Bilateral photoplethysmography studies of the leg arterial stenosis

Abstract

A newly developed portable multi-channel photoplethysmography (PPG) device has been used for comparative studies of 20 healthy control subjects and 45 patients with diagnosed arterial stenosis in a leg. The peripheral blood pulsations were detected simultaneously at four body sites-the same fingers and toes of both arms and legs. The PPG pulses recorded at the periphery of the stenotic leg, if compared with those of the healthy leg, were much weaker, with delayed arrival as a consequence of increased pulse wave transit time (PWTT) due to higher vascular resistance. The specific PWTT delays for the occluded legs were in the range of 20-80 ms, while in the case of healthy subjects the leg PPG signals arrived without delays or with smaller time-shifts not exceeding 14 ms. The reference bilateral PPG signals detected at the fingertips did not show any notable PWTT delays in both groups. Parallel measurements of local blood pressures by means of the oscillometry method with subsequent calculation of the ankle-brachial index were performed. Convincing correlation between the bilateral differences in the local blood pressure (a routine tool for diagnostics of leg stenosis) and in the corresponding PWTT delay (Pearson's coefficient r = 0.93), as well as between the PWTT delay and the ankle-brachial index (r = -0.96) has been established. From the point of view of PWTT delay, the average value of leg stenosis diagnostic threshold was established to be in the range of 23 +/- 9 ms, with full reliability above 32 ms. The obtained data may find further applications in alternative methodologies for detection and/or assessment of arterial occlusions in human extremities.

A prospective comparison of bilateral photoplethysmography versus the ankle-brachial pressure index for detecting and quantifying lower limb peripheral arterial disease

“…One technique that has this potential is the optical pulse technology, photoplethysmography (PPG), [11][12][13][14][15][16][17][18] which detects changes in the blood volume in the microvascular bed of tissue. Its waveform comprises a pulsatile ("AC") physiologic waveform attributed to cardiac synchronous changes in the blood volume with each heart beat that is superimposed on a slowly varying ("DC") baseline, with various lower-frequency components attributed to respiration, sympathetic nervous system activity, and thermoregulation.…”

Instruments in Biotechnology and Medicine

“…A study by Simonson et al [60] found significant changes in the rise time in impaired arteries. The potential of differences in PTT between the left and the right sides was further stated in recent studied [61,62]. It was also shown that frequency analysis of the PPG signal can reveal differences between healthy arteries and those with arteriosclerosis [63].…”

Analysis through dynamic temporal sequence alignment in SpO2 signals

“…These parameters have allowed for the assessment of the vascular effects of aging, hypertension, and atherosclerosis [6] [7] [8]. Other notable applications in which PPG peak signal detection has played a key role, are related to the measurement of baroreflex sensitivity [9], diagnosis of damage to the arteries [10], as well as diagnosis of peripheral vascular disease [11], ventricular ejection time, and arterial stiffness [12].…”