Extracochlear eight-channel electrode system

Abstract

SummaryThe Cologne-Diiren research group has developed a new extracochlear eight-channel electrode system. The first observations on six cases have shown encouraging psychoacoustic results.

Cochlear Implants

“…Each electrode carried speech information from third-octave band-pass filters. In 1984, 46 patients had the operation (Banfai et al 1986;Banfai 1987). Although studies showed that pitch discrimination could be obtained by extracochlear stimulation at different sites over the cochlea (Banfai et al 1986), this was not conclusive.…”

“…In 1984, 46 patients had the operation (Banfai et al 1986;Banfai 1987). Although studies showed that pitch discrimination could be obtained by extracochlear stimulation at different sites over the cochlea (Banfai et al 1986), this was not conclusive. In a larger group of patients the author reported that "11% of the first 129 implantees showed some signs of developing open-speech perception" (Banfai 1987).…”

“…The study was undertaken on 10 human temporal bones. The medial wall has also been the site for drilling the overlying bone to site extracochlear electrodes (Banfai et al 1984(Banfai et al , 1985. The relationships of the cochlear turns to the overlying inner wall of the middle ear are also of particular relevance to surgery for labyrinthitis ossificans.…”

“…An extracochlear multiple-electrode array was considered a possible alternative to an intracochlear array by Banfai et al (1984b) and Banfai et al (1985), because trauma to the cochlea would be less. It was necessary, however, to drill down to the endosteum of the cochlea as the spread of current could be extracochlear and not provide localized stimulation for place coding, and as bone has a high impedance the receiver-stimulator would run out of voltage compliance and not be able to stimulate the neurons as discussed above.…”

“…These include electrodes inserted directly into the auditory nerve via holes drilled into the modiolus , electrodes inserted into the scala tympani via fenestrations made into the otic capsule following the compartmentalizing of the scala with Silastic Chouard 1980;, and ball electrodes placed into holes created in the otic capsule (Banfai et al 1984b;Banfai et al 1985). However, as discussed above, the most common approach has been to introduce the array along the scala tympani via an approach through the round window Burian et al 1980;Schindler and Bjorkroth 1979;Schindler et al 1987Schindler et al , 1993.…”