How do water plethysmography, strain gauge plethysmography, and pulsed Doppler flowmetry compare in measuring hand blood flow?
Water plethysmography is the most sensitive and accurate method for measuring hand blood flow, while pulsed Doppler flowmetry offers precise instantaneous arterial flow measurement without venous occlusion.
Hand blood flow was measured at rest, with local warming, and with local cooling. Three methods were simultaneously used: water plethysmography (WP), mercury-in-rubber strain gauge plethysmography (SG), and pulsed Döppler flowmetry (D). Of these, water plethysmography is the most sensitive and accurate; strain gauge plethysmography is simpler but less accurate; and pulsed Döppler flowmetry precisely measures instantaneous arterial blood flow without venous occlusion.
Levy et al. (1979) studied this question.