Understanding the Benefits of Optical Nerve Stimulators for Neural Interfaces

项目总结/摘要 神经假体的目标是将神经功能恢复到具有健康系统保真度的状态。 然而，当代的神经假体，包括人工耳蜗，无法实现这一目标。的 这些装置使用电流刺激神经元，电流在组织中传播， 允许刺激集中的神经元群体。因此，高保真刺激是不可能的。在我们 模型系统，耳蜗，有人认为，人工耳蜗使用者的表现可能是 如果位于沿着电极的神经元的更多离散的非重叠位置可以 同时受到刺激。这可能是可能的设备，使用聚焦光辐射，以刺激 神经元今天，我们知道红外神经刺激（INS）是可能的，刺激率可以 实现了允许对声学信息进行编码，耳蜗中的空间选择性更具选择性 在慢性实验中，单通道刺激显示没有功能性 耳蜗损伤至少六周。本R 01中提出的发展是符合逻辑的 以前实验的进展。目标包括光电混合器件的制造和测试 通过手术插入猫耳蜗的阵列，并显示多通道INS的每个通道可以 独立地编码要由听觉系统感知的信息。来自下级的录音 丘将用于构建空间调谐曲线（STC）。不重叠的STC表示 渠道。刺激模式将系统地改变，直到实现最佳匹配 在听觉诱发的反应和从编码策略获得的反应之间。长期 将多通道装置长期植入猫耳蜗后的刺激将决定安全性。 诸如组合光电刺激或整形光脉冲的策略可以降低功率 需要光学刺激，并将进行探索。将通过组织学确认结果。在 该项目的结论是，一个原型人类光学耳蜗植入物将可用于临床研究， 在物理和光学要求上。

Project Summary / Abstract The goal for neuroprostheses is to restore neural function to a condition having the fidelity of a healthy system. However, contemporary neural prostheses, including cochlear implants, are not able to achieve this goal. The devices use electrical current to stimulate the neurons, which spreads in the tissue and consequently does not allow stimulation of focused neuron populations. Therefore, high fidelity stimulation is not possible. In our model system, the cochlea, it has been argued that the performance of cochlear implant users could be increased significantly if more discrete non-overlapping locations of neurons situated along the electrode could be stimulated simultaneously. This might be possible with devices that use focal optical radiation to stimulate neurons. Today we know that infrared neural stimulation (INS) is possible, that stimulation rates can be achieved that allow encoding of acoustic information, that the spatial selectivity in the cochlea is more selective than electrical stimulation, and that single channel stimulation in chronic experiments shows no functional damage of the cochlea over at least six weeks. The developments proposed in this R01 are a logical progression of previous experiments. The aims include the fabrication and testing of hybrid opto-electrical arrays to be surgically inserted into a cat cochlea and showing that each channel of multichannel INS can independently encode information to be perceived by the auditory system. Recordings from the inferior colliculus will be used to construct spatial tuning curves (STCs). Non-overlapping STCs indicate separation of the channels. The stimulation pattern will be changed systematically until an optimum match is achieved between and acoustically evoked response and the response obtained from the coding strategy. Long-term stimulation after chronic implantation of a multi-channel device into a cat cochlea will determine the safety. Strategies such as combined opto-electrical stimulation or shaping the optical pulses can reduce the power required for optical stimulation and will be explored. Results will be confirmed through histology. At the conclusion of this project, a prototype human optical cochlear implant will be available for a clinical study based on the physical and the optical requirements.