Floating Light Activated Micro-Electrical Stimulators for Neural Prosthetics

描述(申请人提供)：电激活中枢和周围神经系统用于治疗神经疾病已经研究了几十年，一些设备已经进入临床阶段，并取得成功。随着我们对脊髓和大脑中的神经回路有了更多的了解，新的应用针对的是中枢神经系统中更具体的回路，因此需要更多局部的电刺激手段。一些神经假体应用的例子是微刺激脊髓以恢复脊髓损伤中的运动或排尿，微刺激耳蜗核、中脑或听觉皮质以恢复听力，以及刺激盲人的视觉皮质。为了满足这些应用的需求，在过去的十年里发展了微电极阵列。然而，目前的植入式微电极阵列使用有线互连来施加电刺激。这些细丝是设备故障的主要来源，因为它们是第一个在慢性植入物中断裂的。此外，大脑和脊髓在头骨和脊柱内经历了大量的平移。由于电极材料和神经组织之间的机械失配，组织围绕这些刚性微电极的运动会产生显著的剪切力。这些剪切力被布线互连的绳索力加剧，导致在电极周围形成厚厚的包裹组织层。机械失配和牵引力不仅导致细胞损伤，而且由于电极和靶神经元之间形成的这种屏障，刺激的特异性也会丧失。我们提出了一种浮动微电子器件作为微电极阵列的替代技术。所提出的微刺激器将通过位于硬脑膜外的光纤通过红外线光束来提供能量。浮动微刺激器将不受任何互连和绳索力的影响。因为整个装置的尺寸要小得多，对神经组织的侮辱也会减少很多。这项提议的主要目标是开发和表征这些浮动光激活的微电刺激器(火焰)。这项技术可以帮助将许多神经假体方法转化为临床，特别是那些涉及脊髓微刺激的方法。与公共健康相关：这项提案的主要目标是开发和测试无线微刺激器(&lt；300微米)，用于在神经假体应用中电激活中枢神经系统，例如为脊髓损伤患者恢复一些重要功能而开发的应用。我们相信，这些无线微刺激器将消除目前微电极技术遇到的问题，从而使许多神经假体项目能够转移到临床上。

DESCRIPTION (provided by applicant): Electrical activation of central and peripheral nervous system has been investigated for treatment of neural disorders for many decades and a number of devices have already moved into clinical phase with success. As we learn more about the neural circuitry in the spinal cord and the brain, new applications are targeting more specific circuits in the central nervous system and thus requiring much more localized means of electrical stimulation. Some example neural prosthetic applications are microstimulation of the spinal cord to restore locomotion or micturition in spinal cord injury, microstimulation of the cochlear nucleus, midbrain, or auditory cortex to restore hearing, and stimulation of the visual cortex in the blind subjects. In order to satisfy the demand in these applications, microelectrode arrays have been developed over the past decade. However, the current implantable microelectrode arrays use wired interconnects for applying the electric stimulations. These fine wires are a major source of device failure since they are the first to break in chronic implants. Moreover, the brain and the spinal cord experience significant amounts of translation inside the skull and the spinal column. Movement of the tissue around these rigid microelectrodes causes significant shear forces due to the mechanical mismatch between the electrode material and the neural tissue. These shear forces, exacerbated by the tethering forces of the wired interconnects, result in a thick encapsulation tissue layer that forms around the electrode. The mechanical mismatch and tethering forces not only cause cellular damage but also the loss of specificity of the stimulations because of this barrier that forms between the electrode and the targeted neurons. We propose a floating micro-electrical device as an alternative technology to micro-electrode arrays. The proposed micro-stimulators will be energized with an infrared light beam through an optical fiber located just outside the dura mater. The floating microstimulators will be free from any interconnects and tethering forces. Because the overall device size is much smaller, the insult to the neural tissue will also be much reduced. The main objective of this proposal is to develop and characterize these floating light activated micro-electrical stimulators (FLAMES). This technology can be instrumental in translation of many neural prosthetic approaches into the clinic, particularly those that involve microstimulation of the spinal cord. PUBLIC HEALTH RELEVANCE: The main objective of this proposal is to develop and test wireless microstimulators (<300 micron) for electrical activation of the central nervous system in neural prosthetic applications, such as those developed for individuals with spinal cord injury to regain some vital functions. We believe that these wireless micro-stimulators will eliminate the problems encountered with current microelectrode technology and thus enable the transfer of many neural prosthetic projects into the clinic.