Chen Yixi, Li Xinwei, Su Hao, Zhang Dingguo, Yu Hongliu
School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China.
Shanghai Engineering Research Center of Assistive Devices, Shanghai, China.
Front Neurorobot. 2022 May 9;16:791169. doi: 10.3389/fnbot.2022.791169. eCollection 2022.
Inter-leg coordination is of great importance to guarantee the safety of the prostheses wearers, especially for the subjects at high amputation levels. The mainstream of current controllers for lower-limb prostheses is based on the next motion state estimation by the past motion signals at the prosthetic side, which lacks immediate responses and increases falling risks. A bio-inspired gait pattern generation architecture was proposed to provide a possible solution to the bilateral coordination issue. The artificial movement pattern generator (MPG) based on the temporal convolution network, fusing with the motion intention decoded from the surface electromyography (sEMG) measured at the impaired leg and the motion status from the kinematic modality of the prosthetic leg, can predict four sub gait phases. Experiment results suggested that the gait phase decoder exhibited a relatively high intra-subject consistency in the gait phase inference, adapted to various walking speeds with mean decoding accuracy ranging from 89.27 to 91.16% across subjects, and achieved an accuracy of 90.30% in estimating the gait phase of the prosthetic leg in the hip disarticulation amputee at the self-selected pace. With the proof of concept and the offline experiment results, the proposed architecture improves the walking coordination with prostheses for the amputees at hip level amputation.
双腿协调对于确保假肢佩戴者的安全非常重要,尤其是对于高位截肢者。当前下肢假肢控制器的主流方法是基于假肢侧过去的运动信号来估计下一个运动状态,这种方法缺乏即时响应,增加了跌倒风险。提出了一种受生物启发的步态模式生成架构,为双边协调问题提供了一种可能的解决方案。基于时间卷积网络的人工运动模式生成器(MPG),融合从残肢测量的表面肌电图(sEMG)解码的运动意图和假肢腿运动学模态的运动状态,可以预测四个子步态阶段。实验结果表明,步态阶段解码器在步态阶段推断中表现出相对较高的受试者内一致性,适用于各种步行速度,受试者的平均解码准确率在89.27%至91.16%之间,并且在自选步速下估计髋关节离断截肢者假肢腿的步态阶段时准确率达到90.30%。通过概念验证和离线实验结果,所提出的架构改善了髋关节截肢者与假肢的行走协调性。