of local temperature in tissue undergoing Laser Ablation (LA) could be particularly beneficial to optimize treatment outcomes. A number of both invasive and non-invasive thermometric techniques may be employed to perform this task. Among others, Fiber Bragg Grating (FBG) sensors show the following valuable characteristics for temperature monitoring during LA: good sensitivity and accuracy, and immunity from electromagnetic interferences. Their main drawbacks are their intrinsic invasiveness and the sensitivity to strain, which can entail measurement error for respiratory and patient movements. The aim of this work is to experimental assess the characteristics of an FBG sensor, housed within a metallic needle, employed in temperature monitoring of tissue undergoing LA. The use of a metallic needle allows neglecting errors due to patient movement, but induces an increase in sensor response time and a temperature overestimation due to direct absorption of laser light by the needle. The developed sensor is tested during LA of ex-vivo swine livers, and the tissue temperature measured by the FBG housed within the needle is compared to the temperature measured by an FBG without needle. This comparison showed that the needle induces a temperature overestimation, strongly dependent on the distance between sensor and laser applicator (e.g., about 2 °C at 6 mm, 4.4 °C at 4 mm). Furthermore, the needle causes an increase of response time (about 140 ms vs 40 ms). Since this response time is sufficient for the particular application and the overestimation can be reduced by using different techniques of data processing, the use of a needle to protect FBG seems to be a feasible solution to overcome the concern related to patient movements.
- 15:10 On-site, parallel detection of bio-analytes in water by an integrated capillary flow based opto-microfluidic device
- An integrated capillary-flow driven opto-microfluidic device for on-site, parallel detection of bio-analytes has been demonstrated in this work. An array of capillary-induced flow microchannels and chambers were arranged on a microfluidic chip made of poly(methyl methacrylate). This poly(methyl methacrylate) chip was further integrated with an array of eight ring-shaped organic photodiodes for measuring chemiluminescence of pathogen immunoassays. Highly sensitive detection of chemiluminescence was ensured by the use of gold nanoparticles, which were attached to the chambers of the microfluidic chip. The developed device demonstrated a detection limit in the range of ~104 cells/mL for bacteria detection in water. Furthermore, the device revealed feasibility to perform parallel detection of two types of bacteria and two types of viruses quantitatively. The presented concept may offer a promising route to realize truly in-the-field devices for medical and/or environmental measurements.
- 15:30 A Photoacoustics based Continuous Non-Invasive Blood Glucose Monitoring System
- The paper examines the use of photoacoustic spectroscopy (PAS) for making continuous non-invasive blood glucose measurements. An apparatus for performing photoacoustic (PA) measurements is constructed and the technique is verified in vitro and in vivo through measurements on glucose solutions and live tissue. The signal amplitude is observed to increase with the glucose concentration in both cases. A linear calibration method is applied on each individual to obtain a glucose concentration value from each PA measurement. The glucose values obtained are compared with reference glucose concentrations measured using a standard glucose meter, giving a mean absolute difference (MAD) of 23.75 mg/dl and a mean absolute relative difference (MARD) of 18.03%. A plot of 196 measurement pairs taken over 30 normal subjects on a Clarke Error Grid gives a point distribution of 67.86%, 31.12%, 0.0%, 1.02% and 0.0% over zones A to E of the grid. This performance is an improvement over those obtained previously using PAS and point to the potential of the technique for non-invasive glucose measurements. An FPGA based reconfigurable embedded architecture is proposed for high speed data acquisition, noise reduction and display of PA measurements. The architecture operates at 274.823 MHz on a Xilinx Virtex-II Pro FPGA providing an SNR improvement of 30 dB and enabling a portable blood glucose monitoring system.
T2.2: Special Session: Ultrasound technology in medical applications
Room 2 (Stanza dello Zodiaco)
Chairs: Giovanni Durando (Istituto Nazionale di Ricerca Metrologica, Italy), Baki Karaböce (Tübitak Ulusal Metroloji Enstitüsü, Turkey)
- 14:10 Measurements of temperature increase induced on a tissue-mimicking material by a clinical US-guided HIFU system
- A framework for the evaluation of temperature increase in a tissue-mimicking material (TMM) induced by a clinical Ultrasound-guided High Intensity Focused Ultrasound (US-guided HIFU) system was developed. HIFU procedures are minimally invasive treatments that achieve deep tumor ablation, with the sparing of normal tissues, through thermal or mechanical effects induced by a HIFU beam generated with a focused transducer. Temperature evaluation is therefore crucial for the assurance of patient safety and treatment effectiveness. Nevertheless, it is a very difficult task on the US-guided systems, where high-pressure fields are involved. As far as we know, this study is the first attempt of temperature evaluation on a clinical US-guided HIFU system. Temperature evaluation was performed at typical clinical settings (between 80 W and 400 W, for 3s sonications) by the use of needle thermocouples connected to a voltmeter and inserted in a polyacrylamide gel phantom, prepared in-house to reproduce soft tissue behavior. Data sampling was performed with the use of acquisition software developed with LabView, while US-imaging was used to verify the position of the thermocouple. Typical rising curves of temperature were recovered, and rapid decrease was found when the HIFU field turned off. The highest temperature increases were concentrated inside the geometrical focus and were higher than 55 Celsius degrees at all power outputs. Repeatability of measurements was not possible after sonications at the highest power outputs (400W). The absolute temperature of 98 Celsius degrees was never exceeded.
- 14:30 Heat capacity measurements of novel tissue-mimicking materials
- In this work, innovative jelly tissue-mimicking materials (TMM) have been characterized measuring their specific heat capacity in the temperature range of (10 and 80) °C. These new specimens have improved acoustic characteristics and are promising for improving the efficacy of oncological treatments based on high intensity focused ultrasounds (HIFU). For this reason, it appears very important to have available quantitative measurements of materials thermophysical properties, necessary both for the evaluation of the expected temperature in the focus of HIFU and to validate the numerical software used for planning the adopted therapy. Obtained results have been compared with those available in literature and a detailed uncertainty analysis associated to the obtained results is discussed. Furthermore, preliminary tests have been carried out in the temperature range of (10 and 80) °C for investigating their thermal stability.
- 14:50 Acoustic Characterization of Ultrasound Fields Able to Induce Sonodynamic Activity in an in Vitro Cancer Model
- The corner stone of cancer management is by far chemotherapy, unfortunately toxicity and undesired side-effects of these antineoplastic approach often limit its usefulness. Recently it has been found that certain dye compounds non cytopathogenic per sé, in particular porphyrins, can achieve a cytopathogenic effect when the neoplastic site is subjected to ultrasounds irradiation, this technique is referred to as sonodynamic therapy (SDT). Despite the promising results, the poor reproducibility of the treatment, due to the poor investigation between the ultrasounds field parameters and the SDT activity, hampered the development of robust treatment protocol. Therefore the aim of this work has been the characterization of high intensity ultrasound fields needed to reach the SDT activity. First, by an ultrasound generator system, an in vitro sonodynamic treatment has been performed on HT-29 cell line, previously pre-incubated with 50 μg/mL of aminilevulinic acid, therefore a complete characterization of the ultrasound field in measurement conditions has been carried out. An ONDA type AIMS III scanning tank system with needle hydrophone ONDA type has been used and the real energy that hit the cellular culture in the burette has been evaluated. During insonation process the energy supplied to the cells has been about 5 10-6 J introducing, for the first time in the sonodynamic field, a clear parameter of energy supplied to the cells.
- 15:10 New formulations for realization and characterization of homogeneous tissue mimicking materials for HIFU exposures
- In this paper a novel formulation for the realization of homogenous transparent and tunable attenuating tissue-mimicking materials (TMMs) is reported. Although many hydrogel based materials have been proposed for high intensity ultrasonic field characterization, no one fully satisfies the requested acoustic and optical properties. Using concentrated inorganic salts solutions and different polysaccharide molecules, a simple preparation method has been developed to obtain this new class of TMMs. Physical properties of these TMMs have been investigated by an accurate mechanical and acoustic characterization. Furthermore a short discussion about the mechanism of ultrasonic absorption given by inorganic salt solution embedded in polymeric matrix is reported. Shown results supply a new starting point for the production of TMMs suitable for HIFU characterization.
- 15:30 Focused ultrasound temperature effect in tissue-mimicking material and sheep liver
- The temperature distribution produced by a HIFU (High Intensity Focused Ultrasound) transducer have been investigated by different set ups using T type thermocouple temperature sensors in the automated scanning system. The temperature change and the temperature distribution due to applied ultrasound power have been characterized. Pennes' bioheat transfer equation for the temperature rise caused by absorption of HIFU energy were investigated. The temperature measurements were carried out in water and in a tissue phantom (TMM-tissue mimicking material) that has very similar human tissue characteristics. A temperature measurement set up in a tissue phantom has been constructed at TÜBİTAK UME (The Scientific and Technological Research Council of Turkey, the National Metrology Institute) Ultrasound laboratory.
T3.2: Special Session: Precise motion measurement using Inertial Measurement Units (IMU)
Room 3 (Stanza della Caccia)
Chairs: Marion Gebhard (Westphalian University of Applied Sciences, Germany), Axel Graeser (University of Bremen, Germany)
- 14:10 Evaluation of Control Modes for Head Motion-Based Control with Motion Sensors
- Head-controlled human-machine interfaces play an important role in restoring the autonomy of severely disabled people like tetraplegics. In previous research different control modes to map head displacement onto a single degree of freedom of the object to be controlled have been presented. However, they have not been compared with other control modes. Within this work we close this gap by evaluating two of the most promising control modes, namely position mode and velocity mode, under different conditions in order to illuminate the advantages and disadvantages of these control modes and make suggestions which mode should be used for which application. Head movements were measured using a smart 9-axis motion sensor system. Both control modes were compared subjectively with an evaluation sheet as well as objectively. The comparison was carried out exemplarily for cursor control using a two-dimensional Fitts' Law Test at two different screen distances. Position mode turned out to be significantly faster than velocity mode. On the other hand, the error rate for position mode increased significantly with screen distance while velocity mode was insensitive to screen displacements. This was in agreement with the significantly higher ratings of accurate pointing for velocity mode. For that reason velocity mode is the preferred choice for safety-critical applications, like robot control, while position mode should be used when speed is more important than accuracy, e.g. for cursor control. Therefore, both modes are useful depending and the application and further investigations will focus on either position and velocity mode.
- 14:30 Real-time gait detection based on Hidden Markov Model: is it possible to avoid training procedure?
- In this paper we present and validate a methodology to avoid the training procedure of a classifier based on an Hidden Markov Model (HMM) for a real-time gait recognition of two or four phases, implemented to control pediatric active orthoses of lower limb. The new methodology consists in the identification of a set of standardized parameters, obtained by a data set of angular velocities of healthy subjects age-matched. Sagittal angular velocities of lower limbs of ten typically developed children (TD) and ten children with hemiplegia (HC) were acquired by means of the tri-axial gyroscope embedded into Magnetic Inertial Measurement Units (MIMU). The actual sequence of gait phases was captured through a set of four foot switches. The experimental protocol consists in two walking tasks on a treadmill set at 1.0 and 1.5 km/h. We used the Goodness (G) as parameter, computed from Receiver Operating Characteristic (ROC) space, to compare the results obtained by the new methodology with the ones obtained by the subject-specific training of HMM via the Baum-Welch Algorithm. Paired-sample t-tests have shown no significant statistically differences between the two procedures when the gait phase detection was performed with the gyroscopes placed on the foot. Conversely, significant differences were found in data gathered by means of gyroscopes placed on shank. Actually, data relative to both groups presented G values in the range of good/optimum classifier (i.e. G ≤ 0.3), with better performance for the two-phase classifier model. In conclusion, the novel methodology here proposed guarantees the possibility to omit the off-line subject-specific training procedure for gait phase detection and it can be easily implemented in the control algorithm of active orthoses.
- 14:50 Wearable sensors for gait analysis
- Systems based on inertial sensors are increasingly used in motion analysis due to their low cost, portability and wearability. However, since accuracy is crucial in clinical gait analysis, it is important to assess it in new systems. The aim of this study is to compare the performances of a magnetic and inertial sensors system (MIMUs) to a gold standard, the electromechanical system STEP32. Results shows that spatio-temporal parameters are accurately estimated by the MIMUs system. Joint kinematics does not reach the accuracy of the STEP32 system. In fact, although MIMUs measurements on the knee and hip joints are clinically acceptable, they are not yet reliable for the ankle joint.
- 15:10 Accelerometer-Based Methods for Energy Expenditure using the Smartphone
- Quantifying the energy expended during physical activity is an important metric to evaluate the quality and progress of individual training. There are several methods to estimate the energy expenditure using accelerometers, the most common are based on calculating counts per minute from the accelerometer signal to determinate the activity intensity in terms of metabolic equivalents (METs). This paper compares three methods to estimate the energy expenditure, the first has been proposed in a previous study and the last two are based on linear regressions derived from the data collected, one using speed, and the other using the feature root mean square (fRMS) of the magnitude of the accelerometer signal. These models were compared with indirect calorimetry outputs of energy expenditure during an incremental speed treadmill protocol. No statistically significant differences (p$<$0.05) were found between the indirect calorimetry and the model derived using the RMS feature, obtaining a normalized error of 20\% for the METs estimation. In conclusion, this was found to be the most suitable method to estimate the energy expenditure from accelerometer data collected using a smartphone placed in the belt.
- 15:30 Compensating magnetic disturbances on MARG units by means of a low complexity data fusion algorithm
- The paper proposes a new algorithm for the estimation of orientation of MARG (Magnetic, Angular Rate and Gravity) units, capable of compensating the influence of short-duration magnetic disturbances on the magnetometer, with application in motion tracking for rehabilitation. The proposed algorithm has been designed starting from a widely used low-complexity orientation estimation algorithm, based on the gradient descent minimization. The proposed algorithm has been validated by means of laboratory experiments, aimed at verifying its capability of correctly estimating orientation, by compensating the magnetic disturbances both in static and in dynamic conditions. The results of such experimental phase are presented and discussed in the paper.
Thursday, May 7, 15:50 - 16:20
Room: Sala delle Colonne
Thursday, May 7, 16:20 - 18:00
T1.3: Measurement for patient safety and quality control
Room 1 (Salone d'Onore)
Chairs: Sabrina Grassini (Politecnico di Torino, Italy), Annamária R. Várkonyi-Kóczy (Óbuda University, Hungary)
- 16:20 An Anytime Voice Controlled Ambient Assisted Living System for Motion Disabled Persons
- Home surveillance systems, intelligent or smart homes are basically built to monitor and support ill and/or disabled persons in their independent living, possibly as part of the medical attendance. Intelligent Space or iSpace is a new kind of computing system aiming at improving the environments of humans, creating a natural and easy to use solution. From this two concepts a new family of applications, the Ambient Assisted Living (AAL) systems have grown. This paper presents an Anytime Voice Controlled Ambient Assisted Living System developed for a highly motion disabled person. The equipment and fixtures of the living environment of the lady can be controlled by a limited set of voice commands. The system applies a new anytime speech recognition algorithm by executing interruptible speech analyzer modules in order to determine the most probable instruction. The analysis is executed with high reliability in a far off optimal acoustic environment (continuously varying, distorted speech of the user, loud background noise containing human speech, etc.)
- 16:40 Home telemonitoring of vital signs through a TV-based application for elderly patients
- The early detection of changes in the health status of older people can be exploited to avoid unnecessary hospitalization and promoting independent living, reducing the costs associated with medical care. For this reason, there is a growing interest in technologies tailored for seniors that can provide home-based monitoring programs. This paper introduces a novel TV-based system capable of acquiring users' vital parameters such as blood pressure, pulse rate, body weight and blood glucose level from Bluetooth commercial devices installed at home, transmitting them to a remote server hosting an interoperable software framework for telemonitoring. The core of the system is a novel Android application hosted on a mini-computer connected to the TV set and controlled simply through the remote control. In this work we include support for several Bluetooth profiles and protocols, analysing their different requirements and proposing a modular expandable implementation.
- 17:00 Integration of Outcome Estimations with a Clinical Decision Support System: Application in the Neonatal Intensive Care Unit (NICU)
- Our previous research led to the development of mortality risk estimations for infants in the neonatal intensive care unit (NICU) using quality archived databases. A decision support system was created with a clinician module containing relevant patient information and a variety of outcome estimations; the PPADS (Physician-Parent Decision Support) tool also contains a module for parents with the aim to help them make joint decisions with physicians on the direction of care for their infant. New work developed the ANN-Builder which uses an open-source artificial neural network library that would enable handling real-time data streaming and automate the process of providing risk estimations of mortality. Additionally, the patient data and risk estimations were successfully integrated into the PPADS tool. The mortality estimations surpass the clinical expectations. The next and final step will be to replace missing values in the data and add alarms for major changes in the risk estimations provided by the system.
- 17:20 Towards a Probabilistic Model Checking-based Approach for Medical Device Risk Assessment
- Medical Devices (MDs) are subject to a Risk Management process to guarantee their safety with respect to risks patients and healthcare operators may experience. Well known classical Probabilistic Risk Assessment (PRA) techniques widely used in the MD sector, such as Failure Model and Effective Critical Analysis (FMEA) and Fault-Tree/Event-Tree do not allow to model the dynamics of hazardous situations which involves interactions among system components, human actions, process operations and the environment. This lack is overcome by using a dynamic PRA (DPRA) approach which aids in specifying risk scenarios. DPRA is extensively used in the nuclear, avionics, and space industries to identify possible accident scenarios, but to the best of our knowledge it is not so in the MD field. In this paper we propose a DPRA approach for MD Risk Assessment which relies on the use of a Probabilistic Model Checking (PMC) technique to perform quantitative analysis of risk scenarios. Particularly, our approach combines the ease of Event Sequence Diagram (ESD) to capture the dynamics of risk scenarios and the Markov Decision Processes formalism used as a stochastic model by which to encode ESD. By using a PMC technique to evaluate the MDP-based risk scenarios, we achieve two main benefits. Firstly, hundreds of different scenario realisations can be analysed in seconds due to the computational effectiveness of current PMC algorithms. Secondly, since such technique is based on a state-transition representation, we take advantage of the reachability analysis of states within the risk scenario state space to also quantify the effectiveness of control mechanisms or mitigation actions used to prevent and/or reduce the MD exposition to risk factors. Our ultimate objective is to derive an intuitive, easy, and computationally efficient formal method to perform quantitative risk scenario analysis oriented towards increasing the MD safety. We have applied our approach to an actual MD taken as a case study to demonstrate the features of our DPRA solution.
- 17:40 An Automatic Sensing Test Procedure for Implantable Cardioverter Defibrillators
- An automatic test procedure for evaluating the sensing performances of Implantable Cardioverter Defibrillators (ICDs) is presented in this paper. It is based on the Sensitivity Test prescribed by international standards and consists of determining the ICD sensing thresholds at different heartbeat frequencies. Consequently, a more extensive evaluation of ICD sensing performances can be achieved than that obtainable by one Sensitivity Test only. The proposed procedure has been implemented by means of a Virtual Instrument, which is developed in the Labview environment. It is then experimentally validated through several tests, which have been performed inside an anechoic RF chamber. Such an environment guarantees proper shielding against external electromagnetic interferences, thus ensuring reliability and repeatability of the tests.
T2.3: Special Session: Wireless Communications in Healthcare
Room 2 (Stanza dello Zodiaco)
Chairs: Gregorio Andria (Politecnico di Bari, Italy), Octavian Adrian Postolache (Instituto de Telecomunicações, Lisboa/IT & Instituto Universitario de Lisboa, ISCTE-IUL, Portugal)
- 16:20 A Mobile Approach for Neurofeedback Cognitive Enhancement
- The neurofeedback training is recently used in enhancement of cognitive function or amelioration of clinical symptoms. The present study used power of alpha rhythm (8-12Hz) as the feedback index. The proposed system contained an EEG signal analysis device and a smartphone connected wirelessly based on the Bluetooth technology. The wireless technology and the mobility of the smartphone allow the subjects to perform training in their daily environments. Our mobile neurofeedback system demonstrated significant increase in alpha rhythms in terms of power and duration. Moreover, memory was significant enhancement in the alpha training group but not in the control group in terms of the word pair and backward digital span tests. Our results suggest that the mobile neurofeedback system shows an advantage for enhancement of alpha rhythms in coincidence with increased memory.
- 16:40 A Wireless Personal Sensor Node for the Dosimetry of Interventional Radiology Operators
- Wireless sensor networks (WSNs) are an important technology for large-scale monitoring, providing sensor measurements at high temporal and spatial resolution. In healthcare applications, a variety of system prototypes and commercial products has been designed and manufactured with the aim to provide an alternative and more efficient method for real time patient monitoring. In the framework of the Real time Active PIxel Dosimetry (RAPID) project, the attention has been focused on dose monitoring of Interventional Radiology operators. In this work, we present a study on the RF interface with the optimization of the antenna design to obtain a compact solution making the system portable. The effect of human body influence on the performance of the antenna has been simulated: a distance of 1.5 cm from the body shows that the artificial body structure has a negligible detuning effect on the antenna performances. The Packet Error Rate (PER) of the network has been evaluated considering different values of Transmitter Output Power (TPO) and comparing the performance of two different antennas: the maximum obtained PER was lower than 0.2%, which is acceptable for the specific application.
- 17:00 Connected vision care for eradication of preventable blindness
- 90% of the visually impaired worldwide live in a low income setting, and 80% of all visual impairment can be prevented or cured provided, a timely care is given. A large portion of at risk population does not avail timely vision care due to low awareness and inability to afford nor access quality vision care. Generating high patient volumes by reaching out into the community is a general approach taken by many hospitals to provide quality and affordable vision care. However, all of them rely on semi-skilled field workers to reach out to the community. A significant challenge to the effectiveness of field workers is the paper-based systems they use to register patients, gather information about them, and analyze the collected data. The lack of online monitoring and access to real-time analytics makes the process inefficient when scaled across large geographies. This paper proposes a connected vision care wireless solution comprising of a mobile decision support system and an analysis and reporting server connected via an existing cellular infrastructure. This solution upgrades every field worker to a knowledge worker, enables automatic compliance and status tracking of patients, and provides real-time analysis for efficient program management. This paper highlights the improved efficiency of the vision care program achieved using the solution in a field trial conducted by Sankara Eye Care hospital in Tamil Nadu, India.
- 17:20 Gait rehabilitation assessment based on microwave Doppler radars embedded in walkers
- The gait rehabilitation is performed using for the user assistance during the training sessions of specific devices including crutches, canes, and walkers. The objective evaluation of physiotherapy effectiveness requires measurements that are done by sensors embedded in regular devices as wheeled walkers. Thus informations about the forces applied during the gait, the legs motion signals are considered inputs for processing algorithms that may provide the gait rehabilitation outcomes. The article presents a smart wheeled walker with microwave embedded radars and force sensors connected to an embedded processing platform that provide informations about the regular or un-regular gait during the testing session as so as the rehabilitation rate considering the captured gait patterns through the motion sensor. An implemented wireless sensor network may be used for simultaneously assessment of different walker users.
- 17:40 s-Health as a driver towards better emergency response systems in urban environments
- The unprecedented global shift towards cities is drastically changing the urban environment. With the aim to mitigate the problems that these changes may introduce , cities are gradually being transformed into the so-called ``Smart Cities''. This transformation involves the deployment of numerous sensors and communication infrastructures that are used to provide better management and resource allocation. Recently, the concept of smart health (s-health) was proposed in order to bridge healthcare services with Smart Cities' infrastructures and offer novel services to the cities and their citizens. In this article we propose a new s-Health embodiment for emergency response systems in urban and sub-urban environments.
T3.3: Special Session: Mechanical and Thermal Measurements for Medicine and Biology
Room 3 (Stanza della Caccia)
Chairs: Zaccaria Del Prete (SAPIENZA University of Rome & Center for Life Nano Science IIT@Sapienza, Italy), Rinaldo Vallascas (University of Cagliari, Italy)
- 16:20 Thermocouples for temperature monitoring during pancreatic laser ablation: analysis of the measurement error
- Laser ablation (LA) is a minimally invasive procedure used to remove cancer by inducing hyperthermia. It is based on the interaction between laser light and tissue: the absorbed light is converted into heat causing a tissue temperature increase. The amount of damaged volume depends on temperature and time exposure of the tissue to the hyperthermia. As a consequence, the monitoring of tissue temperature during LA could be particularly beneficial to optimize treatment outcomes. Temperature can be measured by different transducers and techniques; thermocouples are one of the most employed. Their main drawback is related to the strong light absorption of the two metallic wires which constitute a thermocouple. The light absorption causes an overestimation of actual temperature, in literature known as artifact. This work aims at assessing this artifact on ex vivo swine pancreases undergoing LA. The artifacts have been estimated at the three laser powers (1.6 W, 2 W and 5 W) and at two distances from the optical applicator. In particular, the artifact decreases with the distance from the optical applicator and depends on P: at 1.6 W and 2 W it is negligible at 12 mm of distance, on the other hand at 5 W it is significant also at 15 mm (1.7 °C). Summing up: the artifact is strongly influenced by the distance between the thermocouple and the optical applicator, and by the laser power; also at high distance from the applicator it can cause error which are not acceptable for the application of interest (e.g., at 5 W and 10 mm the error is about 4 °C). Although the use of thermocouples entails the concern related to the artifact, it must be considered that proper model can be employed to correct the measurement error.
- 16:40 A new Arterial Blood Pressure Holter based on the oscillometric method
- From the comparison of the data available in the field literature, it follows that the range of oscillometric relations is quite extensive, with an interval of 20% for systolic and around 30% for diastolic blood pressure. Current commercial devices were not designed to perform the task of calculating these oscillometric ratios, and they utilize average values set for all measurements regardless of the physiological characteristics of the individual user and the yielding of the cuff used. While, as noted, oscillometric reports are unique to each user as they contain much individual and operational information, such as cuff pulsatility, physiology of the measurement site, environmental conditions and the clinician's ability in performing the measurement. Hence, the need to revise current standards by making more restrictive rules is clear. In the author's opinion, this innovative solution has the special features providing greater accuracy in the measurement of systolic and diastolic pressures, and simulations and preliminary clinical trials have confirmed this.The work is devoted to both the presentation of the pressure Holter prototype and to the communication of results obtained during the characterization of the methodology and the algorithms used. Validation involved 33 subjects (22 men and 11 women) aged between 23 and 82 years, with arm circumferences from 21 to 41 cm, with systolic blood pressure (PSYS) in the 94 ÷ 204 mmHg range and diastolic (PDIA) 49÷106 mmHg. The results largely satisfy the requirements of the Protocol AAMI SP-10.
- 17:00 A measurement procedure for the assessment of thermoregulatory activitity in premature babies
- Many important vital signs are commonly measured in preterm infants when they are recovered in intensive care units: cardiac rate, respiration activity, blood saturation, temperature. The later is, in particular, a key quantity to assess when the aim is to verify if the patient has fully developed the capacity to regulate his/her temperature. Presently, the procedure followed by clinicians is based on a test, which sees the heating system of the curl switched off; if the central temperature of the patient will not be reduced below 35°C in the next two hours, the patient is considered able to thermoregulate himself. The aim of this paper is to present a measurement procedure aiming to shortly verify if the patient has the ability to autonomously thermoregulate. The procedure is based on the use of a temperature, multi-point (16) measurement system which can follow the temperature of the patient when the curl heating system is switched off. We have tested the procedure on a population of 48 premature patients with mean gestation age 34 week and mean height 1791 g. Results demonstrate that from the measured data it is possible to correctly identify (sensitivity of 0.81 and specificity of 0.89), in the first 5 minutes, the patients with an adequate thermoregulation capacity from the others.
- 17:20 Pharyngeal and esophageal pressure measurements to evaluate respiratory mechanics in infants on high flow nasal cannula: a feasibility study
- High-flow humidified nasal cannula (HFNC) is often used to relieve respiratory distress in children with acute pulmonary disease, although its effects on respiratory mechanics have not been objectively studied. The purpose of this study was to test the feasibility of measuring pharyngeal (PP) and esophageal (Pes) pressures of young children on HFNC oxygen therapy through a specifically designed new monitoring, acquisition, and elaboration system (M.A.E.S.). Through M.A.E.S. we recorded and elaborated Pes and PP tracings obtained through esophageal and pharyngeal catheters in a group of young children hospitalized in a Pediatric Intensive Care Unit because of respiratory distress. All traces were recorded during spontaneous breathing and on HFNC 1 and 2 L/kg/min. To determine the onset and the end of inspiration, the Pes and PP signals were synchronized with the inspiratory flow obtained by a flow transducer placed in the HFNC circuit. Direct measurement of inspiratory flow measured by a face mask pneumotachograph also allowed for inspiratory tidal volume (TV) measurement which was used together with Pes to build Campbell's diagram as well as the static lung and chest wall recoil curves required for pressure time product (PTP) evaluation. Using M.A.E.S. we were able to obtain: time interval between the beginning of inspiratory effort and inspiration (Tdelay), TV, intrinsic positive end expiratory pressure (PEEPi), total inspiratory Pes variation (∆Pes), static transpulmonary pressure variation (Ptpee,) dynamic lung compliance (CLdyn), total lung resistance (RLtot) along with all the relevant components of the inspiratory work of breathing (WOB) and PTP. We believe that this new system will allow clinicians for a bedside monitoring of respiratory distress in infants treated with HFNC and to modify flow rates accordingly.
- 17:40 Preliminary measurements of elasticity properties of lung tumor living cells for cancer detection
- Recent studies recognized the cell stiffness changes as a marker for cancer detection. Reliable and reproducible measurements of elastic modulus, mapping different cell regions are the basis for developing a new methodology for cancer detection. To this aim, a metrological characterized AFM microscope has been developed, micro- and nano-indentation of soft materials, used as elastic modulus reference, were done and a robust statistical data analysis has been performed. Contact images and force mapping of A549 living cells allowed 4% measurement relative reproducibility. A modal cell elastic modulus 0.5 kPa, was obtained. A highly spatially resolved stiffness distribution on the overall cell regions has been obtained through data analysis, realizing a powerful tool for cell mechanics analysis.
Thursday, May 7, 18:00 - 18:30
Vocal performance of the Choir of Politecnico di Torino
Room 1 (Salone d'Onore)
Thursday, May 7, 18:30 - 20:00
Room: Sala delle Colonne
Friday, May 8
Friday, May 8, 09:00 - 10:40
F1.1: Biosignal processing II
Room 1 (Salone d'Onore)
Chairs: Voicu Groza (University of Ottawa, Canada), Aime' Lay-Ekuakille (University of Salento, Italy)
- 09:00 A Compressive Sensing Spectral Model for fNIRS Haemodynamic Response De-Noising
- In the biomedical scenario, near-infrared spectroscopy (NIRS) is employed as a non-invasive brain imaging technique. In particular, functional near-infrared spectroscopy (fNIRS) provides the neural evoked response, also known as haemodynamic response (HR), to pre-defined stimuli. Processing of fNIRS data requires a great effort to extrapolate the informative component from a noisy mixture of physiological and spurious contributions. In this paper a novel fNIRS de-noising algorithm is presented and validated over both simulation and experimental data. For each evoked response, a specific noise model is identified and subtracted from the acquired data. The algorithm relies on a combination of a super-resolution technique based on Compressive Sensing theory and a spectral analysis performed via Taylor-Fourier transform. Preliminary experimental results show a significant reduction of spurious components in all the considered conditions. No significant distortions are introduced in the recovered HR, ensuring reliable clinical interpretation of the acquired trace.
- 09:20 A New Ultrasound Parameter for Osteoporosis Diagnosis: Clinical Validation on Normal- and Under-Weight Women
- Aim of this work was to evaluate the effectiveness of a recently introduced ultrasound (US) method for osteoporosis diagnosis, when extensively used in a clinical context to investigate adult women of variable age. A total of 384 female patients (46-65 years; body mass index < 25 kg/m2) underwent a spinal dual X-ray absorptiometry (DXA) and an abdominal US scan of lumbar spine, acquiring both echographic images and unprocessed radiofrequency signals. US data were analyzed through a new fully automatic algorithm, which performed a series of spectral and statistical analyses to calculated the parameter called Osteoporosis Score (O.S.). Diagnostic effectiveness of O.S. was assessed through a direct comparison with DXA measurements (assumed as the gold standard reference), quantifying the agreement between the two methods through accuracy calculation, Cohen's kappa (k) and Pearson correlation coefficient (r). The overall accuracy of O.S.-based diagnoses resulted 84.6%, ranging from a minimum of 81.7% for the oldest patients (aged in 61-65 y) to a maximum of 87.2% for the youngest patients (aged in 46-50 y). Cohen's kappa showed an analogous trend, confirming a significant agreement between DXA and US-based diagnoses along the whole considered age interval (k=0.758, p<0.0001). A good correlation was also found between O.S.-derived BMD values and corresponding DXA measurements (r=0.72, p<0.001). These results demonstrated that US-measured O.S. is significantly correlated with spinal BMD in normal- and under-weight adult women belonging to a wide age interval. Therefore, the routine clinical application of this innovative approach to osteoporosis diagnosis can be envisioned.
- 09:40 Scalable ECG Hardware and Algorithms for Extended Runtime of Wearable Sensors
- Everything in nature tries to reach the lowest possible energy level. Therefore any natural or artificial system must have the ability to adjust itself to the changing requirements of its surrounding environment. In this paper we address this issue by an ECG sensor designed to be adjustable during runtime, having the ability to reduce the power consumption on cost of the informational content. Accessible for everyone, standard ECG hardware and open source software has been used to realize an ECG processing system for wearable applications. The average power consumption has been measured for each mode of operation. Finally we take conclusion to conciser context-aware scaling as key feature to address the energy issue of wearable sensor systems.
- 10:00 Seismocardiography:Toward Heart Rate Variability (HRV) Estimation
- Heart rate variability (HRV), the time interval variation between the heartbeats, is a clinically important measure in assessing the status of the cardiovascular autonomic function. The purpose of this study was to cross-validate the beat-by-beat time variations in seismocardiography (SCG) with electrocardiography (ECG) for determining ultra-short term HRV indexes. Twenty healthy young volunteers were examined in this study by performing an ultra-short term data acquisition protocol. Kubios HRV software was utilized to assess the HRV parameters. The HRV indexes were analyzed in both time-domain and frequency-domain processes. High linear relationship(r>0.98) and agreement was observed between the HRV indexes calculated from SCG and ECG data. In conclusion, SCG and ECG HRV indices were found to be statistically close enough to warrant the use of SCG for estimating HRV values.
- 10:20 Method for Evaluation of Trustworthiness of Oscillometric Blood Pressure Measurements
- Simple, unobtrusive, and reliable estimation of cardiovascular parameters is a challenge. We present a novel, simple, and noninvasive method called Ratio2 that provides acceptable ranges for systolic and diastolic pressure values estimated by any given algorithm, and a trustworthy evaluation of vessel compliance. Ratio2 was developed in the frame of the oscillometric approach for blood pressure estimation and it exploits the equality between the arterial blood pressure and the cuff pressure at the mean arterial pressure (MAP). This method is based on the observation that the brachial arterial blood pressure pulses, with MAP used as baseline, are characterized by a peak to trough ratio close to 2. This ratio is employed to characterize acceptable ranges for estimates of systolic and diastolic blood pressure. Ratio2 also provides parameters that are used in a mathematical model of arterial blood pressure (BP) to evaluate vessel stiffness. We tested the performance of the Ratio2 method on 150 oscillometric recordings and their corresponding Omron BP estimates obtained from 10 healthy subjects. Results are encouraging, whereby, (a) out-of-range values obtained with the maximum amplitude algorithm (MAA) and the maximum/minimum slope algorithm (MMSA) methods were successfully detected, and (b) linear correlation between age and vessel compliance is –85% (p<0.005). Therefore, we conclude that the proposed work shows promise towards providing noninvasive BP (NIBP) monitors with an inbuilt mechanism for assessing the fidelity of their BP estimates along with an indicator of vessel compliance.
F2.1: Imaging and communication II
Room 2 (Stanza dello Zodiaco)
Chairs: Stephanie Bennett (Carleton University, Canada), Marco Parvis (Politecnico di Torino, Italy)
- 09:00 Data-driven selection of motion correction techniques in breast DCE-MRI
- It is well known that some sort of motion correction technique (MCT) should be performed before DCE-MRI data analysis in order to reduce movement artefacts. However, it is not clear if a single MCT can produce optimum results for every single examination, since for example different movements can occur. In this paper we investigated the possibility of choosing the best MCT per each specific patient, before performing further data analysis (e.g. tumour segmentation). In particular, our aim is the proposal of some physiological model-based quality indexes (QIs) for ranking different MCT on a patient basis. Moreover, for practical feasibility, we investigated the performance of our proposal when only a small fraction of the available data were used. We performed tests on a dataset of patients with breast tumour. Specifically, per each patient we compared the 'reference ranking' of different MCT obtained by using the results of tumour segmentation with the rankings produced with each QI. Our results indicate that the ranking obtained by using the QI based on the Extended Tofts-Kermode model (with the Parker arterial input function) are in accordance with the 'reference ranking'. Moreover, computational load can be significantly reduced without affecting the overall performance by using only 5% of the available data.
- 09:20 A web-based application for dermoscopic measurements and learning
- Image processing techniques have been long proposed for automatic analysis of skin lesions in the field of early detection of melanoma. Nevertheless, Computer Aided Systems are not yet able to outperform the diagnostic accuracy of expert dermatologists. They could instead reveal very useful in providing with a second opinion and improving the detection results from physicians with short clinical experience. The paper introduces an original web-based application for the automatic detection of dermoscopic structures within pigmented lesions and the support to novel dermatologists. It is able to receive and store digital images captured by digital cameras and smartphones equipped with dermoscopy, measure morphological and chromatic parameters, and take into account the measurement uncertainty to finally provide a clinical decision according to the diagnostic method 7-Point Checklist.
- 09:40 Development of a Reliable Method for Orbit Segmentation & Measuring
- Injuries of the bony orbit that, which contains the eye, not only have aesthetic implications but also impair stereoscopic vision. Different techniques are used for surgical treatment. In this work we will present a tool that allows the reliable segmentation of the reconstructed and the unaffected orbit. For this we present a novel anterior closing that follows the clinical understanding of anatomy. To assist in the post-surgical evaluation, we suggest parameters with respect to clinically relevant regions (orbital floor, medial wall) and demonstrate a method to automatically determine them. We evaluate our methods on clinical cases.
- 10:00 A novel automatically initialized level set approach based on region correlation for lumbar vertebrae CT image segmentation
- Despite recent advances, robust automatic segmentation for vertebrae computed tomography (CT) image still presents considerable challenges, mainly due to its inherent limitations, such as topological variation, irregular boundaries (double boundary, weak boundary) and image noises, etc. Therefore, this paper proposes a novel automatically initialized level set approach based on region correlation, which is able to deal with these problems in the segmentation. First, an automatically initialized level set function (AILSF) is designed to automatically generate a smooth initial contour. This AILSF comprises hybrid morphological filter (HMF) and Gaussian mixture model (GMM), which can guarantee the initial contour precisely adjacent to the object boundary. Second, we introduce a region correlation based level set formulation, which simultaneously consider the histogram information of inside and outside the level set contour, to overcome the weak boundary leaking and image noises problem. Experimental results on clinical lumbar vertebrae CT images demonstrate that our proposed approach is more accurate in segmenting with irregular boundaries and more robust to different levels of salt-and-pepper noises.
- 10:20 ChiMerge Discretization Method: Impact on a Computer Aided Diagnosis System for Prostate Cancer in MRI
- Discretization is an important step introduced in the field of Knowledge Discovery in Databases to better represent the knowledge domain and increase the learning speed and performance of Data Reduction and Data Mining algorithms. However, no studies evaluated the benefits of introducing a discretization step into a more complex system. In this study we seek to evaluate how the ChiMerge discretization method could improve the performance of a CAD system for the automatic detection of prostate cancer (PCa) based on multi-parametric Magnetic Resonance (mp- MR) imaging. 16 semiquantitative and quantitative features were extracted from malignant and normal region of interest in 56 patients, who underwent mp-MR exam before prostatectomy. By using ChiMerge on a training set, we computed different cut points for each feature to transform the continuous attributes into discrete variables. Both the continuous and the discretized 16-dimensional vector generated for all voxels have been separately fed into the SVM classifier used by the CAD system and the performances were compared. Moreover, a feature selection (FS) method based on the correlation between parameters was applied to both the continuous and the discrete features, and the performances of the CAD system when using the resulting subset of features have been evaluated. Results showed that the CAD system obtained the best performance when it uses all the discretized parameters. Besides, FS applied on the discretized parameters did not affect the results obtained with all the discretized parameters (p=0.565), thus making the use of the FS method feasible to reduce dimensionality. Finally, our results showed that the discretization greatly improves the results of patients having a starting area under the ROC curve <0.75, that represents a critical situation for a CAD system. In conclusion, preliminary results show that discretization can effectively and substantially increase the performance of a CAD system.
F3.1: Special Session: Mechanical and Thermal Measurements for Medicine and Biology
Room 3 (Stanza della Caccia)
Chairs: Paolo Cappa (Sapienza University of Rome, Italy), Lorenzo Scalise (Università Politecnica delle Marche, Italy)
- 09:00 MRI-thermometry on ex vivo swine liver: preliminary trials to assess the sensitivity of two sequences
- Minimally invasive thermal procedures are gaining acceptance in tumor treatment. Among others, laser ablation (LA) is considered a valid alternative to surgical resection for inoperable patients. LA damages the tumor by increasing the tissue temperature. The temperature distribution within the tissue strongly influences the outcomes of the procedure. Hence, some thermometric techniques are employed in this scenario. Among them, MRI-based thermometry presents some advantages, such as the non-invasiveness. In this work, two sequences (EPI and FIESTA) have been used to monitor liver temperature. During the whole MRI procedure, the liver temperature has been monitored by MRI-compatible, fiber optic-based sensors. The temperature measured by these sensors has been used as reference in order to assess the sensitivity of MRI-thermometry. Moreover, the influence of Region of interests (ROIs) size on precision has been investigated. Results show that the absolute value of thermal sensitivity of FIESTA is double with respect to the sensitivity obtained with EPI (about -15 °C-1 vs -7 °C-1). Regarding the influence of ROI size, results show that the wider the extension the better the precision.
- 09:20 Preliminary study for a water-paraffin based phantom in MRI quality assurance test
- MRI scanners are widely used both for diagnostic purposes and in studies on mechanical properties of materials . As a consequence they play an important role in diagnosis of diseases and in materials investigations. MRI quality assurance tests are mandatory to obtain and maintain during time optimal images, some institutional organizations have proposed requirements on MRI image quality even if there are no worldwide standardized procedures. The aim of this study is to design and develop a novel MRI phantom suitable for image quality assurance and to compare the MRI response between water and other materials: our phantom is designed, developed and tested in order to implement quantitative specific image assurance protocols and tests. Moreover the developed device is low cost, reusable, and it can be filled with different MRI-compatible materials. In our application the phantom is filled with water and paraffin to compare contrast-to-noise ratio and signal-to-noise ratio measurements for a same scanner. Tests have been performed on a 3T scanner with 7 different scansion settings. First experimental results are encouraging and confirm a previous theoretical investigation on the employed material visibility compared with water. Collected data uphold the possibility to make material properties investigations, in static conditions, using a magnetic resonance system. Therefore other tests and data are going to be collected for the future development and performance improvement of the introduced device.
- 09:40 A Digital Image Correlation based technique to control the development of a skeletal muscle engineered tissue by measuring its surface strain field
- X-MET (Ex-vivo Muscle Engineered Tissue) is a promising 3-dimensional model of skeletal muscle for in vitro tests and in vivo transplant. X-MET is an in vitro cultured tissue and has several properties in common with adult skeletal muscle, from biological and morphological to functional ones. To monitor the improvements of the X-MET contractile capability we developed a system based on Digital Image Correlation (DIC) to precisely measure tissue's growing, thus trying to prevent the formation of any anisotropic or inhomogeneous parts. We employed a high speed camera mounted on a stereomicroscope, and synchronized the image acquisition with the force response measurement and the electrical stimulation. The capability of measuring the 2-dimensional surface strain field in any desired Region Of Interest (ROI) allowed obtaining a comprehensive monitoring of the tissue's growing, both at a global and a local level. Preliminary results confirmed the adequacy of the system to measure tissue's strain field in complete accordance with the force measurement. Moreover, an in-depth analysis allowed to precisely pinpoint the sub-zones where discontinuities arise during tissue formation, returning essential information to improve X-MET generation process.
- 10:00 Effect of the calibration procedure of an optoelectronic system on the joint kinematics
- Optoelectronic systems are largely employed for human movement analysis, where marker trajectories are used to estimate the articular joint kinematics. From a literature analysis it emerged that the error associated to the joint variables can be reduced performing the data collection in the center of the system calibration volume. According to human movement analysis literature, the foot-ankle complex appears to be the anatomical joint most affected by instrument inaccuracy, as it moves in the lower bound of the calibration volume during a gait cycle. A multi-segment marker-based model of the lower limb - including the pelvis, thigh, tibia, hindfoot, forefoot and hallux- was investigated in this paper. One healthy subject was asked to walk on the central and on two boundary areas of the capture volume calibrated for the experiments. The calibration procedure was focused on the exploitation of the effects on the joint angles of: (i) calibration volumes (i.e. the global one and two of its sub-volumes) and (ii) number of frames acquired for the calibration procedure (refinement frames). The RMSE calculated for different refinement frames using both the global volume and the two sub-volumes was computed as an index of the joint angles variation estimated on the sagittal plane. Two two-way ANOVAs were performed to evaluate whether the calibration volumes or the walking areas affect the kinematics. The statistical analysis highlighted a good robustness of the reconstruction algorithm implemented by the optoelectronic system manufacturer. Few variables showed significant differences for the RMSEs, with p-values lower than 0.05. No clear dependence on the body segments here analyzed emerged from the analysis. We conclude that reconstructed trajectories can be affected by the same magnitude errors, regardless to the calibrated volume or the considered walking area. This finding allows to conduct the gait analysis without paying too much attention when calibrating the system and without having to impose excessive restrictions to the tested subjects, allowing to keep their movement as natural as possible.
- 10:20 Performance assessment of FBG temperature sensors for laser ablation of tumors
- The paper presents the characterization results of temperature sensors designed to be employed during thermal treatments of tumors, such as in the laser ablation of malignant cells. The developed sensors are based on Fiber Bragg Gratings, a sensing element able to measure the temperature in proximity of the laser beam without significantly modifying the radiation pattern or perturb the temperature at the sensor site. Different sensor embodiments are analyzed and compared in term of linearity and dynamic response; then a preliminary test during an emulated ablation using a phantom is also presented.
Friday, May 8, 10:40 - 11:00
Room: Sala delle Colonne
Friday, May 8, 11:00 - 12:30
Steering Committee meeting
Room: Stanza del Valentino
PS1: Poster session 1
Room: Stanza dei Gigli
Chairs: Matteo Bertocco (University of Padova, Italy), Francesco Lamonaca (University of Sannio, Italy)
- 11:00 Submovements composition and quality assessment of reaching movements in subjects with Parkinson's Disease
- The segmentation of seemingly continuous movements into segments has been theorized for many years. These segments may be considered as movement "primitives", or building blocks of more complex movements. The existence of these fragments, or sub-movements as they are called, has been supported by a wide range of studies over the past 100 years. Evidence for the existence of discrete sub-movements underlying continuous human movement has motivated many attempts to "extract" them. Recently, the sub-movement theory gained a great appeal in the rehabilitation field. In fact, understanding movement deficits following CNS lesions and the relationships between these deficits and functional ability, is fundamental to the development of successful rehabilitation therapies. So, here is proposed a novel sub-movement decomposition method based on a EM constrained algorithm. This representation allowed us to explore whether the movements are built up of elementary kinematic units by decomposing each signal into a weighted combination of 2D Gaussian functions. These can be used to assess the quality of reaching movements in subjects with Parkinson's Disease
- 12:30 Development of Intraoperative Noninvasive Force Measuring System During Femoral Fracture Reduction
- Reduction is a critical step in minimally invasive treatment of displaced femoral fracture reduction. We developed a set of measurement system to determine intraoperative counteracting soft tissue forces during fracture reduction in several patients with fractures of the femoral shaft. The measurement system mainly includes measuring device and data acquisition system. Distraction and alignment can be performed individually in the process of the operation, and indeed, the surgeons do this in practice. Forces of traction and alignment were measured by three sensors, and the results were registered instantaneously during the reduction process. According to a test, the maximum alignment forces in X-axis and Y-axis directions were 48.4N and 240.1N, respectively. The maximum traction force was 379.7N, occurred because of the surgeon slight valgus positioning of the leg convenient to insert the intramedullary nail. The highest forces were mostly observed along the shaft axis for distraction. These results can be used to develop new instruments and treatment procedures to ease the fracture reduction operation.
- 14:00 Mechanical Ventilator Spontaneous Breathing Detection Tested by Robot SIMVENT
- Mechanical Ventilators (MV) are only tested at the manufacturer's facilities in their ability to detect spontaneous breathing so as to trigger concomitant support. A robot patient was developed (called SIMVENT) to test MVs after repair or to compare MVs in hospitals. SIMVENT is a complete active patient simulator, as opposed to rubber bag simulation. SIMVENT implements lung equations under given user selected parameters of ventilatory mechanics to simulate different respiratory conditions. By producing spontaneous breathing pressure drops (1-10 cm H2O) at random times or phase-locked to ventilation cycles, SIMVENT tests the capacity of MVs to sense spontaneous ventilation. SIMVENT also calculates basic mechanical parameters (frequency, airway pressure, esophageal pressure, resistance and compliance). SIMVENT was designed with a step-motor powered piston moving in a 2-litre cylinder, a second cylinder mimicking residual volume, pressure sensors, a variable resistance tube, a microcontroller and a computer interface. A normalized spontaneous breathing detection capacity graph was constructed for two MVs: one behaved well and the other could be harmful if ventilating a patient during weaning, because spontaneous breathing was not sensed at the set pressure-drop value.
- 15:30 Contribution of different handwriting modalities to differential diagnosis of Parkinson's Disease
- In this paper, we evaluate the contribution of different handwriting modalities to the diagnosis of Parkinson's disease. We analyse on-surface movement, in-air movement and pressure exerted on the tablet surface. Variety of standard kinematic, spatio-temporal and novel handwriting features based on entropy and empirical mode decomposition of signal are derived and used.The results indicate that while the most predictive modality is on-surface movement, giving AUC = 89.09%, pressure and in-air movement also possess information that is relevant for the diagnosis of PD from handwriting.
- 17:00 Forward Autoregressive Modeling for Stride Process Analysis in Patients with Idiopathic Parkinson's Disease
- In this paper, we derive forward autoregressive models to describe the stochastic process underlying stride interval series related to idiopathic Parkinson's disease. The parameters of the autoregressive model that specify pole locations in the complex z-plane were used as dominant features for the separation of gait series of healthy subjects and patients with Parkinson's disease. Based on the autoregressive parameters, linear discriminant analysis and support vector machines can provide classification accurate rates over 74% and area larger than 0.8 under the receiver operating characteristic curve. The results obtained show that the autoregressive model parameters could be useful for classification of stride series.
- 18:30 A software - based platform for multichannel electrophysiological data acquisition
- Recent improvements in microelectrodes technology have enabled neuroscientists to record electrophysiological signals from hundreds of neurons and simultaneously from a large number of channels. However, several environmental factors may introduce noise and artefacts and affect proper interpretation of recordings. Thus, the development of appropriate signal acquisition and processing platforms dealing with large data sets and in realtime represents a current fundamental challenge. In the present work, we present an easily-expandable Lab VIEW based software for handling data in real-time during a multichannel neurophysiological signal acquisition. The software was designed to exploit modern MultiCore CPUs for large scale data processing and, by freely setting key acquisition parameters, to work with virtually any kind of biological signal. The software allows for data storage in MATLAB format to facilitate off-line signal processing. Examples of local field potential signal acquisitions from the mouse hippocampus are reported to illustrate software features.
- 20:00 Blood Oxygen Saturation Measurement by Smartphone Camera
- This study investigates about the usability of the smartphone camera for the evaluation of the arterial blood oxygenation (SpO2%). The advantage of this solution derives from the pervasiveness of the smartphone that makes available the evaluation of the SpO2% everywhere. Differently from the pulse oximeter, that uses well-defined wavelength light, the smartphone uses the Light Emitting Diodes as light source to evaluate the SpO2%. The change of the light intensity in the Red and Green colour channels in the video frames of the patient fingertip are properly processed. Two PPG signals are obtained at the wavelengths 600nm and 940nm, respectively. These two PPGs are used to evaluate the SpO2% without calibration coefficients and independently from the smartphone hardware and skin characteristics. Experimental tests are performed to compare the proposed procedure with respect to commercial pulse oximeter and gas chromatograph. The experimental tests assess the effectiveness of the proposal.
- 21:30 Automated Cardiac Self-gated Radial CMRI
- Distortions in electrocardiogram (ECG) signals affect the image quality and increase scan time of Cardiac Magnetic Resonance Imaging (CMRI) exams. This study proposes an alternative method of acquiring CMRI cine images in mouse heart using a self-gated Ultra-short Echo Time (UTE) protocol. In our method, a bandpass filter and a lowpass filter are adopted to extract the self-gated signals from the center of the raw no-gated k-space measurements, A live mouse has been tested as the example to verify the method. The results demonstrated that this method could be used for reconstruction of the no-gated UTE CMRI measurements without using of external ECG signals.
- 23:00 A novel approach to a phantom based method for maximum depth of penetration measurement in diagnostic ultrasound: a preliminary study
- In the present work a new approach for maximum depth of ultrasound signal visualization has been proposed by means of a tissue mimicking phantoms: the novel method is based on a threshold on the tangent applied to the mean depth profile that is drawn by averaging adjacent columns in the diagnostic image. It has been implemented and preliminary tested on three different diagnostic systems equipped with linear array probes under similar settings: results have been compared with the mean judgment of 5 observer and with output from another method, based on a threshold of the mean depth profile above the noise level, as suggested in literature. Even though a not negligible difference among some results is observed, due likely to the high electronic noise level displayed in the ultrasound image, the tangent method seems to agree with observer judgment and be more sensitive to echo signal than the other one, even at higher noise levels. Nevertheless other test are going to be performed in the next future for a more detailed characterization of the method.
- 00:30 Comparison of vision-based and sensor-based Systems for Joint Angle Gait Analysis
- Gait analysis has become recently a popular research field and been widely applied to clinical diagnosis of neurodegenerative diseases. Various sensor-based and vision-based systems are developed for capturing the hip and knee joint angles. However, the performances of these systems have not been validated and compared between each other. The purpose of this study is to set up an experiment and compare the performances of a sensor-based system with multiple inertial measurement units (IMUs), a vison-based gait analysis system with marker detection, and a markerless vision-based system on capturing the hip and knee joint angles during normal walking. The obtained measurements were validated with the data acquired from goniometers as ground truth measurement. The results indicate that the IMUs-based sensor system gives excellent performance with small errors, while vision systems produce acceptable results with slightly larger errors.
- 02:00 A novel approach for features extraction in physiological signals
- The authors have investigated a novel processing algorithm to measure possibly relevant features in biological signals acquired from different biomedical sensors (based on electrical, optical, acoustical and mechanical principles) and to characterize their waveforms according to their morphology. The aim of this work is to demonstrate the possible use of such measurement method as an alternative to standard approaches (e.g. Pan & Tompkins). Results have been obtained on 8 healthy subjects and show a deviation (2σ) of ±3.3 bpm, ±2.3 bpm and ±1.5 bpm between ECG (electrocardiography) and PCG (phonocardiography), PPG (photoplethysmography) and VCG (vibrocardiography) respectively. In addition, the performance of the algorithm proposed for the identification of the R-peak in ECG signal has been compared with respect to what is in literature and the results are discussed in the paper.
- 03:30 Impedance Plethysmography System With Inertial Measurement Units for Motion Artefact Reduction: Application to Continuous Breath Activity Monitoring
- This paper presents an impedance plethysmography system suitable to perform a continuous monitoring of human breath activity. The problem of motion artifact is mitigated through the use of a correction technique exploiting an additional inertial sensor able to detect movements of the arms of the subject under test. The correction algorithm is based on a simple correlation technique and only requires a very brief training at the beginning of the acquisition session, with the monitored subject performing random movements in apnea condition. Application of the proposed system to a healthy adult volunteer demonstrates the potentiality of the correction algorithm, which, thanks to its extreme simplicity and low computational cost, is a suitable candidate for implementation in a low-cost and portable monitoring system.
- 05:00 Measurement of Vehicle Acceleration in Studies of Older Drivers from GPS Position and OBDII Velocity Sensors
- This paper demonstrates the validity of vehicle acceleration/deceleration signals derived from 1Hz sampled GPS position and OBDII velocity sensors through comparison to 40Hz sampled accelerometer measurements. Measurement of acceleration and deceleration is important as it is a key measure of driving habits and needs to be measured without the cost and complexity of installing additional accelerometers for long term studies while the OBDII interface is built-in and GPS sensors are easily deployed are shown to provide alternative acceleration signal. The results show a maximum average correlation of 0.810 between the GPS and the accelerometers and 0.808 between the OBDII and the accelerometer. The paper analyzes the effects of noise for each of the derivative difference equations and shows that the Central 2-point formula provides the best noise performance whereas the Central 4-point formula (correlation 0.801) would be expected to provide the best performance in a noise free signal. Forward/Backward 3-point are predicted to have similar performance to Central 2-point in noise free signals but are shown to have poor performance (correlation of 0.667 and 0.687 respectively) in the presence of noise.
- 06:30 Nano-Structured Polypyrrole as a Low-Cost Substrate for Glucose Biosensing Applications in Rural Health
- This paper presents different techniques used in fabricating polypyrrole substrates for the use in disposable blood glucose measurements. It compares the two main fabrication methods used and their variants with achieved sensitivities and linear ranges. The results show that polypyrrole is a very good substrate material which can be easily fabricated into a nano-surface to adsorb higher amount of glucose oxidase.
- 08:00 Smart textiles for wearable sensor networks: review and early lessons
- Field of wearable computing has great implications for medical applications, including early detection, treatment, compliance monitoring, care for the frail and elderly, telemedicine, physical therapy and many others. Unfortunately such wearable technology solutions are still custom made and time and resource intensive to develop. In this paper the current progress of development of a universal smart textile system is discussed which would solve this problem and accelerate the field of smart wearable electronics. Such a textile must be able to accommodate several hundreds of sensors, providing power and data transmission lines in such a way, that mass production of smart garments from such a textile is feasible. The main problems and potential solutions discussed in this article include topology, allowing the textile to be arbitrarily cut and sewn into smart clothing, data transmission architecture providing high bandwidth and low energy data transfer and support for miniaturization and elasticity, making the potential end product as unobtrusive as possible.
- 09:30 Sensors in LTCC-technology with embedded microfluidic featurs, for medical applications
- The LOC/POC testing units based on microfluidics technology are booming nowadays, due to robustness, simplicity of use and reliability. Multilayer ceramics, functionalized with nano-scaled sensing materials, and further integrated within microfluidic test elements, are of great challenge and represent the purpose of the paper. The LTCC technology versatility allows the 3D integration of electrochemical sensors with microfluidic features, and further with advanced signal processing and wireless communication.
- 11:00 Microsensors and Energy Harvesting for Thermotherapy: Design and Characterization
- Thermotherapy is often used for diverse biomedical applications. One of them is treating human body area under pain, for example, lumbar pain. Thermotherapy can be used for such purpose by means of, for instance, metal-based bands that produce heat on the area under treatment. The heat delivered by such bands end after a specific time. This is a thermotherapy system based on a contact between dedicated bands and human body area under pain. The bands generally contain materials as polyester, iron or copper, salt, cellulose, active carbons, etc…The paper presents an energy harvesting system based on Seebeck's effect using micro-thermogenerators that convert heat from neck to electrical energy to be used on lumbar area with a further conversion from electrical to heat. This approach, even apparently complicated, allows to use a system that can be utilized every time and for a long period. It is useful because the heat produced by human body is displaced from neck to another area of the same body.
- 12:30 An Efficient Home-Based Risk of Falling Assessment Test Based on Smartphone and Instrumented Insole
- The aim of this study is to improve and facilitate the methods used to assess risk of falling among older people at home. We propose an automatic version of One-Leg Standing (OLS) test for risk of falling assessment by using a Smartphone and an instrumented insole. For better clinical assessment tests, this study focuses on exploring methods to combine the most important parameters of risk of falling into a single score. Twenty-three (23) volunteers participated in this study for evaluating the effectiveness of the proposed system which includes eleven (11) elderly participants: seven (7) healthy elderly (67.16±4.24), four (4) Parkinson disease (PD) subjects (70±12.73) and twelve (12) healthy young adults (28.27±3.74). Our work suggests that there is an inverse relationship between OLS score proposed and risk of falling. Proposed instrumented insole and application running on Android could be useful at home as a diagnostic aid tool for analyzing the performance of elderly people in OLS test.
- 14:00 Characterization of Therapeutic Ultrasound Devices for Rehabilitation and Physical Medicine
- The study describes the results obtained in ultrasound power measurements carried out on physiotherapy ultrasound equipment in Department of Orthopaedics, Traumatology and Rehabilitation, AO Città della Salute e della Scienza, CTO Hospital, Torino, Italy.
- 15:30 Study on the influence of wireless communication technology on sensitive medical equipment
- In this paper we studied the influence of electromagnetic wireless communications traffic on sensitive medical equipment used in intensive care units. We have identified the main sources of disruptive electromagnetic field existing in a neonatal intensive care unit and studied the influence of wireless communication systems GSM 900and DECT on the main operating parameters set to a neonatal mechanical ventilator. After studies we observed that the important parameters used in assisted mechanical ventilation like expiratory volume, inspiratory pressure, expiratory pressure, mean pressure and tidal volume suffers significant changes when wireless communication disturbing source is at walking distance of sensitive medical equipment.
- 17:00 An innovative measurement system based on MEMs for telerehabilitation
- Rehabilitation is a time and resource consuming activity whose direct and indirect costs could be substantially reduced by the use of ICT and MEMs technologies. Such technologies could avoid patient transportation to the rehabilitation center and, at the same time, let a single physiotherapist follow and monitor more than one patient per time. Last but not least, the use of quantitative measures makes the rehabilitation outcomes more objective and repeatable. The paper reports the experience of a research project, the PRO DOMO SUD, in which a system for telerehabilitation was designed and implemented. The platform was focused on lower limb rehabilitation and it is composed of a Central Remote Unit where all the measures are collected and stored and a set of wearable MEMs sensors detecting the 3D orientation of the limbs. The platform has been designed to detect the Range of Motion (ROM) of hip, knee and ankle joint and for a commonly used clinical test called Six Minute Walking Test (6MWT). Preliminary results are presented in the paper.
- 18:30 A novel approach for design and testing digital m-health applications
- The management of age related diseases is one of the most discussed and controverted topic in Healthcare policy: cost-efficient solutions are needed to reduce the economic impact on welfare systems and to improve the quality of life of the patient. This is particularly true for chronic diseases, in which a simple, but continuous monitor of few parameters from patients, would allow a consistent reduction of hospitalization. In this paper we present the experience derived from a Living Lab project, a novel model of participated innovation in which the end-user plays a crucial role. We designed, implemented and tested a solution for remote monitoring of physiological parameters directly from chronic patients' house according to a clinical protocol defined by healthcare professionals. Every measure was composed by a set of parameters such as Blood Pressure, Body Weight, Heart Rate, Pulse Oximetry and, if needed, the answers to a questionnaire provided by healthcare professionals to the patient. The new system proved to reduce the hospitalization rate and to increase the empowerment of the patient in the self-management of his chronic condition
- 20:00 Three-Dimensional Gesture Interactive System Design of Home Automation for Physically Handicapped People
- In this paper, we propose a three-dimensional gesture interactive system design of home automation for physically handicapped people. In order to provide a convenient and comfortable environment, we design a finger and hand gesture user interface for physically handicapped people based on stereo cameras to achieve remote control and gesture recognition system. We use stereo camera to capture stereo image and calculate disparity map and depth map for supplying physically handicapped people a real-time interface based on hand gesture and finger action. The system can achieve 93% accuracy of eight direction function, 93.75% accuracy of zoom function, and 90% accuracy of click function. The experimental results prove the efficiency of the proposed system.
- 21:30 New FEM 3D model for arm-cuff interface simulation
- The aim of the work is focused on the generation of a FEM 3D model, by using Ansys code, able to arm-cuff interface simulation during deflation. For this purpose the circumferential distribution of the pressure produced by the cuff on the arm during the inflation and the deflation has been measured. The parameters of the arm have been identified by searching vessel-occluded conditions at the systolic blood pressure for the bladder/arm ratio equal to 80%. The model was validated preliminarily checking its ability to correctly simulate the phenomenon of miscuffing by comparison with the data derived from the consolidated bibliography of the sector. The code has been then applied using as external load an experimental circumferential distribution of the pressure. The model has allowed to simulate the shape of the lumen of the arterial vessel during the deflation, properly highlighting the moments in which the pressure of deflation equals the systolic and diastolic pressures of the patient.
Friday, May 8, 12:30 - 13:00
Award ceremony in the memory of Prof. De Benedetti
Room 1 (Salone d'Onore)
Friday, May 8, 13:00 - 14:30
Room: Sala delle Colonne
Friday, May 8, 14:30 - 16:00
Bus transfer to the University of Gastronomic Science, Pollenzo
Friday, May 8, 16:00 - 16:30
Anthimos Georgiadis - "Mechanical and electrical characterization of fibrous nano-materials in medicine"Room: Pollenzo conference room
Friday, May 8, 16:30 - 17:45
Round table - "International network in metrology for patient health care"
A. Georgiadis, R. Goubran, C. Gulotta, M. Inguscio, B. Karaboce, - Chair: P. VassiliouRoom: Pollenzo conference room
Friday, May 8, 17:45 - 18:00
Preview of MeMeA2016 in Benevento, Italy
Room: Pollenzo conference room
Friday, May 8, 18:00 - 19:00
Wine & Cheese tour at the University of Gastonomic Science, Pollenzo
Friday, May 8, 19:00 - 21:00
Gala Dinner - Albergo dell'Agenzia, Pollenzo
Friday, May 8, 21:00 - 23:00
Bus transfer to Torino
Saturday, May 9
Saturday, May 9, 09:00 - 10:40
S1.1: Bioengineering and rehabilitation - Monitoring of rehabilitation
Room 1 (Salone d'Onore)
Chairs: Rafik Goubran (Carleton University, Canada), Mauro Serpelloni (University of Brescia, Italy)
- 09:00 Fuzzy Sliding Mode Control of an Upper Limb Exoskeleton for Robot-assisted Rehabilitation
- Robot-assisted therapy has become an important technology used to restore and reinforce the motor functions of the patients with neuromuscular disorders. In this paper, we proposed an upper-limb exoskeleton intended to assist the rehabilitation training of shoulder, elbow and wrist. The proposed therapeutic exoskeleton has an anthropomorphic structure able to match the upper-limb anatomy and enable natural human-robot interaction. A modified sliding mode control (SMC) strategy consisting of a proportional-integral-derivative (PID) sliding surface and a fuzzy hitting control law is developed to guarantee robust tracking performance and reduce the chattering effect. The Lyapunov theorem is utilized to demonstrate the system stability. In order to evaluate the effectiveness of proposed algorithm, several trajectory tracking experiments were conducted based on a real-time control system. Experimental results are presented to prove that, when compared to the conventional PID controller, the fuzzy SMC strategy can effectively reduce the tracking errors and achieve favorable control performance.
- 09:20 Needle Detection by Electro-Localization for a Needle EMG Exam Robotic Simulator
- Until now is difficult to reproduce a large number of pathological conditions of the muscle nerves by needle EMG (electromyography) exam (NEE) for medical students. A robotic simulator that reproduce similar conditions to NEE with various pathological disorders can be of great help for skill training of neurology interns and novice medical technicians. Needle localization, which is a key component of the robotic simulator, has been investigated for many medical tests and applications, such as prostate brachytherapy. However, only few studies have been reported on the simulation of the process of needle operation in muscle based on needle tip position dependent of EMG signals. Our idea is to apply a conductive tissue-equivalent phantom to realize both physical sense of insertion, and needle localization for the NEE simulation. A pair of surface electrodes was designed to generate a pseudo-linear voltage distribution along the depth direction of the tissue-equivalent phantom, by which the inserted needle could be localized. The influence of the shape of phantom and electrodes on detection accuracy were investigated by a set of measurement experiment and a computer simulation. The results showed that, the estimated depth values agreed with that of the computer simulation model, and the curved phantom had a much steeper distribution in the deeper region. Consequently, the needle tip could be detected with 1-mm accuracy for the NEE robotic simulator.
- 09:40 Power Harvesting Integrated in a Knee Implant for Autonomous Sensors Implanted in Human Body
- This paper describes an energy harvesting system (EHS) composed of an electromechanical generator (EMG) and a dedicated energy management circuit integrable in a human total knee prosthesis, in which the mechanical energy from the knee joint is converted into electrical energy. Since the energy supplied by the proposed EMG is discontinuous in time, a tailored energy management circuit is necessary to adapt the harvested energy to the load energy requirements. The electromechanical generator is composed by two series of NdFeB magnets positioned into each condyle and a coil, placed in the pin of the tibial insert, which collects the magnetic flux variations, generated by the knee movements. A total knee replacement (TKR) prototype has been developed and realized in order to reproduce the knee mechanics. Therefore, electrical performances have been evaluated, at the first, measuring the EMG open circuit voltage by means of a high impedance buffer amplifier, and, subsequently, connecting the EMG to the energy management circuit able to manage the produced energy and to power an implanted circuit for force measurement inside the human knee. The tests showed that the EHS is able to supply the measuring circuit guaranteeing a tension between 2.45 V and 2.15 V for 25 ms almost every 1.5 s. The tests successfully demonstrate the possibility to power a measurement circuit transmitting the measurement data outside the prosthesis every about one-step and half.
- 10:00 Using a Seminorm for Wavelet Denoising of sEMG Signals for Monitoring During Rehabilitation with Embedded Orthosis System
- This paper deals with the noise detection of discrete sEMG signals using wavelets. More specifically, it compares the usefullness of the Haars and Daubechies wavelets for the denoising and compression of the digitalized biosignal. The work is based upon the Discrete Wavelet Transform (DWT) version of Wavelet Package Transform (WPT). A denoising algorithm is proposed to detect unavoidable measured noise in the acquired data. With the help of a seminorm the noise of a sequence is defined. Using this norm it is possible to rearrange the wavelet basis, which can illuminate the differences between the coherent and incoherent parts of the sequence, where incoherent refers to the part of the signal that has either no information or contradictory information. In effect, the procedure looks for the subspace characterised either by small components or by opposing components in the wavelet domain. Concerning the proposed application, an orthosis embedded with a surface electromyography (sEMG) measurement system, integrated with conductive multifilament yarn, was used to monitor the electrical activity of the forearm muscles during movement. This method was developed for long term monitoring during rehabilitation. The proposed method is general, can be applied to any low frequency signal processing, and was built with wavelet algorithms from the WaveLab 850 library of the Stanford University (USA).
- 10:20 Improving Classification of Sit, Stand, and Lie in a Smartphone Human Activity Recognition System
- Human Activity Recognition (HAR) allows healthcare specialists to obtain clinically useful information about a person's mobility. When characterizing immobile states with a smartphone, HAR typically relies on phone orientation to differentiate between sit, stand, and lie. While phone orientation is effective for identifying when a person is lying down, sitting and standing can be misclassified since pelvis orientation can be similar. Therefore, training a classifier from this data is difficult. In this paper, a hierarchical classifier that includes the transition phases into and out of a sitting state is proposed to improve sit-stand classification. For evaluation, young (age 26 ± 8.9 yrs) and senior (age 73 ± 5.9yrs) participants wore a Blackberry Z10 smartphone on their right front waist and performed a continuous series of 16 activities of daily living. Z10 accelerometer and gyroscope data were processed with a custom HAR classifier that used previous state awareness and transition identification to classify immobile states. Immobile state classification results were compared with (WT) and without (WOT) transition identification and previous state awareness. The WT classifier had significantly greater sit sensitivity and F-score (p<0.05) than WOT. Stand specificity and F-score for WT were significantly greater than WOT for seniors. WT sit sensitivity was greater than WOT for the young population, though not significantly. All outcomes improved for the young population. These results indicated that examining the transition period before an immobile state can improve immobile state recognition. Sit-stand classification on a continuous daily activity data set was comparable to the current literature and was achieved without the use of computationally intensive feature spaces or classifiers.
S2.1: Embedded systems - Medical and Instrumentation uncertainty
Room 2 (Stanza dello Zodiaco)
Chairs: Alessandro Depari (University of Brescia, Italy), Abdulmotaleb El Saddik (University of Ottawa, Canada)
- 09:00 A configurable biopotentials acquisition module suitable for fetal electrocardiography studies
- The problem of the acquisition of biopotentials from the skin surface has been studied for several years, during which a number of techniques for reliably acquire such signals were developed. Today these form a solid ground of well established practices employed in every commercially available biomedical acquisition unit. Nevertheless in some application fields such a deep knowledge has not yet been reached, this pushing the research. Non-invasive fetal electrocardiography is one of those field. Hence, in order to better investigate aspects connected with the signal acquisition, which sometimes has strong reflections also on the signal processing techniques used to post-process the signal, we developed a custom acquisition unit, highly configurable in terms of measurement setup, able to support studies on the signal acquisition for fECG extraction on the animal model. The developed system has been compared to a commercially available biosignal acquisition system (PORTi by TMSi), in order to verify its performances in terms of achievable signal quality, with good results. Also preliminary measurements on animals are presented.
- 09:20 A smartphone-enhanced pill-dispenser providing patient identification and in-take recognition
- The wider and wider availability of powerful, low-cost mobile devices (e.g., smartphones or tablets) is deeply changing healthcare, so that the mHealth term has been coined. The announcement of healthcare projects by market big players as Apple and Samsung confirms this trend. In particular, the opportunity to collect reliable patient data automatically allows to enhance patient/user self-management and helps in better delivering therapies. In this paper, authors propose an innovative architecture for a smart pill-dispenser enhanced by a smartdevice that furnishes the capability of automatically identifying the user, other than logging medicine in-take activities. A real-world prototype, based on an emulated pill-dispenser connected via an NFC link to different smartdevices, has been purposely realized. Experimental tests confirm the architecture feasibility. Low-cost requirements are satisfied and a user-friendly interface has been implemented.
- 09:40 Ultrasound and Mocap to Improve Non Invasive Hip Joint Center Calculation
- The hip joint center (HJC) location is needed for calculation of hip kinematics in various applications. The functional method utilizes the movement of femur with respect to acetabulum to find the location of the center. A popular way for measuring this movement is through an optical motion capture system. This method is fast and economical for most applications where we require an instant HJC even though the reconstruction error in bone position calculation exists due to skin artifact. This error is caused by the motion of markers placed on skin rather than on actual bone. However while the thigh muscle is contracting and relaxing during the leg movement, the position of the bone relative to the skin is changing. Here we introduce ultrasound imaging to measure the change in soft tissue thickness above Femur bone while leg is moved, so that this information can be further used to eliminate soft tissue artifact by estimate bone location more correctly in calculation of the center of rotation. The advantage of using ultrasound machine is its non-invasiveness and portability while the bone position is measured. We determine a position on bone and show that there is a linear relationship between angle of rotation and tissue thickness. We use this new recalculated bone position to calculate the center of rotation through a traditional method and compare it with the calculated center through markers on skin. Our new algorithm shows that the residual has been improved by 46%.
- 10:00 Genomic based personalized chemotherapy analysis to support decision systems for breast cancer
- Personalized approach to anti-cancer therapy necessitates the adaptation of standardized guidelines for chemotherapy schedules to individual cancer patients. We introduce a methodology, namely Personalized Relevance Parameterization (PReP-G), based on the genomic data of breast cancer patients to compute time course of drug efficacy on tumor progression. The pharmacodynamic (PD) parameters of transit compartmental systems are computed to quantify the drug efficacy and kinetics of cell death. We integrate the genetic information of 74 breast cancer related genes for 78 patients with clinical t-stage of 3 from the I-SPY 1 TRIAL with the tumor volume measurements from NBIA database into our PReP-G model to compute tumor growth and shrinkage parameters. The performance of the method is evaluated for the breast cancer cell lines of BT-474, MDA-MB-435 and MDA-MD-231 for a given chemotherapy, where the anti-cancer agents Doxorubicin and Cyclophosphamide are administered to animal models and the change of tumor size is measured in time. We compare our results from PReP-G model with the experimental measurements. The consistency between computed results and the volume measurements is encouraging to develop personalized tumor growth models and decision support systems based on genetic data.
- 10:20 Measurement Issues in Probing Depth Evaluation of Periodontal Pockets
- Measurement of periodontal pocket depth, a key step in detection and analysis of periodontal diseases, is frequently affected by substantial uncertainty. Estimation of distance between gingival margin and connective ligament, an apparently straightforward measurement task routinely performed with simple probes, entails a fairly complex pattern of single and combined effects. Layout of marks on probe affects readings, since, when interpolation is involved, operator's experience comes into the picture. Compliance of tissues at pocket bottom implies dependence of probe penetration from insertion force, whose control again is affected by operator's experience. Hazy definition of gingival margin further contributes to scatter in results, liable to lead to diagnostic mistakes and wrong therapeutic decisions. An investigation on measurement issues, aimed at identification of main factors affecting uncertainty in evaluation of pocket depth, was performed in vitro with an ad hoc device, developed in order to get traceability and evaluate reproducibility of measurements of pockets with different depths. Measurements were performed by operators with different experience and skill, using three types of periodontal probes currently in use. Results showed a different performance of the probes in terms both of bias and scatter. Occurrence of false positives and negatives were found to be strongly dependent upon operator experience.
S3.1: Special Session: Metrology in Biosciences
Room 3 (Stanza della Caccia)
Chairs: Anthimos Georgiadis (Leuphana University Lueneburg, Germany), Mariapaola Sassi (Istituto Nazionale di Ricerca Metrologica, Italy)
- 09:00 Mechanical Characterisation and Modelling of Electrospun Materials for Biomedical Applications
- Electrospun nonwovens, due to their intrinsic beneficial properties, have found many applications in biomedical areas such as tissue engineering, drug delivery, or active wound management. Exploiting its porous structure, electrospun is often used as scaffolds for tissue growth which can be stimulated by mechanical properties of the structure. Cells proliferation can be controlled by stress distribution in the scaffold, thus improving its efficiency. Anticipation of this parameter is possible by using Finite Elements Model of electrospun structure presented in this study. Fully parametric model of nonwoven material with random fibrous distribution was developed enabling the calculation of mechanical properties of material on the basis of input parameters such as mechanical characteristics and geometry of single component fibres. Relatively low production ratio of electrospinning process and time consuming characterisation methods were motivation to develop the tool that would shorten the design and optimisation of electrospun materials. The model was validated experimentally by mechanical testing of electrospun material; modelling and experimental results were in a good agreement.
- 09:20 Coplanar Micro-Strips/Electrospun sensor system to Measure the Electronics Properties of the Polyethylene Oxide (PEO) Electrospun
- In the literature we found different kind of conducting polymers, as Polyaniline (PANI) and Polypyrrole (PPY), which was used as film for the detection of gas and photogenes. We present a CPμS/electrospun sensor system prototype based on the combination of a coplanar micro strip (CPμS) and polymer nanofibres electrospun, where the nanofibers acting as sensing element. The work involved experimental and theoretical efforts to investigate and understand low frequency (0.1 to 1 MHz) electrodynamics response properties of the CPμS/nanofibres sensor system with and without nanofibers. The polymer nanofibers were produced by electrospinning, this method produced a net of nanofibers called electrospun. We develop a mathematical model of the CPμS/nanofibres sensor system based on the transmission line theory, which was simulated with Scilab and its result was compared with the experimental data of the CPμS in order to see the agreement between model and experiment. The works present the impedance spectroscopy results for the CPμS/nanofibres sensor system with and without nanofibers. The curves obtained from the data are agreed with the model, which predict that the impedance curve of CPμS/nanofibres is under the impedance curve of CPμS. Therefore from the difference between both curves is possible to calculate the electronics properties of the PEO electrospun. Furthermore the curves exhibited a sub-linear power law decrease with frequency, which is consistent with the behavior found in polymers.
- 09:40 Flow cytometer for reference measurements of blood cell concentrations with low uncertainty
- A method is described to determine cell concentrations for erythrocytes and leukocytes with typical uncertainties of 0.8% and 2% respectively. The results are traceable to SI derived units. The sample suspensions are prepared under gravimetric control. The sample volume measured in cell counting is determined by weighing, including separate density measurements. Random coincidences are a significant challenge in particle counting leading to underestimated cell concentrations. In the method described here this challenge is met by recording the dead time in particle counting and applying dilution series. This method is routinely applied for quality assurance of German hematology laboratories for the complete blood count.
- 10:00 Reproducible measurements of human mesenchymal stem cells counting and proliferation in 3D scaffolds for Regenerative Medicine
- Human mesenchymal stem cells (hMSCs) are good candidate to repair and to regenerate tissues for regenerative medicine applications. Their use in combination with 3D scaffolds has been largely studied in vitro to characterize their properties and differentiation potential prior to apply them in vivo. One of the most important clues in vitro is given by their proliferation trend, leading to information about their viability, their wellness, their interaction with scaffolds, etc. In order to measure the proliferation of hMSCs on scaffolds for regenerative medicine, it is important to adopt accurate counting methods in both research and diagnostic studies. This work aims to develop a reproducible method for hMSCs proliferation measurement in 3D cell cultures on coralline scaffolds (Biocoral®). Results demonstrated that proliferation curves obtained in this work are reproducible at different initial cell densities on several scaffolds cultured with hMSC in long term experiments (3 weeks).
- 10:20 Targeted Quantitation of HMGB1 Protein by label-free Mass Spectrometry Technique
- Mass spectrometry (MS)-based methods have become popular in recent years for the quantitation of biomolecules, especially peptides and proteins. There are several methodologies for carrying out the quantitation of proteins using both stable isotope labelling or label-free workflows. High Mobility Group Box-1 protein (HMGB1) is a nuclear DNA-binding protein that resides inside the nucleus and can be released to the extracellular space under specific conditions. HMGB1 has been reported as circulating mechanistic indicators of cell death mode in animal models and in clinical studies. There is accumulating evidence that HMGB1 contributes to the pathogenesis of inflammatory and autoimmune diseases. Moreover, HMGB1 has been found to play an important role in tumor development, growth, and spread. Circulating HMGB1 level could be a useful and specific marker for evaluating different disease status and predicting prognosis in patients. The label-free quantitative comparison without any standard reference or normalization of the target peptide signal is the simplest Liquid Chromatographic-MS (LC-MS) method for the quantitation of a protein. Peptides with sequences unique to the target protein are selected as its surrogates. The peak areas for multiple reaction monitoring (MRM) transitions, which are the signal created by the peptide fragmentation, are integrated as measures of peptide abundance and are used as basis for quantitative comparison. The aim of the research was the development of an analytical method for the quantitation of HMGB1 by label-free Mass Spectrometry technique. Through the use of standard concentration curve of purified HMGB1 protein, the quantitation of HMGB1 and its peptides recovery was assessed. The developed method can be considered a typical shot-gun approach for the analysis of proteins and consists of a sample digestion with trypsin and the identification and quantification of HMGB1 specific peptides. The developed technique could be useful in an environment where rapid turnaround of protein samples is needed, as well as analytical precision. Aside from improving the efficiency and speed of the experiments, future efforts will involve performing a more complete validation training to demonstrate the full bio analytical viability of this approach in different complex matrices such as cell lysates and biological fluids.
Saturday, May 9, 10:40 - 12:10
PS2: Poster Session 2
Room: Stanza dei Gigli
Chairs: Luca De Vito (University of Sannio, Italy), Maria Riccio (University of Sannio, Italy)
- 10:40 A Modular Mobile Exergaming System With an Adaptive Behavior
- Obesity rates in the world, especially in the developed countries are alarming. This has forced scientists to consider obesity as an epidemic due to its huge negative consequences on the societies' physical and mental health. Obese Children constitute a large portion of those affected by this epidemic and researchers are striving to find solutions which can curb its spread. Exergames have emerged as promising tools that can help in the fight against obesity because it promotes physical activity through playing. In this paper, we present a mobile-based exergaming system that targets children of different ages and that aims to encourage them to do running and jumping exercises in an enjoyable manner. It currently incorporates 1 game but its modular structure enables to easily accept even more games. The system uses a novel foot interface and a heart monitor that allow interacting with a special game that can adapt to the user's performance. The preliminary evaluations with two children have shown that the system can be an effective tool that engages users into physical activity.
- 12:10 Low Power Wearable System for Vital Signs Measurement in All Day Long Applications
- The growing demand for wearable devices is dictated by the ability to monitor in real-time critical situations in the different areas of daily life. However, such devices have not yet had a considerable development. This is because of some technological aspects not yet fully consolidated. One of these aspects is the battery power supply that due to the weight and overall dimensions can prevent the movement and / or increase the invasiveness of the system. The present work describes an instrumented autonomous T-shirt adopting a low power circuit board consuming only 8.15 mA in run mode. The proposed low power wearable system can permit smaller and lighter batteries and continuous monitoring in all day long applications. The instrumented T-shirt is capable of measuring the frequency of respiration, heart rate and movement of the body, transmitting data to a readout unit and sending alarms if necessary. The methodology adopted, the design choices and the experimental results are clearly reported and discussed. The proposed methodology can be an effective solution for all wearable devices
- 13:40 A Smartphone-Based Indoor Localization System for Visually Impaired People
- The World Health Organization assesses the number of visually impaired people to be nearly 285 million in August 2014, of whom 39 million are blind. One of the most important discomfort factors for these persons is known to be the difficulty in moving and orienting by themselves in unfamiliar surroundings. Nowadays, several devices are currently available for supporting these persons in there everyday life. To this end, the attention in this paper is mainly focused on the localization and navigation in indoor environment. The solution adopted here is based on an inertial platform represented by a set of sensors (basically accelerometer, gyroscope, electronic compass) placed in a device worn by user. This approach does not require the installation of external equipments since it relies on a smartphone, which is used both as measurement platform and user interface. The application will be described in the paper where some experimental preliminary results will also be discussed.
- 15:10 Smart Environments using Near-Field Communication and HTML5
- Home health care and home automation increasingly allows more seniors to maintain independence, and remain longer in their own homes. Similarly, a post-surgical patient may be discharged from a medical facility to their house, which electronically facilitates their recuperation and promotes recovery. Smart environments are making the task of providing assistive technology in the home easier and more affordable. Near-field communication (NFC) has become popular in recent years. Increasing uptake of NFC-enabled smartphones has opened a new avenue to facilitate creation of a smart environment without the need for significant infrastructure. HTML5 is the latest version of the hypertext markup language, and has unique code that enables access to advanced features on a smartphone. Proprietary apps can potentially be inconvenient and inconsistent and may even decrease uptake of the technology. In this paper, we propose a new methodology to enable NFC tags and NFC smartphones in conjunction with HTML5 backbone code, to be used for smart environments in home health care applications without the need for specific applications to be installed on the smartphone. Results show significant promise with just the built in phone software with use of NFC and HTML5 for various applications of smart environments. In many common tasks in a smart environment that increase patient safety, NFC tags can be not only informative, but an integral component of the system by triggering specific HTML5 code to provide appropriate responses - without the need to install specialized apps as long as the NFC is enabled in the mobile device.
- 16:40 An innovative framework for rare neurodegenerative diseases analysis
- In this paper we introduce a new non - invasive, inexpensive and functional tool in order to support physicians and specialists during visits of patients who are affected by neurodegenerative diseases, as well as Huntington's one. The proposed framework succeeds in automatizing International Affective Picture System (IAPS) test which consists of two phases: the first allows to show a sub set of pictures stored in a database, while the second takes note of Self Assessment Manikin (SAM) scale evaluations; during the session, the patient's face is captured by a webcam for extracting emotional features for each frame. This framework, therefore, saves data in a SQLite Database. The proposed framework provides a medical efficient evaluation to evaluate the emotional impairment in these patients by comparing the results given by facial expressions analyzer and those given by the leading layer themselves in a long observation period.
- 18:10 Very Low Field MRI: a fast system compatible with Magnetoencephalography
- In recent years, ultra-low field (ULF) MRI is being given more and more attention, thanks to the possibility of integrating ULF-MRI with Magnetoencephalography (MEG) in the same set-up. We here present a room-temperature, MEG-compatible very-low field (VLF)-MRI device working in the hundreds of kHz without sample prepolarization. Considering the same imaging conditions and SNR, the system has better performances in terms of scan time if compared with existing ULF devices while preserving many of the ULF-MRI advantages.
- 19:40 Efficient Techniques to Enhance Nearfield Imaging of Human Head for Anomaly Detection
- This paper proposes efficient processing techniques to enhance the nearfield electromagnetic imaging of human head. Forward problem is modelled with geometrically complex shaped SAM head phantom containing brain tumor anomalies and with a circular applicator antenna array. Scattered signals are compressively sensed at only a few sensing positions. The sensed signals are preprocessed efficiently by proposed novel technique to extract the difference signals of useful samples, resulting in temporal compressed sensing. A dictionary is formed and tested in inverse problem solution using compressed sensing for head imaging of multiple brain tumor targets of different shapes and sizes at different locations. Compressed Sensing based imaging results are compared with standard back-projection (SBP) technique and are later post processed by applying proposed techniques to improve the quality and the spatial resolution. Additionally, imaging results are compared quantitatively by image quality metric in terms of peak signal-to-noise ratio (PSNR) values, expressed in decibels. Quality of the reconstructed images and the corresponding PSNR values clearly reveals the validity of the proposed processing techniques.
- 21:10 A New Risk Assessment Methodology for Dermoscopic Skin Lesion Images
- The incidence of melanoma has been increasing steadily over the past few decades throughout most of the world. The development of computer diagnosis systems that use dermoscopic images can be of great help for the diagnosis of melanoma. This paper presents an image processing and analysis methodology using supervised classification to independently assess the Asymmetry, Border, Color and Dermoscopic Structures score according to the ABCD rule, and the corresponding Total Dermatoscopy Score of a skin lesion using dermoscopic images. A dermoscopic image dataset was used to test the proposed approach, annotated by dermatology specialists according to the ABCD rule and being the confirmed malignant melanomas also identified. Accuracy rates of 74.0%, 78.3% and 53.5% were achieved for the estimation of the ABCD score of the Asymmetry, Border and Color criterion, as well as accuracy rates for the presence of the five Differential Structures of 72.4%, 68.5%, 74.0%, 74.0% and 85.8% for dots, globules, streaks homogeneous areas and pigment network. Moreover, sensitivity and specificity rates of 93.3% and 69.1% were achieved for the classification of the dermoscopic images as melanoma or non-melanoma.
- 22:40 Receiver Operating Characteristic: A Tool for Cell Confluence Estimation
- Image thresholding techniques are focused on quantitative estimation of cell confluence in microscopy imaging. Receiver operating characteristic (ROC) analysis is presented and discussed with application to uncertainty affecting cell confluence estimated by inspection of fluorescence micrographs.
- 00:10 3D Face Detection using IPC Based Depth and Intensity images
- A very important preprocessing step in 3D face recognition system is the face detection. The goal of our approach is to extract the face area from the depth and intensity (RGB) image which are generated from 3D (x, y, z) surface representation. The nose tip is our key point in the face detection, this point usually has the largest z value; but there is a problem in some additional information such as: shoulders, hair, neck and some parts of clothes which are unusable and may take a largest z value, so in this case we have an error in the detection of nose tip. To address this problem, we propose the use of Horizontal and Vertical Integral Projection Curves (IPC) in order to remove the areas which are not usable then the detection of nose tip with simple method is used to centering an elliptic mask on this point and cropping the face area. Experimental results implemented on two 3D face databases CASIA3D and GavabDB; demonstrate that our proposed method achieves a high detection rate especially in illumination variation.
- 01:40 Quantitative detection of Escherichia coli and measurement of urinary tract infection diagnosis possibility by use of a portable, handheld sensor
- Electrochemical nitrite sensor was used to quantitatively detect the nitrite concentration in urine and by building the approximate relationship between the nitrite concentration and number of E.coli bacterias, electrochemical nitrite sensor can count the numbers of Escherichia coli and do the Urinary Tract Infection (UTI) Diagnosis. Electrochemical nitrite sensor was assembled and calibrated, the artificial urine sample was detected; the feasibility of electrochemical nitrite sensor including the errors effect had been checked and proved at around -5.1~2.3%; the possibility to detect UTI out is around 95.5%; the approximate relationship between the number of E.coli and electrode potential had been built as Ε=228.3193-3.78225×Ln (N+2.29101e6)， thereby building the relationship between UTI possibilities and the measurement. Finally, the conception and design of electrochemical sensor array had been made, thus to measure different biomarkers for the maximum possibilities of UTI and can show the data of the possibility of UTI directly on the screen. Finally it can easily be used and transported for the home-users or patients in hospitals.
- 03:10 Yield-oriented Biopotential Amplifier Design for PCB-based Active Dry Electrodes
- In physiological measurement systems, the most critical stages are the transduction and the amplification, mainly when tolerances of components are taken into account. In this case, if there is a small difference between DC input voltages of the biopotential amplifier, its DC output voltage may be saturated, even when DC suppression circuits are used. In this paper, we propose an active biopotential electrode and, based on a yield-oriented analysis, a maximum gain condition that guarantees a constant DC output voltage of the proposed biopotential amplifier without using laser trimming. A DC Monte-Carlo simulation is performed to demonstrate our results and an experimental procedure is also carried out to analyze the proposed system by measuring heartbeat frequency.
- 04:40 A preliminary study on quality of knee strength measurements by means of Hand Held Dynamometer and Optoelectronic System
- Strength measurements are popular in the clinical practice to evaluate the health status of patients and quantify the outcome of training programs. Currently a common method to measure strength is based on Hand Held Dynamometers (HHD) which is operator-dependent. Some studies were conducted on repeatability of strength measurements but they were limited to the statistical analysis of repeated measurements of force. In this work, the authors developed a methodology to study the quality of knee flexion/extension strength measurements by measuring the effective HHD position and orientation with respect to the patient. HHD positioning attitude was measured by means of an Optoelectronic System for which a marker protocol was defined ad-hoc. The approach allowed to assess quality of measurements and operator's ability by means of quantitative indices. The protocol permitted the evaluation of: angles of HHD application, angular range of motion of the knee and range of motion of the HHD. RMSE parameters allowed to quantify the inaccuracy associated to the selected indices. Results showed that the operator was not able to keep the subject's limb completely still. The force exerted by the subject was higher in knee extension and the knee range of motion was higher than expected, however the operator had more difficulties in holding the HHD in knee flexion trials. This work showed that HHD positioning should be as accurate as possible, as it plays an important role for the strength evaluation. Moreover, the operator should be properly trained and should be strong enough to counteract the force of the subject.
- 06:10 The effects of the vibratory stimulation of the neck muscles for the evaluation of stepping performance in Parkinson's Disease
- The equilibrium system needs the coordination of three subsystems: sensory, skeletal and central nervous system. The central nervous system (CNS) counteracts equilibrium perturbations by mean of compensatory and anticipatory postural adjustments (APAs). While compensatory adjustments deal with actual perturbation of balance, the APAs precede perturbations. The APAs consist of preprogrammed activation of the muscles, according to task parameters  and are important to minimize the effects of planned postural perturbations. APAs are specific to the movement, adapt to changes in external postural support by changing APA timing and magnitude. These APAs are altered in Parkinson disease (PD) where have characterized by a reduced amplitude, an increased duration and a delayed onset of APAs in tasks such as gait initiation. This study investigate the effects of a vibratory stimulus applied to the neck muscle groups in subjects with PD.
- 07:40 Metrological Properties Evaluation Of A Chest Wall Simulator During Simulated Quiet Breathing
- Opto-electronic Plethysmography (OEP) is a motion analysis system used to measure chest wall kinematics and to indirectly evaluate respiratory volumes during breathing. Its working principle is based on the time-per-time computation of marker displacements placed on the thorax. This work aims at evaluating the metrological properties of a custom made chest wall simulator (CWS) developed to reproduce human chest wall kinematic. The CWS metrological properties have been estimated by the comparison of two different motion control strategies of the CWS: the first one is based on the script writing into each motion controller, the second one on macro command sent to the CWS. Three sets of experiments have been performed with the aim to: (i) evaluate precision and accuracy in reaching target displacements (i.e., ranging from 2 mm to 8 mm), (ii) evaluate the differences between set and simulated breathing period (i.e., from 10 to 30 breathing per minute), and (iii) assess the movement reproducibility. The precision error, expressed as the ratio between measurement uncertainty and the measured displacement, is always lower than 0.32% (27 µm) with script-based motion control and 0.25% (6 µm) with the macro one, for all the target displacements. The difference between the simulated breathing period and the set one is always lower than 0.30 s in both strategies of motion control (percentage error always lower than 15%). Standard deviation between measure, assumed as reproducibility index, showed values always lower than 37 µm. The observed performances allows considering both the strategies of control adoptable to be employed for CWS motion control during the OEP performance in further works.
- 09:10 Non-contact Assessment of Muscle Contraction: Laser Doppler Myography
- Electromyography (EMG) is the gold-standard technique used for the evaluation of muscle activity and contraction. The EMG signal supports analysis of a number of important parameters including amplitude and duration, engagement of motor units, and functional characteristics associated with factors such a force production and fatigue. Recently, a novel measurement method (Laser Doppler Myography, LDM) for the non-contact assessment of muscle activity has been proposed to measure the vibro-mechanical behavior of the muscles that conventionally is referred to as the mechanomyogram (MMG). The fact that contracting skeletal muscles produce vibrations and sounds has been known for more than three centuries. The aim of this study is to report on the LDM technique and to evaluate its capacity to measure without contact some characteristics properties of skeletal muscle contractions. This is accomplished with the very high vibration sensitivity inherent in the Laser Doppler Vibrometry method (in comparison to commonly used devices such as microphones, piezo electric pressure sensors, and accelerometers). Data measured by LDM are compared with signals measured using standard surface EMG (sEMG) which requires the use of skin electrodes. sEMG and LDM signals are simultaneously acquired and processed. The LDM and sEMG signals are compared with respect to the critical features of muscle activation timing, signal amplitude and force production. LDM appears to be a reliable and promising technique that allows measurement without the need for contact with the patient skin. LDM has additional potential advantages in terms of sensor properties, insofar as there are no significant issues relating to bandwidth or sensor resonance, and no mass loading is applied to the skin.
- 10:40 A chemo-optical approach for recognising early degradation in cartilage from NIR absorbance measurements
- Near-infrared spectroscopy is a widely adopted technique for characterising biological tissues. The high di- mensionality of spectral data, however, presents a major chal- lenge for analysis. In this paper, we present a chemo-optical technique aimed at projecting spectral data onto a lower dimension feature space characterised by the constituents of the target tissue type. Measurements in the constituent based feature space were then used to classify damages in articular cartilage. Testing the proposed technique on an experimental set of 145 bovine cartilage samples before and after enzymatic degradation, we achieved 96% classification accuracy with a simple, smallest detectable difference classifier.
- 12:10 Study on the use of AFM to make traceable measurements of lipoproteins size distribution
- Lipids and lipoproteins concentration in human plasma are directly correlated to the risk of C cardiovascular diseases. Enumeration of certain classes of lipoproteins by their size, e.g. mean and modal diameter, wants to be developed in alternative of the traditionally used method based of their density. Traceable size measurement of certified nanospheres were performed by AFM, obtaining resolution better than 1 nm; size measurement of spheres organized in line allowed to improve accuracy of the mean diameter measured, single entity measurement allowed to design the size distribution experiment. VLDL lipotroteins were imaged to perform size distribution measurement. A preliminary list of main uncertainty sources is given.
- 13:40 Uncertainty in cell confluency measurements
- Cell-based imaging assays are strongly supported by high-content screening technologies (such as automated immunostaining, automated image acquisition and automated image analysis) constantly under development to improve, make faster and simplify the data analysis. These high content screening-based assays allow quick evaluation of the effects of thousands of molecules and provide starting points for drug design and for understanding the interaction or role of particular biochemical processes. The pharmaceutical industries have declared their need of metrology in the cellular field, in order to improve reliability and comparability of results, reduce the number of the tests, narrow the time from discovery to the marketing of new drugs and limit costs. Confluency fraction of cells on a bi-dimensional (2D) surface, i.e., the fraction of the area occupied by cells, represents a measurand that can describe a biological effect of a molecule under examination. The confluency is measured through analysis of images acquired via microscopy techniques for the measurement of the surface covered by cells. An extremely wide range of algorithms is available for the image analysis aimed at recognizing objects. The algorithms are typically based on the identification of a threshold to distinguish objects from the background. The methods and methodologies of acquisition of images, and image analysis methodologies contribute to the uncertainty of the confluency measurement. The visual assessment of the images based on the operator's experience, to date remains the most reliable reference for the quantification of the confluency for all algorithms developed. An objective estimation of measurement uncertainty has never been taken into account. This work proposes a method for the estimation of the contribution to the uncertainty of the analysis of the image of the confluency measurement. The method is based on the quantification of a maximum threshold and a minimum threshold such as to identify an area of image containing the edge of the cells. The method was applied to images, acquired in fluorescence microscopy, of 2D cell cultures of PT-45 cells (pancreatic carcinoma cell line). Results show that the method can be a promising solution to associate an uncertainty to cell confluency measurements.
- 15:10 Development and characterization of porous magnesium bioresorbable implants
- The use of temporary implants in bone surgery is widely diffused and typically requires surgical procedures to remove the implants after bone healing. A bioresorbable implant, which does not need to be surgically removed would reduce both patient morbidity and risks. Magnesium and magnesium alloys have been proposed as materials for self-degrading implants since magnesium is not toxic; in addition, if the implant could be arranged by using a porous structure, the implant could also stimulate the bone growth. This paper describes the results obtained by employing Spark Plasma Sintering (SPS) to produce a magnesium foam with a porosity which is suitable for the bone growth.
- 16:40 Low-cost wearable measurement system for continuous real-time pedobarography
- Pedobarography is fundamental for kinetic gait analysis and for diagnosis and investigation of a number of neurological and musculoskeletal diseases, such as peripheral neuropathy or Parkinson. Wearable plantar pressure sensing systems represent a powerful tool in this field. The continuous data they can provide are crucial for rehabilitation, sport applications, and to generate real-time alarms for foot ulceration prevention of neuropathic patients. Requirements of compactness, spatial resolution, range, power-consumption lead to the high cost of commercially available pedobarographic systems, which represents the major issue hindering their widespread use. Efforts of the authors' work are therefore aimed at the realization of a single system able to match all these requirements while overcoming the cost issue. This work presents a high-spatial-resolution flexible system enabling wide-dynamic-range pressure measurements with different sensing materials, and suitable for both platforms and low-cost sensing insoles embeddable into normal shoes. Experimental tests and comparisons adopting an in-house developed piezoresistive substrates and a commercial sensing material are presented and discussed.
- 18:10 Investigating the On-board Data Processing for IMU-based Sensors in Motion Tracking for Rehabilitation
- This paper investigates the effects of shifting computation-intensive workload for motion tracking based on sensor network from a dedicated remote server to an embedded microcontroller. The importance of battery life is exacerbated for devices designed to work in biomedical field as the prolonged operability could make a vital difference in mobile contexts. Onboard processing usually drives to less communication, so the balance between the power consumed by more operations and that saved by limiting the radio transmissions has been evaluated. A measurement station has been realized to measure the energy budget needed to let more patients be monitored simultaneously and, at the same time, to increase the number of sensor nodes working together in the network. Finally, functional equivalence of the implementation has been proven.
- 19:40 NIRS assessment of brain hemodynamics
- Near Infrared Spectroscopy (NIRS) allows for assessing brain hemodynamics non-invasively. In NIRS studies, the maneuver of breath holding is frequently used as an activation of the brain autoregulation response. However, breath holding is not always feasible or effective in the clinical practice. We explored the possibility of using kapalabathi, an ancient yoga respiration technique, as an alternate activation maneuver. We studied the brain oxygenation response to kapalabathi, in yoga practitioners, in three different postures. In all the three postures considered Kapalabathi produces a measurable effect on the oxygen availability at the brain cortex level. Remarkable differences were observed in the brain autoregulatory response of smoker and non-smoker practitioners.
Saturday, May 9, 12:10 - 12:30
Closing session - Best poster award
Room 1 (Salone d'Onore)
Saturday, May 9, 12:30 - 14:00
Room: Sala delle Colonne