title: Highly Flexible Silicone Coated Neural Array for Intracochlear Electrical Stimulation.
abstract: We present an effective method for tailoring the flexibility of a commercial thin-film polymer electrode array for intracochlear electrical stimulation. Using a pneumatically driven dispensing system, an average 232 ± 64 μm (mean ± SD) thickness layer of silicone adhesive coating was applied to stiffen the underside of polyimide multisite arrays. Additional silicone was applied to the tip to protect neural tissue during insertion and along the array to improve surgical handling. Each array supported 20 platinum sites (180 μm dia., 250 μm pitch), spanning nearly 28 mm in length and 400 μm in width. We report an average intracochlear stimulating current threshold of 170 ± 93 μA to evoke an auditory brainstem response in 7 acutely deafened felines. A total of 10 arrays were each inserted through a round window approach into the cochlea's basal turn of eight felines with one delamination occurring upon insertion (preliminary results of the in vivo data presented at the 48th Annual Meeting American Neurotology Society, Orlando, FL, April 2013, and reported in Van Beek-King 2014). Using microcomputed tomography imaging (50 μm resolution), distances ranging from 100 to 565 μm from the cochlea's central modiolus were measured. Our method combines the utility of readily available commercial devices with a straightforward postprocessing step on the order of 24 hours.
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA ; Department of Rehabilitative Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: P
authors.initials: P
authors.lastname: Bhatti
authors.affiliation: Department of Otolaryngology-Head & Neck Surgery, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: J
authors.initials: J
authors.lastname: Van Beek-King
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sharpe
authors.affiliation: Department of Neurology, Brain and Behavior Discovery Institute, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: J
authors.initials: J
authors.lastname: Crawford
authors.affiliation: School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA ; Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tridandapani
authors.affiliation: The Shea Ear Clinic, Memphis, TN 38119, USA ; Department of Otolaryngology-Head and Neck Surgery, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA.
authors.forename: B
authors.initials: B
authors.lastname: McKinnon
authors.affiliation: Department of Neurology, Brain and Behavior Discovery Institute, Georgia Regents University, Augusta, GA 30912, USA.
authors.forename: D
authors.initials: D
authors.lastname: Blake
mesh_terms: D000818:Animals; D002415:Cats; D003054:Cochlear Implants; D017097:Electric Impedance; D004558:Electric Stimulation / Q000295:instrumentation*; D004566:Electrodes; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D008297:Male; D018583:Pliability; D012828:Silicones / Q000737:chemistry*; D014057:Tomography, X-Ray Computed
chemical_list: D012828:Silicones