Optical Techniques in the Assessment of Peripheral Arterial Disease

Abstract

A variety of optical techniques have been developed over the years for experimental use in vascular disease, mainly for the assessment of lower limb peripheral arterial disease (PAD). Optical techniques have several advantages over more traditional experimental approaches. Photoplethysmograph (PPG) was one of the earliest methods used for this purpose; PPG satisfies many of the conditions for a non-invasive technique to estimate skin blood flow using infrared light, not only for research but also in clinical practice. PPG is a promising, safe and easy-to-use tool for diagnosis and early screening of various atherosclerotic pathologies and could be useful for regular GP-assessment or even self-monitoring of PAD at home or during individual physical exercises. This review discusses the application of PPG in the assessment of PAD.

Real-time optoacoustic monitoring and three-dimensional mapping of a human arm vasculature

“…27,28 Clinical conditions that would benefit from such analysis include atherosclerotic peripheral arterial disease, veno-occlusive disease, and venous valvular insufficiency. 29,30 A further advantage of OA imaging over plethysmography 31 is that OA imaging provides localized information ͑with high spatial resolution͒ about an individual artery or vein, versus the regional information about entire vascular beds that is obtained using plethysmographic methods.…”

Investigation of photoplethysmographic signals and blood oxygen saturation values on healthy volunteers during cuff-induced hypoperfusion using a multimode PPG/SpO2 sensor

“…When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia, vasoconstriction, low cardiac output and low mean arterial pressure [2], pulse oximeter readings become unreliable or cease altogether [8,11]. The oxygen saturation readings become unreliable in these circumstances because conventional pulse oximeter sensors are usually placed at the most peripheral parts of the body such as the finger, where pulsatile flow is most vulnerable [5].…”

Review of near-infrared methods for wound assessment

“…[102][103][104] This small difference in blood volume between the systolic and diastolic phases of the cardiac cycle produces a modulation in the measured attenuation of light by well perfused tissue (see Fig. 10).…”

“…This well-known phenomenon is exploited in pulse oximetry and photoplethysmography (PPG) to provide information about the arterial blood supply to the underlying tissue. The measurement of PPG "pulses" at the toes and fingers is routinely performed in patients with peripheral vascular disease (PVD) to confirm the extent of compromised circulation in the extremities [102][103][104][105][106] as well as being helpful in assessing the success of revascularization procedures 107 and predicting wound healing following amputation. 108 PPG offers a simple, reliable, 109 and effective noninvasive means to detect a robust arterial supply to the extremities by measuring the depth of the pulsatile modulation of the optical attenuation.…”