Stimulation of the human auditory nerve with optical radiation Andrew Fishman 1,5 , Piotr Winkler 6 , Jozef Mierzwinski 5 , Wojciech Beuth 6 , Agnella Izzo Matic 1* , Zygmunt Siedlecki 6 , Ingo Teudt 4 , Hannes Maier 4 , Claus-Peter Richter 1-3 1 Department of Otolaryngology – Head and Neck Surgery, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, U.S.A. 2 Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, U.S.A. 3 Hugh Knowles Center, Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, U.S.A. 4 Department of Otolaryngology – Head and Neck Surgery, University Medical Clinic Hamburg- Eppendorf, Hamburg, Germany 5 Department of Otolaryngology, Nicolaus Copernicus University of Torun, University Hospital of dr Jurasz in Bydgoszcz, Poland. 6 Department of Neurosurgery, Nicolaus Copernicus University of Torun, University Hospital of dr Jurasz in Bydgoszcz, Poland. *Corresponding author: Agnella Izzo Matic, PhD Phone: (312) 503-4027 FAX: (312) 503-1616 e-mail: a-izzo@northwestern.edu ABSTRACT A novel, spatially selective method to stimulate cranial nerves has been proposed: contact free stimulation with optical radiation. The radiation source is an infrared pulsed laser. The Case Report is the first report ever that shows that optical stimulation of the auditory nerve is possible in the human. The ethical approach to conduct any measurements or tests in humans requires efficacy and safety studies in animals, which have been conducted in gerbils. This report represents the first step in a translational research project to initiate a paradigm shift in neural interfaces. A patient was selected who required surgical removal of a large meningioma angiomatum WHO I by a planned transcochlear approach. Prior to cochlear ablation by drilling and subsequent tumor resection, the cochlear nerve was stimulated with a pulsed infrared laser at low radiation energies. Stimulation with optical radiation evoked compound action potentials from the human auditory nerve. Stimulation of the auditory nerve with infrared laser pulses is possible in the human inner ear. The finding is an important step for translating results from animal experiments to human and furthers the development of a novel interface that uses optical radiation to stimulate neurons. Additional measurements are required to optimize the stimulation parameters. Keywords – infrared nerve stimulation, cochlear implant, optical stimulation, human 1. INTRODUCTION The ideal design of speech processors for cochlear implants relies on several assumptions regarding users' perceptual responses to electrical stimulation. These assumptions are that each electrode contact is distinct, both spatially and temporally, or equivalently that electrode interaction (i.e. overlap in areas of stimulation) does not occur. Thus, a multichannel cochlear implant should transfer a maximum of information to discrete groups of auditory nerve Photons and Neurons, edited by Anita Mahadevan-Jansen, E. Duco Jansen, Proc. of SPIE Vol. 7180 71800M · © 2009 SPIE · CCC code: 1605-7422/09/$18 · doi: 10.1117/12.814944 Proc. of SPIE Vol. 7180 71800M-1