A wearable device for monitoring galvanic skin response to accurately predict changes in blood pressure indexes and cardiovascular dynamics

Predicting acute hypotensive episode (AHE) in patients in emergency rooms and in intensive care units (ICU) is a difficult challenge. As it is well accepted that physiological compensatory adaptations to circulatory shock involve blood flow redistribution and increase in sympathetic stimulation, we recently investigated if galvanic skin response (GSR) or electro-dermal activity (EDA), a measure of sympathetic stimulation, could give information about the impending danger of acute hypotensive episode or circulatory collapse (Subramanya and Mudol, 2012). In this current study, a low-cost wearable device was developed and tested to help progress towards a system for predicting blood pressure (BP) and cardiovascular dynamics. In a pilot study, we examined hypotheses about the relation between GSR values and four BP indexes (systolic BP, diastolic BP, mean arterial pressure and pulse pressure) in apparently healthy human volunteers before and immediately after treadmill exercise. All four BP indexes had significant relationship with GSR, with pulse pressure possibly the strongest predictor of variations in the GSR and vice-versa. This paper opens up opportunities for future investigations to evaluate the utility of continuous monitoring of GSR to forecast imminent cardiovascular collapse, AHE and shock, and could have far-reaching implications for ICU, trauma and critical care management.