Computational Design, Fabrication, and Evaluation of Optimized Patient-Specific Transtibial Prosthetic Sockets

摘要 标题：优化患者专用经胫骨假体窝的计算设计、制造和评价 首席研究员：Hugh Herr博士 背景：本申请的总体目标是进一步开发和临床评估一种计算和数据驱动的 用于定量生产经胫骨假体接受腔的机械接口的设计和制造框架 比传统方法更快和更经济的方法。传统上，假肢接受腔的生产 手工艺活动，主要基于修复师的经验。即使计算机辅助设计和 计算机辅助制造（CAD/CAM），设计过程仍然是手动的。该过程的手动性质意味着 它是不可重复的，目前主要是非数据驱动的，定量数据要么得不到，要么得不到 就业。此外，不适、皮肤问题和压力性溃疡形成仍然普遍。通过拟议的 计算建模框架，使得可重复的、数据驱动的和患者特异性的设计过程可用， 是基于科学原理的 目的/假设：该提案的主要假设是，使用新颖的计算设计设计的插座 框架，在以下方面等同于或优于传统的承窝（由修复师设计）：1）皮肤接触 压力，2）步态对称性，3）步行代谢成本，4）皮肤科医生评估的皮肤刺激水平，以及5） 从问卷调查中评估的舒适度。我们的假设得到了现有试点数据的支持，这些数据显示， 几个关键解剖区域的等效皮肤接触压力和受试者报告的舒适度水平。 具体目的：1）针对N=18名受试者的受试者特定生物力学建模，2） N=18例受试者的窝，以及3）N=18例受试者的新型窝的临床评价。 研究设计：本研究将招募18例受试者队列。将记录所有受试者的MRI数据。通过 图像分割将构建几何精确的3D有限元分析（FEA）模型。此外，非- 将进行侵入性压痕测试，通过与反向有限元分析相结合，提供准确的主题- 所有受试者的特定机械性能。由此产生的预测有限元分析模型，然后将用于一个新的，数据- 驱动和自动计算设计框架的假肢接受腔，设计假肢接受腔的所有科目。 通过皮肤接触压力和内部组织应变评估，该框架优化了插座设计， 虚拟测试套接字的迭代调整。最终设计随后进行3D打印。评估假肢接受腔 对于每个受试者，每个受试者将使用他们的传统插座或新颖的插座进行站立和行走锻炼。 插座同时记录皮肤接触力、步行代谢成本和步态对称性。运动后，皮肤 皮肤科医生将评估刺激性，并使用问卷调查评估插座舒适性。这些数据 提供了一个定量和定性的评价和比较的新型和传统的插座。

Abstract Title: Computational Design, Fabrication, and Evaluation of Optimized Patient-Specific Transtibial Prosthetic Sockets Principle investigator: Dr. Hugh Herr Background: The overall goal of this application is to further develop and clinically assess a computational and data-driven design and manufacturing framework for mechanical interfaces that quantitatively produces transtibial prosthetic sockets in a faster and more cost-effective way than conventional processes. Traditionally, prosthetic socket production has been a craft activity, based primarily on the experience of the prosthetist. Even with advances in computer-aided design and computer-aided manufacturing (CAD/CAM), the design process remains manual. The manual nature of the process means it is non-repeatable and currently largely non-data-driven, and quantitative data is either not obtained or insufficiently employed. Furthermore, discomfort, skin problems and pressure ulcer formation remain prevalent. Through the proposed computational modeling framework, a repeatable, data-driven and patient-specific design process is made available which is based on scientific rationale. Objective/hypothesis: The main hypothesis of this proposal is that a socket, designed using the novel computational design framework, is equivalent to, or better than, a conventional socket (designed by a prosthetist) in terms of: 1) skin contact pressures, 2) gait symmetry, 3) walking metabolic cost, 4) skin irritation levels as assessed by the dermatologist, and 5) comfort as evaluated from a questionnaire. Our hypothesis is supported by the presented pilot data which shows reduced or equivalent skin contact pressures and subject reported comfort levels for several critical anatomical regions. Specific Aims: 1) Subject-specific biomechanical modeling for N=18 subjects, 2) Computational design and fabrication of sockets for N=18 subjects, and 3) Clinical evaluation of novel sockets for N=18 subjects. Study Design: A cohort of 18 subjects will be recruited for this study. MRI data will be recorded for all subjects. Through image segmentation geometrically accurate 3D finite element analysis (FEA) models will be constructed. Further, non- invasive indentation testing will be performed which, through combination with inverse FEA, provides accurate subject- specific mechanical properties for all subjects. The resulting predictive FEA models will then be used in a novel, data- driven, and automated computational design framework for prosthetic sockets, to design prosthetic sockets for all subjects. The framework optimizes the socket designs, as assessed by skin contact pressures and internal tissue strain, through iterative adjustment of the virtual tests sockets. Final designs are subsequently 3D printed. To evaluate the prosthetic sockets with each of the subjects each subject will do a standing and walking exercise using their conventional sockets or the novel sockets. Meanwhile skin contact forces, walking metabolic cost, and gait symmetry are recorded. After the exercises, skin irritation will be assessed by a dermatologist, and socket comfort is assessed using a questionnaire. Together this data provides a quantitative and qualitative evaluation and comparison of the novel and conventional sockets.