Assist-Knee: Energy Harvesting for Sit-to-Stand-to-Sit Transitions

项目摘要 该SBIR第二阶段项目将创建和评估一种新型低技术能量收集膝关节假体，或 辅助膝关节假体，能够更有效地帮助经股动脉肢体缺失的老年人 并且安全地执行从坐到站到坐的转换。从坐姿到站姿的转变 对于经股动脉肢体缺失的个体，尤其是老年人群， 膝盖和脚踝肌肉组织下降或缺失。当从椅子上站起来时，这些人严重依赖于 他们的对侧肢体和上肢力量，以解除他们的体重。老年假肢使用者，他们经常 有边际和下降的力量，可以保持他们的独立性，如果假肢膝关节能够 协助从坐到站再到坐的转换。不幸的是，大多数商业上可获得的现有设计 假肢膝关节不能帮助完成从坐到站再到坐的过渡，而这是正常人的基本任务。 日常生活活动。辅助膝关节的设计收获假肢使用者的潜在能量， 并适当地返回能量以辅助坐到站的转换。而 收集能量，辅助膝关节提供了一个阻力膝关节伸展的时刻，模仿离心收缩 股四头肌的肌肉来控制站到坐。能量的返回提供膝盖伸展，模仿 的股四头肌的同心活动，为辅助坐到站。这一技术创新 设计不需要大型电机、电池或复杂系统来为膝关节伸展提供外部动力 协助。我们的低成本、轻量化设计是外部动力假肢装置的替代品。以来 外部电源未添加到系统中，辅助膝关节预期不会复制最大力矩 膝关节处的输出，但提供有用的膝关节伸展力矩部分，以帮助开始坐姿， 到站的过渡。该项目的具体目标包括：更新和优化辅助膝关节设计 基于我们成功的第一阶段的研究结果，并采用以用户为中心的设计方法， 与利益相关者举行会议，并通过实验室和家庭临床试验验证辅助膝关节的日常使用。 辅助膝关节的成功设计和实施将使老年人的经股动脉肢体 更容易地完成坐到站到坐的转换，通过减少 护理人员辅助，并在站到坐的操作过程中帮助控制使用者的降低。商业 辅助膝关节的应用是一种低成本，轻便的假体替代，以帮助个人经股动脉 在老年人群中，肢体丧失能够独立完成日常生活活动。

PROJECT SUMMARY This SBIR Phase II project will create and evaluate a novel low-tech Energy-Harvesting Knee Prosthesis, or Assist-Knee Prosthesis, capable of helping geriatric individuals with transfemoral limb loss more effectively and safely perform sit-to-stand-to-sit transitions. Transitioning from a sitting to a standing position is much more difficult for an individual with transfemoral limb loss, especially within the geriatric population, due to declining or absent knee and ankle musculature. When rising from a chair, these individuals heavily rely on their contralateral limb and upper limb strength to lift their body weight. Geriatric prosthesis users, who often have marginal and declining strength, could retain their independence if a prosthetic knee was capable of assisting with sit-to-stand-to-sit transitions. Unfortunately, the current designs of most commercially available prosthetic knees do not assist with the sit-to-stand-to-sit transition, a task that is fundamental for normal activities of daily living. The Assist-Knee design harvests the prosthesis user’s potential energy during the stand-to-sit transition and appropriately returns that energy to assist with the sit-to-stand transition. While harvesting energy, Assist-Knee provides a resistive knee extension moment that imitates eccentric contraction of the quadriceps muscles for a controlled stand-to-sit. The return of energy provides knee extension, imitating concentric activity of the quadriceps muscles, for an assisted sit-to-stand. The technological innovation of this design does not require a large motor, battery, or complex system to provide external power for knee extension assist. Our low-cost, lightweight design is an alternative to externally powered prosthetic devices. Since external power is not being added to the system, Assist-Knee is not intended to replicate maximum moment output at the knee but to provide a useful fraction of knee extension moment to assist with initiation of the sit- to-stand transition. The specific aims of this project involve: updating and optimizing the Assist-Knee design based on our successful Phase I findings and with a user-centered design approach that includes biannual meetings with stakeholders, and validating Assist-Knee in daily use with a laboratory and at-home clinical trial. Successful design and implementation of Assist-Knee will enable geriatric individuals with transfemoral limb loss to more easily complete sit-to-stand-to-sit transitions, increase independence by reducing the need for caretaker assistance, and help control the lowering of a user during the stand-to-sit maneuver. The commercial application of Assist-Knee is a low-cost, lightweight prosthetic alternative to assist individuals with transfemoral limb loss within the geriatric population to independently complete activities of daily living.