Laser Speckle Integrated Multispectral Imaging System for In-Vivo Assessment of Diabetic Foot Ulcer Healing

The high prevalence of the world's population diagnosed with diabetes mellitus, with a significant number suffering from diabetic foot ulcer (DFU), has always been a global concern over the years. The rapid rise of this disease in the last decades is deemed increasingly alarming as it has left deleterious effects not only on affected patients but also on the society and nation. This paper aims to develop a reliable diagnostic tool to address the tremendous need for coordinated and efficient DFU management via prediction of transcutaneous oxygen saturation (StO ₂ ) and relative blood perfusion (τ) in the affected limb. This system integrates the use of a multispectral imaging and laser speckle contrast imaging technique for two-dimensional (2D) mapping of tissue oxygen and blood perfusion level in ulcerated foot. Longitudinal study revealed a slightly higher mean StO ₂ and τ level in healed ulcer than in impaired healing, despite the data indicating no statistical significance between these two groups (p - value > 0.05). It was observed that a mean StO ₂ of at least 70 % and τ value of 1.5 (×10 ³ ) are necessary during the proliferative phase to ensure progressive healing. Based on these findings, this study concluded that high tissue oxygenation and perfusion levels are pivotal to ensure progressive wound healing. This work provides a rationale for evaluating the healing outcomes of skin grafting procedures in diabetic ulcers based on observation of quantitative changes in blood perfusion and tissue oxygen level during its revascularization phase.