SAFE AN EFFECTIVE STIMULATION OF NEURAL TISSUE

正在研究的几种新的神经假体将需要 多次大脑皮质皮质内刺激 微电极。单次皮层内刺激的研究 穿透性微电极已经建立了安全的刺激水平 在某些刺激条件下，但需要更多的信息 关于多个、紧密间隔、穿透的安全界限 微电极，如将用于先进的视觉假体。 这是本研究项目的目标之一。 在了解组织损伤的原因方面取得了进展 可能发生在高水平的刺激下。为了使组织最小化 损害，将获得更多关于预防方法的信息 损害，新生物材料的安全性，以及更好的方法 神经组织中物理上稳定的微电极。这个 使用多触点硅微电极的可能性 此外，还将调查Shanks能否接触到埋在地下的皮质组织。 硅微电极目前正在由另一家公司制造 承包商。 组织病理学、神经化学和神经生理学技术必须 用于确定急性激活和慢性激活的影响 大脑皮层组织。当生理学或组织病理学证据表明 注意到神经功能或结构的有害改变， 将进行研究以确定其机制(S)。电极 正在使用的还包括离散的线皮质内微电极 作为项目提供的硅微电路微电极 警官。 这项工作的结果不仅对神经假体有价值 调查人员，也向使用电信号的神经生理学家 刺激作为神经系统基础研究的一种工具。

Several new neural prostheses are being investigated that will require intracortical stimulation of cerebral cortex with multiple microelectrodes. Studies of intracortical stimulation with single penetrating microelectrodes have established safe levels of stimulation under certain stimulating conditions, but more information is needed about the safe limits for multiple, closely spaced, penetrating microelectrodes such as would be used in advanced visual prostheses. This is one of the objectives of this research project. Progress has been made on understanding the causes of tissue damage that can occur at high levels of stimulation. In order to minimize tissue damage, more information will be obtained on methods of preventing damage, the safety of new biomaterials, as well as better methods of physically stabilizing microelectrodes in neural tissue. The possibility of using multicontact, silicon microelectrodes with long shanks to access buried cortical tissue will also be investigated. Silicon microelectrodes are presently being fabricated by another contractor. Histopathological, neurochemical and neurophysiological techniques must be applied to determine the effects of both acute and chronic activation of cortical tissue. When physiological or histopathological evidence of detrimental alteration of neural function or structure is noted, research will be undertaken to determine the mechanism(s). Electrodes being used include discrete wire intracortical microelectrodes as well as silicon microcircuit microelectrodes furnished by the Project Officer. The results of this work will be of value not only to neural prosthesis investigators, but also to neurophysiologists who utilize electrical stimulation as a tool in fundamental studies of the nervous system.