Design and development of an impedimetric-based system for the remote monitoring of home-based dialysis patients.

A key clinical challenge is to determine the desired 'dry weight' of a patient in order to terminate the dialysis procedure at the optimal moment and thus avoid the effects of over- and under-hydration. It has been found that the effects of haemodialysis on patients can be conveniently monitored using whole-body bioimpedance measurements. The identified need of assessing the hydrational status of patients undergoing haemodialysis at home gave rise to the present Dialydom (DIALYse à DOMicile) project. The aim of the project is to develop a convenient miniaturised impedance monitoring device for localised measurements (on the calf) in order to estimate an impedimetric hydrational index of the home-based patient, and to transmit this and other parameters to a remote clinical site. Many challenges must be overcome to develop a robust and valid home-based device. Some of these are presented in the paper.

Cerebral temperature varies across circadian phases in humans.

The 24-hour rhythm of core body temperature (CBT) is commonly used in humans as a tool to assess the oscillation of the central endogenous circadian pacemaker. The invasive nature of the rectal sensor used to collect CBT makes it difficult to use in ambulatory conditions. Here we validate the use of a newly developed brain temperature (BT) sensor against that of a standard rectal temperature sensor using a 72-hour ultra-rapid sleep-wake (URSW) cycle procedure. A significant circadian variation of both body temperature recordings was observed from which a phase and amplitude was reliably determined. These results indicate that BT can be refined as a non-invasive alternative to CBT measurements in the evaluation of circadian phase in field conditions.

Flexible technologies and smart clothing for citizen medicine, home healthcare, and disease prevention.

Improvement of the quality and efficiency of healthcare in medicine, both at home and in hospital, is becoming more and more important for patients and society at large. As many technologies (micro technologies, telecommunication, low-power design, new textiles, and flexible sensors) are now available, new user-friendly devices can be developed to enhance the comfort and security of the patient. As clothes and textiles are in direct contact with about 90% of the skin surface, smart sensors and smart clothes with noninvasive sensors are an attractive solution for home-based and ambulatory health monitoring. Moreover, wearable devices or smart homes with exosensors are also potential solutions. All these systems can provide a safe and comfortable environment for home healthcare, illness prevention, and citizen medicine.

Wearable medical devices using textile and flexible technologies for ambulatory monitoring.

Health smart clothes are in contact with almost all the surface of the skin offer large possibilities for the location of sensors for non invasive measurements. Head band, collar, tee-shirt, socks, shoes, belts for chest, arm, wrist, legs ... provide localization with specific purpose taking into account their proximity of an organ or a source of biosignal, and also its ergonomic possibility (user friendly) to fix a sensor, and the associated instrumentations (batteries, amplifiers, signal processing, telecom, alarm, display ...). Progress in science and technology offers, for the first time, intelligence, speed, miniaturization, sophistication and new materials at low cost. In this new landscape, microtechnologies, information technologies and telecommunications are a key factor. Microsensors : Microtechnologies offer the possibility of small size, but also intelligent, active device, working with low energy, wireless and non invasive or mini invasive. These sensors have to be thin, flexible and compatible with textile, or made using textile technologies, new fibers with specific properties: mechanical, electrical, optical ... The field of applications is very large, e.g. continuous monitoring on elderly population, professional and military activities, athlete's performance and condition, and people with disabilities. The research are oriented toward two complementary directions: Improving the relevancy of each sensor and increasing the number of sensors for having a more global synthetic and robust information.