INTERFACE MECHANICS, MATERIALS AND TISSUE RESPONSE

描述(申请人提供)：本申请的广泛、长期目标是开发预测和治疗日常和长期残馀肢体形状变化的方法，以减少下肢截肢患者皮肤破裂的发生。研究的具体目的是评估截肢受试者在不同的插座改装治疗下的界面应力稳定性，这些治疗旨在克服形状改变引起的适合性问题。另一个目的是更好地了解昼夜和长期形状变化的来源，并将它们与残馀肢体液体运输和其他可在临床评估中评估的患者组织特征相关联。为了满足AIMS在可控体积下的充液单元的要求，在软组织丢失的部位使用均匀厚度的插件和固定在插座内侧的材料贴片，与现有的界面压力和剪应力测量系统以及定制的高分辨率残肢扫描仪一起使用。确定了尽管残肢形状发生变化，但处理组在每天和12个月的时间间隔内保持界面应力一致的能力，并与不处理组进行了比较。预计对于昼夜波动：充液细胞的表现优于其他处理；保持界面应力一致的最佳细胞液体体积与残馀肢体体积损失相匹配；使用液体细胞在插口中的肢体远端运动与初始配合时相同。对于长期的变化，预计需要粘贴到插座内侧的局部材料补丁和充满流体的单元来稳定界面应力。为了更好地了解残肢形状改变的生理来源，对一组经胫骨截肢的受试者进行了残肢细胞外水分含量、液体转运和组织含量的测量。预计白天的收缩反映了一天中细胞外水分的缓慢损失。然而，长期的收缩预计将反映肌肉组织含量的减少。该项目与健康有关的是改善截肢者的生活质量。预测和克服残肢形状变化的有害影响并最终防止软组织破坏的方法的发展将有助于预防截肢者群体中的继发性残疾和发病率。

DESCRIPTION (provided by applicant): The broad, long-term objectives of this application are to develop methods to predict and treat diurnal and long-term residual limb shape changes to reduce the occurrence of skin breakdown in persons with lower-limb amputation. The specific aims are to assess interface-stress stability in trans-tibial amputee subjects under different socket-modification treatments designed to overcome fit problems induced by shape changes. A further aim is to better understand the sources of diurnal and long-term shape changes and to correlate them with residual limb fluid transport and other patient tissue characteristics that can be assessed in clinical evaluation. To address the aims fluid-filled cells at controlled volumes, a uniform-thickness insert, and material patches affixed to the inside of the socket at locations of soft-tissue loss are used with an existing interface pressure and shear stress measurement system and a custom, high-resolution, residual-limb scanner. The capabilities of the treatments to keep interface stresses consistent over both diurnal and 12-mo intervals, despite changes in residual limb shape, are determined and compared with no treatment. It is expected that for diurnal fluctuations: the fluid-filled cells perform better than the other treatments; the optimal cell fluid volume to keep interface stresses consistent matches the residual limb volume loss; and using the fluid cells distal limb movement in the socket is identical to that of the initial fit. For long-term changes, it is expected that both local material patches affixed to the inside of the socket and the fluid-filled cells are needed to stabilize interface stresses. To better understand the physiologic sources of residual limb shape change, residual limb extracellular water content, fluid transport, and tissue content are measured on a population of trans-tibial amputee subjects. It is expected that diurnal shrinkage reflects a slow loss of extracellular water over the course of the day. Long-term shrinkage, however, is expected to reflect a reduction in muscle tissue content. The health relatedness of this project is improvement in the quality of life of persons with amputated limbs. The development of methods to predict and overcome the detrimental effects of residual limb shape change and ultimately prevent soft-tissue breakdown will help to prevent secondary disability and morbidity in the amputee population.