SBIR Phase I: A SWING-ASSIST KNEE PROSTHESIS FOR INCREASING MOBILITY IN TRANSFEMORAL AMPUTEES

这项小企业创新研究（SBIR）第一阶段项目的更广泛影响和商业潜力是使经股截肢者更安全、更容易行走。在这个人群中，摔倒和害怕摔倒是普遍存在的。经股截肢者跌倒的比率大约是同龄健康个体的200倍，他们因跌倒寻求医疗照顾的比率与住在机构的老年人相同。这种摔倒最常见的原因是在摆动后期缺乏充分的膝关节伸展，同时缺乏膝关节本体感觉，在这种情况下，使用者在加载后不久进入不可恢复的膝关节屈曲状态。这个项目提出了一种膝关节假体，它提供了一个动力，运动控制的膝关节摆动，保证在脚跟撞击之前膝关节完全伸展，因此大大降低了跌倒的可能性。此外，膝关节的动力运动减少了对补偿性运动的需求，因此行走所需的努力也减少了。因此，拟议的膝盖将提供更安全，更轻松的行走，使用户更有信心地行走。根据现行的报销代码，该假体将可报销，并将改善最终用户的行动能力、健康状况和生活质量。这个小型企业创新研究（SBIR）项目提出了一种新型膝关节假体，它结合了一种混合方法来提供膝关节假体的两种主要功能：站立和摆动控制。在这个装置中，姿态控制由一个多中心关节提供，而摆动控制利用一个小型电机辅助。因此，该装置被称为多中心摆动辅助（PSA）膝关节。不同于典型多中心膝关节的被动伸展辅助，摆动辅助马达能够在摆动中期帮助屈曲，在摆动后期帮助伸展。PSA假体旨在在步态的摆动阶段注入少量的力量，以引导膝关节通过摆动轨迹。由于辅助与低扭矩和低功率运动有关，因此与全动力膝关节假体相比，电机、传动装置和电池可以更小、更轻、更安静。本研究的目的是设计、构建和测试PSA膝关节原型。假体原型的功效将与商业膝盖进行比较。研究人员将测试假体是否能更好地模拟健康的运动学，通过结果测量，如脚趾间隙和膝关节弯曲峰值在步行速度。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to make walking both safer and easier for transfemoral amputees. Falling and fear of falling are pervasive in this population. Transfemoral amputees fall at a rate approximately 200 times that of healthy age-matched individuals, and they seek medical attention from falls at the same rate as the institution-living elderly. Such falls result most commonly from a lack of full knee extension in late swing, combined with a lack of knee proprioception, in which case the user enters a non-recoverable knee buckling state shortly after loading. This project proposes a knee prosthesis that provides a powered, motion-controlled knee swing which guarantees full knee extension prior to heel strike, and it therefore substantially reduces the likelihood of a fall. Further, powered knee movement lessens the need for compensatory movements, and therefore the effort required for walking is lessened. As a result, the proposed knee will provide safer and easier walking, enabling users to walk with greater confidence. The prosthesis will be reimbursable under current reimbursement codes and will result in improved mobility, health, and quality of life for end users.This Small Business Innovation Research (SBIR) project proposes a novel knee prosthesis that incorporates a hybrid approach to providing the two major functions of a knee prosthesis: stance and swing control. In this device, stance control is provided by a polycentric joint, while swing control utilizes a small motor for assistance. Consequently, the proposed device is called a polycentric swing-assist (PSA) knee. Unlike a passive extension aid employed in a typical polycentric knee, the swing-assist motor is able to aid both flexion in mid swing and extension in late swing. The PSA prosthesis is intended to inject small amounts of power during the swing phase of gait in order to guide the knee through the swing trajectory. Since the assistance is associated with low-torque and low-power movements, the motor, transmission, and battery can be small, lightweight, and quiet relative to a fully-powered knee prosthesis. The goal of this work is to design, construct, and test a PSA knee prototype. The efficacy of the prosthesis prototype will be compared to a commercial knee. The investigators will test whether or not the prosthesis better emulates healthy kinematics through outcome measures such as toe clearance and peak knee flexion across walking speeds.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.