The main objective of this paper was to assess the performance of the ambulatory device μHematron to measure indirectly skin blood flow relative to the well-established Laser Doppler flowmetry method. The μHematron device is dedicated to the non-invasive measurement of effective thermal conductivity of living tissues, based on the thermal clearance method. Its major advantage is its ambulatory functionality, as available methods for evaluation of microcirculatory activity are non-ambulatory methods. An experiment was conducted on ten healthy women exposed for one hour in three different thermal environments (22°C, 25°C and 30°C). Skin microcirculatory activity was analyzed after an acclimatization period of 30minutes. The time between each exposure was at least one hour. Performances of the μHematron device were assessed and a comparative study with a laser Doppler perfusion monitor (LDPM) was performed. Good correlation coefficients between the two devices (r=0.71 at T1=22°C, r=0.77 at T2=25°C and r=0.83 at T3=30°C) were obtained while the LDPM signal was filtered by a low pass filter (0.1Hz). These results showed that continuous monitoring of effective thermal conductivity was possible in neutral and warm ambiences. Then, the μHematron device could be considered as a complementary tool to Doppler techniques for the investigation of skin blood flow, when ambulatory conditions are required.

Given the soaring costs associated with the treatment of ever more prevalent chronic disease, it is widely agreed that a revolution is required in health care provision. It is often thought that the necessary technology already exists for the home-based monitoring of such patients and that it is other factors which are holding back the more widespread clinical uptake of these new tools. The authors suggest that the necessary sensor-related technologies are often not as advanced as may first appear; certainly they are generally not adequate for the robust, long-term monitoring of patients under real-life conditions. An additional problem is the evident efforts to apply a given sensor and related technology platform to any and all monitoring scenarios without sufficient consideration of patient needs and the clinical requirements. The authors review the key sensing platforms and suggest the applications for which they are best suited.

Real time monitoring of the thermal parameters on firefighter when operating is one of the ProeTEX project goals. The newly developed equipments in the framework of this project, integrate one temperature sensor and one heat flux sensor in the rescuer's outer garment. The environment in which firefighters operate is dangerous and the thermal risks can occur everywhere. Consequently the heat flux is so not necessarily symmetrical. To improve the thermally at risk situation detection, a modified platinum sensors array was integrated in the jacket in order to monitor simultaneously heat flux and temperature surrounding the rescuer. The sensors were placed in the most exposed area (shoulders and chest) to monitor thermal parameter in different directions. The heat flux is calculated from the temperature difference. This sensors array enables the detection of temperature increases and heat flux even when the heat source is localized on one side.

The study of skin blood flow (SBF) by measuring the thermal conductivity of living tissues is performed using a non-invasive Hematron sensor designed by A. Dittmar. This paper presents the design and realization of the instrumentation (μHematron) associated with the Hematron probe. The miniaturization of the conditioning electronics was achieved using a Programmable System-on-Chip (PSoCTM) component from Cypress Semiconductor Corporation. Validation of the μHematron device was done using analog reference conditioning electronics. Experiments have been performed on a physical model and under in-vivo conditions. Characteristics of the new instrument are promising, facilitating monitoring of skin blood flow under ambulatory conditions, thus enabling new monitoring applications.

Cerebral temperature and autonomic nervous system (ANS) activity are relevant complementary parameters for the monitoring of physical and mental activities. At the moment, no study has been performed combining these thermal and neurophysiological parameters.

Improvement in quality and efficiency of health and medicine, at home and in hospital, has become of paramount importance. The solution to this problem would require the continuous monitoring of several key patient parameters, including the assessment of autonomic nervous system (ANS) activity using non-invasive sensors, providing information for emotional, sensorial, cognitive and physiological analysis of the patient. Recent advances in embedded systems, microelectronics, sensors and wireless networking enable the design of wearable systems capable of such advanced health monitoring. The subject of this article is an ambulatory system comprising of a small wrist device connected to several sensors for the detection of the autonomic nervous system activity. It affords monitoring of skin resistance, skin temperature and heart activity. It is also capable of recording the data on a removable media or sending it to computer via a wireless communication. The wrist device is based on a programmable system-on-chip (PSoC) from Cypress. (C) 2009 Elsevier Masson SAS. All rights reserved.

The percentage of the population classified as being elderly has been predicted to increase dramatically in size over the next 30-40 years. Figures produced by the World Health Organisation (WHO) anticipate an increase from around 600 million in the year 2000 to close to 2 billion by the year 20501. By 2050, 22% of the world’s population will be over 602 in Europe it will be over 30%3. In addition, according to the WHO, approximately 10% of the population experience some form of disability. Already 21% of people above the age of 50 have severe vision, hearing and/or mobility problems.

The non-invasive Hematron sensor is an active sensor used in studying skin blood flow (SBF) by measuring thermal conductivity of living tissues. Up to now, the Hematron device was composed of the Hematron probe and a heavy analog conditioning electronics. This paper presents the design, realization and validation of an ambulatory device (microHematron) associated with the original Hematron probe. The electronic architecture is based on a Programmable System on Chip (PSoC), which contributes in reducing the number of discrete components, and consequently, the electronic conditioning circuit of Hematron. The microHematron device can be worn on the wrist of the patient thanks to its size (4x3x1cm3) compared to the non-ambulatory conditioning electronics sized 20x30x20cm3. In addition, data can be stored in a microSD card or transmitted using a ZigBee module. The validation of the microHematron device was performed using the analog conditioning electronics as a reference. Experiments were performed first on a physical model reproducing microcirculation in order to characterize the linearity of the thermal conductivity as a function of water flow. Then, two experiments were hold in-vivo conditions highlighting the performances of this new device. In a first experiment, effects of mental calculation on effective tissue perfusion were measured and in a second one, effects of an anti-cellulite cream on micro-vascularisation and skin temperature were studied.

To improve rescuer safety, coordination and efficiency, the European program ProeTEX aims at developing new equipment for the intervention staff. This equipment is based on micro and nanotechnologies and consisted of smart textile integrated sensor to monitor physiological parameters, environment of the rescuer but also acquisition module and communication module. Thermal parameters are of primer interest. Internal temperature, external temperature and heat flux are relevant parameters to prevent heat stroke in fire fighter when exposed to intense fire. These parameters are recorded during fire exposition and highlight, on one hand, that the outer garment of fire fighters' equipment insulates the fire fighter from the external environment, and on the other hand, that the thermal monitoring is relevant.

Nowadays, the proportion of elderly is increasing. As many of them live alone, their health problems and accidents are often not reported. Falling is one of the most significant problems and in some reported cases, detectors have been used, based on accelerometers.

Physiological signals like Heart Rate, Respiration and Skin Resistance are relevant indicators to evaluate driver's mental state.

The paper is aimed at studying the perceived strain in professional air-traffic controllers both through self-evaluation and physiological indicators from the autonomic nervous system (ANS). The number of aircraft to be monitored was the main independent variable and could evolve at random within 1 and 10. Five ANS variables were recorded continuously in 25 participants while they handled real traffic: skin potential, skin conductance, skin blood flow, skin temperature and instantaneous heart rate. The tonic level of each physiological variable was averaged to match the times spent monitoring a constant number of aircraft. After the session, participants reacted in compliance with the NASA-TLX rating scale. Subjective ratings and physiological values were closely correlated to the number of aircraft, especially when data were standardized thus reducing inter-subjects differences in baseline levels. Results provide objective information to prevent air-traffic controllers from overloaded situations as well as to improve passengers' safety.

Living beings are inventing, testing, improving new concepts, solutions and devices from hundred millions years. These living systems are able of self-feeding, they take their energy for the environment and also, they are able of reproduction, adaptation and self-repairing. Living beings as birds, butterflies, sharks and dolphins have optimized flight and swimming and their surface for moving with the lowest energy cost. The golf ball, the wings of aircraft, ships and submarines... are now inspired by the Nature's aero- and hydrodynamism. Our organs and tissues are under the control of millions of microsensors, which measure physical, chemical, mechanical... parameters and are associated to microactuators. This distributed intelligence is present even in the structure of living beings. The wing of fly or dragon fly and also bones have extraordinary characteristics of mechanical resistance and lightness and their complex structure is designed so that at any place there is exactly and appropriate quantities of matter with the good orientation and the smallest weight. The new materials, micro- and nanotechnologies, signal processing, the progress in chemistry and optics... allow us to understand and also to design and build at the scale and size of Nature, using its concepts and taking advantage of the human technologies. It is not always possible to copy directly living beings and their solutions; nature does not give us blue print "ready to copy". We have to analyze the content of the "huge data bank" of living beings for the adaptation of our technologies. Miniaturization, intelligence, low energy, recycling, low cost, high reliability are the main qualities of "bioinspired devices". They fit exactly with the needs of modern users. The multidisciplinary and the bioinspired approach have to link engineers, scientists and industrials for taking real benefits. (C) 2008 Elsevier Masson SAS. Tous droits reserves.

Previous recordings of the variations of autonomic nervous system (ANS) parameters associated with each primary taste (sweet, salty, sour and bitter) showed that sweet taste induced very weak ANS responses, in the same range or weaker than responses evoked by mineral water. The purpose of this study was then to determine whether this weak ANS activation reflects the pleasant hedonic valence of sweet or the habituation of the organism to this innate-accepted taste. Twenty healthy volunteer subjects (8 males and 12 females, mean age=22.85 years) participated in the experiment. Taste stimuli were a solution of 0.3 M sucrose and three sweet flavours (orange juice, coke, lemonade) as "pleasant" sweet stimuli, and a solution of 0.15 M NaCl as an "unpleasant" stimulus. "Evian" mineral water served as the diluent and as a neutral stimulus. Throughout the test, five ANS parameters (skin potential and skin resistance, skin blood flow and skin temperature, instantaneous heart rate) were simultaneously and continuously recorded. After they had tasted each solution, subjects filled out a questionnaire in which they had to evaluate the hedonic dimension and the sweet intensity of each gustative stimulus. The lack of correlation between the mean hedonic scores associated with the four sweet stimuli and the mean values of the autonomic parameter variations tends to indicate that the weak ANS responses induced by the sweet gustative stimuli rather reflect the habituation of the organism to sweet taste than a gradation in sensory pleasure.

The purpose of MAPI project is to propose a method for interface pressure measurement integrated into a seat. This device must be exact, low cost and must take into consideration viscoelastic characteristics of the skin and of human morphology. The main areas we aim at are ergonomics of seating surfaces and prevention of pressure ulcer using a principle of measurement based on the patent FR 0402037. We passed an additional stage by developing an electropneumatic interface-pressure sensor directly integrated into a seat. The sensor is easy to use and presents acceptable characteristics. The average error is 2.58% and the standard deviation is 1.66 mmHg. Spatial resolution is 3 cm. This first prototype will be optimized, with better spatial resolution, and used for different pressure ulcer study and prevention tests. (c) 2008 Publie par Elsevier Masson SAS.

The purpose of MAPI project is to propose a method for interface pressure measurement. This method must be exact, easy to build, low cost, and must take into consideration viscoelastic characteristics of the skin and of human morphology. The main areas of the project is related to ergonomics of seating surfaces and prevention of pressure ulcers. An additional stage was performed by developing an electro-pneumatic interface pressure sensor directly integrated into a seat. The sensor is easy to use and presents acceptable characteristics. The average error is 2.58%, and the standard deviation is 1.66 mmHg. Spatial resolution is 3 cm. This first prototype will be improved, with better spatial resolution, and used for different pressure ulcer study and prevention tests.

Pressure ulcers are a serious health problem for people with mobility disorders, like elders in acute care, long-term care, and home care settings. It also concerns paraplegics, tetraplegics or persons with burned injuries. Pressure ulcers result in significant morbidity and mortality. Consequences are a high human suffering, with high cost in terms of treatment. Several risk factors have been identified for the development of pressure ulcers: they are classified into extrinsic and intrinsic factors. Extrinsic factors include interface pressure, shear forces, friction. Intrinsic factors are the nutritional state of the patient, its age, diseases. There is little information about the mechanism of the formation of pressure sores but it is agreed that it is a complex process. The difficulty of the prevention lies in the evaluation of these factors. It is an essential stage to optimize the preventative measures. Actually, no quantifiable parameters exist to predict the formation of a pressure ulcer. This article is aimed to propose new techniques developed for the early detection of pressure ulcers. First, extrinsic parameters as the interface pressure and its consequences on the mobility are investigated. A new actimeter is presented to monitor the movements of the patient. The second part is dedicated to the presentation of a new imaging technique which can help the physician to control tissue elasticity of the patient. The technique is called elastography, it is a 3D strain estimation of soft biological tissues. Finally, the last way of investigation is the combination of extrinsic and intrinsic factors evaluation for a most relevant earlier diagnosis. Before the description of these techniques, it is essential to understand the phenomenology associated to the development of pressure sores. Only in this way, new techniques can be developed.