Journal article

Chronic intracochlear electrical stimulation at high charge densities: reducing platinum dissolution

Robert K Shepherd, Paul M Carter, Ya Lang Enke, Alex Thompson, Brianna Flynn, Ella P Trang, Ashley N Dalrymple, James B Fallon

Journal of Neural Engineering | IOP PUBLISHING LTD | Published : 2020

Abstract

OBJECTIVE: Cochleae of long-term cochlear implant users have shown evidence of particulate platinum (Pt) corroded from the surface of Pt electrodes. The pathophysiological effect of Pt within the cochlea has not been extensively investigated. We previously evaluated the effects of Pt corrosion at high charge densities and reported negligible pathophysiological impact. The present study extends this work by examining techniques that may reduce Pt corrosion. APPROACH: Deafened guinea pigs were continuously stimulated for 28 days using biphasic current pulses at extreme charge densities using: (i) electrode shorting; (ii) electrode shorting with capacitive coupling (CC); or (iii) electrode shor..

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Grants

Awarded by National Institute on Deafness and Other Communications Disorders


Funding Acknowledgements

This work was supported by National Institute on Deafness and Other Communications Disorders (R01DC015031) and Cochlear Ltd. The Bionics Institute acknowledges support of the Victorian Government through Operational Infrastructure Support Program. We thank C Singleton, C McGowan, H Feng, J Zhou, N Critch, Dr T Nguyen, C Grenness, C Sloan, D Tuari, S Barone and J Firth from the Bionics Institute, R Curtain from the SEM Facility at Bio21, University of Melbourne for their excellent technical assistance, A/Prof A Wise for histological advice, the staff at the National Measurement Institute of the Australian Government for ICP-MS analysis and Prof Richard Williams, Pathology Department, St Vincent's Hospital, Melbourne for histopathology advice.