Study of Skin flow motion pattern using photoplethysmogram

Abstract

Microcirculatory dysfunction is related to many diseases and occurs long before their clinical manifestation. We used wavelet transform to study the microcirculatory regulatory mechanism in three different groups (18-diabetic, 8-peripheral arterial disease (PAD) and 14 healthy controls) using toe photoplethysmogram (PPG) and 11 different features were derived. Compared to healthy subjects we obtained a significant decrease in the neurogenic (VNe: 286.41 vs. 125.29 (a. u), p-value = 0.000), myogenic (VMe: 281.55 vs. 29.02, p-value = 0.000) and respiratory activity (VRe: 37.68 vs. 9.35, p-value = 0.022) in the diabetic group and significant increase in the cardiac activity (VCe: 19.69 vs. 33.89, p-value = 0.007) in PAD group. Result of linear multiple regressions analysis showed a significant negative association of age and BMI with myogenic activity (p-value = 0.002, r-value = 0.173) and neurogenic activity (p-value = 0.036, r-value = 0.375) respectively. Our study showed that PPG signal can be used as a non-invasive tool for studying the vasomotion impairment in the diabetic patient during resting condition.