Yudovsky Dmitry, Nouvong Aksone, Pilon Laurent
Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, CA, USA.
J Diabetes Sci Technol. 2010 Sep 1;4(5):1099-113. doi: 10.1177/193229681000400508.
Diabetic foot ulceration is a major complication of diabetes and afflicts as many as 15 to 25% of type 1 and 2 diabetes patients during their lifetime. If untreated, diabetic foot ulcers may become infected and require total or partial amputation of the affected limb. Early identification of tissue at risk of ulcerating could enable proper preventive care, thereby reducing the incidence of foot ulceration. Furthermore, noninvasive assessment of tissue viability around already formed ulcers could inform the diabetes caregiver about the severity of the wound and help assess the need for amputation. This article reviews how hyperspectral imaging between 450 and 700 nm can be used to assess the risk of diabetic foot ulcer development and to predict the likelihood of healing noninvasively. Two methods are described to analyze the in vivo hyperspectral measurements. The first method is based on the modified Beer-Lambert law and produces a map of oxyhemoglobin and deoxyhemoglobin concentrations in the dermis of the foot. The second is based on a two-layer optical model of skin and can retrieve not only oxyhemoglobin and deoxyhemoglobin concentrations but also epidermal thickness and melanin concentration along with skin scattering properties. It can detect changes in the diabetic foot and help predict and understand ulceration mechanisms.
糖尿病足溃疡是糖尿病的一种主要并发症，在1型和2型糖尿病患者的一生中，有多达15%至25%的人会受到影响。如果不进行治疗，糖尿病足溃疡可能会感染，需要对受影响的肢体进行全部或部分截肢。早期识别有溃疡风险的组织可以进行适当的预防护理，从而降低足溃疡的发生率。此外，对已形成溃疡周围组织活力的无创评估可以让糖尿病护理人员了解伤口的严重程度，并有助于评估截肢的必要性。本文综述了如何利用450至700纳米之间的高光谱成像来评估糖尿病足溃疡发生的风险，并无创预测愈合的可能性。文中描述了两种分析体内高光谱测量数据的方法。第一种方法基于修正的比尔-朗伯定律，生成足部真皮中氧合血红蛋白和脱氧血红蛋白浓度的图谱。第二种方法基于皮肤的两层光学模型，不仅可以获取氧合血红蛋白和脱氧血红蛋白的浓度，还可以获取表皮厚度和黑色素浓度以及皮肤散射特性。它可以检测糖尿病足的变化，并有助于预测和理解溃疡形成机制。
