Delaying Ambulation Mode Transition Decisions Improves Accuracy of a Flexible Control System for Powered Knee-Ankle Prosthesis.
Delaying Ambulation Mode Transition Decisions Improves Accuracy of a Flexible Control System for Powered Knee-Ankle Prosthesis.
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DOI：
10.1109/tnsre.2016.2613020
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发表时间：
2017-08
期刊：
影响因子：
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通讯作者：
Hargrove LJ
中科院分区：
文献类型：
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作者：
Simon AM;Ingraham KA;Spanias JA;Young AJ;Finucane SB;Halsne EG;Hargrove LJ
动力下肢假肢可以通过提供膝关节和/或踝关节动力来在各种截肢模式中辅助使用者。这项研究的目标是开发一种灵活的控制系统，使用户能够以自然，准确和可靠的方式执行各种任务。6名经股截肢者使用动力膝踝关节假体上/下坡道，爬3级和4级楼梯，进行步行和站立过渡到楼梯和从楼梯，并以不同的速度走动。开发了一种特定于模式的分类架构，以允许在四个离散步态事件的无缝过渡。假体模式转换（即，假体的机械响应）延迟了90 ms。总体而言，用户不受此小延迟的影响。离线分类结果表明，与非延迟系统相比，延迟系统的错误率显著降低（p<0.001）。对于非延迟系统和延迟系统，所有足跟接触决策的平均错误率分别为1.65% [0.99%]和0.43% [0.23%]。对于非延迟系统和延迟系统，所有脚趾离地决策的平均错误率分别为0.47% [0.16%]和0.13% [0.05%]。结果是令人鼓舞的，并提供了一个临床上可行的意图识别系统的动力膝踝关节假体的另一个步骤。
Powered lower limb prostheses can assist users in a variety of ambulation modes by providing knee and/or ankle joint power. This study's goal was to develop a flexible control system to allow users to perform a variety of tasks in a natural, accurate, and reliable way. Six transfemoral amputees used a powered knee-ankle prosthesis to ascend/descend a ramp, climb a 3- and 4-step staircase, perform walking and standing transitions to and from the staircase, and ambulate at various speeds. A mode-specific classification architecture was developed to allow seamless transitions at four discrete gait events. Prosthesis mode transitions (i.e., the prosthesis' mechanical response) were delayed by 90 ms. Overall, users were not affected by this small delay. Offline classification results demonstrate significantly reduced error rates with the delayed system compared to the non-delayed system (p<0.001). The average error rate for all heel contact decisions was 1.65% [0.99%] for the non-delayed system and 0.43% [0.23%] for the delayed system. The average error rate for all toe off decisions was 0.47% [0.16%] for the non-delayed system and 0.13% [0.05%] for the delayed system. The results are encouraging and provide another step towards a clinically viable intent recognition system for a powered knee-ankle prosthesis.