Method for transient heat flux determination in human body surface using a direct calorimetry sensor

Abstract

A calorimetric sensor has been developed for the measurement of the heat power dissipated by a superficial and localized area of the human body. In this work we present a method for the determination of the transient heat flux between the surface of the human body and the thermostat located inside the sensor. This method consists of the reconstruction of the calorimetric signal (CSRM) from the hypothesis that the power measured by the sensor is adjusted to a mathematical model consisting of a sum of exponentials of the form W-body (t) = A(0) + Sigma A(i) exp (-t/tau(i)). We show the experimental results obtained on the human body and on Joule dissipations of reference, by applying this new method (CSRM) and also the inverse filter method (IFM). The CSRM method allows to easily separate and identify the different phenomena that take place in the dissipation, from the instant the sensor is placed on the surface where the dissipation takes place, until the power reaches the steady state, and also in the instant the sensor is removed from the surface and placed back in its base. This sensor allows to obtain the power dissipated by a surface of 4 cm(2) with a resolution of 10 mW. In relation to the dissipation measured in the different areas of the human body, this sensor will allow to study the possible correlations between these transient phenomena and the human physiopathology. (C) 2019 Elsevier Ltd. All rights reserved.