ABSTRACT
OBJECTIVE: To validate a newly designed cochlear implant electrode (TRACE) in the standard monopolar mode and compare it to a patient group implanted with a standard Nucleus Contour cochlear implant electrode. The electrode contacts of the TRACE electrode have the same active surface area for stimulation, but the position in the scala tympani is different from that of the Nucleus Contour electrode. MATERIAL AND METHODS: The following parameters, used in cochlear implant fitting and evaluation procedures, were determined: the threshold and comfort stimulation current levels; the electrode impedances; and the phoneme discrimination and speech recognition scores using the ACE speech algorithm. CONCLUSION: The new electrode does not differ significantly from the standard Nucleus Contour electrode in terms of the investigated parameters within the test group.
Subject(s)
Cochlear Implants , Deafness/rehabilitation , Speech Perception , Acoustic Impedance Tests , Algorithms , Audiometry , Auditory Threshold , Cochlear Implants/standards , Electric Impedance , Electrodes/standards , Humans , Male , Prosthesis Design , Prosthesis Fitting , Scala Tympani/surgery , Speech Discrimination Tests , Treatment OutcomeABSTRACT
Different individual test methods and protocols have been reported for the in-vitro evaluation of temporal bones implanted with newly designed cochlear implant electrodes, prior to human implantation. In practice, however, these methods may not always give the required information. In this study, a large battery of tests has been evaluated using the electrode as a fixed parameter. Standard clinical x-ray gave the best information to evaluate the electrode's position. Light microscopic evaluation and polishing technique studies proved to be the most valuable techniques to evaluate endocochlear damage.
ABSTRACT
A 48 contact cochlear implant electrode has been constructed for electrical stimulation of the auditory nerve. The stimulating contacts of this electrode are organised in two layers: 31 contacts on the upper surface directed towards the habenula perforata and 17 contacts connected together as one longitudinal contact on the underside. The design of the electrode carrier aims to make radial current flow possible in the cochlea. The mechanical structure of the newly designed electrode was optimised to obtain maximal insertion depth. Electrode insertion tests were performed in a transparent acrylic model of the human cochlea.
