Table 1.

Physiologic parameters commonly measured by portable biosensors

Physiologic parameter	Definition
Electrodermal activity (EDA)	A measure of electrical conductance of the skin, which varies with the amount of cutaneous sweat production. Sweat production is mediated by the sympathetic nervous system, and therefore, EDA is an indirect measure of sympathetic nervous system activity [5], which may be heightened or depressed with exposure to various drugs
Skin temperature	A measure of the temperature of the skin/body surface. Skin temperature may differ from core temperature depending on the vasoconstriction or vasodilation effects of sympathetic nervous system activity that can be mediated by drug use
Locomotion	A measure of a patient’s motor activity with respect to the body location on which the sensor is worn, measured in three axes (x, y, and z). Movement patterns are expected to vary with sympathetic nervous system activity. The X-axis is the anterior-posterior direction; the Y-axis is the lateral direction; the Z-axis is the caudad-cephalad.