Video capillaroscopy clarifies mechanism of the photoplethysmographic waveform appearance.

ABSTRACT: Photoplethysmography (PPG) devices are widely used in clinical practice but the origin of PPG signal is still under debating. The classical theory assumes that the PPG waveform stems from variations of blood volume in pulsating arteries. In this research we analysed high-speed video recordings of capillaries in a fingernail bed. It was found that speed of erythrocytes in capillaries has pronounced modulation in time, which follows variations of instantaneous blood pressure in arteries. However, the mean speed significantly differs even for neighbour capillaries whereas change of the speed occurs in phase for the most of capillaries. Moreover, the light intensity remitted from the papillary dermis is also modulated at the heartbeat frequency displaying significant correlation with waveforms

SUBMITTER: Volkov MV 

PROVIDER: S-EPMC5643323 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature