Gianmarco Angius

Peripheral Neural Activity Recording and Stimulation System

This paper presents a portable, embedded, microcontroller-based system for bidirectional communication (recording and stimulation) between an electrode, implanted in the peripheral nervous system, and a host computer. The device is able to record and digitize spontaneous and/or evoked neural activities and store them in data files on a PC. In addition, the system has the capability of providing electrical stimulation of peripheral nerves, injecting biphasic current pulses with programmable duration, intensity, and frequency. The recording system provides a highly selective band-pass filter from 800 Hz to 3 kHz, with a gain of 56 dB. The amplification range can be further extended to 96 dB with a variable gain amplifier. The proposed acquisition/stimulation circuitry has been successfully tested through in vivo measurements, implanting a tf-LIFE electrode in the sciatic nerve of a rat. Once implanted, the device showed an input referred noise of 0.83 μVrms, was capable of recording signals below 10 μ V, and generated muscle responses to injected stimuli. The results demonstrate the capability of processing and transmitting neural signals with very low distortion and with a power consumption lower than 1 W. A graphic, user-friendly interface has been developed to facilitate the configuration of the entire system, providing the possibility to activate stimulation and monitor recordings in real time.

A sleep apnoea keeper in a wearable device for Continuous detection and screening during daily life

Sleep apnoea syndrome is one of the most common sleep disorders which affects around one out of every 100 people. There is some evidence that sleep apnoea may be linked to hypertension, strokes and heart attacks. The aim of this work is to develop a wearable biomedical system for the continuous and real-time monitoring of the sleep apnoea disease at home. Embedded in a comfortable glove, the proposed wearable device acquires the photoplethysmographic (PPG) signal coming from a standard SpO2 wrapped sensor placed in one of the fingers. Real-time heart rate variability analysis is performed from NN intervals measured in the PPG signal in order to activate an alarm if the number of sleep apnoea events cross a guard level. Through a radio frequency link in the ISM band, the glove communicates with a Internet gateway connected with a remote station for continuous data analysis, monitoring and alarm catch.

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.

Cooperative VLSI tiled architectures: stigmergy in a swarm coprocessor

Stigmergy is a form of indirect interaction for coordination and communication purposes that can be found in many swarm systems. In this paper we present a tiled coprocessor for computation-intensive applications that explicitly exploits stigmergy to achieve adaptability avoiding the usual time-consuming handshakes involved in direct interactions. This adaptability, without any centralized control, directly implies architectural scalability at design time, flexibility in multitasking environment, adaptive load balancing and fault-tolerance at run-time. A CMOS 0.13μm implementation of such architecture for simple array processing operations is presented and evaluated. Obtained results show the potentiality of the proposed approach.

A DVB-T framework for the remote monitoring of cardiopathic and diabetic patients

Tele-home care systems enable patients with chronic diseases to be remotely and constantly monitored by the healthcare staff reducing the need for frequent visits to the hospital. Besides the advantages for patients, this solution could also provide significant cost savings through the exploitation of low-cost equipment for simple physiological measurements to be performed at home, sending the recorded data to the healthier staff placed elsewhere. Tile aim of this work is the development of a low-cost tele-home care system based on the digital video broadcasting terrestrial (DVB-T) technology for the remote monitoring of cardiopathic and diabetic patients. Easy to use even by untrained or elderly people, such tele-home care system could represent the best solution in terms of simplicity, quality and costs.

DESIGN OF A PROGRAMMABLE BIOELECTRICAL IMPEDANCE SYSTEM FOR BIOMEDICAL APPLICATIONS

The design of a portable, versatile and programmable bioelectrical impedance system is presented. The device uses inexpensive off-the-shelf components to perform multi-frequency current injection and voltage measurements through skin electrodes. The impedance measurement system can be configured as multi-frequency bioelectrical impedance analyzer as well as acupuncture point detector, for localizing pathologically changed acupuncture points on the body. In order to improve the accuracy and the flexibility of the measurements, a programmable wide frequency bandwidth current source has been designed. It allows to generate sinusoidal and square waveforms with a frequency up to 1MHz and amplitude values in the range of [12μApp−1.2mApp]. The measured signals can be amplified with a programmable gain and converted with 16 bits of resolution before being transmitted to a PC through USB transmission for further processing.