Arnoldner Christoph, Riss Dominik, Baumgartner Wolf-Dieter, Kaider Alexandra, Hamzavi Jafar-Sasan
Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria.
Audiol Neurootol. 2007;12(5):313-24. doi: 10.1159/000103212. Epub 2007 May 23.
There are a variety of factors which can influence cochlear implantation outcome. Channel interaction is one of the variables responsible for audiological performance deterioration in multichannel implants. Electrode design is--among others--one way to decrease the incidence of channel interaction. At present, electrodes differ in overall length, diameter, contact design and distribution, but none of the electrodes available have a distinct variability in the amount of space between contacts across the length of the electrode. The aim of this study was to investigate whether a new electrode design featuring larger contact spacing in the apical part of deeply inserted electrodes would lead to an increase in speech perception. Eighteen postlingually deafened patients fitted with MedEl Combi 40+ or MedEl Pulsar cochlear implants using the MedEl implementation of continuous interleaved sampling participated in this study. Patients were tested in 6 conditions, in which the channel spacing and distribution of electrode contacts in each patient were artificially varied by activating or deactivating different channels. Performance was tested immediately after each change in setup with a monosyllable and sentence test (Hochmaier, Schultz and Moser). Our results showed that the condition with the highest distance between contacts in the apical part (up to 6.4 mm instead of 2.4 mm) is the most effective for the matched map condition: the results improved statistically significantly for the sentence test from 72% in the standard 12-channel condition to 83.2% and from 40.8 to 50% for the monosyllable test. Based on these findings, we present a new electrode design which can help achieve further increases in speech perception with cochlear implants.
有多种因素会影响人工耳蜗植入的效果。通道相互作用是导致多通道植入物听力性能下降的变量之一。电极设计是减少通道相互作用发生率的一种方法。目前，电极在总长度、直径、触点设计和分布上存在差异，但现有的电极在整个电极长度上触点之间的空间量都没有明显的变化。本研究的目的是调查一种新的电极设计，即在深度插入电极的顶端部分具有更大的触点间距，是否会提高言语感知能力。18名语后聋患者使用美迪乐连续交错采样技术，佩戴美迪乐Combi 40+或美迪乐Pulsar人工耳蜗参与了本研究。患者在6种条件下接受测试，通过激活或停用不同通道，人为改变每位患者电极触点的通道间距和分布。每次设置改变后，立即用单音节和句子测试（霍赫迈尔、舒尔茨和莫泽）对性能进行测试。我们的结果表明，在顶端部分触点间距最大的条件下（高达6.4毫米，而不是2.4毫米），对于匹配图谱条件最为有效：句子测试的结果从标准12通道条件下的72%在统计学上显著提高到83.2%，单音节测试从40.8%提高到50%。基于这些发现，我们提出了一种新的电极设计，它有助于进一步提高人工耳蜗的言语感知能力。
