• ETRI Journal
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• v.37 no.2
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• pp.204-211
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• 2015

For this study, we designed an implantable rectangular spiral antenna for medical biotelemetry in the Medical Implant Communications Service band (402 MHz to 405 MHz). The designed antenna has a U-shaped loop for impedance matching. The antenna impedance is easily adjusted by controlling the shape and length of the U-shaped loop. Significant design parameters were studied to understand their effects on the antenna performance. To verify the potential of the antenna for the desired applications, we fabricated a prototype and measured its performance in terms of the resonant characteristics and gain radiation patterns of the antenna. In the testing phase, the prototype antenna was embedded in human skin tissue-emulating gel, which was developed to simulate a real operation environment. The measured resonant characteristics show good agreement with the simulations, and the -10 dB frequency band is within the range of 398 MHz to 420 MHz. The antenna exhibits a maximum gain of -22.26 dBi and an antenna efficiency of 0.215%.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.112-115
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• 2016

This paper demonstrates a scalp-implantable miniaturized antenna at the medical implant communication service (MICS) (402-405MHz) band. The antenna size is only $27.63mm^3$($8.5mm{\times}6.5mm{\times}0.5mm$), which is the smallest antenna for the MICS band. Miniaturization is achieved by using a symmetrical serpentine shaped radiating patch and placing open-end slots in the ground plane. In addition, co-axial feeding is used for excitation with a shorting pin connected between the radiator and ground. The antenna was simulated in a homogeneous skin model and in the human scalp. An experimental prototype of the proposed antenna was fabricated and measured in a skin-mimicking gel. Good agreement was obtained between the measurement and simulation results, showing a broad bandwidth of 49 MHz (from 395 to 444 MHz) for |S11| less than -10 dB and a maximum gain of -42.87 dBi. This gain is higher than the previous MICS antenna with respect to antenna size.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.383-386
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• 2017

In this study, we introduce a triple-band flexible implantable antenna that is tuned by using a ground slot in three specific bands, namely Medical Implanted Communication Service (MICS: 402-405 MHz) for telemetry, the midfield band (lower gigahertz: 1.45-1.6 GHz) for Wireless Power Transfer (WPT), and the Industrial, Scientific and Medical band (ISM: 2.4-2.45 GHz) for power conservation. This antenna is wrapped inside a printed 3D capsule prototype to show its applicability in different implantable or ingestible devices. The telemetry performance of the proposed antenna was simulated and measured by using a porcine heart. From the simulation and measurement, we found that use of a ground slot in the implantable antenna can improve the antenna performance and can also reduce the Specific Absorption Rate (SAR).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.776-781
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• 2008

In this study, ubiquitous health care system attaching in chair to monitor ECG for health care was developed at the unconsciousness state. The system conveniently and simple measured ECG at non-consciousness. We measured the contact impedance to skin-electrode of metal mesh electrodes of the system. Contact impedance enable the electrode to use for ECG measurement. The results are that the impedance of the metal mesh electrodes according to sizes is low when the size is 4$cm^2$. As the result, when the size of the metal mesh electrode is 4$cm^2$, the electrode is fit for ECG measurement. We can acquired by positing the arm on the metal mesh electrode. The ECG signal was detected using a high-input-impedance bio-amplifier, and then passed filter circuitry. The measured signal transmitted to a PC through the bluetooth wireless communication and monitored. Data of the non-constrained ECG system attaching in chair is noise-data when comparing metal mesh electrode with the Ag/Agcl electrode but the data is significant to monitor ECG for check the body state.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.172-180
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• 1994

Implantable biotelemetry systems are indispensable tools not only in animal research but also in clinical medicine as such systems enable the acquisition of otherwise unavailable physiological data. We present the manufacture of CMOS IC and its system for implantable multichannel biotelemeter system. The internal circuits of this system are designed not only to achieve as multiple functions and low power dissipation as possible but also to enable continuous measurement of physiological data. Its main functions are to enable continuous measurement of physiological data and to accomplish on-off power swiching of an implantable battery by receiving appropriate commanc signals from an external circuit. The implantable circuits of this system are designed and fabricated on a single silicon chip using $1.5\mu$m n-well CMOS process technology. The total power dissipation of implantable circuits for a continuous operation was 6.7mW and for a stand-by operation was 15.2$\mu$ W. This system used together with approriate sensors is expected to contribute to clinical medicine telemetry system of measuring and wireless transmitting such significant physiological parameters as pressure pH and temperature.