title: Silicone-coated thin film array cochlear implantation in a feline model.
abstract: OBJECTIVE
  Some limitations of cochlear implants can be attributed to a restricted spectral representation of sound provided by contemporary electrode arrays. Microfabricated high-density thin film array (TFA) technology enables a greater density of stimulating sites and, thus, a more complete spectral representation. Previous pilot cadaveric studies have documented insertion characteristics, although not electrical characteristics.
  
  
  METHODS
  Electrode evoked auditory brainstem response (ABR) testing in a feline model.
  
  
  METHODS
  Six healthy, normal hearing cats were unilaterally deafened and implanted with a silicone coated TFA, measuring 27.8 × 0.4 × 80μm (L × W × H). Monopolar stimulation of single electrodes was used to evoke a triple peaked ABR. Thresholds to evoke a minimal ABR were determined.
  
  
  RESULTS
  All 6 cats underwent successful full insertion and activation. Thresholds to evoke minimal ABR's varied among implants ranging from 75 to 450 μA. Over the basal portion of the array, thresholds were either larger or unable to evoke an ABR.
  
  
  CONCLUSIONS
  Two-thirds of the implants showed ABR's along the entire array, whereas the others evoked ABR's at the apical end and less robustly more basally. This may reflect increased distance of the electrodes from the modiolus, as the basal half of the array is narrower relative to the width of the scala. A tapered design to ensure array distance to modiolus is minimized may enable the basal half of the arrays to stimulate more consistently.
authors: *Department of Otolaryngology-Head and Neck Surgery, Georgia Regents University, Augusta; †School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia; and ‡Department of Otolaryngology-Head and Neck Surgery, University of Tennessee Health Sciences Center, Memphis Tennessee, U.S.A.
authors: Jessica M
authors: JM
authors: Van Beek-King
authors: Pamela T
authors: PT
authors: Bhatti
authors: David
authors: D
authors: Blake
authors: Jonathan
authors: J
authors: Crawford
authors: Brian J
authors: BJ
authors: McKinnon
mesh_terms: D000818:Animals; D001309:Auditory Threshold / Q000502:physiology*; D002415:Cats; D003051:Cochlea / Q000601:surgery; D019929:Cochlear Implantation; D003054:Cochlear Implants; D003056:Cochlear Nerve / Q000502:physiology / Q000601:surgery*; D004558:Electric Stimulation; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D008297:Male; D012828:Silicones
chemical_list: D012828:Silicones