Danilo Pani

Fully Textile, PEDOT:PSS Based Electrodes for Wearable ECG Monitoring Systems

Goal: To evaluate a novel kind of textile electrodes based on woven fabrics treated with PEDOT:PSS, through an easy fabrication process, testing these electrodes for biopotential recordings. Methods: Fabrication is based on raw fabric soaking in PEDOT:PSS using a second dopant, squeezing and annealing. The electrodes have been tested on human volunteers, in terms of both skin contact impedance and quality of the ECG signals recorded at rest and during physical activity (power spectral density, baseline wandering, QRS detectability, and broadband noise). Results: The electrodes are able to operate in both wet and dry conditions. Dry electrodes are more prone to noise artifacts, especially during physical exercise and mainly due to the unstable contact between the electrode and the skin. Wet (saline) electrodes present a stable and reproducible behavior, which is comparable or better than that of traditional disposable gelled Ag/AgCl electrodes. Conclusion: The achieved results reveal the capability of this kind of electrodes to work without the electrolyte, providing a valuable interface with the skin, due to mixed electronic and ionic conductivity of PEDOT:PSS. These electrodes can be effectively used for acquiring ECG signals. Significance: Textile electrodes based on PEDOT:PSS represent an important milestone in wearable monitoring, as they present an easy and reproducible fabrication process, very good performance in wet and dry (at rest) conditions and a superior level of comfort with respect to textile electrodes proposed so far. This paves the way to their integration into smart garments.

Reconfigurable Coprocessor for Multimedia Application Domain

A new reconfigurable architectural template is presented. Such a template is composed of coarse-grained and fine-grained reconfigurable datapath and control to obtain performances at custom designed chip level. To show the adaptability/performance of such architectural template, the architecture has been customized (i.e. datapath and control features of the template have been properly sized) for multimedia application domain. To evaluate complexity and maximum clock frequency of the proposed architecture, it has been synthesized using Synopsys Design Compiler on a standard-cell 0.18 μ m technology. Estimated number of transistors is 335 K, while maximum allowable frequency is 460 MHz. Performances have been evaluated comparing the number of clock cycles and the processing time required to process application domain dominant kernels with commercial devices: we obtained up to 95% reduction with respect to ARM and up to 94% reduction with respect to TMS320C5510 in terms of clock cycles.

RVC: A multi-decoder CAL Composer tool

The Reconfigurable Video Coding (RVC) framework is a recent ISO standard aiming at providing a unified specification of MPEG video technology in the form of a library of components. The word “reconfigurable” evokes run-time instantiation of different decoders starting from an on-the-fly analysis of the input bitstream. In this paper we move a first step towards the definition of systematic procedures that, based on the MPEG RVC specification formalism, are able to produce multi-decoder platforms, capable of fast switching between different configurations. Looking at the similarities between the decoding algorithms to implement, the papers describes an automatic tool for their composition into a single configurable multi-decoder built of all the required modules, and able to reuse the shared components so as to reduce the overall footprint (either from a hardware or software perspective). The proposed approach, implemented in C++ leveraging on Flex and Bison code generation tools, typically exploited in the compilers front-end, demonstrates to be successful in the composition of two different decoders MPEG-4 Part 2 (SP): serial and parallel.

Telemedicine Applied to Kinesiotherapy for Hand Dysfunction in Patients with Systemic Sclerosis and Rheumatoid Arthritis: Recovery of Movement and Telemonitoring Technology

Objective. To describe a feasibility study focused on a telemonitoring approach to self-managed kinesiotherapy sessions for the rehabilitation of hand function in patients with systemic sclerosis (SSc) and rheumatoid arthritis (RA). Methods. Ten patients with SSc and 10 with RA were enrolled in a 3-month controlled trial (approval no. 9751/2012 – Italian Department of Health) to perform a home kinesiotherapy protocol, consisting of strengthening and mobility exercises, using a newly developed telemedicine system (a portable device and the related telemonitoring infrastructure). A further 10 patients with SSc and 10 with RA were enrolled as controls to perform a similar home kinesiotherapy protocol with the aid of common daily-life objects. Both groups were evaluated at baseline and at followup, after 6 and 12 weeks. The primary outcome of the trial was hand function measured by Dreiser’s index (Functional Index for Hand OA, FIHOA), Health Assessment Questionnaire (HAQ), and the Hand Mobility in Scleroderma (HAMIS) test (only for SSc). Results. Patients with SSc showed an improvement of FIHOA in both arms (p < 0.01) but the HAQ (p = 0.016) and the HAMIS test (right hand p = 0.016, left hand p = 0.075) improved significantly only in the experimental arm. Patients with RA showed a statistically significant improvement of FIHOA (p = 0.013) and HAQ (p = 0.015) in the experimental arm, while patients in the control arm did not significantly improve. However, no statistically significant differences in outcome measures between treatment methods were observed. Withdrawals were higher in control arms (SSc 20%; RA 30%) than in experimental arms (SSc 10%; RA 10%). Conclusion. Telemonitoring of self-administered kinesiotherapy programs is a promising approach to the rehabilitation of hand functions in patients with rheumatic disease.

A coarse-grained reconfigurable approach for low-power spike sorting architectures

Spike sorting is a critical task in neural signal decoding because of its computational complexity. From this perspective, the research trend in the last years aimed at designing massively parallel hardware accelerators. However, for implantable system with a reduced number of channels, as could be those interfaced to the Peripheral Nervous Systems (PNS) for neural prostheses, the efficiency in terms of area and power is in contrast with such a parallelism exploitation. In this paper, a novel approach based on high-level dataflow description and automatic hardware generation is presented and evaluated on an on-line spike sorting algorithm for PNS signals. Results in the best case revealed a 71% of area saving compared to more traditional solutions, without any accuracy penalty. With respect to single kernels execution, better latency performance are achievable still minimizing the number of adopted resources.

First objective evaluation of taste sensitivity to 6- n -propylthiouracil (PROP), a paradigm gustatory stimulus in humans

Practical and reliable methods for the objective measure of taste function are critically important for studying eating behavior and taste function impairment. Here, we present direct measures of human gustatory response to a prototypical bitter compound, 6-n-propyltiouracil (PROP), obtained by electrophysiological recordings from the tongue of subjects who were classified for taster status and genotyped for the specific receptor gene (TAS2R38), and in which taste papilla density was determined. PROP stimulation evoked negative slow potentials that represent the summated depolarization of taste cells. Depolarization amplitude and rate were correlated with papilla density and perceived bitterness, and associated with taster status and TAS2R38. Our study provides a robust and generalizable research tool for the quantitative measure of peripheral taste function, which can greatly help to resolve controversial outcomes on the PROP phenotype role in taste perception and food preferences, and be potentially useful for evaluating nutritional status and health.

Real-time processing of tfLIFE neural signals on embedded DSP platforms: A case study

Spike sorting is a typical neural processing technique aimed at identifying the firing activity of individual neurons. It plays a different role in the processing of the signals coming either from a single electrode or an electrode array. In presence of highly noisy recordings, a preliminary denoising stage is required in order to improve the SNR. Despite the significant number of studies in the field, only a few of them deal with peripheral nervous system (PNS) recordings and often the possibility of a real-time implementation is only hinted without any real implementation study. In this paper, a real-time PNS signal processing and classification technique is presented end evaluated on real electroneurographic signals taken from the sciatic nerve of rats. A state-of-the-art algorithm, composed of a wavelet denoising preprocessing stage followed by a correlation-based spike sorting and a support vector machine, has been adapted to work on-line in order to improve the processing efficiency while preserving at the most its effectiveness. The algorithm provides some level of adaptiveness with respect to an off-line implementation. On average, the correct classification reach 92.24% with isolated errors that can be easily filtered out. Cycle-accurate profiling results on an off-the-shelf Digital Signal Processor demonstrate the real-time performance.

A Device for Local or Remote Monitoring of Hand Rehabilitation Sessions for Rheumatic Patients

Current clinical practice suggests that recovering the hand functionality lost or reduced by injuries, interventions, and chronic diseases requires, beyond pharmacological treatments, a kinesiotherapic intervention. This form of rehabilitation consists of physical exercises adapted to the specific pathology. Its effectiveness is strongly dependent on the patients adhesion to such a program. In this paper, we present a novel device with remote monitoring capabilities expressly conceived for the needs of rheumatic patients. It comprises several sensorized tools and can be used either in an outpatient clinic for hand functional evaluation, connected to a PC, or afforded to the patient for home kinesiotherapic sessions. In the latter case, the device guides the patient in the rehabilitation session, transmitting the relevant statistics about his performance to a TCP/IP server exploiting a GSM/GPRS connection for deferred analysis. An approved clinical trial has been set up in Italy, involving 10 patients with rheumatoid arthritis and 10 with systemic sclerosis, enrolled for 12 weeks in a home rehabilitation program with the proposed device. Their evaluation has been performed not only with traditional methods, but also with the proposed device. Subjective (hand algofunctional Dreisers index) and objective (ROM, strength, and dexterity) parameters showed a sustained improvement throughout the follow-up. The obtained results proved that the device is an effective and safe tool for assessing hand disability and monitoring kinesiotherapy exercise, portending the potential exploitability of such a methodology in the clinical practice.

KeepInTouch: A telehealth system to improve the follow-up of chronic patients

With the progressive ageing of the western people, the number of chronic patients requiring a continuous follow-up by the physicians increases. Even though telehealth solution can be potentially effective in such a scenario, both the age factor and often the cost of the systems hamper the diffusion of telehealth systems. KeepInTouch is a low cost system for telehomecare conceived for the daily off-line monitoring of diabetic and cardiac patients. It exploits a mixed approach offering a simple TV-based front-end from the patient side, and a web-based one from the physician side. The web-based approach enables the authorized medical professionals to access the patient data from the web, exchanging useful information and providing textual feedback to the patient, all within the system interface. The patients front-end is based on the Digital Video Broadcasting Terrestrial (DVB-T) technology, exploiting an acquisition unit connected to the patients certified biomedical devices (sphygmomanometer, glucometer, body weight scale) and with the interactive DVB-T set-top box in order to provide a user-friendly interface on the TV for people not accustomed with computers. The system is going to be used for a first clinical trial in Italy.

A DSP algorithm and system for real-time fetal ECG extraction

Fetal ECG (FECG) extraction from maternal abdominal potential recordings is a task of paramount importance for pediatric cardiologists, but there is a lack of established solutions for it. In this paper the real-time implementation of a block-on-line independent component analysis (ICA) algorithm for FECG extraction is presented and evaluated over real long lasting recordings. The problem of the signals permutation, typical of ICA algorithms and particularly severe for block-on-line ones, is analyzed in detail. The comparison with batch approaches applied to different segments of the signals demonstrates the quality of the proposed solution. The performances of the real-time implementation enable further developments of the system to automatically provide other interesting clinical parameters.