Development of Prosthetic Foot with Controlled Energy Storage and Release

描述（由申请人提供）：该项目的长期目标是开发一种智能假肢脚，以减少截肢者行走的能量消耗。商业假肢使用被动机制，以提供关节，缓冲脚跟的冲击，和弹性能量返回，但截肢者行走的能量成本很高。目前最复杂的假肢是智能膝盖，它通过主动控制膝盖的制动来改善步态。根据最近的实验室结果，我们提出，控制能量储存和释放可以显着提高假肢脚的效率。这种脚在脚撞击地面之后将存储弹性能量，如在当前产品中那样。但是主动控制不是自发地返回能量，而是用闩锁机制捕获能量，并在步态周期的后期释放能量，与健全行走的推离阶段相一致。所提出的机制将是微处理器控制的，并将需要电池电源主要是致动闩锁，而不是主动电源步态。这种低功率需求意味着假肢将能够使用轻质电池一次运行数小时。该项目的第二阶段将开发原型假肢，并通过实验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，它具有比传统设计更大的能量返回和舒适性，并且具有紧凑和轻便的包装。拟议的研究有三个具体目标：设计和制造，对健全受试者进行测试，以及对经胫骨（膝盖以下）截肢者进行测试。（1.）设计部分包括开发一种轻便紧凑的计算机控制机制，用于控制并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。健全受试者将用于监测原型器械、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中测试该器械。我们将为受试者提供原型设备的长期贷款，以便他们能够练习行走并熟悉它。然后，我们将比较他们使用自己的假肢、使用高性能传统假肢以及使用原型设备行走时的能量需求。我们将测试受控能量存储是否减少了步行的代谢需求，这是该设备功效的客观衡量标准。相关性：这项研究解决了使用假脚的下肢截肢者活动能力降低的公共卫生问题。这些截肢者行走速度较低，能量消耗高，距离和舒适度低于健全的人。所提出的受控能量存储假足旨在在这些方面的移动性提供可测量的改进。该项目旨在减少下肢截肢者行走时的能量需求，因为对他们来说，带着假肢行走比身体健全的人更疲劳。该项目将开发一种假脚，能够有效地储存通常在传统假肢中消耗的能量，然后将该能量返回到动力行走中，以减少截肢者行走的努力。

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.