• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.49-56
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• 2004

A low power consuming voice signal processing and control module was designed using a small $\mu$-controller for use in a totally implantable middle ear system. The module was designed that it can control the implanted system as well as process the fitting algorithm of input sound signal. In ordinary operation mode, the $\mu$-controller processes the applied sound signal for compensating the hearing loss of the patients. When the control signal is applied from the IR receiving module, the $\mu$-controller interrupts the signal processing and executes the order of the control signals such as power on/off, volume up/down. The designed module was implemented and verified the performance of the system through several experiments.

• Journal of Sensor Science and Technology
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• v.14 no.2
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• pp.78-84
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• 2005

A contactless recharging device for totally implantable middle ear systems has been designed as a pillow type that the user can recharge the implanted battery with taking a rest. The proposed device uses the electromagnetic coupling between the transmitting coil and the receiving coil. To supply sufficient power for the implanted circuits, each coil uses LC resonance and the implanted device uses voltage doubler. A power MOSFET is used for switching the DC voltage of LC parallel circuit and the switching frequency demands on a programmable frequency generator which is controlled by microcontroller. In order to improve the electromagnetic coupling efficiency at specific positions of coil which may vary with the displacement of head, the optimal location of receiving coil was studied, and the 5 transmitting coils in a pillow for recharging the implant module was designed. From such a recharging experiment, it was found that the proposed device could provide the sufficient operating voltage within the distance of 4 cm between pillow and the implanted device.

• Journal of Biomedical Engineering Research
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• v.26 no.3
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• pp.139-144
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• 2005

An implantable microphone that can be utilized as part of a totally implantable hearing aid is designed and implemented. The proposed microphone is implanted in the center of the pinna, and designed to ensure the speech frequency range and the appropriate sensitivity. The characteristics of the proposed microphone are evaluated using a finite element analysis (FEA). The microphone is composed of a small electric condenser microphone, titanium case 6.2mm in diameter and 3mm high, and $10{\mu}m$ SUS316L vibrating membrane in contact with hypodermic tissue to maintain the sensitivity of the microphone. The microphone components are all made of biocompatible materials, then the assembled microphone is hermetically sealed using a polymer and ceramic. Experiments with the fabricated microphone confirm an operational bandwidth of up to 5kHz without any decline of sensitivity in 6mm of hypodermic tissue.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.71-78
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• 2004

An infrared remote control-type transcutaneous control device using a $\mu$-processor is design for the totally implantable middle ear system. An infrared light transmission model for the tissue of skin was introduced and then a radiant intensity and the required current of the infrared light emitting diode(IR LED) driving circuit at transmission part were calculated for the external control device. And the transmission part generates IR signal by the system's own data protocol which prevents interferences from other infrared remote controls of the household appliances. The control part of the implanted device was designed to analyze functions of the received infrared(IR) signal that indicate the power ON/OFF and volume UP/DOWN. After the system is implemented, a data transmission experiments using 4 mm thickness of porcine skin were carried out. From the experiment, it was verified that the infrared control signal was transmitted to receiving module of the implemented system without any error.