University of Michigan Department of Surgery, Section of Plastic Surgery, 570 MSRB II Level A, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109-5456, USA.
University of Michigan Department of Mechanical Engineering, Ann Arbor, MI, USA.
J Neuroeng Rehabil. 2018 Nov 20;15(1):108. doi: 10.1186/s12984-018-0452-1.
Regenerative peripheral nerve interfaces (RPNIs) are biological constructs which amplify neural signals and have shown long-term stability in rat models. Real-time control of a neuroprosthesis in rat models has not yet been demonstrated. The purpose of this study was to: a) design and validate a system for translating electromyography (EMG) signals from an RPNI in a rat model into real-time control of a neuroprosthetic hand, and; b) use the system to demonstrate RPNI proportional neuroprosthesis control.
Animals were randomly assigned to three experimental groups: (1) Control; (2) Denervated, and; (3) RPNI. In the RPNI group, the extensor digitorum longus (EDL) muscle was dissected free, denervated, transferred to the lateral thigh and neurotized with the residual end of the transected common peroneal nerve. Rats received tactile stimuli to the hind-limb via monofilaments, and electrodes were used to record EMG. Signals were filtered, rectified and integrated using a moving sample window. Processed EMG signals (iEMG) from RPNIs were validated against Control and Denervated group outputs.
Voluntary reflexive rat movements produced signaling that activated the prosthesis in both the Control and RPNI groups, but produced no activation in the Denervated group. Signal-to-Noise ratio between hind-limb movement and resting iEMG was 3.55 for Controls and 3.81 for RPNIs. Both Control and RPNI groups exhibited a logarithmic iEMG increase with increased monofilament pressure, allowing graded prosthetic hand speed control (R = 0.758 and R = 0.802, respectively).
EMG signals were successfully acquired from RPNIs and translated into real-time neuroprosthetic control. Signal contamination from muscles adjacent to the RPNI was minimal. RPNI constructs provided reliable proportional prosthetic hand control.
再生周围神经接口 (RPNI) 是一种生物结构，可放大神经信号，并在大鼠模型中表现出长期稳定性。尚未在大鼠模型中展示神经假肢的实时控制。本研究的目的是：a) 设计并验证一种系统，用于将大鼠模型中 RPNI 的肌电图 (EMG) 信号转换为神经假肢的实时控制；b) 使用该系统演示 RPNI 比例神经假肢控制。
动物被随机分配到三个实验组：(1) 对照组；(2) 去神经组；(3) RPNI 组。在 RPNI 组中，将伸趾长肌 (EDL) 解剖游离，去神经，转移到大腿外侧，并与切断的腓总神经残端神经化。大鼠通过单丝接受后肢触觉刺激，并用电极记录 EMG。使用移动样本窗口对信号进行滤波、整流和积分。RPNI 的处理后 EMG 信号 (iEMG) 与对照组和去神经组的输出进行验证。
自愿反射性大鼠运动产生的信号激活了对照组和 RPNI 组的假肢，但去神经组没有激活。后肢运动与静止 iEMG 之间的信噪比为对照组 3.55，RPNI 组 3.81。对照组和 RPNI 组的 iEMG 对数呈线性增加，与单丝压力增加相对应，允许分级控制假肢手速度（分别为 R=0.758 和 R=0.802）。
成功从 RPNI 获得 EMG 信号并将其转换为实时神经假肢控制。RPNI 附近肌肉的信号污染最小。RPNI 结构提供可靠的比例假肢手控制。
