Gföhler M, Lugner P
Department of Mechanics, Vienna University of Technology, Austria.
IEEE Trans Rehabil Eng. 2000 Jun;8(2):233-43. doi: 10.1109/86.847825.
The goal of this paper was the development of an optimized stimulation pattern of leg muscles that would allow paraplegic subjects to perform the movement of pedaling and thereby to drive a tricycle by means of functional electrical stimulation (FES). To obtain maximum average power output with minimum muscle force, the start, duration and amplitude of the stimulation signal applied to the individual muscles had to be optimized depending on the pedaling frequency. For the basic theoretical investigations the rider-tricycle system was modeled as a rigid body system on which the muscle forces are applied as joint moments. The muscles gluteus maximus, rectus femoris, vastii, and hamstrings were stimulated and the passive forces of some other muscles were considered. The modeling and simulation approach was then used to produce maximum power pedaling and steady-state pedaling at 35 rpm. Hamstrings (41.9%) and vastii (35.8%) were the primary contributors to the optimization cost function of maximum power with minimum muscle loading. Based on these theoretical investigations an efficient stimulation pattern could be provided, taking into account the realistic possibilities of today's practical applications.
本文的目标是开发一种优化的腿部肌肉刺激模式，使截瘫患者能够通过功能性电刺激（FES）进行蹬踏动作，从而驱动三轮车。为了以最小的肌肉力量获得最大的平均功率输出，必须根据蹬踏频率优化施加于各个肌肉的刺激信号的起始、持续时间和幅度。对于基础理论研究，将骑手-三轮车系统建模为一个刚体系统，肌肉力量作为关节力矩施加于其上。刺激了臀大肌、股直肌、股四头肌和腘绳肌，并考虑了其他一些肌肉的被动力。然后，使用建模和仿真方法在35转/分钟的转速下实现最大功率蹬踏和稳态蹬踏。在最小肌肉负荷下，腘绳肌（41.9%）和股四头肌（35.8%）是最大功率优化成本函数的主要贡献者。基于这些理论研究，可以提供一种高效的刺激模式，同时考虑到当今实际应用的现实可能性。
