Closed-loop neuroprostheses show promise in restoring motion in individuals with neurological conditions. However, conventional activation strategies based on functional electrical stimulation (FES) fail to accurately modulate muscle force and exhibit rapid fatigue because of their unphysiological recruitment mechanism. Here, we present a closed-loop control framework that leverages physiological force modulation under functional optogenetic stimulation (FOS) to enable high-fidelity muscle control for extended periods of time (>60 minutes) in vivo. We first uncovered the force modulation characteristic of FOS, showing more physiological recruitment and significantly higher modulation ranges (>320%) compared with FES. Second, we developed a neuromuscular model that accurately describes the highly nonlinear dynamics of optogenetically stimulated muscle. Third, on the basis of the optogenetic model, we demonstrated real-time control of muscle force with improved performance and fatigue resistance compared with FES. This work lays the foundation for fatigue-resistant neuroprostheses and optogenetically controlled biohybrid robots with high-fidelity force modulation.

中文翻译：

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闭环光遗传学神经调节可实现高保真抗疲劳肌肉控制


闭环神经假体有望恢复神经系统疾病患者的运动能力。然而，基于功能性电刺激（FES）的传统激活策略由于其非生理性募集机制而无法准确调节肌肉力量并表现出快速疲劳。在这里，我们提出了一种闭环控制框架，该框架利用功能性光遗传学刺激（FOS）下的生理力调制来实现体内长时间（> 60 分钟）的高保真肌肉控制。我们首先发现了 FOS 的力调节特性，与 FES 相比，其显示出更多的生理募集和显着更高的调节范围 (>320%)。其次，我们开发了一种神经肌肉模型，可以准确描述光遗传学刺激肌肉的高度非线性动力学。第三，基于光遗传学模型，我们证明了肌肉力量的实时控制，与 FES 相比，其性能和抗疲劳能力得到了改善。这项工作为抗疲劳神经假体和具有高保真力调制的光遗传学控制生物混合机器人奠定了基础。