Advanced technology for neural interfaces based on microstimulation

基于微刺激的神经接口先进技术

基本信息

批准号：
9094696
负责人：
Douglas Buchanan McCreery
金额：
$ 42.3万
依托单位：
HUNTINGTON MEDICAL RESEARCH INSTITUTES
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-15 至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9094696
关键词：
Acoustic Nerve Acoustics Adult Advanced Development Animal Model Animals Area Astrocytes Bathing Beds Brain Buffers Cell Nucleus Charge Clinical Clinical Medicine Cochlea Cochlear Implants Cochlear nucleus Coupling Data Defect Devices Electric Stimulation Electrodes Exhibits Extravasation Felis catus Film Goals Health Hearing Histologic Hour Implant Individual Inferior Colliculus Ions Laboratories Life Mental Depression Metals Methods Microelectrodes Modeling Monitor Movement Disorders Neuraxis Neuronal Injury Neurons Neurosciences Performance Persons Phase Physical Medicine Physiologic pulse Procedures Prostheses and Implants Pulse Rates Qualifying Regimen Risk Role Safety Saline Science Silicon Site Staining method Stains Stimulus Surface Technology Testing Time Tissues Titania Titanium Training Translating Trauma Work base cell type density design electric impedance implantation improved in vivo meetings microstimulation neuronal excitability relating to nervous system research study sound speech recognition

项目摘要

DESCRIPTION (provided by applicant): This proposal has two mutually supporting goals; to advance the design of multisite microstimulating arrays and microstimulation technology for their use in rehabilitation medicine and basic neuroscience, and to advance the development of cochlear nucleus auditory prostheses towards providing speech recognition that is at least equivalent to that of users of cochlear implants. Persons who lack a functional auditory nerve cannot benefit form cochlea implants, but some hearing can be restored by a prosthesis implanted in or on the cochlea nucleus. However, the devices now in clinical use do not restore hearing that is comparable to that of cochlea implants. They are mechanically sturdy and with their ground tips can be inserted into the brain with minimal trauma. In a cat model, we will evaluate the safety of 140 hours of microstimulation in the cat cochlear nucleus at a pulse rate of 500 pps, in order to determine the roles of stimulus pulse rate and stimulus charge density in stimulation-induced neuronal injury when the pulse rate is high (250 to 500 pps), and the electrodes' geometric surface areas is in the upper part of the range for microstimulation (2,000 to 4,000 μm2). We will determine a combination of electrode geometric surface area and stimulus charge per phase that is not injurious to the neurons and other cell types close to the electrodes. Functional electrical stimulation in the central nervous system with penetrating microelectrodes has potential applications in clinical medicine and basic neural science, and high-rate stimulation can convey more temporal information and may elicit neuronal activity that more closely resemble naturally-occurring activity by minimizing locking of neuronal activity to the individual stimulus pulses, and may find other uses in clinical medicine, including treatment of movement disorders. In a study just completed, we found that encoding of amplitude modulation by microstimulation in the cochlear nucleus is improved by using a pulse rate of 500 pps. We will enhance our multisite silicon substrate microstimulation probes in order to increase their lifetime in vivo, with the goal of qualifying them for clinical use. Our devices have 5 independent electrode sites on each shank, allowing placement of a large number of electrodes into the target nucleus with the minimum tissue displacement and damage .The silicon shanks are mechanically sturdy and their ground tips can be inserted into the brain with minimal trauma. We will develop probes of this configuration that will meet at least the following performance standards after 1 year of soak in buffered saline at 39oC , and for which accelerated testing indicates that the standards will be met for at least 8 years (1) ; inter-channel crosstalk (channe interaction) between the electrodes on the same probe shank during controlled-current pulsing below 5% for all channels on the probe shank and (2) the leakage impedance of each channel to the saline bath greater than 1 MgΩ. A multisite stimulating array that maintains these performance standards will retain essentially full functionality. We will optimize procedures for encoding the amplitude modulation (AM) of sound into an electrical stimulus that is applied in the ventral cochlear nucleus. Based on work completed in our laboratory on encoding of amplitude modulation by neurons in the inferior colliculus of the cat, this will require a high stimulus pulse rate (500 pps). This work also will serve as a test bed for the long-lived microstimulation arrays we will develop.

描述（由申请人提供）：该提案有两个相互支持的目标：推进多位点微刺激阵列和微刺激技术在康复医学和基础神经科学中的应用，并推动耳蜗核听觉假体的开发以提供语音识别功能。这至少与人工耳蜗使用者的听力相当。缺乏功能性听觉神经的人无法从人工耳蜗中受益，但植入的假体可以恢复部分听力。然而，目前临床使用的设备无法恢复与耳蜗植入物相当的听力，它们的机械结构坚固，并且可以以最小的创伤插入猫的大脑中。在模型中，我们将评估脉冲速率为 500 pps 时对猫耳蜗核进行 140 小时微刺激的安全性，以确定脉冲速率和刺激电荷密度在刺激引起的神经元损伤中的作用。高（250 至 500 pps），并且电极的几何表面积处于微刺激范围的上部（2,000 至 4,000 μm2），我们将确定电极几何表面积和每相刺激电荷的组合。使用穿透性微电极对中枢神经系统中的神经元和其他细胞类型不造成伤害，在临床医学和基础神经科学中具有潜在的应用。高速率刺激可以传递更多的时间信息，并且可以通过最小化神经活动对个体刺激脉冲的锁定来引发更接近自然发生的活动，并且可以在临床医学中找到其他用途，包括治疗运动障碍。在刚刚完成的一项研究中，我们发现通过使用 500 pps 的脉冲速率可以改善耳蜗核中微刺激的幅度调制编码。我们将增强我们的多位点硅基板微刺激探针，以延长其在体内的寿命。我们的设备的每个柄上都有 5 个独立的电极位点，可将大量电极放置到目标核中，同时将组织位移和损伤降至最低。硅柄机械坚固，尖端经过磨削。我们将开发这种配置的探针，在 39oC 的缓冲盐水中浸泡 1 年后至少满足以下性能标准，并且加速测试表明将满足以下标准：至少 8 年 (1)；在受控电流脉冲期间，同一探头柄上的电极之间的通道间串扰（通道相互作用）低于 5%（对于探头柄上的所有通道）以及 (2) 每个通道的漏阻抗大于 1 MgΩ 的盐水浴保持这些性能标准将保留基本完整的功能，我们将优化将声音的幅度调制 (AM) 编码为应用于电刺激的程序。根据我们实验室完成的关于猫下丘神经元振幅调制的编码工作，这将需要高刺激脉冲率（500 pps）。我们将开发长寿命的微刺激阵列。