A temperature-controlled glove with non-invasive arterial pulse sensing for active neuro-vascular assessment

A non-invasive, active neuro-vascular assessment system was developed using a modified temperature-controlled glove and feedback techniques. The glove incorporates local heating and cooling of the hand using multi-point skin temperature measurements as feedback, and thereby induces local and central mechanisms involved in thermoregulation. Electrocardiogram (ECG), photoplethysmogram (PPG) and non-invasive finger-cuff based blood pressure (BP) measurements were used to monitor electrophysiology and hemodynamic changes in response to temperature modulation. Then, the triggered neuro-vascular mechanisms associated with thermoregulation were quantified by extracting parameters from the measured waveforms, specifically heart rate variability (HRV), vascular tone, and BP. The system was tested on six young, healthy individuals with no history of microvascular diseases. During heating, vasodilation, decrease in systolic BP, and a decrease in parasympathetic tone were observed, while during cooling, vasoconstriction and increased BP were observed. While such changes are expected physiologically using passive experiments, the ability to modulate the physiology non-invasively with a controlled, quantitative, and inexpensive instrument can potentially enable serial assessments of neuro-vascular control outside of clinical settings.