Sandvik provides medical grade wires which act as electrodes and implants which are used to treat hearing disorders. The wires find their end use in applications such as cochlear implants, middle ear implants and bone conduction systems. Precious metals such as platinum iridium (PtIr) as well as telemetry coils are used for cochlear implants. This type of alloy maximizes the fatigue strength which is critical in implant devices such as lead wires for cochlear implants and critical electrodes.
Devices to stimulate the damaged portions of the inner ear to deliver sound signals to the brain. The cochlear implant consists of the following parts:
- Speech processor Transmitter
- Electrode array.
The sound energy is first received by the microphone which transmits this to the speech processor. The function of the speech processor is to filter and convert the sound energy into a numerical code. This code is transferred back to the headpiece cord where it is transmitted to the internal receiver via radio frequencies. The internal receivers are connected to the electrode which is planted inside the cochlea. When the signals are received by the electrodes, they stimulate the auditory nerves directly without passing through the damaged portion of the ear. The fibres of the cochlear nerve are stimulated and sound is perceived.
- Sandvik manufactures and provides high quality wires which are alloys of platinum and iridium and are encased within the silicone of the electrode array.
Middle ear implants
A comparatively recent development in the field of hearing stimulation and it stimulates the nerves of the inner ear using mechanical energy impulses. It consists of two parts, the processor and the internal part with is surgically placed. The function of the processor is to transmit the sound energy to the internal part of the device which consists of a receiver which picks up the sound. The implant is attached to the bones of the middle ear and vibrates the membrane windows upon transmission of the sound signals via the receiver through a tightly coiled metal wire.
- The metal wire is provided by Sandvik in drawn condition, annealed or coated with a suitable polymer or PTFE coating.
Bone conducting systems
Transmit sound and stimulate the acoustic signal via bone conduction. They contain a titanium implant, an abutment and a sound processor which are placed behind the ear. The bone conducting system works in a similar way to a conventional hearing aid in that the sound waves are picked up by the processor. Unlike a conventional hearing aid, it transmits the sound waves to the inner ear through vibrations of the skull bone.