Abstract：
The ability of a novel biorealistic hand prosthesis for grasp force control reveals improved neural compatibility between the human-prosthetic interaction. The primary purpose here was to validate a virtual training platform for amputee subjects and evaluate the respective roles of visual and tactile information in fundamental force control tasks. We developed a digital twin of tendon-driven prosthetic hand in the MuJoCo environment. Biorealistic controllers emulated a pair of antagonistic muscles controlling the index finger of the virtual hand by surface electromyographic (sEMG) signals from amputees\' residual forearm muscles. Grasp force information was transmitted to amputees through evoked tactile sensation (ETS) feedback. Six forearm amputees participated in force tracking and holding tasks under different feedback conditions or using their intact hands. Test results showed that visual feedback played a predominant role than ETS feedback in force tracking and holding tasks. However, in the absence of visual feedback during the force holding task, ETS feedback significantly enhanced motor performance compared to feedforward control alone. Thus, ETS feedback still supplied reliable sensory information to facilitate amputee\'s ability of stable grasp force control. The effects of tactile and visual feedback on force control were subject-specific when both types of feedback were provided simultaneously. Amputees were able to integrate visual and tactile information to the biorealistic controllers and achieve a good sensorimotor performance in grasp force regulation. The virtual platform may provide a training paradigm for amputees to adapt the biorealistic hand controller and ETS feedback optimally.
摘要：
一种新颖的生物逼真的手假肢用于控制力的能力揭示了人与假体相互作用之间神经相容性的改善。这里的主要目的是验证截肢者的虚拟训练平台，并评估视觉和触觉信息在基本力控制任务中的各自作用。我们在MuJoCo环境中开发了肌腱驱动假手的数字孪生体。生物逼真的控制器通过截肢者残留的前臂肌肉的表面肌电图（sEMG）信号来模拟一对拮抗肌肉，从而控制虚拟手的食指。通过诱发触觉（ETS）反馈将抓握力信息传递给截肢者。六名前臂截肢者在不同的反馈条件下或使用其完整的手参加了力量跟踪和握住任务。测试结果表明，视觉反馈在力跟踪和保持任务中的作用比ETS反馈更重要。然而,在部队保持任务期间没有视觉反馈的情况下，与单独的前馈控制相比，ETS反馈显着增强了电机性能。因此，ETS反馈仍然提供了可靠的感觉信息，以促进截肢者稳定地掌握力控制能力。当同时提供两种类型的反馈时，触觉和视觉反馈对力控制的影响是特定于对象的。截肢者能够将视觉和触觉信息整合到生物现实控制器中，并在抓握力调节方面实现良好的感觉运动性能。虚拟平台可以为截肢者提供训练范例,以最佳地适应生物逼真的手控制器和ETS反馈。
