OBJECTIVES: Electrode impedance increases following implantation and undergoes transitory reduction with onset of electrical stimulation. The studies in this paper measured the changes in access resistance and polarization impedance in vivo before and following electrical stimulation, and recorded the time course of these changes. DESIGN: Impedance measures recorded in (a) four cats following 6 months of cochlear implant use, and (b) three cochlear implant recipients with 1.5-5 years cochlear implant experience. RESULTS: Both the experimental and clinical data exhibited a reduction in electrode impedance, 20 and 5% respectively, within 15-30 minutes of stimulation onset. The majority of these changes occurred through reduction in polarization impedance. Cessation of stimulation was followed by an equivalent rise in impedance measures within 6-12 hours. CONCLUSIONS: Stimulus-induced reductions in impedance exhibit a rapid onset and are evident in both chronic in vivo models tested, even several years after implantation. Given the impedance changes were dominated by the polarization component, these findings suggest that the electrical stimulation altered the electrode surface rather than the bulk tissue and fluid in the cochlea.
OBJECTIVES: Electrode impedance increases following implantation and undergoes transitory reduction with onset of electrical stimulation. The studies in this paper measured the changes in access resistance and polarization impedance in vivo before and following electrical stimulation, and recorded the time course of these changes. DESIGN: Impedance measures recorded in (a) four cats following 6 months of cochlear implant use, and (b) three cochlear implant recipients with 1.5-5 years cochlear implant experience. RESULTS: Both the experimental and clinical data exhibited a reduction in electrode impedance, 20 and 5% respectively, within 15-30 minutes of stimulation onset. The majority of these changes occurred through reduction in polarization impedance. Cessation of stimulation was followed by an equivalent rise in impedance measures within 6-12 hours. CONCLUSIONS: Stimulus-induced reductions in impedance exhibit a rapid onset and are evident in both chronic in vivo models tested, even several years after implantation. Given the impedance changes were dominated by the polarization component, these findings suggest that the electrical stimulation altered the electrode surface rather than the bulk tissue and fluid in the cochlea.
Authors: Viral D Tejani; Hyejin Yang; Jeong-Seo Kim; Helin Hernandez; Jacob J Oleson; Marlan R Hansen; Bruce J Gantz; Paul J Abbas; Carolyn J Brown Journal: J Assoc Res Otolaryngol Date: 2021-10-22
Authors: Rachel A Scheperle; Viral D Tejani; Julia K Omtvedt; Carolyn J Brown; Paul J Abbas; Marlan R Hansen; Bruce J Gantz; Jacob J Oleson; Marie V Ozanne Journal: Hear Res Date: 2017-04-12 Impact factor: 3.208
Authors: Robert K Shepherd; Paul M Carter; Ashley N Dalrymple; Ya Lang Enke; Andrew K Wise; Trung Nguyen; James Firth; Alex Thompson; James B Fallon Journal: J Neural Eng Date: 2021-03-17 Impact factor: 5.379
Authors: Deborah J Colesa; Jenna Devare; Donald L Swiderski; Lisa A Beyer; Yehoash Raphael; Bryan E Pfingst Journal: Hear Res Date: 2021-02-21 Impact factor: 3.208
Authors: Maciej Wilk; Roland Hessler; Kenneth Mugridge; Claude Jolly; Michael Fehr; Thomas Lenarz; Verena Scheper Journal: PLoS One Date: 2016-02-03 Impact factor: 3.240