The optimization of an implantable tinnitus suppressor using an extracochlear stimulation method

Abstract

Tinnitus patients have been treated using simple electrical stimulation to the promontory of the cochlea. With this treatment about 60% of the patients reported that the tinnitus was suppressed. This method, however, suppresses tinnitus for only a short period of time, so many tinnitus sufferers have long been waiting for an implant system which will be able to suppress tinnitus whenever it appears. For this reason, an implantable tinnitus suppressor has been developed using extracochlear stimulation technologies. The implantable tinnitus suppressor consists of a wave generator, a primary coil set behind the auricle, a secondary chip coil implanted in the mastoid cavity, a Pt–Ir electrode covered with a polyvinyl alcoholic gel placed on the promontory, and a return electrode fixed to the subcutaneous tissue near the mastoid tip. The wave generated by the electric circuit of the wave generator is sent to the primary coil. The current that is induced in the secondary coil by using electromagnetic coupling is transmitted to the Pt–Ir electrode. The main purpose of this study is to optimize the function of this implantable tinnitus suppressor. [Work supported by the Ministry of Education, Science and Culture, Grant-in-Aid for Scientific Research (A)(2) No. 06402067.]