Analysis of blood perfusion on foot in critical limb ischemic and healthy subjects using diffuse optics

Abstract

The diffuse optics technology has progressed rapidly over the years and is now able to penetrate deeper into the human tissue, yielding even more useful information on blood flow in the body. The new system PEDRA hybridises the existing diffuse correlation spectroscopy (DCS) and laser spectral contrast imaging (LSCI), forming the diffuse speckle contrast analysis (DSCA) technology, able to analyse relative blood flow (rBF) effectively. The aim of this clinical study was to obtain rBF readings by looking at blood flow index (BFI), on the lower limbs targeting at foot angiosome areas.

A total of 26 healthy subjects and 26 subjects with Critical Limb Ischemia were involved to evaluate the validity of PEDRA system on its ability to differentiate characteristic between the two groups of samples. Results through boxplot and Error-bar analysis were used to prove that there were significant differences in both curves patterns and mean values between the sample groups. The results were substantiated by the theory that for ischemic patients, BFI tends to be lower and fluctuates more whereby the curves do not coincides with each other. A demographic study on effects of different emotions on BFI readings was also performed. 11 subjects were experimented at 2 channels which are Forehead and Palm. Results proved that rBF varies between Forehead and Palm due to activities of AVAs. However, the extent of emotions’ influence, it is dependent on time and individual’s S.H (Sense of Humour) score.