Displacement plethysmographs for measuring limb segment blood flow (forearm, hand, calf, foot) with independent control over local skin temperature: a project for an older tool

Measuring cutaneous blood flow is an essential building block for understanding thermoeffector responses to changes in central and peripheral tissue temperatures. Under thermoneutral conditions, skin blood flow modifications are the primary pathway for heat exchange. Outside this zone, flow changes provide information pertaining to the thermoregulatory control mechanisms that modulate vasomotor tone. Whilst there are numerous methods available for measuring regional blood flow in humans, the most common method for evaluating the cutaneous flow is via venous-occlusion plethysmography, which has been used for over a century (an older tool), with strain-gauge plethysmographs being most commonly used today.