Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling.

The objective of this study was to test the feasibility of Selective Thermal Stimulation (STS) as a method to upregulate glabrous skin blood flow. STS is accomplished by mild surface heating along the spinal cord. 4 healthy subjects were tested in this study. Each participated in a control experiment and an intervention experiment (STS). Both experiments included establishing a maximum level of vasodilation, considered unique to a subject on a test day, and then cooling to a maximum level of vasoconstriction. Perfusion was measured by a laser Doppler flow probe on the index fingertip. The percent of perfusion in the range of minimum to maximum was the primary outcome variable. The data was fit to a linear mixed effects model to determine if STS had a significant influence on perfusion during whole body cooling. STS had a statistically significant effect on perfusion and increased glabrous skin blood flow by 16.3% (P<.001, CI [13.1%, 19.5%]) as skin temperature was decreased. This study supports the theory that STS improves the heat exchanger efficiency of palmar and plantar surfaces by increasing the blood flow. Copyright (c) 2019 by ASME.