A Device to Measure Heat Flow Through the Skin in People with Diabetes

Introduction: As people age, and especially for older people with diabetes, there is increased susceptibility to burns. However, this is not true for all older people or all people with diabetes. The factors that predict burn susceptibility in specific members of the population with diabetes have not been elucidated. To understand the heat transfer properties of the skin in different parts of the body and how it is altered by skin blood flow, age, and glycemic control, a new device was developed.

Methods: The device was a Plexiglas (Arkema, Colombes, France) capsule (thermode) that has a footprint on the skin of 20 cm(2), with the side contacting the skin made of thin brass. The thermode was machined to allow the free flow of water through the interior with the exception of a small hole for a laser Doppler flow meter to assess blood flow under the capsule. Flow directors kept the water flow even on the under surface of the capsule and minimized turbulent flow until high water flow rates are forced through the capsule.

Results: When tested, the device provided even heat on the brass surface and could show the movement of heat into the skin and the corresponding changes in skin blood flow and temperature. In limited testing, clear differences were seen in heat flux in people with diabetes versus controls.

Conclusion: This device might be very useful in determining the early onset of diabetes-related skin damage. Future studies should include examining different regions of the body and variables such as hemoglobin A1c.