Technology for an advanced cochlear nucleus auditory prosthesis

先进的耳蜗核听觉假体技术

• 批准号: 7652422
• 负责人: Douglas Buchanan McCreery
• 金额: $ 38.52万
• 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/7652422
• 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; Data; 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; Operative Surgical Procedures; Outcome Measure; Patients; Performance; Persons; Positioning Attribute; Prevalence; Probability; Prostheses and Implants; Prosthesis; Protocols documentation; Psychoacoustics; Pulse Rates; Reference Standards; Relative (related person); Silicon; Site; Specificity; Speech; Speech Perception; Spinal Cord; Staging; Stimulus; Surface; Surgeon; System; Technology; Thick; Time; Tissues; Vertebral column; Width; analog; bilateral vestibular Schwannoma; data acquisition; deafness; design; design and construction; experience; implantable device; implantation; improved; microstimulation; minimal risk; public health relevance; 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，能够更好地向佩戴耳蜗核听觉假体的人传达声音的频谱和时间特征。耳蜗核水平的听觉假体（“听觉脑干植入物，ABI”）可以使缺乏功能性听觉神经的人恢复有用的听力，但他们的语言感知能力比大多数人工耳蜗植入者要差得多，尤其是对于患有 2 型神经纤维瘤病 (NF2) 的人来说效果较差，这是双侧第 8 神经缺失的最常见病因。 NF2 患者还表现出高调制检测阈值，这是已发现的唯一将 ABI 的 NF2 用户与其他病因导致的耳聋患者区分开来的心理声学变量。现有数据表明，所有 ABI 用户（包括 NF2 患者）都将受益于改进的调制检测。大多数 ABI 在脑干表面利用一系列宏电极，该阵列允许对耳蜗核的音位组织进行一些但有限的访问。在动物研究中，穿透性微电极能够更好地传达声音的光谱信息，听觉脑干植入物包括表面电极和穿透电极阵列的 NF2 患者可以从混合阵列中受益。然而，我们对现有穿透阵列的经验揭示了我们将在拟议研究中解决的几个问题。我们将在 24 个多位点硅基板柄微电极上设计一个包含 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，即使在移除阵列后已知不确定该阵列的位置。第八神经肿瘤。组成该阵列的探针将通过深反应离子蚀刻（DRIE）光刻技术制造，产生的探针柄足够耐用，可以穿透人类耳蜗核上的胶质细胞限制。我们将通过反复插入猫脊髓来验证阵列的机械耐久性。 DRIE 探针阵列将被长期植入猫的耳蜗核中，以评估机械坚固的 DRIE 探针植入过程中可能出现的组织损伤。比较的标准将是比 DRIE 探针薄得多的密歇根型探针。同样在猫模型中，我们将确定相对于目前临床 ABI 系统中使用的 250 Hz 电荷平衡脉冲刺激，是否以及如何增强腹侧耳蜗核的 1 型多极细胞的调制检测。我们将评估较高刺激脉冲频率（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 64 位点、4 柄记录阵列，适合长期植入猫的下丘。公共健康相关性：植入耳蜗核水平的听觉假体（“听觉脑干植入物，ABI”）可以使缺乏功能性听觉神经的人恢复有用的听力，但他们的言语感知和对环境声音的识别能力比人工耳蜗差得多。对于大多数人工耳蜗使用者来说，这种情况尤其严重，对于患有 2 型神经纤维瘤病 (NF2) 的人来说尤其糟糕，这是双侧耳蜗损失最常见的病因的听觉神经。通常，在手术切除双侧前庭神经鞘瘤的过程中，神经会被破坏，这是这种情况的典型特征。现在使用的 ABI 不能有效地向用户传达声音的时间调制，患有 NF2 的人在这方面表现尤其差。在动物模型中，我们将比较几种将声音编码为传递到刺激电极的电刺激的协议。我们的目标是开发一种改进的方法来向 ABI 用户传达声音的时间特征。大多数 ABI 在脑干表面利用一系列宏电极，允许部分但有限地接触耳蜗核的音位组织。在动物研究中，穿透性微电极能够更好地传达声音和 NF2 患者的光谱信息，这些患者的听觉脑干植入物包括表面电极阵列和从混合阵列中受益的穿透电极阵列。而且，穿透电极已被证明在患者未从表面电极接收到听觉感知的情况下是有用的。然而，我们对现有版本穿透阵列的经验揭示了我们将在拟议研究中解决的许多问题。鉴于 NF2 相对于双侧听神经丧失的其他原因的患病率，最不幸的是，NF2 患者没有从听觉脑干植入物中获得与其他病因导致的耳聋患者一样多的益处。然而，NF2 的患病率约为四万分之一，双侧声学肿瘤的可能性很高，因此，虽然幸运的是这种情况相当罕见，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，除了与手术切除肿瘤相关的风险和不适之外，由于在手术切除肿瘤的同一手术过程中将装置植入耳蜗核中，因此风险和不适也最小。因此，需要改进植入物本身以及将声音编码为电刺激的方法，该方法针对植入耳蜗核中的听觉假体进行优化。