Development of Prosthetic Foot with Controlled Energy Storage and Release

描述(申请人提供)：该项目的长期目标是开发一种智能假肢，减少截肢者行走的能量消耗。商业假体使用被动机制来提供关节、缓冲脚跟撞击和弹性能量回馈；然而，截肢者行走的能量成本很高。目前最先进的假体是智能膝盖，它通过主动控制膝盖的刹车来改善步态。根据最新的实验室结果，我们认为受控的能量储存和释放可以显著提高假肢的效率。就像目前的产品一样，这样的脚在落地后会储存弹性能量。但是，主动控制不是自发地恢复能量，而是通过闩锁机制捕捉能量，并在步态周期的晚些时候释放它，这与健全行走的推出阶段不谋而合。拟议的机制将是微处理器控制的，需要电池供电主要是为了启动锁扣，而不是主动为步态供电。这种低电力需求意味着，该假体将能够使用轻型电池一次运行数小时。该项目的第二阶段将开发一个原型假体，并从实验上测试智能控制能量释放的概念可行性。我们打算将这一概念发展成一种商业假体，在紧凑和轻便的包装中，比传统设计具有更大的能量回报和舒适性。这项拟议的研究有三个具体目标：设计和制造、对健全受试者的测试以及对胫骨(膝盖以下)截肢者的测试。(1.)设计部分包括开发一种轻便紧凑的计算机控制机构，用于控制机械能，然后将机械能返回给用户。(2)我们将在身体健全的受试者身上测试该设备，以比较他们在行走过程中消耗的代谢能量。身体健全的受试者将被用来监测原型装置、传统假肢和健全行走之间的差异。(3)我们还将在经胫骨截肢者的目标人群上测试该设备。我们将为受试者提供该原型装置的长期借阅，让他们练习行走并熟悉它。然后，我们将比较他们在使用自己的假肢行走时的能量需求，与高性能的传统假肢，以及与原型装置。我们将测试受控的能量储存是否会降低步行的代谢需求，这是该设备有效性的客观衡量标准。相关性：这项研究解决了使用假肢的截肢者活动能力降低的公共卫生问题。这些截肢者的行走速度较慢，能源成本较高，与健全的人相比，其行走范围和舒适度都较低。拟议的受控储能假肢的目的是在这些方面提供可测量的移动性改善。该项目旨在减少截肢者行走的能量需求，因为对于截肢者来说，戴假肢行走比健全的人更疲惫。该项目将开发一种假肢，能够有效地储存传统假肢中通常会耗散的能量，然后将这些能量转化为行走的动力，以减少截肢者行走的工作量。

DESCRIPTION (provided by applicant): The long-term goal of this project is to develop an intelligent prosthetic foot that reduces the energy consumption of walking in amputees. Commercial prostheses use passive mechanisms to provide articulation, cushioning against heel impact, and elastic energy return; yet the energetic cost of amputee walking is high. Currently the most sophisticated prostheses are intelligent knees, which improve gait by actively controlling braking of the knee. Based on recent laboratory results, we propose that controlled energy storage and release could significantly improve the efficiency of a prosthetic foot. Such a foot would store elastic energy after the foot strikes the ground, as in current products. But instead of returning energy spontaneously, active control would capture that energy with a latch mechanism, and release it later in the gait cycle, coinciding with the push-off phase of able-bodied walking. The proposed mechanism will be microprocessor-controlled, and will require battery power mainly to actuate a latch rather than to actively power gait. This low power demand means that the prosthesis will be able to operate for hours at a time using lightweight batteries. Phase II of this project will develop a prototype prosthesis, and experimentally test the conceptual feasibility of intelligently controlled energy release. We intend to develop this concept into a commercial prosthesis with greater energy return and comfort than conventional designs, in a compact and lightweight package. The proposed research has three Specific Aims: design and fabrication, testing on able-bodied subjects, and testing on transtibial (below-knee) amputees. (1.) The design component consists of developing a lightweight and compact, computer-controlled mechanism for controlling and then returning mechanical energy to the user. (2.) We will test the device on able-bodied subjects, to compare the metabolic energy that they expend during walking. Able-bodied subjects will be used to monitor the differences between the prototype device, conventional prostheses, and able-bodied walking. (3.) We will also test the device on the target population of transtibial amputees. We will provide subjects with long-term loans of the prototype device so that they can practice walking and become familiar with it. We will then compare their energy demand when walking on their own prosthesis, with a high performance conventional prosthesis, and with the prototype device. We will test whether controlled energy storage reduces the metabolic demand for walking, which serves as an objective measure of the device's efficacy. Relevance: This research addresses the public health problem of reduced mobility in lower-limb amputees using prosthetic feet. These amputees walk at lower speed, high energy cost, and with lower range and comfort than able-bodied individuals. The proposed controlled energy storage prosthetic foot is intended to provide measurable improvements in these aspects of mobility. This project seeks to reduce the energetic demand of walking in lower limb amputees, for whom walking with a prosthesis is more fatiguing than for able-bodied persons. The project will develop a prosthetic foot with an ability to efficiently store energy that is normally dissipated in conventional prostheses, and then to return that energy to power walking, in order to reduce the effort of walking for amputees.