Study On Electrode Array Of Cochlear Implant Based On MEMS

Deafness affects a large number of people throughout the world. Deafness, which may be due to many different causes, is generally of two types, conductive and sensorineural. Conductive deafness may often be help by use of conventional hearing aids. Sensorineural deafness is due to the absence of, or destruction of, the hair cells in the cochlea which transducer acoustic signals into nerve impulses. These people are thus unable to derive suitable benefit from conventional hearing aid systems.It is for this purpose that cochlear implant systems have been developed. In our country, the deaf patients cannot benefit from the high technology, just because they cannot afford the high it. So, we should develop the cochlear implant system depending on ourselves, and we should improve its quality and lower its price to meet the requirement of deaf patients in our country, which can lead to great social benefit and economic benefit. Cochlear implant (CI) is a system designed to functionally replace the human cochlea for the severe to profound hearing impaired patients. Sound energy is converted to electrical signal and processed through a speech processor. The electrical signal is then delivered via a headpiece or antenna to the electrode array implanted in the inner ear. Specifically, the energy is then channeled to the hearing nerve. Clinically, CI is found to be quite effective in restoring hearing to hearing impaired patients. It has the following features in common: a microphone that picks up the sound, a signal processor that converts the sound into electric signals, a transmission systemthat transmits the electrical signals to the implanted electrodes, and an electrode or an electrode array (consisting of multiple electrodes) that is inserted into the cochlea by a surgeon. This paper focuses primarily on the electrode array design. The design of electrodes for cochlear prosthesis has been the focus of research for over two decades. In signals-channel implants only one electrode is used. In multichannel cochlear implants, an electrode array is inserted in the cochlea so that different auditory nerve fibers can be simulated at different places in the cochlea, thereby exploiting the place mechanism for coding frequencies. Typically, the electrical stimulation are done in common ground mode, monopolar mode and bipolar mode. Since bipolar mode allows better focus of the electrical energy, this paper will study the CI electrode array in bipolar mode only. This paper gives four-channel electrode array design by CAD,CoventorWare based on existing technology. This paper can provide some use of reference for developing some high quality and low price cochlear implant, which can bring a lot of benefits to deaf patients in our country.