Evaluation of Carbon Nanotube Electrodes for Neural Stimulation

碳纳米管电极神经刺激的评价

• 批准号: 8114704
• 负责人: Charles Bernard Parker
• 金额: $ 18.3万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-05 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8114704
• 关键词: Biocompatible; Brain; Carbon Nanotubes; Cells; Charge; Chemicals; Chronic; Consumption; Deep Brain Stimulation; Electrodes; Electrolyses; Essential Tremor; Evaluation; Film; Goals; Growth; In Vitro; Injection of therapeutic agent; Intercellular Fluid; Lead; Length; Life; Measurement; Measures; Metals; Modification; Morphology; Nickel; Outcome; Oxidative Stress; Oxygen; Parkinson Disease; Performance; Pharmaceutical Preparations; Physiologic pulse; Platinum; Porosity; Rattus; Scanning; Solutions; Source; Specificity; Spectrum Analysis; Surface; Symptoms; System; Testing; Tissues; Water; base; catalyst; density; electric impedance; functional group; implantable device; interfacial; iridium oxide; neural prosthesis; neural stimulation; platinum electrode; relating to nervous system; response; voltage

DESCRIPTION (provided by applicant): The goal of this project is to evaluate carbon nanotubes (CNTs) as lower impedance, smaller electrodes for neurostimulation, using deep brain stimulation (DBS) as a test case. Lower impedance of the electrode-tissue interface results in lower power consumption, as a smaller voltage is required to achieve the same charge injection. Low power consumption extends battery life and decreases the size of the batteries and thus of the implanted device. The size of stimulating electrodes is limited by the minimum charge injection required for effective stimulation and the impedance of the electrode-tissue interface. As well, the size of the electrode is an important factor in the insertion damage created by the electrode and the specificity of the volume that can be stimulated. Lower impendence and smaller electrodes will lead to less damaging electrodes and a combination of smaller and longer lasting batteries. We will compare the performance of CNT electrodes to AIROF and traditional platinum electrodes using quantitative in vitro measurements. We expect to increase the reversible charge injection capacity, Qinj, (in ¿C/cm2) by 230% over the same-sized Pt electrode and exceed AIROF electrodes by 200% in the water electrolysis window, or to reduce the size of the electrode from a standard 0.06 cm2 to 0.026 cm2 while maintaining the same charge injection capacity, or a combination thereof. We expect to reduce the impedance, Z, by 65% vs a platinum electrode and 40% vs an AIROF electrode of the same size. The specific aims of this project are: (1) Quantify the effect of CNT morphology (length, density, orientation) on charge injection and interfacial impedance, and identify those combinations that increase charge injection and reduce interfacial impedance. The charge injection capacity will be determined by measuring voltage transients during in vitro current pulse stimulation, and the charge injection mechanisms will be determined by cyclic voltammetry. The interfacial impedance will be measured in vitro by electrochemical impedance spectroscopy. (2) Using the best electrode configuration from Aim #1, evaluate chemical modification of the CNT surface, such as oxygen functional groups, e.g., =O and -COOH, to further increase the charge injection capacity and decrease the impedance. (3) Test the top 5 electrode configurations from Aim #2 in vitro with rat neural tissue for a glial response and assess the CNT electrode performance (Qinj, Z, power consumption) in the presence of neural tissue and compare the performance to platinum and AIROF electrodes. Further, the electrodes will undergo chronic pulse testing in solution to evaluate the stability of charge injection capacity and interfacial impedance. The outcome of this project will be a comprehensive in vitro assessment of carbon nanotubes, grown with a platinum catalyst, as highly efficient neural stimulation electrodes. If realized, it will lead to neural stimulation electrodes that are smaller, limiting insertion damage, and consume less power, thereby reducing the size and increasing the lifetime of batteries. PUBLIC HEALTH RELEVANCE: Carbon nanotube-based electrodes for neural stimulation will allow the creation of neural electrodes to alleviate symptoms of Parkinson's disease, Essential tremor, and potentially other neural stimulation applications. These electrodes will be smaller, causing less damage to the brain, and have lower power consumption, so batteries will last longer and need to be replaced less frequently.

描述（由适用提供）：该项目的目的是将碳纳米管（CNT）评估为较低的阻抗，使用深脑刺激（DBS）作为验证案例，将碳纳米管（CNT）评估为较小的神经刺激电极。电极组织接口的较低阻抗会导致较低的功率消耗，因为需要较小的电压才能获得相同的电荷注入。低功耗可以延长电池寿命，并降低电池的大小以及植入设备的尺寸。刺激电子的大小受到有效刺激所需的最小电荷注入和电极组织接口的阻抗。同样，电极的大小也是电极插入损伤的重要因素，以及可以刺激的体积的特异性。较低的燃料和较小的电极将导致较小的破坏性电子以及较小且持久的电池组合。我们将使用定量的体外测量值将CNT电极与AIROF和传统铂电极的性能进行比较。我们预计在相同尺寸的PT电极上将可逆的电荷注入能力QIINJ（在€c/cm2中）增加230％，并在水电窗口中将电极超过200％，或者从标准的0.06 cm2到0.026 cm2的电极大小，同时维持同一电荷注射能力，或者保持相同的电荷注射能力。我们期望将阻抗Z降低65％，而铂电极和40％的阻抗和相同尺寸的Airof电极。该项目的具体目的是：（1）量化CNT形态（长度，密度，方向）对电荷注入和界面阻抗的影响，并确定那些增加电荷注入并减少界面阻抗的组合。电荷注入能力将通过测量体外电流脉冲刺激期间的电压瞬变来确定，并且电荷注入机制将由循环伏安法确定。界面阻抗将通过电化学阻抗光谱在体外测量。 （2）使用AIM＃1的最佳电极构型评估CNT表面的化学修饰，例如氧官能团，例如= O = O和-cooH，以进一步增加电荷注入能力并降低阻抗。 （3）在神经元组织的存在下，与大鼠神经元组织的AIM＃2的前5个电极构型在体外与大鼠神经元组织一起测试CNT电极性能（QINJ，Z，功耗），并将性能与铂和电极相比。此外，电极将在溶液中进行慢性脉冲测试，以评估电荷注入能力和界面阻抗的稳定性。该项目的结果将是对碳纳米管的全面体外评估，该碳纳米管具有铂催化剂，作为高效的神经元刺激电极。如果实现的话，它将导致较小的神经元刺激电极，限制插入损伤，并消耗更少的功率，从而降低电池的尺寸并增加了寿命。 公共卫生相关性：用于神经刺激的基于碳纳米管的电极将使神经刺激的产生减轻帕金森氏病的症状，必需树和可能其他神经刺激应用。这些电极会较小，对大脑造成较小的损害，并具有较低的功耗，因此电池的使用寿命将持续更长的时间，并且需要更换频率。