Showing papers by "Domenico Formica published in 2020"

A Multi-Parametric Wearable System to Monitor Neck Movements and Respiratory Frequency of Computer Workers.

Abstract: Musculoskeletal disorders are the most common form of occupational ill-health. Neck pain is one of the most prevalent musculoskeletal disorders experienced by computer workers. Wrong postural habits and non-compliance of the workstation to ergonomics guidelines are the leading causes of neck pain. These factors may also alter respiratory functions. Health and safety interventions can reduce neck pain and, more generally, the symptoms of musculoskeletal disorders and reduce the consequent economic burden. In this work, a multi-parametric wearable system based on two fiber Bragg grating sensors is proposed for monitoring neck movements and breathing activity of computer workers. The sensing elements were positioned on the neck, in the frontal and sagittal planes, to monitor: (i) flexion-extension and axial rotation repetitions, and (ii) respiratory frequency. In this pilot study, five volunteers were enrolled and performed five repetitions of both flexion-extension and axial rotation, and ten breaths of both quite breathing and tachypnea. Results showed the good performances of the proposed system in monitoring the aforementioned parameters when compared to optical reference systems. The wearable system is able to well-match the trend in time of the neck movements (both flexion-extension and axial rotation) and to estimate mean and breath-by-breath respiratory frequency values with percentage errors ≤6.09% and ≤1.90%, during quiet breathing and tachypnea, respectively.

Respiratory Monitoring During Physical Activities With a Multi-Sensor Smart Garment and Related Algorithms

Abstract: Unobtrusive and wearable devices are gaining large acceptance in the continuous monitoring of physiological parameters. Among the five vital signs, respiratory rate ( ${f}_{R}$ ) can be used to detect physiological abnormalities and health status changes. The purpose of this work was to investigate the performances of a multi-sensor smart garment in estimating the ${f}_{R}$ during walking and running activities. Bespoke algorithms have been implemented to retrieve ${f}_{R}$ values from raw data. Experiments were carried out on ten male volunteers during walking and running activities at selected speeds controlled by a treadmill (i.e., from 1.6 km $\cdot \text{h}^{-{1}}$ to 8.0 km $\cdot \text{h}^{-{1}}$ ). Data were analysed in both frequency and time domains. In the frequency domain, ${f}_{R}$ was analyzed considering a time window of 20 s. The 97% of ${f}_{R}$ estimated by the garment agreed with the reference (i.e., flowmeter) values in the range ±3 breaths per minute (bpm). In the time domain, breath-by-breath ${f}_{R}$ analysis was carried out. The garment performance was evaluated in terms of mean absolute error (MAE), standard error (SE), mean percentage error (mean $\%{E}[{i}]$ ) and by the Bland-Altman analysis. Good agreement with the reference device was testified by low MAE ( $\%{E}[{i}]$ ( ${f}_{R}$ on both average and breath-by-breath bases even during physical activities.

PDMeter: A Wrist Wearable Device for an at-Home Assessment of the Parkinson’s Disease Rigidity

Abstract: This work focuses on the design and the validation of a wearable mechatronic device for an at-home assessment of wrist stiffness in patients affected by Parkinson’s Disease (PD). The device includes one actuated joint and four passive revolute joints with a high overall intrinsic backdriveability. In order to allow the user to freely move the wrist during activities of daily living, we implemented a transparent controller on the basis of the interaction force sensed by the embedded load cell. Conversely, in order to provide perturbations for estimating the wrist flexion-extension rigidity, we implemented a torque controller. Firstly, we report a pilot study that aimed at characterizing the device in terms of range of motion (ROM) allowed, transparency perceived and torque-tracking capability. Then, we present a case study in which we tested our device with seven PD patients in both drug-OFF and drug-ON conditions and we compared the measured stiffness with the one measured in fourteen healthy controls and with the outcome of the most used clinical scale (MDS-UPDRS). The device allowed to successfully estimate the stiffness as different depending on the movement direction. Indeed, extension stiffness was higher than the flexion one, accordingly to the literature. Moreover, the device allowed to discriminate both Healthy subjects from PD subjects, and PD subjects in OFF condition from PD subjects in ON condition. In conclusion, we demonstrate the feasibility of the device in measuring wrist rigidity, thus enabling the possibility to implement an at-home assessment of the PD rigidity.

A Wearable Device Based on a Fiber Bragg Grating Sensor for Low Back Movements Monitoring.

Abstract: Low back pain (LBP) is one of the musculoskeletal disorders that most affects workers. Among others, one of the working categories which mainly experiences such disease are video terminal workers. As it causes exploitation of the National Health Service and absenteeism in workplaces, LBP constitutes a relevant socio-economic burden. In such a scenario, a prompt detection of wrong seating postures can be useful to prevent the occurrence of this disorder. To date, many tools capable of monitoring the spinal range of motions (ROMs) are marketed, but most of them are unusable in working environments due to their bulkiness, discomfort and invasiveness. In the last decades, fiber optic sensors have made their mark allowing the creation of light and compact wearable systems. In this study, a novel wearable device embedding a Fiber Bragg Grating sensor for the detection of lumbar flexion-extensions (F/E) in seated subjects is proposed. At first, the manufacturing process of the sensing element was shown together with its mechanical characterization, that shows linear response to strain with a high correlation coefficient (R2 > 0.99) and a sensitivity value (Se) of 0.20 nm∙me-1. Then, the capability of the wearable device in measuring F/E in the sagittal body plane was experimentally assessed on a small population of volunteers, using a Motion Capture system (MoCap) as gold standard showing good ability of the system to match the lumbar F/E trend in time. Additionally, the lumbar ROMs were evaluated in terms of intervertebral lumbar distances (Δ d L 3 - L 1 ) and angles, exhibiting moderate to good agreement with the MoCap outputs (the maximum Mean Absolute Error obtained is ~16% in detecting Δ d L 3 - L 1 ). The proposed wearable device is the first attempt for the development of FBG-based wearable systems for workers' safety monitoring.

Influence of torso movements on a multi-sensor garment for respiratory monitoring during walking and running activities

Abstract: Unobtrusive and wearable technologies are gaining broad acceptance in the continuous monitoring of physiological parameters Among others, the respiratory frequency is increasingly being considered as it allows to detect physiological abnormalities and health status changes, both in clinical and occupational scenarios and in sports scienceThe respiratory monitoring during physical activity is still challenging because of the artifacts caused by body movements These breathing-unrelated movements may negatively affect the signal used for respiratory monitoringThis study aimed to investigate the influence of the torso movements that occur during walking and running activities on the signals recorded by a multi-sensor garment The garment consists of three bands positioned at the level of upper and lower thorax and abdomen Each band embeds two conductive sensors The torso movements were recorded by a magneto-inertial measurement unit embedded into the garmentExperimental trials were carried out on four male volunteers during walking and running activities at selected speeds controlled by a treadmill A flowmeter was used to retrieve reference respiratory frequency values All the signals were analyzed in the frequency domain to investigate the frequency contentResults show that movements related to the torso rotation (arms and shoulders swing) cause motion artifacts on the garment sensors’ signals Sensors positioned on the upper thorax and abdomen were found to be much more influenced by breathing-unrelated movementsDespite the influence of the torso movements on the conductive sensors, the garment can provide robust information about the average respiratory rate even during physical activities

Modulation of Body Representation Impacts on Efferent Autonomic Activity.

Abstract: The afferent branch of the autonomic nervous system contributes with interoception to the multimodal sensory correlation continuously needed to update our representation of the body. To test whether the modulation of body representation would have an impact on the efferent branch of the autonomic nervous system, nonspecific skin conductance has been measured in three rubber hand illusion (RHI) experiments, controlled with asynchronous brush-stroking and incongruent fake hand position. Nonspecific skin conductance standard deviation (SCSD) computed along the whole 90 sec of stroking was found to be increased by the illusion and to correlate with all the typical measures of embodiment. Computing SCSD in shorter time windows strongly enhanced the difference between illusion and controls. The highest difference was found in the 10-55 sec window, being the 14-34 sec window as the most informative one. The higher correlations with the validated measures of embodiment (all but the proprioceptive drift) were found for time windows ranging between 35 and 65 sec. The SCSD was no longer significantly higher when the RHI was repeated twice (two trials each iteration), but it was still significantly higher in synchronous stroking even when considering only the second trial. However, after the first iteration of the RHI paradigm, the effect of the embodiment on nonspecific skin conductance response results to be attenuated, suggesting that novelty in presentation of the RHI can contribute to the effect on nonspecific skin conductance response. Results candidate SCSD as a noninvasive, cheap, easy, and objective measure of embodiment, especially sensible to onset and strength of the illusion. Alike the already known enhanced autonomic reaction to a threatening, SCSD does not interfere with the collection of other behavioral measures. Correlations and their dynamics, presence of the effect in the second presentation of the setup but relative low robustness against multiple repetition, suggest that the increased fluctuations of skin conductance caught by SCSD are not just the effect of different presented sensory stimuli but more likely a stronger arousal response to the novelty of the updated perceptual status.

Breath-Jockey: Development and Feasibility Assessment of a Wearable System for Respiratory Rate and Kinematic Parameter Estimation for Gallop Athletes

Abstract: In recent years, wearable devices for physiological parameter monitoring in sports and physical activities have been gaining momentum. In particular, some studies have focused their attention on using available commercial monitoring systems mainly on horses during training sessions or competitions. Only a few studies have focused on the jockey’s physiological and kinematic parameters. Although at a glance, it seems jockeys do not make a lot of effort during riding, it is quite the opposite. Indeed, especially during competitions, they profuse a short but high intensity effort. To this extend, we propose a wearable system integrating conductive textiles and an M-IMU to simultaneously monitor the respiratory rate (RR) and kinematic parameters of the riding activity. Firstly, we tested the developed wearable system on a healthy volunteer mimicking the typical riding movements of jockeys and compared the performances with a reference instrument. Lastly, we tested the system on two gallop jockeys during the “137∘ Derby Italiano di Galoppo”. The proposed system is able to track both the RR and the kinematic parameters during the various phases of the competition both at rest and during the race.

The Influence of Posture, Applied Force and Perturbation Direction on Hip Joint Viscoelasticity

Abstract: Limb viscoelasticity is a critical neuromechanical factor used to regulate the interaction with the environment. It plays a key role in modelling human sensorimotor control, and can be used to assess the condition of healthy and neurologically affected individuals. This paper reports the estimation of hip joint viscoelasticity during voluntary force control using a novel device that applies a leg displacement without constraining the hip joint. The influence of hip angle, applied limb force and perturbation direction on the stiffness and viscosity values was studied in ten subjects. No difference was detected in the hip joint stiffness between the dominant and non-dominant legs, but a small dependency was observed on the perturbation direction. Both hip stiffness and viscosity increased monotonically with the applied force magnitude, with posture being observed to have a slight influence. These results are in line with previous measurements carried out on upper limbs, and can be used as a baseline for lower limb movement simulation and further neuromechanical investigations.

An fMRI Compatible Smart Device for Measuring Palmar Grasping Actions in Newborns

Abstract: Grasping is one of the first dominant motor behaviors that enable interaction of a newborn infant with its surroundings. Although atypical grasping patterns are considered predictive of neuromotor disorders and injuries, their clinical assessment suffers from examiner subjectivity, and the neuropathophysiology is poorly understood. Therefore, the combination of technology with functional magnetic resonance imaging (fMRI) may help to precisely map the brain activity associated with grasping and thus provide important insights into how functional outcomes can be improved following cerebral injury. This work introduces an MR-compatible device (i.e., smart graspable device (SGD)) for detecting grasping actions in newborn infants. Electromagnetic interference immunity (EMI) is achieved using a fiber Bragg grating sensor. Its biocompatibility and absence of electrical signals propagating through the fiber make the safety profile of the SGD particularly favorable for use with fragile infants. Firstly, the SGD design, fabrication, and metrological characterization are described, followed by preliminary assessments on a preterm newborn infant and an adult during an fMRI experiment. The results demonstrate that the combination of the SGD and fMRI can safely and precisely identify the brain activity associated with grasping behavior, which may enable early diagnosis of motor impairment and help guide tailored rehabilitation programs.

Wearable stretchable sensor based on conductive textile fabric for shoulder motion monitoring

Abstract: Wearable stretchable sensors are gaining significant interest in application related to joint motion monitoring. Stretchable strain sensors are a promising technological solution to develop wearable systems for several applications (e.g., sports, rehabilitation, health science) thanks to their flexibility, lightweight, compliance, and ease to wear. The aim of this study is twofold: i) to perform the metrological characterization of a stretchable sensing element based on a conductive textile fabric for developing a wearable sensor intended for joint motion monitoring and ii) to provide a preliminary assessment of the developed sensor in shoulder motion monitoring. The static characterization and the hysteresis analysis at different speeds (i.e., 50 mm.min−1, 100 mm.min−1, 200 mm.min−1, 400 mm.min−1and 600 mm.min−1) were carried out to assess the sensor's characteristics to mechanical strain. An explorative test to assess the sensor feasibility in monitoring horizontal flexion-extension of the shoulder was performed on one healthy volunteer. Results showed that the sensor's resistance decreased from $75 k \Omega$ at 0% strain level to $52 k \Omega$ at 10% strain level during static characterization. Moreover, the maximum hysteresis error $e_{H}\%$ was always lower than 2.59% during loading-unloading hysteresis cycles at different speeds. The developed stretchable sensor seems to be a promising solution for monitoring shoulder range of motion in applications were unobtrusiveness and wearability are key factors.

A Novel Proprioceptive Feedback System for Supernumerary Robotic Limb

Abstract: A novel system to provide the user with proprioceptive feedback from a supernumerary robotic limb through vibrotactile stimulation is presented. The system is composed of a dedicated electronic board that converts the robot state, acquired through serial communication, into a vibration amplitude-frequency value and commands up to sixteen eccentric motors, placed on the user’s leg skin. The system is designed to allow the subject to have cues on the robot state even without visual feedback. Two different feedback encoding paradigms, one based on a kinematic approach and the other on a dynamic one, have been tested in three healthy subjects to validate the platform. In a planar task and with slow robot motions, conveying the robot state through the cartesian position (kinematic method) allows to achieve hugely better (d=4.278) performance than using joint torques (dynamic approach) or non-informative feedback.

Conductive textile element embedded in a wearable device for joint motion monitoring

Abstract: Wearable strain sensors potentially hold great significance in several areas, such as rehabilitation, research, sports. Conductive textile elements are excellent candidates for the development of wearable devices as human motion capture systems because of their intrinsic properties of lightweight, compliance, flexibility, and stretchability. Herein, the metrological characterization of sensing elements based on a conductive textile intended for joint motion monitoring is presented.The aim of this study is twofold: (i) analyzing the influence of the shape on the metrological properties of conductive textiles, (ii) providing a preliminary assessment of the performance of a custom-made wearable device (i.e., a glove) embedding a conductive textile element to monitor wrist joint movements. The static characterization and the hysteresis analysis were performed on two samples of conductive textile elements, i.e., the zig-zag pattern and the rectangular one. The feasibility assessment of a glove embedding one sensing element for wrist flexion-extension monitoring was performed on a single volunteer.Results showed that the zig-zag patterned conductive element had a resistance change range comparable to the rectangular one (i.e., 100 kΩ – 170 kΩ vs. 40 kΩ – 80 kΩ), higher averaged sensitivity (i.e., -3.96 kΩ•%-1 vs. -2.42 kΩ•%-1), and a lower hysteresis error, 6.83%). the % (i.e., averaged 5.22% vs. Regarding feasibility assessment of %the wearable device, results showed good performance in tracking wrist flexion-extension in real-time. The proposed wearable device embedding a conductive textile element seems to be suitable for wrist motions monitoring with promising applications in contexts as rehabilitation, sports, and clinical research.

A new pressure guided management tool for epidural space detection: feasibility assessment in a clinical scenario.

Abstract: BACKGROUND The detection of epidural space is usually performed by the technique of loss of resistance (LOR) without technological support, although there are few commercial options. In this work, we aimed to assess the feasibility of a new, non-invasive, mechatronic system for LOR detection in clinical settings. The system allows monitoring the pressure exerted on the syringe plunger by the clinician during the puncture. The LOR is related to the mentioned pressure. METHODS Pressure exerted on the syringe plunger by an expert anesthesiologist was monitored using the proposed system. 58 epidural punctures were performed on 34 patients using six configurations with different sensitivities and ranges of measurements. The system capability in LOR detection was evaluated comparing the LOR detected by the system with the feedback provided by the clinician. The procedure time was estimated using the system and without its use. RESULTS The detection of LOR is strongly related to the system configuration; it ranged from 93.3% to 27.7%, while 3 configurations never detected it. The procedure time showed a non-significant increase (p=0.56) using the proposed system (average time 71 s vs. 62 s). CONCLUSIONS The proposed mechatronic system successfully detected the LOR in the large part of cases using the configurations characterized by the best trade-off between system sensitivity and range of measurements. A non-significant increment of the procedure time is related to the use of the system.

A wearable system for respiratory and pace monitoring in running activities: a feasibility study

Abstract: Wearable devices are extensively used for monitoring physiological parameters both in clinical settings and in sports science. Among others, respiratory rate is mostly neglected but is a valid index to assess athletes' performance. The purpose of this work was to test a wearable device composed of two elastic bands embedding conductive textiles during a running session of approximately 9.5 km. The test has been carried out by a young healthy volunteer who worn two bands on the rib cage (one on the upper thorax and one on the umbilicus). The frequency-domain analysis allowed estimating both respiratory parameters (i.e., the average respiratory rate, $\overline{f_{R}})$ and running related parameters (i.e., estimated running distance and average running pace). The wearable system was able to perform a good estimation of both respiratory and gait parameters allowing a better understanding of the relationship between the fatigue and the respiratory activity, enabling a more accurate running performance evaluation.

Clean-Breathing: a Novel Sensor Fusion Algorithm Based on ICA to Remove Motion Artifacts from Breathing Signal

Abstract: Although smart-textile solutions based on piezoresistive technology have emerged as a tool to assess unobtrusively breathing activity, their signals are affected by the artifacts related to the subjects' movements during common activities (e.g. walking or running). In order to remove such artifacts, we implemented a novel algorithm combining the information recorded by four piezoresistive textile sensors, which allowed to measure rib cage movements due to the breathing activity, with the data synchronously recorded by an inertial measurement unit. Specifically, by using an Independent Component Analysis (ICA), our algorithm allowed to blindly reduce movement artifacts from the signals recorded by the piezo sensors, leading to highlight the breathing activity. We tested our algorithm in a pilot study, in which we enrolled one healthy subject during a free-running task. In order to assess our approach, we compared the signal spectrum obtained applying our algorithm with the one computed after a standard band-pass filter at 0.05-3 Hz. To this aim, we compared the average amplitude of the Power Spectral Densities (PSDs), computed after both approaches, along three frequency ranges: i) [0–1] Hz, related to the breathing activity; ii) [1-2] Hz, related with the torso rotation, during a running a task; iii) [2-3] Hz, related with the pace, during a running a task. Although the study was performed on one single subject, the results obtained seem to be promising. Indeed, within the range [0–1] Hz, the average reduction of the Power Spectral Density (PSD) is only about 4%, while it is considerably higher within frequency range related to the walking/running activity. Specifically, considering the ranges [1-2] Hz and [2-3] Hz such a reduction is around 39% and 36% respectively.

Evaluation of thoraco-abdominal asynchrony using conductive textiles

Abstract: The desynchronisation between the rib cage and the abdomen known as thoraco-abdominal asynchrony (TAA) is an important parameter in the respiratory field. It can provide useful information about respiratory failures and work of breathing in different scenarios (e.g., clinical setting, sports science) and populations (e.g., neonates, athletes). The purpose of this work was to evaluate the capability of a multi-sensor smart garment to quantifity the TAA. The proposed garment is composed by three elastic bands embedding two conductive sensing element each. Experimental trials were carried out on five healthy volunteers who worn the elastic bands at the level of the upper rib cage, lower rib cage and abdomen. TAA was investigated by analysing the time shift between the rib cage and abdomen respiratory waveform. Data analysis demonstrated the ability of the garment to identify the thoracoabdominal time shift. This result is testified by the good agreement between the data of the proposed system and a commercial motion capture system used as gold standard: the Bland-Altman analysis showed a mean of difference of 170 ms.

A complementary filter design on SE(3) to identify micro-motions during 3D motion tracking

Abstract: In 3D motion capture, multiple methods have been developed in order to optimize thequality of the captured data. While certain technologies, such as inertial measurement units (IMU),are mostly suitable for 3D orientation estimation at relatively high frequencies, other technologies,such as marker-based motion capture, are more suitable for 3D position estimations at a lower frequencyrange. In this work, we introduce a complementary filter that complements 3D motion capture datawith high-frequency acceleration signals from an IMU. While the local optimization reduces the error ofthe motion tracking, the additional accelerations can help to detect micro-motions that are useful whendealing with high-frequency human motions or robotic applications. The combination of high-frequencyaccelerometers improves the accuracy of the data and helps to overcome limitations in motion capturewhen micro-motions are not traceable with 3D motion tracking system. In our experimental evaluation,we demonstrate the improvements of the motion capture results during translational, rotational,and combined movements.

Feasibility Assessment of an FBG-based Wearable System for Monitoring Back Dorsal Flexion-Extension in Video Terminal Workers

Abstract: In recent years, ever more workers are employed in sedentary jobs spending many hours sitting at video terminals. Discomfort office furniture and incorrect video screen positioning, as well as bad postural attitudes lead to the occurrence of back musculoskeletal disorders. Low back pain is one of the most widespread disease which causes a heavy socio- economic burden as it leads to absence from workplace and use of the National Health Service. In this scenario, being able to continuously evaluate poor postural attitudes may be beneficial to correct postural habits, and so to reduce the incidence of such a disease. For this purpose, many technologies capable to detect the spinal range of motions (ROMs) have been developed. Among others, the use of optical fiber sensors is gaining momentum, since these sensors allow the development of wearable, light and non-invasive monitoring systems. The present work aims at assessing the capability of a custom-made smart textile based on FBG sensors in detecting back dorsal flexion-extension (F/E) movements. Experimental results show high sensitivity to strain of the smart textile and confirm the system capability of monitoring back dorsal F/E movements in time.

A wearable system for knee flexion/extension monitoring: design and assessment

Abstract: Human gait is a significant health indicator used in a wide range of applications, including diagnosis, monitoring, rehabilitation, and sport. Among all the human joints movements, the knee flexion/extension is a crucial movement, and its evaluation may provide valuable information related to pathologies, walking disorders, to evaluate the efficiency of prescribed therapies and the rehabilitation of patients, and to improve performances of athletes. In this work, we designed, fabricated, and tested a wearable system (i.e., an instrumented knee brace) for monitoring knee movements under static and dynamic conditions. The system consists of a single fiber Bragg grating (FBG) sensor encapsulated in a soft and flexible polymer matrix in contact with the knee brace. The metrological characterization of two sensors (dimensions 50 mm × 30mm × 10mm and 40mm × 30mm × 10mm) has been performed by applying strains up to 2% which correspond to max length variations (ΔL MAX ) of 0.76 mm and 0.55 mm for the big and the small sensors, respectively. Additionally, pilot trials have been carried to preliminary test the instrumented knee brace for monitoring flexion/extension movements during walking at different speeds (i.e., 3 km/h, 4 km/h, 5 km/h). Both the sensors showed an approximately linear response in the range of interest and sensitivities up to 3.944 nm-mm−1, The wearable system was able to monitor the number of gait cycles and to discriminate the knee flexion and extension movements during walking.

Altered Proprioceptive Feedback Influences Movement Kinematics in a Lifting Task

Abstract: Movement control process can be considered to take place on at least two different levels: a high, more cognitive level and a low, sensorimotor level. On a high level processing a motor command is planned accordingly to the desired goal and the sensory afference, mainly proprioception, is used to determine the necessary adjustments in order to minimize any discrepancy between predicted and executed action. On a lower level processing, the proprioceptive feedback later employed in high level regulations, is generated by Ia sensory fibers positioned in muscle main proprioceptors: muscle spindles. By entraining the activity of these spindle fibers through 80Hz vibration of triceps distal tendon, we show the intriguing possibility of inducing kinematics adjustments due to negative feedback corrections, during a lifting task.

A Test Bench to Assess Systems for Respiratory Monitoring of Workers

Abstract: Safety at work is driving the development of new technological solutions in the era of Industry 4.0. Among others, systems able to monitor physiological parameters are gaining high relevance since such devices have the potential to improve the workers' safety. In this perspective, the respiratory rate can provide useful information since it is sensitive to many environmental stressors. In this study, we focused on the development of a test bench to assess the performance of a wearable system for respiratory monitoring. The presented system achieves data collection and synchronization from FBG sensors, a reference flowmeter and, an M-IMU unit. In addition, a GUI has been developed in order to guide the volunteer in the execution of selected movements during the experimental session. The proposed system could further facilitate the design and development of solutions for assessing wearables for workers' activities monitoring.

Assessment of running training sessions using IMU sensors: evaluation of existing parameters and choice of new indicators

Abstract: The fatigue is not simple to be evaluated and it is most commonly referred to a reduced capacity for maximal performance. It is a parameter that constantly affects the performance of runners and there are no wearable devices on the market enable to calculate it. The purpose of the study is to find a correlation between the parameters of the gait cycle and fatigue. An inertial sensor had been placed on the dorsum of the right foot during two 5-minute running trials in an high-intensity intermittent exercise (HIIE) protocol. The parameters of the gait analysis have been calculated and studied according to the heart rate in order to define a fatigue index. A linear regression algorithm was used to establish this relationship. The mid-high $R^{2}$ indicates a good regression. Therefore it suggests us that it is possible to compute the FI using the only gait parameters without the use of an HR band.

Flexion-Extension Wrist Impedance Estimation Using a Novel Portable Wrist Exoskeleton: a Pilot Study

Abstract: Although the wrist plays a crucial role in performing interactive tasks, the wrist impedance has not been deeply studied so far. Moreover, all studies that aimed at estimating wrist impedance cannot be carried out in unstructured environments, thus limiting the gamut of possible research in this field. The major reasons underlying such limitations are the encumbrance and the non-portability of the robots used for this kind of applications. Within this work we presented the validation of a novel portable wrist exoskeleton to estimate the passive impedance of the wrist in Flexion-Extension (FE). To this aim, we enrolled 9 subjects whose wrist was passively moved around FE of ± 20deg by the device, characterized by 1 active degree of freedom. During the experimental sessions, we measured the joint torque and joint displacement, and we derived the angular velocities through numerical differentiation. Considering the wrist as a linear time-invariant second order mechanical system, we estimated impedance evaluating stiffness and damping coefficients, neglecting the contribution of the inertia due to the low speed of the movement applied by the robot. To this aim, we run a linear regression which allowed us to estimate stiffness and damping values. Passive stiffness estimated was equal to 1. $794\pm 0.514\mathrm{N}\mathrm{m}/\mathrm{r}\mathrm{a}\mathrm{d}$ for extension and $1.418\pm 0.445\mathrm{N}\mathrm{m}/\mathrm{r}\mathrm{a}\mathrm{d}$ for flexion, confirming also the wellknown difference between extension and flexion (p=0.027). Passive damping was found equal to $2.054\pm 1.202\mathrm{N}\mathrm{m}\mathrm{s}/\mathrm{r}\mathrm{a}\mathrm{d}$ for extension and 1. $403\pm 1.196\mathrm{N}\mathrm{m}\mathrm{s}/\mathrm{r}\mathrm{a}\mathrm{d}$ for flexion. These results are consistent with previous studies reported in literature, demonstrating the efficacy of our fully portable wearable wrist robot in estimating the wrist impedance around FE.

A virtual reality platform for multisensory integration studies

Abstract: A unique virtual reality platform for multisensory integration studies is presented. It allows to provide multimodal sensory stimuli (i.e. auditory, visual, tactile, etc.) ensuring temporal coherence, key factor in cross-modal integration. Four infrared cameras allow to real-time track the human motion and correspondingly control a virtual avatar. A user-friendly interface allows to manipulate a great variety of features (i.e. stimulus type, duration and distance from the participants’ body, as well as avatar gender, height, arm pose, perspective, etc.) and to real-time provide quantitative measures of all the parameters. The platform has been validated on two healthy participants testing a reaction time task which combines tactile and visual stimuli, for the investigation of peripersonal space. Results proved the effectiveness of the proposed platform, showing a significant correlation (p=0.013) between the participant’s hand distance from the visual stimulus and the reaction time to the tactile stimulus. More participants will be recruited to further investigate the other measures provided by the platform.

A non-invasive system for epidural space detection: comparison with Compuflo®

Abstract: Epidural blockade is a method often used in clinical practice to obtain pain relief during labor. Basically, the epidural puncture blocks the nerve impulses from the lower spinal segments with a consequent decrease of sensation in the lower half of the body. In this arena, the correct localization of the epidural space is crucial to perform the procedure. The loss of resistance (LOR) technique is the most popular approach to localize the epidural space. The LOR is caused by the fact that the ligamentum flavum is much harder than the epidural space, therefore when the needle tip pierces this ligamentum, there is an abrupt decrease of pressure (known as LOR). Although, there are several commercially available tools to support the clinicians in this task, the large part of epidural punctures is performed without any support. Our group of research has developed a novel and noninvasive tool to detect the LOR during epidural puncture. The aim of this study is to compare the output collected by the proposed system (i.e., the Epidural Space Management Tool, ESMT) with the output provided by a commercial system (i.e., CompuFlo®, Milestone Scientific, Inc.). Experiments were performed by an expert anesthesiologist (M.C.) on a simple simulator that allows mimicking the real scenario. Results showed a good agreement between the trends of the output of the two mentioned systems. Finally, the proposed system (ESMT), showed promising results in terms of LOR detection during all the five procedures performed on the simulator.

Manipulating The Body Representation: Assessment Of A Novel Platform

Abstract: The Rubber Hand Illusion can be used to induce the illusion that a fake hand is part of one’s own body. Thus, it can be used to alter the body representation. It was also reported that the Rubber Hand Illusion induces a proprioceptive drift of one’s real hand toward the fake hand. The Rubber Hand Illusion can be induced when the fake hand is placed farther in the sagittal plane (distally) compared to the real hand. In this case, the induced update of the body representation is an elongation of the arm. Virtual Reality and haptic technologies can be used to manipulate the perceived scenario in a virtual version of the Rubber Hand Illusion, the Virtual Hand Illusion. We developed a novel platform consisting in a virtual reality application integrating an optical motion capture device and haptic stimulators to study the manipulation of the body representation. We developed two experimental protocols to induce embodiment of an elongated arm: one validated in previous studies, that employs congruent visuo-motor-tactile stimulation, and one reproducing the typical Virtual Hand Illusion where only congruent visuo-tactile stimulation was employed. We tested both protocols with healthy participants.