In vivo estimation of the shoulder joint center of rotation using magneto-inertial sensors: MRI-based accuracy and repeatability assessment.

BACKGROUND: The human gleno-humeral joint is normally represented as a spherical hinge and its center of rotation is used to construct humerus anatomical axes and as reduction point for the computation of the internal joint moments. The position of the gleno-humeral joint center (GHJC) can be estimated by recording ad hoc shoulder joint movement following a functional approach. In the last years, extensive research has been conducted to improve GHJC estimate as obtained from positioning systems such as stereo-photogrammetry or electromagnetic tracking. Conversely, despite the growing interest for wearable technologies in the field of human movement analysis, no studies investigated the problem of GHJC estimation using miniaturized magneto-inertial measurement units (MIMUs). The aim of this study was to evaluate both accuracy and precision of the GHJC estimation as obtained using a MIMU-based methodology and a functional approach. METHODS: Five different functional methods were implemented and comparatively assessed under different experimental conditions (two types of shoulder motions: cross and star type motion; two joint velocities: ωmax = 90°/s, 180°/s; two ranges of motion: Ɵ = 45°, 90°). Validation was conducted on five healthy subjects and true GHJC locations were obtained using magnetic resonance imaging. RESULTS: The best performing methods (NAP and SAC) showed an accuracy in the estimate of the GHJC between 20.6 and 21.9 mm and repeatability values between 9.4 and 10.4 mm. Methods performance did not show significant differences for the type of arm motion analyzed or a reduction of the arm angular velocity (180°/s and 90°/s). In addition, a reduction of the joint range of motion (90° and 45°) did not seem to influence significantly the GHJC position estimate except in a few subject-method combinations. CONCLUSIONS: MIMU-based functional methods can be used to estimate the GHJC position in vivo with errors of the same order of magnitude than those obtained using traditionally stereo-photogrammetric techniques. The methodology proposed seemed to be robust under different experimental conditions. The present paper was awarded as "SIAMOC Best Methodological Paper 2016".

Stretchable screen-printed PEDOT:PSS electrodes for upper-arm surface electromyography.

In the past ten years, wearable electronics underwent tremendous growth. Undoubtedly, one of the fields that led this trend is represented by biomedical applications. In this field, wearable technologies can provide unique features such as the unobtrusive monitoring of biopotentials. Polymerbased electrodes developed for this purpose can take advantage of their seamless integration in the garments. However, the available solutions exhibit fragility in relation with the stretchability of the fabric, causing significant performance degradation.In this work, this problem is tackled by a novel deposition approach based on screen-printing technology. The electrodes are deposited onto the pre-stretched fabric to ensure the full functionality during common operating conditions. To this aim, a novel PEDOT:PSS conductive ink formulation and printing procedure were conceived. In order to prove the electrode performance for surface electromyography, we printed the electrodes directly onto a commercial stretchable polyester sleeve for sport applications. The electrodes allowed to reliably record the muscular activity of the forearm with performance comparable to that of commercial gelled Ag/AgCl electrodes. The obtained results suggest that the proposed approach can be valuably used in health and fitness applications.

DoMoMEA: a Home-Based Telerehabilitation System for Stroke Patients.

After a cerebral stroke, survivors need to follow a neurorehabilitation program including exercises to be executed under a therapist's supervision or autonomously. Technological solutions are needed to support the early discharge of the patients just after the primary hospital treatments, by still providing an adequate level of rehabilitation. The DoMoMEA Project proposes a fully-wearable m-health solution able to administer a neurorehabilitation therapy in the patient's home or every other place established by the patient for a rehabilitation session. The exploitation of magneto-inertial measurement units only, wirelessly connected to an Android-operated device, provides robustness to different operating conditions and immunity to optical occlusion problems, compared to RGB-D cameras. Patients' engagement is fostered by the exploitation of the exergame version of the ten rehabilitation exercises, implemented in Unity 3D. Store-and-forward telemonitoring features, supported by cloud-based storage and by a web application accessible from anywhere by medical personnel and patients, enable constant transparent monitoring of the rehabilitation progresses. The clinical trial of the DoMoMEA telerehabilitation system will involve 40 post-stroke patients with mild impairment and will start as soon as the restrictions due to the COVID-19 pandemic will allow to enroll patients.

Validation of Polymer-Based Screen-Printed Textile Electrodes for Surface EMG Detection.

In recent years, the variety of textile electrodes developed for electrophysiological signal detection has increased rapidly. Among the applications that could benefit from this advancement, those based on surface electromyography (sEMG) are particularly relevant in rehabilitation, training, and muscle function assessment. In this work, we validate the performance of polymer-based screen-printed textile electrodes for sEMG signal detection. We obtained these electrodes by depositing poly-3,4-ethylenedioxythiophene doped with poly(styrene sulfonate) (PEDOT:PSS) onto cotton fabric, and then selectively changing the physical properties of the textile substrate. The manufacturing costs are low and this process meets the requirements of textile-industry production lines. The validation of these electrodes was based on their functional and electrical characteristics, assessed for two different electrode sizes and three skin-interface conditions (dry, solid hydrogel, or saline solution), and compared to those of conventional disposable gelled electrodes. Results show high similarity in terms of noise amplitude and electrode-skin impedance between the conventional and textile electrodes with the addition of solid hydrogel or saline solution. Furthermore, we compared the shape of the electrically induced sEMG, as detected by conventional and textile electrodes from tibialis anterior. The comparison yielded an [Formula: see text] value higher than 97% for all measurement conditions. Preliminary tests in dynamic conditions (walking) revealed the exploitability of the proposed electrode technology with saline application for the monitoring of sEMG for up to 35 min of activity. These results suggest that the proposed screen-printed textile electrodes may be an effective alternative to the conventional gelled electrodes for sEMG acquisition, thereby providing new opportunities in clinical and wellness fields.

A tele-home care system exploiting the DVB-T technology and MHP.

OBJECTIVES: The aim of this research work is the development of a low-cost system for telemedicine based on the DVB-T technology. The diffusion of DVB-T standard and the low cost of DVB-T set-top boxes bring the vision of a capillary distribution of tele-home care monitoring systems with easy-to-use patient's interface. METHODS: Exploiting the potentiality of the DVB-T set-top box, we transformed it into an "on-demand tele-home care interface". The Xlet we developed is able to govern the functionality of an external microcontroller-based unit for the acquisition of the bio-signals of interest. The uplink connection is used to send the exam results to a remote care center. RESULTS: The Xlet providing the patient interface on the set-top box is uploaded by a DVB-T broadcaster without any intervention in the patient's home. A prototypal low-cost base station for the acquisition of the patient's signals (1-lead ECG) has been developed. It is able to be connected to the set-top box via an infrared link. A smart-card-based system is in charge for the customization of the Xlet for every patient. CONCLUSIONS: The proposed system, based on a currently widespread infrastructure, is able to allow the patients monitoring from home without any installation procedure. Even untrained (or elderly) people can easily use such system due to their practice with the basic DVB-T home-entertainment equipments.

Home tele-rehabilitation for rheumatic patients: impact and satisfaction of care analysis.

Introduction In this paper, we evaluated patients' perspectives on the use of a system for home tele-rehabilitation, designed for subjects with low computer literacy suffering hand impairment due to rheumatic diseases. Methods After a clinical trial assessing device effectiveness, the Psychosocial Impact of Assistive Devices Scale (PIADS), Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) and Individually Prioritised Problem Assessment (IPPA) questionnaires were administered to evaluate the system's impact on each patient's life, and the results were correlated with clinical indices. Patients were asked to continue self-administered rehabilitation with common objects. One year later, a semi-structured telephone interview gathered data on their experience. Results The system received a positive QUEST score (4.5 ± 0.3) and a modest PIADS score (0.84 ± 0.8) due to the small impact on adaptability and self-esteem. The IPPA (3.7 ± 3.4) revealed improvement in the ability to perform tasks considered important, which was significantly correlated ( r = 0.60; p < 0.02) with the clinical Health Assessment Questionnaire (HAQ) index improvement. The interviews revealed a positive engagement effect, enhanced by the need to develop skills to be able to use the device (technological challenge) and by the perception of more attention by the medical staff. This may explain the significant dropout rate (80%) from the post-trial rehabilitation of the patients who used the device. Discussion The system was largely accepted by the patients. The results suggest that the need for information on their rehabilitation progress and the technological challenge deserves further study to make patients more autonomous in cases of continuous rehabilitation.

Estimation of the center of rotation using wearable magneto-inertial sensors.

Determining the center of rotation (CoR) of joints is fundamental to the field of human movement analysis. CoR can be determined using a magneto-inertial measurement unit (MIMU) using a functional approach requiring a calibration exercise. We systematically investigated the influence of different experimental conditions that can affect precision and accuracy while estimating the CoR, such as (a) angular joint velocity, (b) distance between the MIMU and the CoR, (c) type of the joint motion implemented, (d) amplitude of the angular range of motion, (e) model of the MIMU used for data recording, (f) amplitude of additive noise on inertial signals, and (g) amplitude of the errors in the MIMU orientation. The evaluation process was articulated at three levels: assessment through experiments using a mechanical device, mathematical simulation, and an analytical propagation model of the noise. The results reveal that joint angular velocity significantly impacted CoR identification, and hence, slow joint movement should be avoided. An accurate estimation of the MIMU orientation is also fundamental for accurately subtracting the contribution owing to gravity to obtain the coordinate acceleration. The unit should be preferably attached close to the CoR, but both type and range of motion do not appear to be critical. When the proposed methodology is correctly implemented, error in the CoR estimates is expected to be <3mm (best estimates=2±0.5mm). The findings of the present study foster the need to further investigate this methodology for application in human subjects.

PCR-Based Identification and Characterization of Fusarium sp. Associated with Mango Malformation.

Mango malformation is the most serious disease of mango causing considerable damage to the mango orchards worldwide. It is a major threat for mango cultivation in north Indian belt. In recent years, Fusarium sp. is finding wide acceptability in scientific community as a causal agent of this disease. However, little information is known about the variability in Fusarium isolates from malformed mango tissues. Therefore, the major objective of present study was the identification and analysis of genetic diversity among Fusarium isolates collected from malformed mango tissues. Two texon selective primers, ITS-Fu-f and ITS-Fu-r, were used for quick identification of Fusarium spp. The fungal genomic DNA was extracted from using CTAB method and was utilized as template for PCR amplification. Total 224 bands were amplified by 18 RAPD primers at an average of 12.44 bands per primer. The size of the obtained amplicons ranged from 0.264 kb (minimum) to 3.624 kb (maximum). Data scored from 25 isolates of Fusarium sp. with 18 RAPD primers were used to generate similarity coefficients. The similarity coefficient ranged from 0.17 to 0.945. Based on DNA fingerprints, all isolates were categorized into two major clusters. This study indicated a wide variability among different isolates of Fusarium.