Development of Adaptive Prosthetic Ankle-Foot Systems

自适应假肢踝足系统的开发

• 批准号: 9172622
• 负责人: Andrew H. Hansen
• 金额: --
• 依托单位: MINNEAPOLIS VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9172622
• 关键词: Address; Amputation; Ankle; Area; Cells; Communities; Conflict (Psychology); Coupled; Development; Devices; Diabetes Mellitus; Equilibrium; Failure; Financial compensation; Funding; Goals; Heel; Injury; International; Lead; Limb Prosthesis; Lower Extremity; Measurement; Measures; Mechanics; Motion; Motor; Nature; Oxygen; Persons; Phase; Process; Prosthesis; Protocols documentation; Ramp; Recruitment Activity; Research; Rest; Series; Speed; Structure; Surface; System; Technology; Technology Transfer; Testing; Toes; Torque; Traumatic injury; Vascular Diseases; Veterans; Visit; Walking; active control; combat; commercialization; design; foot; improved; instrument; limb amputation; novel; prosthesis wearer; prosthetic foot; prototype; public health relevance; research and development; research study; response; treadmill; uptake; walking speed

DESCRIPTION (provided by applicant): Many Veterans have lower-limb amputations due to traumatic injuries or complications associated with diabetes and vascular disease. Walking on uneven terrain is unbalanced and uncomfortable for persons with lower-limb amputations because most current ankle-foot prostheses do not adapt their function for different sloped surfaces. This project will examine the advantages of a new adaptable ankle-foot prosthesis that can adapt to different terrain on every step of walking using only passive mechanical parts (i.e., without the need for motors or batteries). This new system also provides plantarflexion in the late stance phase of walking, which should increase the efficiency of walking. To examine the potential benefits of the new adaptable ankle-foot system, twenty Veterans with unilateral transtibial amputations will be recruited for the study. During the first visit, the prosthetic ankle torque versus ankle angle curves will be measured while the Veterans walk on a treadmill at five surface slopes (-10, -5, 0, +5, and +10 degrees). Subjects will also walk up and over a series of ramps to examine first-step adaptation to surface slopes. A load cell in the prosthesis coupled with motion analysis will allow for the measurement of ankle torque vs. ankle angle as the Veterans walk on the various sloped surfaces. It is anticipated that the ankle torque versus ankle angle curves will shift towar dorsiflexion for uphill slopes and toward plantarflexion for downhill slopes when using the adaptable ankle-foot system. These shifts in the ankle torque vs. ankle angle curve are not expected for similar use of a non-adaptable ankle-foot system (Ossur VariFlex with EVO). In the second and third visits, the same Veterans will walk with both the adaptable and non-adaptable ankle- foot prostheses over a range of speeds and surface slopes while their submaximal oxygen uptake is measured. For each condition (prosthesis/speed or prosthesis/slope), subjects will walk for six minutes on a treadmill, followed by at least ten minutes of rest (or longer if needed to return to baseline oxygen uptake). During the second visit, subjects will walk at three speeds (0.75, 1.00, and 1.25 m/s) with both the adaptable and non-adaptable ankle-foot systems (in a random order). During the third visit, subjects will walk with both ankle-foot systems on three slopes (-5, 0, and +5 degrees) in a random order. The adaptable ankle-foot system is expected to reduce submaximal oxygen uptake compared with the non-adaptable ankle-foot system for both speeds and slopes due to its ability to store and release more energy than current passive non- adaptable ankle-foot systems and its ability to adapt its function on every step to changes in surface slope. Durability testing of the adaptable ankle-foot system will be conducted in parallel with research experiments. The adaptable ankle-foot system will be tested using the International Organization of Standards (ISO) 22675 testing protocol. Design revisions will occur throughout the funding period to improve the durability of the adaptable ankle-foot system. The goal of the development activities is to pass the ISO 22675 test of 2,000,000 cycles of testing without failure. The research and development activities planned for the new adaptable ankle-foot system are designed to provide evidence of the system's ability to adapt to different surface slopes on every step of walking as well as to increase walking efficiency. These activities will provide useful information regarding the design approach used by the current system, while improving the chances for commercialization of the technology for Veterans.

描述（由申请人提供）： 许多退伍军人由于外伤或与糖尿病和血管疾病相关的并发症而接受下肢截肢。对于下肢截肢的人来说，在不平坦的地形上行走是不平衡和不舒服的，因为大多数当前的踝足假肢不能适应不同倾斜表面的功能。该项目将审查 新型适应性踝足假肢的优点是，仅使用被动机械部件（即不需要电机或电池）即可适应步行每一步的不同地形。这个新系统还在行走的后期站立阶段提供跖屈，这应该会提高行走的效率。为了研究新的适应性踝足系统的潜在好处，将招募 20 名单侧经胫骨截肢的退伍军人参加这项研究。在第一次访问期间，将测量退伍军人在跑步机上以五个表面坡度（-10、-5、0、+5 和 +10 度）行走时的假肢踝关节扭矩与踝关节角度曲线。受试者还将走上并越过一系列坡道，以检查对表面斜坡的第一步适应。假肢中的测力传感器与运动分析相结合，可以测量退伍军人在各种倾斜表面上行走时的踝关节扭矩与踝关节角度。预计当使用适应性踝足系统时，踝扭矩对踝角度的曲线将转向上坡的背屈和下坡的跖屈。对于非适应性踝足系统（Ossur VariFlex with EVO）的类似使用，预计踝关节扭矩与踝关节角度曲线的这些变化不会发生。在第二次和第三次访问中，同样的退伍军人将佩戴适应性和非适应性踝足假肢以一定的速度和表面坡度行走，同时测量他们的次最大摄氧量。对于每种情况（假肢/速度或假肢/坡度），受试者将在跑步机上行走六分钟，然后至少休息十分钟（如果需要返回基线摄氧量，则休息更长时间）。在第二次访问期间，受试者将使用适应性和非适应性踝足系统以三种速度（0.75、1.00 和 1.25 m/s）行走（按随机顺序）。在第三次访问期间，受试者将使用两个踝足系统以随机顺序在三个斜坡（-5、0 和 +5 度）上行走。与非适应性踝足系统相比，适应性踝足系统有望在速度和坡度方面减少次最大摄氧量，因为它能够比当前被动非适应性踝足系统存储和释放更多能量，并且能够在每一步上调整其功能以适应表面坡度的变化。适应性踝足系统的耐久性测试将与研究实验同时进行。适应性踝足系统将使用国际标准组织 (ISO) 22675 测试协议进行测试。在整个资助期间将进行设计修改，以提高适应性踝足系统的耐用性。开发活动的目标是通过 ISO 22675 2,000,000 次测试周期且无故障。为新型适应性踝足系统计划的研发活动旨在提供证据，证明该系统能够适应步行每一步的不同表面坡度以及提高步行效率。这些活动将提供有关当前系统所使用的设计方法的有用信息，同时提高退伍军人技术商业化的机会。