title: Investigation of a new electrode array technology for a central auditory prosthesis.
abstract: Ongoing clinical studies on patients recently implanted with the auditory midbrain implant (AMI) into the inferior colliculus (IC) for hearing restoration have shown that these patients do not achieve performance levels comparable to cochlear implant patients. The AMI consists of a single-shank array (20 electrodes) for stimulation along the tonotopic axis of the IC. Recent findings suggest that one major limitation in AMI performance is the inability to sufficiently activate neurons across the three-dimensional (3-D) IC. Unfortunately, there are no currently available 3-D array technologies that can be used for clinical applications. More recently, there has been a new initiative by the European Commission to fund and develop 3-D chronic electrode arrays for science and clinical applications through the NeuroProbes project that can overcome the bulkiness and limited 3-D configurations of currently available array technologies. As part of the NeuroProbes initiative, we investigated whether their new array technology could be potentially used for future AMI patients. Since the NeuroProbes technology had not yet been tested for electrical stimulation in an in vivo animal preparation, we performed experiments in ketamine-anesthetized guinea pigs in which we inserted and stimulated a NeuroProbes array within the IC and recorded the corresponding neural activation within the auditory cortex. We used 2-D arrays for this initial feasibility study since they were already available and were sufficient to access the IC and also demonstrate effective activation of the central auditory system. Based on these encouraging results and the ability to develop customized 3-D arrays with the NeuroProbes technology, we can further investigate different stimulation patterns across the ICC to improve AMI performance.
authors: Institute of Audioneurotechnology and Department of Experimental Otology, Hannover Medical University, Hannover, Germany.
authors: Roger
authors: R
authors: Calixto
authors: Behrouz
authors: B
authors: Salamat
authors: Thilo
authors: T
authors: Rode
authors: Tanja
authors: T
authors: Hartmann
authors: Bart
authors: B
authors: Volckaerts
authors: Patrick
authors: P
authors: Ruther
authors: Thomas
authors: T
authors: Lenarz
authors: Hubert H
authors: HH
authors: Lim
mesh_terms: D000200:Action Potentials; D000818:Animals; D003054:Cochlear Implants; D004566:Electrodes; D006168:Guinea Pigs; D011474:Prosthesis Design; D013997:Time Factors