A Method to Determine Human Skin Heat Capacity Using a Non-Invasive Calorimetric Sensor

Area of Science:

• Biomedical Engineering
• Thermal Physiology
• Sensor Technology

Background:

• Accurate measurement of human skin thermal properties is crucial for understanding thermoregulation and developing thermal management systems.
• Existing methods for assessing skin thermal conductance and heat capacity can be invasive or lack precision.
• Calorimetric sensors offer a potential avenue for non-invasive thermal property assessment.

Purpose of the Study:

• To propose and validate a novel non-invasive method for determining the heat capacity and thermal conductance of human skin.
• To design and model a calorimetric sensor system capable of measuring heat flow from a defined skin surface area.
• To establish a method for calculating heat dissipation from the human body based on sensor measurements.

Main Methods:

• A calorimetric sensor was designed to measure heat flow from a 2 x 2 cm^2 skin surface.
• A non-invasive technique involving linear variation of the sensor thermostat temperature was employed.
• The sensor was modeled as a two-input, two-output system to identify skin heat capacity and thermal conductance.
• Transfer functions were derived to relate sensor inputs (power) and outputs (calorimetric signal, thermostat temperature).

Main Results:

• The proposed sensor modeling successfully identified the heat capacity of the skin.
• Transfer functions were constructed, enabling the determination of heat flow dissipated by the skin as a function of thermostat temperature.
• An equivalent thermal resistance for the measured skin area was defined and determined.
• The method demonstrated validity through both simulation and experimental measurements on human skin.

Conclusions:

• The developed calorimetric sensor and non-invasive method provide an effective means to measure skin heat flow and determine thermal properties.
• This approach offers a valuable tool for research in thermal physiology and biomedical applications.
• The validated method allows for precise, non-invasive assessment of human skin's thermal characteristics.