Bilateral photoplethysmography analysis for peripheral arterial stenosis screening with a fractional-order integrator and info-gap decision-making

Peripheral arterial disease and atherosclerosis are common complications in patients with type 2 diabetes or with both diabetes and end-stage renal disease. Lower-limb peripheral arterial disease and hemodialysis (HD) vascular access stenosis are highly prevalent in HD patients; in particular, progressively narrowed vascular access and suboptimal dialysis blood flows are the major issues. In this paper, we propose a fractionalorder integrator (FOI) for indicating the differences in the risetiming and amplitudes of bilateral photoplethysmography (PPG) signals with the aim of improving HD healthcare. The area under the systolic peak ratio was used as an index to separate the patients without arterial stenosis from those with arterial stenosis; subsequently, info-gap decision making was conducted to evaluate risk levels in reference to the patients' health records and the degrees of stenosis. The experimental results indicated that in comparison with 1) the resistive index; 2) bilateral timing parameters; and 3) the hybrid intelligent method, our proposed screening model was more efficient in preventing complications of peripheral arterial stenosis and was easily implemented in an embedded system.