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

描述（由申请人提供）：该项目的目标是开发一种智能神经假肢，能够产生可调节的刺激模式，以实现地上行走。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。为了验证控制运动的中央模式发生器（CPG）的存在，已经进行了大量的研究。这个神经网络被认为整合了一个预置的定时模式，以及通过下肢背根传入的反馈，在运动过程中产生协调和稳定的运动。ISMS是一种新颖的神经刺激方法，利用脊髓中的超细导线传递电刺激，激活脊髓腹角的神经元池。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ISMS电极上产生可调节的刺激模式，其中振幅根据内在和感觉条件进行调整。该假体将整合外部传感器信号或来自背根神经节（DRG）的神经记录形式的传入反馈，以及预定的内在时间阈值，以产生类似于在生物CPG中观察到的变化的刺激波形。先前使用ISMS的工作已经绘制了在脊髓的不同位置激活的运动，这些信息将用于产生有效的功能性运动和地上行走所需的负重力。通过对假肢进行有效的编程，它将产生能够适应诸如打滑、绊倒和肌肉疲劳等扰动的刺激模式，并利用传入反馈。神经假体在猫模型上的成功和可靠性将导致同类设备的第一种，可用于临床环境中涉及脊髓损伤的人类

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