Journal article

Platinum dissolution and tissue response following long-term electrical stimulation at high charge densities

Robert K Shepherd, Paul M Carter, Ashley N Dalrymple, Ya Lang Enke, Andrew K Wise, Trung Nguyen, James Firth, Alex Thompson, James B Fallon



OBJECTIVE: Established guidelines for safe levels of electrical stimulation for neural prostheses are based on a limited range of the stimulus parameters used clinically. Recent studies have reported particulate platinum (Pt) associated with long-term clinical use of these devices, highlighting the need for more carefully defined safety limits. We previously reported no adverse effects of Pt corrosion products in the cochleae of guinea pigs following 4 weeks of electrical stimulation using charge densities far greater than the published safe limits for cochlear implants. The present study examines the histopathological effects of Pt within the cochlea following continuous stimulation at a ch..

View full abstract


Awarded by NIDCD

Funding Acknowledgements

This work was supported by NIDCD (R01DC015031) and Cochlear Ltd The Bionics Institute acknowledges support of the Victorian Government through Operational Infrastructure Support Program. We thank E Trang, C Singleton, C McGowan, H Feng, J Zhou, N Critch, C Grenness, C Sloan, D Tuari, and S Barone from the Bionics Institute, and R Curtain from the SEM Facility at Bio21, University of Melbourne for their excellent technical assistance; staff at the National Measurement Institute of the Australian Government for ICP-MS analysis; Dr Karin Jandeleit-Dahm for advice on kidney function, and Dr Keiko Hirose and Dr Marlan Hansen for advice on macrophage longevity.