Ramos de Miguel Ángel, Riol Sancho Diego, Falcón-González Juan Carlos, Pavone Joana, Rodríguez Herrera Leandro, Borkoski Barreiro Silvia, Falcón Benitez Nadia, Ramos Macias Ángel
Department of Otolaryngology, and Head and Neck Surgery, Complejo Hospitalario Universitario Insular Materno Infantil de Gran Canaria, 35016 Las Palmas, Spain.
Department Otolaryngology, Psychoacoustic & Equilibrium Laboratory, University Institute of Intelligent Systems and Numeric Applications in Engineering, Las Palmas University (ULPGC), 35016 Las Palmas, Spain.
J Clin Med. 2022 Jul 6;11(14):3930. doi: 10.3390/jcm11143930.
New cochlear implant (CI) electrode arrays provide softer insertion dynamics; however, due to their high flexibility, the possibilities of fold-overs or intraoperative displacements must be taken into account. The position of each individual electrode can only be determined by using high-resolution computed tomography or cone-beam CT. The trans-impedance matrix test (TIM) is an electrophysiological method based on electric field imaging that can provide images of electrode position and electrode folding.
In this experimental research, we evaluated the result of TIM as a method of monitoring cochlear insertion for a precurved slim modiolar electrode array in fresh human temporal bones by analyzing the transimpedance matrix patterns and their correlation with electrode position using high-resolution computed tomography.
Sixteen slim modiolar electrode arrays were inserted into eight fresh Human Temporal Bones. Eight electrodes were inserted according to the correct methodology of insertion, and eight were intentionally folded over. After all insertions, a trans-impedance matrix analysis and a Cone Beam CT (CBCT) were performed in each temporal bone.
If we correlated the TIM patterns with the radiological electrode position, we observed that better electrode intracochlear positions indicated more "homogeneous" TIM patterns (intracochlear voltage dropped monotonically as the distance between stimulation and recording contact increased, both toward the apex and toward the base). A correlation where fold-over was detected in the TIM results was found in all eight temporal bone radiological findings.
Trans-Impedance Matrix patterns were correlated with the radiological CI electrode position. When a tip fold-over appeared, a matrix with a secondary ridge in addition to the primary ridge was observed in all cases. TIM can be an effective method in the control of electrode positioning.
新型人工耳蜗（CI）电极阵列具有更柔和的插入动态；然而，由于其高度的灵活性，必须考虑到折叠或术中移位的可能性。每个电极的位置只能通过高分辨率计算机断层扫描或锥形束CT来确定。跨阻抗矩阵测试（TIM）是一种基于电场成像的电生理方法，可提供电极位置和电极折叠的图像。
在本实验研究中，我们通过分析跨阻抗矩阵模式及其与使用高分辨率计算机断层扫描的电极位置的相关性，评估了TIM作为监测新鲜人颞骨中预弯曲纤细蜗轴电极阵列耳蜗插入方法的结果。
将16个纤细蜗轴电极阵列插入8个新鲜人颞骨中。8个电极按照正确的插入方法插入，8个故意折叠。所有插入完成后，对每个颞骨进行跨阻抗矩阵分析和锥形束CT（CBCT）检查。
如果将TIM模式与放射学电极位置相关联，我们观察到，更好的电极耳蜗内位置表明TIM模式更“均匀”（随着刺激与记录触点之间的距离增加，无论是朝向蜗顶还是朝向蜗底，耳蜗内电压均单调下降）。在所有8个颞骨放射学检查结果中，均发现TIM结果中检测到折叠的相关性。
跨阻抗矩阵模式与放射学CI电极位置相关。当出现尖端折叠时，在所有情况下均观察到除主峰外还有一个次峰的矩阵。TIM可以成为控制电极定位的有效方法。
