Development of a medical device for long-term sweat activity measurements

Abstract

A multichannel logger for long-term measurements of sweat activity has been developed. The logger uses skin surface electrodes for unipolar admittance measurements in the stratum corneum. Using lock-in technique to extract the conductive part of the admittance limits the measurement to the filling of the sweat ducts with little influence from the moisture content of the skin. A digital solution is used for a powerful microcontroller to perform most of the measurement tasks, thereby reducing the number of components needed and the total current consumption. The prototype has four channels with complete channel separation. The logger is developed with emphasis on clinical use and is constructed according to such demands. The portability of the logger enables recording of sweat activity under circumstances such as daily errands, exercise and sleep. Before the logger can be used for diagnostic purposes, a study has to be done to determine the normal sweating patterns for the healthy population. © Springer-Verlag 2007.