Evaluation of diabetic foot ulcer development using hyperspectral imaging

This talk discusses the use of hyperspectral imaging for predicting and understanding ulcer formation on diabetic feet. It presents both in vivo experimental measurements and modeling of light transfer through human skin. A commercial hyperspectral oximetry system by HyperMed Inc. was used to measure reflectance of the feet of 256 diabetic patients at risk of developing foot ulcers for wavelengths between 490 and 650 nm. Measurements were performed during 7 visits over an 18-month period after obtaining approval from institutional review boards and informed consent from patients. During the course of the study, 24 foot ulcers formed. A predictive index based on hyperspectral tissue oximetry was developed. Results showed a strong correlation between skin oxygenation derived from hyperspectral imaging and ulcer formation. The index was able to differentiate preulcer tissue from surrounding healthy tissue with a sensitivity of 92% and specificity of 80%.