Design and validation of an ambulatory system for the measurement of the microcirculation in the capillaries: microHematron device.
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.
Toumi
Dareen
D
Biomedical Sensors Group, Nanotechnologies Institute of Lyon, INSA Lyon, 20 Avenue Albert Einstein, F-69621, Villeurbanne Cedex. dareen.toumi@insa-lyon.fr
Gehin
Claudine
C
Dittmar
Andre
A
McAdams
Eric
E
D000328:Adult; D000465:Algorithms; D002196:Capillaries / Q000473:pathology*; D003358:Cosmetics; D004553:Electric Conductivity; D004581:Electronics; D004582:Electronics, Medical; D004867:Equipment Design; D006358:Hot Temperature; D006801:Humans; D008833:Microcirculation; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods; D009991:Oscillometry / Q000379:methods; D012867:Skin / Q000473:pathology; D014159:Transducers
D003358:Cosmetics