A Neural Prosthesis for the Restoration of Locomotion after Spinal Cord Injury

描述（由申请人提供）：本项目的目标是开发一种智能神经假体，能够产生可调节的刺激模式，用于产生地面行走。假体将利用脊柱内微刺激（ISMS）激活脊髓腰骶区腹角中的运动神经元池，在此可以恢复下肢的功能性运动。已经进行了广泛的研究，以验证控制运动的中央模式发生器（CPG）的存在。这种神经网络被认为整合了预处理的时间模式以及通过下肢背根的传入反馈，以在运动过程中产生协调和稳定的运动。ISMS是一种新的神经刺激方法，使用脊髓中的超细电线来传递电刺激以激活脊髓腹角中的神经元池。已经在猫中证明，除了运动所需的腿部运动之外，ISMS还具有产生足够的力来支撑后肢重量的能力。本项目的目的是开发一种移动的神经假体，该假体能够在不同的ISMS电极上产生可调节的刺激模式，其中幅度基于内在和感觉条件进行调节。假体将整合来自背根神经节（DRG）的外部传感器信号或神经记录形式的传入反馈以及预定的固有定时阈值，以产生与在生物CPG中观察到的波形类似的变化的刺激波形。以前的工作，使用ISMS映射的运动被激活在不同的位置沿着脊髓和这个信息将被用来产生有效的功能运动和负重力所需的地上行走。通过有效地编程假体，它将产生刺激模式，该刺激模式可以通过利用传入反馈来适应诸如滑动、绊倒和肌肉疲劳的扰动。神经假体在猫模型中的成功和可靠性将导致其第一种可用于涉及脊髓损伤的人类临床环境的设备

DESCRIPTION (provided by applicant): The goal of this project is to develop a smart neural prosthesis capable of producing an adjustable stimulation pattern for producing over-ground walking. The prosthesis will utilize intraspinal microstimulation (ISMS) to activate the motor neuron pools in the ventral horn of the lumbosacral region of the spinal cord where functional movements of the lower extremities can be restored. Extensive research has been conducted to validate the existence of a central pattern generator (CPG) which controls locomotion. This neural network is thought to integrate a preconditioned timing pattern as well as afferent feedback through the dorsal root from the lower extremities to produce coordinated and stable movements during locomotion. ISMS is a novel method of neural stimulation using ultra fine wires in the spinal cord to deliver electrical stimuli in activating the neuron pools in the ventra horn of the spinal cord. It has been demonstrated in cats that ISMS possesses the ability to generate sufficient force to support the weight of the hind limbs in addition to the desired leg movements required for locomotion. The aims of the present project are to develop a mobile, neural prosthesis capable of producing an adjustable stimulation pattern across different ISMS electrodes where the amplitude adjusts based on intrinsic and sensory conditions. The prosthesis will integrate afferent feedback in the form of external sensor signals or neural recordings from the dorsal root ganglia (DRG) as well as predetermined intrinsic timing thresholds to produce a changing stimulation waveform similar to what is observed in the biological CPG. Previous work using ISMS has mapped which movements are activated at different locations along the spinal cord and this information will be used to produce efficient functional movements and load bearing forces necessary for over-ground walking. By effectively programming the prosthesis, it will produce stimulation patterns which can adapt to perturbations such as slipping, tripping, and muscle fatigue by utilizing the afferent feedback. The success and reliability of the neural prosthesis in a cat model will lead towards the first device of its kind which can be used in a clinical setting involving humans with spinal cord injury