• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.63-71
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• 2009

It is said that the desirable bio-signal measurement and stimulation system should be an implantable type if the several problems such as biocompatibility, electrical safety, and so on are overcome. In addition to the biocompatibility issue, a robust RF communication and a stable electrical power source for the implantable bio-signal measurement and stimulation system are very important matters. In this paper, a wireless telemetry system which adopts the FCC's approved MICS (medical implant communication service) protocol and a wireless power transmission has been proposed. The proposed system composed of a base station (BS) and an implantable medical device (IMD) has the advantages that the interference with other RF devices can be reduced by the use of the specially assigned MICS frequency band of 402.MHz to 405 MHz. Also, the proposed system includes various functions of a multi-channel bio-signal acquisition and an electric stimulation. Since the electrical power for the IMD can be provided by the inductive link between PCB patterned coils, the IMD needs no battery so that the IMD can be smaller size and much less dangerous than the active type IMD which includes the internal battery. Finally, the validity as a wireless telemetry system has been demonstrated through the experiments by using the implemented BS and IMD.

• Journal of Korea Multimedia Society
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• v.18 no.5
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• pp.652-662
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• 2015

It is necessary to develop small, implantable bio-telemetry systems which can measure and transmit patients' bio-signals from internal body to external receiver. When measuring bio-signals, like electrical bio-signals, acoustic bio-signal measurement has also a big clinical usefulness. But, sound signal has larger frequency bandwidth than any other bio-signals. When considering these issues, a wireless telemetry system which has rapid data transmission rate proportional to wide frequency bandwidth is necessary to be developed. The bluetooth module is used to overcome the data rate limitation caused by the large frequency bandwidth. In this paper, a novel multimedia bluetooth biotelemetry system was developed which consists of transmitter module located in the body and receiver device located outside of the body. The transmitter consists of microphone, bluetooth, and wireless charging device. And the receiver consists of bluetooth and codec system. The sound inside the skin is captured by microphone and sent to receiver by bluetooth while charging. The wireless charging system constantly supplies the electric power to the system. To verify the performance of the developed system, an in vitro experiment has been performed. The results show that the proposed biotelemetry system has ability to acquire the sound signals under the skin.

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.249-257
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• 2003

The bio-telemetry technologies, that use the wireless miniaturized telemetry module implanted in the human body and transmits several biomedical signal from inside to outside of the body, have been expected to solve the problem such as the patient's inconvenience and the limit for diagnosis. In the case of transceiver system using the wireless RF transmission method, the method of three-dimensional localization for implantable miniaturized telemetry module is necessary to detect the exact position of disease. A new method for three-dimensional localization using small loop antenna in the implantable miniaturized telemetry module was proposed in this paper. We proposed a method that can accurately determine the position of telemetry module by analyzing the differences in the strength of signal, which is received at each of the small size RF receiver array installed on the body surface.

• Journal of Sensor Science and Technology
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• v.17 no.1
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• pp.23-28
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• 2008

In order to measure bio-signals, it is desirable to build a fully implantable system which connects directly to neural pathways or body tissue. A design scheme for fully implementable measurement system is proposed in this paper. Consisting of an implanted module and an external system, the proposed scheme delivers power and data between the two modules. The external module sends power via inductive link using a simple H-bridge type oscillator. Also, the implanted module sends measured data to the external system utilizing R/F communication technique at a frequency of ISM band. A stable communication and operation is achieved as the two types of channels are separated. Implemented in a compact size enough to be implanted in human body, the system exhibits good performance in experimental studies.

• Progress in Medical Physics
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• v.19 no.1
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• pp.42-48
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• 2008

Bio-implantable devices such as heart pacers, gastric pacers and drug-delivery systems require power for carrying out their intended functions. These devices are usually powered through a battery implanted with the system or are wired to an external power source. This paper describes an inductive power transmission link, which was developed for an implantable stimulator for direct stimulation of denervated muscles. The carrier frequency is around 1MHz, the transmitter coil has a diameter of 46mm, and the implant coil is 46mm. Data transmission to the implant with amplitude shift keying (ASK) and back to the transmitter with passive telemetry can be added without major design changes. We chose the range of coil spacing (2 to 30mm) to care for lateral misalignment, as it occurs in practical use. If the transmitter coil has a well defined and reliable position in respect to the implant, a smaller working range might be sufficient. Under these conditions the link can be operated in fixed frequency mode, and reaches even higher efficiencies of up to 37%. The link transmits a current of 50 mA over a distance range of 2-15 mm with an efficiency of more than 20% in tracking frequency. The efficiency of the link was optimized with different approaches. A class E transmitter was used to minimize losses of the power stage. The geometry and material of the transmitter coil was optimized for maximum coupling. Phase lock techniques were used to achieve frequency tracking, keeping the transmitter optimally tuned at different coupling conditions caused by coil distance variations.