Powered Knee Prosthesis Incorporating Battery-Capacitor Hybrid

描述（由申请人提供）：目前在美国大约有623,000人下肢截肢，每年有30,000例新的经股动脉截肢。最新的商业产品是一个由电动机驱动的假膝，设计成用户的集成延伸。这样的膝盖可以让使用者更自然地完成爬楼梯或从坐姿站起来等任务，从而减少代偿性运动对关节的伤害。目前的设备需要每年更换一次可充电电池。电池组的成本为几百美元，对于拥有动力膝盖假肢的人来说，这是一笔相当大的成本。拟议中的项目将减少更换电池的需要，从而使动力膝盖假肢对普通大众来说更实惠。假膝需要波动的功率需求来完全模拟人类膝关节的机械行为。目前，电力需求主要由电池来满足。电池是为持续供电而设计的，在恒定的工作条件下运行最好；它们在功率波动时表现不佳，不能有效地处理尖峰高功率需求。Giner, Inc.提出通过设计和演示集成电池/电容器混合电源来优化假肢的电源。电容器虽然能量密度很低，但功率密度却很高。在电池/电容器混合（BCH）中，电容器处理大部分功率尖峰，使电池在更恒定的条件下工作。吉纳公司的方法是将其先进的全固态电容器与可充电锂聚合物电池结合起来，以提供高能量和功率密度。可充电电池和电容器的组合有望在步态周期的特定频率下提供特定的高功率。电池继续满足持续的低功耗要求，而电容器将在每个步态周期内提供100-250ms的峰值功率需求。这种设计将允许电池组在更低和更稳定的电流水平下工作，从而增加其寿命。不需要高浓度的硫酸

DESCRIPTION (provided by applicant): Approximately 623,000 people currently live in the United States with a lower limb amputation, with 30,000 new transfemoral amputations conducted each year. The latest commercial product is a prosthetic knee powered by an electric motor designed to function as an integrated extension of its user. Such a knee allows users to more naturally perform tasks such as climbing stairs or rising from a seated position and thereby reduce joint damage caused by compensatory movements. Current devices require replacing the rechargeable battery once a year. The battery pack costs several hundred dollars and represents a considerable cost for owners of powered-knee prosthetics. The proposed project will reduce the need for battery replacement, thereby making powered-knee prosthetics more affordable to the general public. The prosthetic knee requires fluctuating power requirements to fully emulate the mechanical behavior of the human knee joint. Currently, the power requirements are met primarily using a battery. Batteries are designed for continuous energy supply and are best operated at constant operating conditions; they perform poorly in the presence of power fluctuations and cannot efficiently handle spike high power demands. Giner, Inc. proposes to optimize power supplies for prostheses by designing and demonstrating an integrated battery/capacitor hybrid power source. Capacitors, while having very low energy densities, have very high power densities. In a battery/capacitor hybrid (BCH), the capacitor handles most of the power spikes, allowing the battery to function under more constant conditions. Giner Inc.'s approach will be to incorporate its advanced all-solid capacitor with rechargeable lithium-polymer batteries to provide high energy and power densities. The combination of rechargeable batteries and capacitors is anticipated to offer specific high power under certain frequency during gait cycles. The battery continues to meet ongoing low-power requirements while the capacitor will provide peak power needs for 100-250ms during each gait cycle. This design will allow the battery pack to work under much lower and steadier current level, thereby increasing its lifetime. High- concentration sulfuric acid is not required as in the case of typical electrolytic capacitors, thereby eliminating the need for hermetic packaging. Phase I will include: (1) battery testing; (2) computer modeling of potential BCH power supplies; (3) design, fabrication, and testing of capacitor units; (4) electronic investigation of BCH power supplies; and (5) comparisons with commercial battery packs. PUBLIC HEALTH RELEVANCE: The rechargeable batteries in electric motor-powered prosthetic limbs need replacement on a yearly basis. The proposed project will reduce the need for expensive battery replacement by using a battery/capacitor hybrid (BCH) which will allow the battery pack to work under much lower and steadier current level, thereby increasing its lifetime, and making powered-knee prosthetics more affordable to the general public.