Development of an optical spectroscopy-based non-invasive vasodilation assessment method

This study investigates feasibility of a novel spectrophotometric method for the assessment of endothelial dysfunction (ED) in substitution for standard ultrasound flow-mediated dilation test (FMD). Using an 18-channel optical analyzer (410−940 nm), tissue optical spectra during reactive hyperemia were assessed in 21 patients with ED-related condition (atherosclerosis, coronary heart disease, post-COVID syndrome) and 11 control subjects. Vascular occlusion test (VOT) was performed on the subjects with 3-minute ischemia of the brachial artery at 180 mmHg. Statistical analysis revealed significant differences (p < 0.05) in absorption of light at specified wavelengths (410, 560, 585, 610, 680, 705, 760, 860 nm) between groups with most pronounced differences in atherosclerosis patients. Results show promise for ED detection without operatordependent ultrasound measurements, but further validation against FMD is required.