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

摘要 优化患者专用经胫骨假体插槽的计算设计、制造和评估 首席调查员：休·赫尔博士 背景：此应用程序的总体目标是进一步开发和临床评估计算和数据驱动的 用于定量生产经胫骨假体插座的机械接口的设计和制造框架 一种比传统工艺更快、更具成本效益的方法。传统上，假肢插座的生产一直是一种 手工艺活动，主要基于修复师的经验。即使在计算机辅助设计和 计算机辅助制造(CAD/CAM)，设计过程仍然是手工的。这一过程的手动性质意味着 它是不可重复的，目前在很大程度上不是由数据驱动的，量化数据要么得不到，要么不够 受雇的。此外，不适、皮肤问题和压疮形成仍然很普遍。通过建议的 计算建模框架，提供了可重复的、数据驱动的和特定于患者的设计过程， 是有科学依据的。 目标/假设：该建议的主要假设是使用新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插座(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程度，以及5) 舒适度通过问卷调查进行评估。我们的假设得到了提供的试点数据的支持，这些数据显示 相当的皮肤接触压力和受试者报告的几个关键解剖区域的舒适度。 具体目标：1)N=18个受试者的特定于受试者的生物力学建模，2)计算设计和制造 N=18个受试者的牙槽，以及3)N=18个受试者的新型牙槽的临床评价。 研究设计：本研究共招募18名受试者。所有受试者的MRI数据都将被记录下来。穿过 图像分割将构建几何精确的三维有限元分析(FEA)模型。此外，非 将进行侵入性压痕测试，通过与逆向有限元分析相结合，提供准确的对象- 所有受试者的特定机械性能。由此产生的预测性有限元模型将被用于一种新的数据-- 驱动的，自动化的假体插座计算设计框架，为所有受试者设计假体插座。 该框架优化了插座设计，通过皮肤接触压力和内部组织应变进行评估 对虚拟测试套接字进行迭代调整。最终的设计随后被3D打印。对假体插座的评价 每个受试者都要用他们的传统插座或小说做站立和行走练习 插座。同时记录皮肤接触力、步行代谢成本和步态对称性。运动结束后，皮肤 刺激性将由皮肤科医生评估，插座舒适性将通过问卷调查进行评估。将这些数据放在一起 对新型插座和传统插座进行了定量和定性的评估和比较。

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.