Monitoring of reactive hyperemia using photoplethysmographic pulse amplitude and transit time

Abstract

Results suggests that PTT response reflects the myogenic components in the early part of RH and PPG amplitude response reflects the metabolic component reinforcing the later course of RH. PPG amplitude and PTT can be used to quantify the changes in diameter and tone of the vessel wall, respectively during RH. The collective responses of PPG amplitude and PTT can be more appropriate to facilitate PPG technique for monitoring of vasodilation caused by RH.

Impaired endothelium mediated vascular reactivity in endogenous Cushing's syndrome

“…These findings were in close agreement with the results obtained by Selvaraj et al in normal subjects [22].…”

“…On univariate correlation analysis (Fig. 5) it was observed that percent- mal conduit arteries [16,17,22]. This rise in digital pulse waveform amplitude during reactive hyperemia has been shown to be dependent on endothelial nitric oxide synthesis [18].…”

“…This rise in digital pulse waveform amplitude during reactive hyperemia has been shown to be dependent on endothelial nitric oxide synthesis [18]. Vascular tone changes in conduit and resistance vessels during reactive hyperemia are mainly due to myogenic vasorelaxation taking place during the period of arterial occlusion as well as due to the vasorelaxation induced by flow mediated release of NO during the phase of RH [22,32,33].…”

“…Photoplethysmography (PPG) is an optical measurement technique used to record digital volume pulse by measuring the pulsatile changes in blood volume in the finger microvasculature using light of infrared wavelength [19,20,21]. Photoplethysmographic measurement of peripheral pulse waveform changes is a highly objective and operator independent technique used to assess changes in both the calibre and tone of blood vessels during reactive hyperemia [17,22]. In this study we assessed and compared the vascular reactivity and endothelial function in patients of CS with those of healthy human subjects by studying the peripheral pulse wave form and pulse transit time (PTT) responses during reactive hyperemia using R wave gated photoplethysmography.…”

Investigation of peripheral photoplethysmographic morphology changes induced during a hand-elevation study

“…It has been shown that this variable is affected by many cardiovascular responses such as vasoconstriction due to a cold pressor test [11] or vasodilation due to reactive hyperemia [3], etc. However, it is difficult to compare systolic amplitudes between subjects or between measurement sites because absorption of light is dependent on local factors (such as skin pigmentation, sensor location etc.…”