• 전자공학회논문지
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• 제50권4호
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• pp.229-235
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• 2013

본 논문은 최근 활발하게 연구되고 있는 뇌-기계 접속을 위한 완전 삽입형 마이크로 시스템의 구현에 있어서 중요한 이슈들을 고찰한다. 현재까지의 과학 기술적 연구는 신경 신호 증폭기, 무선 신호 전송 등 주로 고성능 저전력 전자기기 및 시스템을 구현하는데 집중되어 왔으나, 마이크로 시스템의 실제적인 응용은 전자 기기의 특성뿐만 아니라 밀봉 구조의 디자인에서 뇌의 생리 해부학적 특성에 이르기까지 여러 가지 요인에 의해 영향을 받게 된다. 본 논문은 특히 뇌 삽입형 마이크로 시스템의 실질적인 구현에 결정적인 영향을 주는 시스템 발열의 영향, 신경 프로브의 감지 부피, 무선 데이터 전송 및 전력 전달, 그리고 뇌의 생리 해부학적인 고려 요인에 대해 논의한다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1990년도 추계학술대회
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• pp.118-121
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• 1990

This paper describes development of an implantable power switching system for biotelemetry system. This system is designed and manufactured to achieve as small size and low power dissipation as possible, using pulse powered circult and CMOS technology. The function of the power switching system is to connect the implantable battery to implanted sensors and, electronics systems by receiving intermittent command signals from external circuits. The power dissipation of this system was about $15{\mu}W$ for a stand-by operation.

• IEIE Transactions on Smart Processing and Computing
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• 제4권3호
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• pp.133-140
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• 2015

Neural stimulating implantable medical devices (IMDs) have been widely used to treat neurological diseases or interface with sensory feedback for amputees or patients suffering from severe paralysis. More recent IMDs, such as retinal implants or brain-computer interfaces, demand higher performance to enable sophisticated therapies, while consuming power at higher orders of magnitude to handle more functions on a larger scale at higher rates, which limits the ability to supply the IMDs with primary batteries. Inductive power transmission across the skin is a viable solution to power up an IMD, while it demands high power efficiencies at every power delivery stage for safe and effective stimulation without increasing the surrounding tissue's temperature. This paper reviews various wireless neural stimulating systems and their power management techniques to maximize IMD power efficiency. We also explore both wireless electrical and optical stimulation mechanisms and their power requirements in implantable neural interface applications.

• 대한의용생체공학회:의공학회지
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• 제26권5호
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• pp.309-317
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• 2005

It is expected that fully-implantable middle-ear hearing devices (FIMEHDs) will soon be available with the advantages of complete concealment, easy surgical implantation, and low power operation to resolve the problems of semi-implantable middle-ear hearing devices (SIMEHDs) such as discomfort of wearing an external device and replacement of battery. Over the last 3 years, a Korean research team at Kyungpook National University has developed an FIMEHD called ACRHS-1 based on a differential floating mass transducer (DFMT). The main research focus was functional improvement, the establishment of easy surgical procedures for implantation, miniaturization, and a low-power operation. Accordingly, this paper reviews the overall system architecture, functions, and experimental results for ACRHS-1 and its related accessories, including a wireless battery charger and remote controller.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.17.1-17.1
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• 2011

Inorganic III-V light emitting diodes (LEDs) have superior characteristics, such as long-term stability, high efficiency, and strong brightness compared to conventional incandescent lamps and OLED. However, due to the brittle property of bulk inorganic semiconductor materials, III-V LED limits its applications in the field of high performance flexible electronics. This seminar introduces the first flexible and implantable GaN LED on plastic substrates that is transferred from bulk GaN on Si substrates. The superb properties of the flexible GaN thin film in terms of its wide band gap and high efficiency enable the dramatic extension of not only consumer electronic applications but also the biosensing scale. The flexible white LEDs are demonstrated for the feasibility of using a white light source for future flexible BLU devices. Finally a water-resist and a biocompatible PTFE-coated flexible LED biosensor can detect PSA at a detection limit of 1 ng/mL. These results show that the nitride-based flexible LED can be used as a type of implantable LED biosensor and as a therapy tool.

• Journal of Yeungnam Medical Science
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• 제24권2호
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• pp.97-106
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• 2007

Functional electrical stimulation (FES) has developed over the last 35 years to become a scientifically, technologically and clinically recognized field of interest in clinical medicine. FES has been applied to locomotion, grasping, ventilation, incontinence, and decubitus healing. However, all of these achievements illustrate the initial applications of FES; its true potential has not yet been realized. Recently, FES systems, which are miniaturized stimulation devices, have been utilized in the clinical setting. However, because the stimulating electrodes of the current FES devices are percutaneous electrodes, which are susceptible to wire breakage, and skin infection an implantable FES stimulating electrode has been introduced in the U.S. and Japan. In the present study, an external power supply method using radio frequency (RF) coupling and data transmission was developed for the control of the implantable FES device. In addition, we review the current understanding of FES devices and their application in clinical medicine.

• The Korean Journal of Pain
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• 제10권2호
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• pp.274-277
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• 1997

The complex regional pain syndrome(CRPS) exhibit symptoms such as: abnormal skin color, temperature change, abnormal pseudomotor activity, edema. If CRPS is not treated appropriately at acute stage, then the affected extremity may become a useless, painful appendage. Treatment of CRPS by sympathetic blockade may be achieved by repeated intravenous regional guanethidine blocks, repeated anesthetic sympathetic blocks, surgical sympathectomy or oral sympatholytic therapy. We treated 29-year-old male patient with CRPS of left upper extremity by continuous cervical epidural blockade. Due to wound infection and dislocation of the epidural catheter, we inserted an implantable port system to inject the mixture of local anesthetics and small amount of morphine. After 10 months of treatment, patient was cured of symptoms and signs of CRPS and was able to resume a normal life.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.762-767
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• 1991

To make electromechanical total artificial heart implantable inside the body, transcutaneous energy transmission system was designed and simulated by using PSPICE program. The fabricated system was evaluated by using Mock circulation system and showed comparable performance with the D.C power supply

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.583-584
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• 2011

• 센서학회지
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• 제19권5호
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• pp.361-368
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• 2010

ACROSS device, which is composed of an implantable microphone, a signal processor, and a vibrating transducer, is a fullyimplantable middle ear hearing device(F-IMEHD) for the recovery of patients with hearing loss. And since a microphone is implanted under skin and tissue at the temporal bones, the amplitude of the sound wave is attenuated by absorption and scattering. And the vibrating transducer attached to the ossicular chain caused also the different displacement from characteristic of the stapes. For the gain control of auditory signals, most of implantable hearing devices with the digital audio signal processor still apply to fitting rules of conventional hearing aid without regard to the effect of the implanted microphone and the vibrating transducer. So it should be taken into account the effect of the implantable microphone and the vibrating transducer to use the conventional audio fitting rule. The aim of this study was to measure gain characteristics caused by the implanted microphone and the vibrating transducer attached to the ossicle chains for the gain compensation of ACROSS device. Differential floating mass transducers (DFMT) of ACROSS device were clipped on four cadaver temporal bones. And after placing the DFMT on them, displacements of the ossicle chain with the DFMT operated by 1 $mA_{peak}$ current was measured using laser Doppler vibrometer. And the sensitivity of microphones under the sampled pig skin and the skin of 3 rat back were measured by stimulus of pure tones in frequency from 0.1 to 8.9 kHz. And we confirmed that the microphone implanted under skin showed poorer frequency response in the acoustic high-frequency band than it in the low- to mid- frequency band, and the resonant frequency of the stapes vibration was changed by attaching the DFMT on the incus, the displacement of the DFMT driven with 1 $mA_{rms}$ was higher by the amount of about 20 dB than that of cadaver's stapes driven by the sound presssure of 94 dB SPL in resonance frequency range.