Technology for an advanced cochlear nucleus auditory prosthesis

先进的耳蜗核听觉假体技术

• 批准号: 7508840
• 负责人: Douglas Buchanan McCreery
• 金额: $ 39.61万
• 依托单位: HUNTINGTON MEDICAL RESEARCH INSTITUTES
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7508840
• 关键词: Acoustic Nerve; Acoustics; Address; Advanced Development; Affect; Animal Model; Animals; Auditory; Auditory Brain Stem Implants; Bilateral; Boron; Brain Stem; Cells; Charge; Chronic; Clinical; Cochlear Implants; Cochlear nucleus; Condition; Data; Depth; Detection; Developed Countries; Developing Countries; Development; Devices; Electric Stimulation; Electrodes; Equilibrium; Etiology; Excision; Exhibits; Family Felidae; Felis catus; Fracture; Hearing; Human; Hybrids; Implant; Inferior; Inferior Colliculus; Ions; Length; Live Birth; Location; Mechanics; Methods; Michigan; Microelectrodes; Modeling; Nerve; Neurofibromatosis 2; Neuroglia; Numbers; Operative Surgical Procedures; Outcome Measure; Patients; Performance; Persons; Placement; Positioning Attribute; Prevalence; Probability; Prostheses and Implants; Prosthesis; Protocols documentation; Psychoacoustics; Public Health; Pulse Rates; Range; Reference Standards; Relative (related person); Risk; Silicon; Site; Specificity; Speech; Speech Perception; Spinal Cord; Staging; Standards of Weights and Measures; Stimulus; Surface; Surgeon; System; Technology; Thick; Time; Tissues; Vertebral column; Width; analog; bilateral vestibular Schwannoma; data acquisition; day; deafness; design; design and construction; experience; implantable device; implantation; improved; sound; speech recognition; tumor

DESCRIPTION (provided by applicant): We propose to develop technology that will better convey both the spectral and the temporal features of sound to persons with cochlear nucleus auditory prostheses. An auditory prosthesis at the level of the cochlear nucleus ("Auditory brainstem implant, ABI") can restore useful hearing to persons who lack functional auditory nerves, but their speech perception is much poorer than that of most users of cochlear implants, and is especially poor for persons afflicted with Type 2 Neurofibromatosis (NF2), the most prevalent etiology for bilateral loss of the 8th nerves. The NF2 patients also exhibit high modulation detection threshold which is the only psychoacoustic variable that has been found to distinguish the NF2 users of the ABIs from those whose deafness is of other etiologies. The available data suggests that all users of ABIs, including those with NF2, would benefit from improved modulation detection. Most ABIs utilize an array of macroelectrodes on the surface of the brainstem, and this array allows some, but limited access to the tonotopic organization of the cochlear nucleus. In animal studies, penetrating microelectrodes are better able to convey the spectral information of sound, and NF2 patients whose auditory brainstem implants includes arrays of surface and penetrating electrodes derive benefit from the hybrid array. However, our experience with the existing penetrating array has revealed several issues that we will address in the proposed studies. We will design an array of 96 microstimulating electrode sites on 24 multisite silicon substrate shanks microelectrodes, that will insure placement of at least 16 microstimulating sites within the human ventral cochlear nucleus, even with the known uncertainly as to where to position the array after removal of the 8th nerve tumor. The probes comprising this array will be fabricated by deep reactive ion etching (DRIE) photolithography, which yields probe shanks that are sufficiently durable to penetrate the glia limitans overlying the human cochlear nucleus. We will verify the mechanical durability of the array by repeated insertions into cat spinal cords. Arrays of DRIE probes will be implanted chronically into cats' cochlear nucleus to evaluate possible tissue damage during implantation of the mechanically robust DRIE probes. The standard of comparison will be Michigan-style probes that are much thinner than the DRIE probes. Also in a cat model, we will determine if and how modulation detection by Type 1 multipolar cells of the ventral cochlear nucleus can be enhanced, relative to that with a 250 Hz charge-balanced pulsatile stimulus used in the present clinical ABI systems. We will evaluate the merits of a higher stimulus pulse rate (500 and 1000 pps) and also of analog electrical stimulation. To support the activities described above, we will develop a 64-site, 4-shank recording array suitable for chronic implantation into the cats' inferior colliculus. PUBLIC HEALTH RELEVANCE: An auditory prosthesis implanted at the level of the cochlear nucleus (an "Auditory brainstem implant, ABI") can restore useful hearing to persons who lack functional auditory nerves, but their speech perception and recognition of environmental sounds is much poorer than that of most users of cochlear implants, and is particularly poor for persons afflicted with Type 2 Neurofibromatosis (NF2), the most prevalent etiology for bilateral loss of the auditory nerves. Typically, the nerves are destroyed during surgical resection of each of the bilateral vestibular schwannomas that are typical of this condition. The ABIs now in use do not efficiently convey to the users the temporal modulation of sound and persons with NF2 fare particularly poorly in this respect. In an animal model, we will compare several protocols for encoding sound into the electrical stimulation that is delivered to the stimulating electrodes. Our objective is to develop an improved method of conveying the temporal features of sound to ABI users. Most ABIs utilize an array of macroelectrodes on the surface of the brainstem that allows some, but limited access to the tonotopic organization of the cochlear nucleus. In animal studies, penetrating microelectrodes are better able to convey the spectral information of sound and NF2 patients whose auditory brainstem implants includes an array of surface electrodes and an array of penetrating electrodes derive benefit from the hybrid array. Also, the penetrating electrodes have proved useful in those instances when the patient does not receive auditory percepts from the surface electrodes. However, our experience with the existing version of the penetrating array has revealed a number of issues that we will address in the proposed studies. In view of the prevalence of NF2 relative to that of other causes of bilateral loss of the auditory nerves, it is most unfortunate that persons with NF2 have not obtained as much benefit from their auditory brainstem implants as have patients whose deafness is of other etiologies. However, the prevalence of NF2 is approximately 1 in 40,000 live births with a high probability of bilateral acoustic tumors, and so while the condition fortunately is quite rare, in developed countries alone, there are many thousands of persons who can benefit from these devices, and with minimal risk and discomfort in addition to those related to the surgical removal of the tumors, since the devices are implanted into the cochlear nucleus during the same surgical procedure in which the tumor is surgically removed. Thus there is a need for improvements to the implants themselves and for methods of encoding sound into electrical stimulus that are optimized for an auditory prosthesis implanted in the cochlear nucleus.

描述（由申请人提供）：我们建议开发一种技术，该技术将更好地将声音的频谱和时间特征传达给具有耳蜗核听觉假体的人。耳蜗核水平的听觉假体（“听觉脑干植入物，ABI”）可以为缺乏功能性听觉神经的人恢复有用的听力，但是他们的言语感知比大多数耳蜗植入物使用者差得多，并且对于患有2型神经纤维瘤病（NF 2）的人尤其差，2型神经纤维瘤病是双侧第8神经丧失的最普遍病因。NF 2患者还表现出高调制检测阈值，这是唯一的心理声学变量，已被发现区分NF 2用户的ABI从那些耳聋是其他病因。现有数据表明，所有ABI用户，包括NF 2用户，将受益于改进的调制检测。大多数ABI利用脑干表面上的宏电极阵列，并且该阵列允许一些但有限地进入耳蜗核的音调组织。在动物研究中，穿透性微电极能够更好地传达声音的频谱信息，并且其听觉脑干植入物包括表面和穿透性电极阵列的NF 2患者从混合阵列中受益。然而，我们的经验与现有的穿透阵列揭示了几个问题，我们将在拟议的研究。我们将在24个多位点硅衬底柄微电极上设计96个微刺激电极位点的阵列，这将确保在人类腹侧耳蜗核内放置至少16个微刺激位点，即使已知不确定在去除第8神经肿瘤后将阵列定位在何处。包括该阵列的探针将通过深反应离子蚀刻（DRIE）光刻法制造，其产生足够耐用以穿透覆盖人类耳蜗核的胶质界膜的探针柄。我们将通过重复插入猫脊髓来验证阵列的机械耐久性。将DRIE探针阵列长期植入猫的耳蜗核中，以评价机械坚固DRIE探针植入期间可能的组织损伤。比较的标准将是比DRIE探针薄得多的里根式探针。此外，在猫模型中，我们将确定是否以及如何调制检测1型多极细胞的腹侧耳蜗核可以增强，相对于目前临床ABI系统中使用的250 Hz的电荷平衡脉动刺激。我们将评估更高刺激脉冲率（500和1000 pps）以及模拟电刺激的优点。为了支持上述活动，我们将开发一种适合于长期植入猫下丘的64位点、4柄记录阵列。公共卫生关系：耳蜗核水平植入的听觉假体（“听觉脑干植入物，ABI”）可以为缺乏功能性听觉神经的人恢复有用的听力，但是他们对环境声音的言语感知和识别比大多数耳蜗植入物使用者差得多，并且对于患有2型神经纤维瘤病（NF 2）的人尤其差，双侧听觉神经丧失的最普遍病因。通常，神经在手术切除双侧前庭神经鞘瘤的过程中被破坏，这是这种情况的典型表现。现在使用的ABI不能有效地向用户传达声音的时间调制，并且具有NF 2的人在这方面表现特别差。在动物模型中，我们将比较几种用于将声音编码到传递到刺激电极的电刺激中的协议。我们的目标是开发一种改进的方法，传达声音的时间特征的ABI用户。大多数ABI利用脑干表面上的宏电极阵列，其允许一些但有限地进入耳蜗核的音调组织。在动物研究中，穿透微电极能够更好地传达声音和NF 2患者的频谱信息，其听觉脑干植入物包括表面电极阵列和穿透电极阵列，从混合阵列中受益。而且，穿透电极已被证明在患者不从表面电极接收听觉感知的情况下是有用的。然而，我们的经验与现有版本的穿透阵列揭示了一些问题，我们将在拟议的研究。鉴于NF 2相对于其他原因导致的双侧听神经丧失的患病率，最不幸的是，NF 2患者从听觉脑干植入物中获得的益处不如其他原因导致耳聋的患者多。然而，NF 2的患病率约为1/40，000活产，双侧听神经瘤的概率很高，因此，虽然幸运的是这种情况非常罕见，但仅在发达国家，就有成千上万的人可以从这些设备中受益，并且除了与手术切除肿瘤相关的风险和不适之外，风险和不适最小，因为这些装置是在手术切除肿瘤的同一手术过程中植入耳蜗核的。因此，需要对植入物本身进行改进，并且需要将声音编码成电刺激的方法，该方法针对植入耳蜗核中的听觉假体进行优化。