A Polymer-Based Multichannel Cochlear Electrode Array

作者：Min Kyou Sik; Oh Seung Ha; Park Min Hyun; Jeong Joonsoo; Kim Sung June^*

来源：Otology & Neurotology, 2014, 35(7): 1179-1186.

DOI：10.1097/mao.0000000000000292

• Atraumatic cochlear electrode
• Cochlear implantation
• Intracochlear electrode array
• Liquid crystal polymer
• polymer-based neural interface

Objective: Compared with conventional cochlear electrode arrays, which are hand assembled and wire-based, polymer-based implants have several advantages. They are very precise, and their fabrication is inexpensive because of the use of thin-film processes. In the present study, a cochlear electrode array based on a high-performance liquid crystal polymer material is devised. Furthermore, the device is encapsulated in silicone elastomer.
Methods: The fabrication steps introduced here include thin-film processes with liquid crystal polymer (LCP) films and customized self-aligning molding processes for the electrode array. To assess the feasibility of the proposed electrode array, the charge storage capacitance and impedance were measured using a potentiostat. Vertical and horizontal deflection forces were measured using a customized fixture and a force sensor. Insertion and extraction forces were also measured using a transparent human cochlear plastic model, and five cases involving human temporal insertion trials were undertaken to assess the level of safety during the insertion process.
Results: The charge storage capacity and impedance at 1 kHz were 33.26 mC/cm(2) and 1.02 k Omega, respectively. Likewise, the vertical force and horizontal force of the electrode array were 3.15 g and 1.07 g. The insertion force into a transparent plastic cochlear model with displacement of 8 mm from a round window was 8.2 mN, and the maximum extraction force was 110.4 mN. Two cases of human temporal bone insertion showed no observable trauma, whereas 3 cases showed a rupture of the basilar membrane.
Conclusion: An LCP-based intracochlear electrode array was fabricated, and its electrical and mechanical properties were found to be suitable for clinical use.

• 出版日期2014-8