Non-contact optical imaging of healing and non-healing diabetic foot ulcers

Diabetic foot ulcer is the most devastating complication of diabetes that is still un-recognized. The treatment costs of these ulcers are very high to eventually save the leg/foot from amputation. To date, clinicians employ visual inspection of the wound site during its standard 4-week of healing process via monitoring of surface granulation. There is a need to develop on-site, low-cost imaging tools that can monitor the wound healing process periodically during the standard 4-week treatment process. A novel ultra-portable near-infrared optical scanner (NIROS) has been developed at the Optical Imaging Laboratory that can perform non-contact 2D area imaging of the wound site. Non-contact optical imaging studies were carried on diabetic subjects with foot ulcers (at Somesh Diabetic Foot Clinic, India) that were of healing and non-healing nature. A 710 nm LED source and a compact NIR sensitive camera were employed during non-contact imaging of the diabetic foot in order to obtain the near-infrared absorption images. From these preliminary studies it was observed that the non-healing wounds had a greater absorption contrast with respect to the normal site, unlike in the healing wounds. Demonstrating the ability of NIROS to differentiate healing vs. non-healing wounds in diabetic subjects can potentially impact early intervention in the treatment of diabetic foot ulcers.