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

描述(申请人提供)：该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。该假体将利用椎管内微刺激(ISMS)来激活脊髓腰骶区腹角的运动神经元池，在那里可以恢复下肢的功能运动。已经进行了广泛的研究来验证是否存在控制运动的中央图案生成器(CPG)。这种神经网络被认为整合了预适应的计时模式以及来自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，通过在脊髓中使用超细导线传递电刺激来激活脊髓文氏角的神经元池。在猫身上已经证明，除了运动所需的腿部运动外，ISMS还具有产生足够的力量来支撑后肢重量的能力。本项目的目标是开发一种可移动的神经假体，能够在不同的ISM电极上产生可调整的刺激模式，其中幅度可根据内在和感觉条件进行调整。该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内在计时阈值，以产生类似于在生物CPG中观察到的变化的刺激波形。之前使用ISMS的研究已经绘制出哪些运动在脊髓不同位置被激活，这些信息将被用来产生地面行走所需的有效功能运动和负重力。通过对假肢进行有效的编程，它将产生能够利用传入反馈来适应打滑、绊倒和肌肉疲劳等扰动的刺激模式。猫模型中神经假体的成功和可靠性将导致第一个可用于临床环境的装置，涉及人类脊髓损伤。

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