Evaluation of a non-contact Photo-Plethysmographic Imaging (iPPG) system for peripheral arterial disease assessment

摘要

The flow of blood, or perfusion, of the skin can be indicative for the local and also systemic health of an individual. Peripheral Artery Diseases (PAD) are caused by the occlusions of arteries in the peripheral locations of the circulatory system. The high impairment of the patients and the high hospitalization rate of this disease make early diagnosis crucial. The severity of PAD is usually assessed using the Ankle Brachial Index (ABI) and the Ultrasound Doppler technique, which are considered as the gold standard in current clinical practice. Non-contact Photoplethysmography (PPG) imaging is a recent emerging technology capable of monitoring skin perfusion. Using an off-the-shelf camera and a light source, is possible to remotely detect the dynamic changes in blood volume in the skin and derive a map correlated to the blood perfusion. The aim of this study is the evaluation of a PPG imaging system (iPPG) for the assessment of Peripheral Arterial Diseases. Reduced blood flow is simulated on 21 volunteers by increasing the pressure in a pressure cuff. For each volunteer, measurements with iPPG, ultrasound, Laser Speckle Contrast Analysis (LASCA) and ABI were acquired, both on the hand and foot. Our experiments show that iPPG can detect reduced perfusion levels, and correlates well with the other measurement systems, suggesting that iPPG imaging is a valuable alternative to the other gold standard technologies for monitoring PAD. The proposed iPPG has the potential of providing a real-time feedback to the surgeons after resolving vessel stenosis.