Strayer Seth T, Moghaddam Seyed Reza M, Gusenoff Beth, Gusenoff Jeffrey, Beschorner Kurt E
University of Pittsburgh.
University of Pittsburgh Medical Center.
J Appl Biomech. 2020 Jul 31;36(5):326-333. doi: 10.1123/jab.2019-0356. Print 2020 Oct 1.
Pressure offloading is critical to diabetic foot ulcer healing and prevention. A novel product has been proposed to achieve this offloading with an insole that can be easily modified for each user. This insole consists of pressurized bubbles that can be selectively perforated and depressurized to redistribute weight to the nonulcer region of the foot. However, the effect of the insole design parameters, for example, bubble height and stiffness, on offloading effectiveness is unknown. To this end, a 3-dimensional finite element model was developed to simulate contact between the rearfoot and insole. The geometry of the calcaneus bone and soft tissue was based on the medical images of an average male patient, and material properties and loading conditions based on the values reported in the literature were used. The model predicts that increasing bubble height and stiffness leads to a more effectively offloaded region. However, the model also predicts that increasing stiffness leads to increasing contact pressures on the surrounding soft tissue. Thus, a combination of insole design parameters was determined, which completely offloads the desired region, while simultaneously reducing the contact pressure on the surrounding soft tissue. This design is expected to aid in diabetic foot ulcer healing and prevention.
减轻压力对于糖尿病足溃疡的愈合和预防至关重要。已提出一种新型产品，通过一种可为每位用户轻松定制的鞋垫来实现这种压力减轻。这种鞋垫由加压气泡组成，这些气泡可被选择性地打孔并减压，从而将重量重新分配到足部的非溃疡区域。然而，鞋垫设计参数（例如气泡高度和硬度）对减压效果的影响尚不清楚。为此，开发了一个三维有限元模型来模拟后足与鞋垫之间的接触。跟骨和软组织的几何形状基于一名普通男性患者的医学图像，并使用了基于文献报道值的材料特性和加载条件。该模型预测，增加气泡高度和硬度会导致更有效的减压区域。然而，该模型还预测，增加硬度会导致周围软组织上的接触压力增加。因此，确定了一种鞋垫设计参数的组合，该组合可完全减轻所需区域的压力，同时降低周围软组织上的接触压力。这种设计有望有助于糖尿病足溃疡的愈合和预防。
