• Journal of Chest Surgery
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• 제40권10호
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• pp.691-695
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• 2007

배경: 중심정맥 도관은 1979년 처음 사용된 이래로 암환자의 치료에 있어 많은 편의를 제공하였다. 이에 본원 흉부외과에서는 완전 거치형 정맥도관의 임상 양상 및 사용에 따른 합병증 등을 분석하여 향후 치료에 도움이 되고자 본 연구를 하였다. 대상 및 방법: 2004년 11월부터 2006년 2월까지 완전 거치형 정맥도관 시술을 받은 100명의 환자를 대상으로 후향적 연구를 하여 다음과 같은 결과를 얻었다. 결과: 완전 거치형 정맥 도관 시술의 삽입정맥으로는 우측 쇄골하정맥 삽입이 74예(74%)였으며 좌측쇄골하 정맥(21예, 21%), 우측 경정맥(3예, 3%), 좌측 경정맥(1예, 1%)을 사용하였으며 1예에서는 우측 대퇴정맥을 사용하였다. 초기 합병증으로는 위치 이상이 5예(5%)와 동맥천자한 경우 5예 있었다. 만기 합병증으로는 쇄골하 정맥 혈전 형성이 한 예 있어 현재 항응고제 복용중이며 pinch off 증후군이 2예 있었다. 그 외의 초기 또는 만기 합병증은 없었다. 결론: 완전 거치형 도관의 사용은 합병증의 발생률은 낮고 비교적 안전한 방법이지만 감염, 혈전 형성, 도관의 절단 등은 장기간 사용시 나타날 수 있는 합병증으로 초기에 진단 및 치료가 된다면 더 큰 합병증을 예방할 수 있다.

• 한국멀티미디어학회논문지
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• 제18권5호
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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.

• 전자공학회논문지SC
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• 제48권5호
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• pp.74-80
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• 2011

본 연구는 유통되는 이식형(implantable) 의료기기의 추적(tracking) 및 회수(recall) 처리를 신속하고 정확하게 수행할 수 있는 통합 전산 관리시스템 설계하는 것을 목적으로 한다. 이를 위해 최신 FDA 규정을 만족하는 시스템을 MSF/CD 설계방법론을 기반으로 설계하였다. 추적과 회수의 주요한 4가지 가상 시나리오를 설정하고 workflow diagram을 작성하여 개념설계하였다. 또한 business workflow를 만족하는 서버의 논리 DB를 개발하여 논리설계 단계까지 시스템을 설계하였다. 제안된 시스템으로 이식형 의료기기의 심각한 부작용 등 문제 발생 시 신속하고 정확한 추적과 회수 처리가 가능하여 이식형 의료기기를 장착한 환자의 생명유지 및 국민 건강 보호를 위한 정부 차원의 효율적인 관리가 가능할 것으로 사료된다.

• 대한의용생체공학회:의공학회지
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• 제31권4호
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• pp.292-301
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• 2010

To restore visual sensation of blind patients, we have proposed a fully implantable retinal prosthesis comprising an three dimensionally (3D) stacked retinal chip for transforming optical signal to electrical signal, a flexible cable with stimulus electrode array for stimulating retina cells, and coupling coils for power transmission. The 3D stacked retinal chip is consisted of several LSI chips such as photodetector, signal processing circuit, and stimulus current generator. They are vertically stacked and electrically connected using 3D integration technology. Our retinal prosthesis has a small size and lightweight with high resolution, therefore it could increase the patients` quality of life (QOL). For realizing the fully implantable retinal prosthesis, we developed a retinal prosthesis module comprising a retinal prosthesis chip and a flexible cable with stimulus electrode array for generating optimal stimulus current. In this study, we used a 2D retinal chip as a prototype retinal prosthesis chip. We fabricated the polymide-based flexible cable of $20{\mu}m$ thickness where 16 channels Pt stimulus electrode array was formed in the cable. Pt electrode has an impedance of $9.9k{\Omega}$ at 400Hz frequency. The retinal prosthesis chip was mounted on the flexible cable by an epoxy and electrically connected by Au wire. The retinal prosthesis chip was cappted by a silicone to pretect from corrosive environments in an eyeball. Then, the fabricated retinal prosthesis module was implanted into an eyeball of a rabbit. We successfully recorded electrically evoked potential (EEP) elicited from the rabbit brain by the current stimulation supplied from the implanted retinal prosthesis module. EEP amplitude was increased linearly with illumination intensity and irradiation time of incident light. The retinal prosthesis chip was well functioned after implanting into the eyeball of the rabbit.

• Archives of Plastic Surgery
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• 제44권1호
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• pp.42-47
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• 2017

Background Skin erosion is a dire complication of implantable cardiac pacemakers and defibrillators. Classical treatments involve removal of the entire generator and lead systems, however, these may result in fatal complications. In this study, we present our experience with a simplified salvage technique for exposed implantable cardiac electronic devices (ICEDs) without removing the implanted device, in an attempt to reduce the risks and complication rates associated with this condition. Methods The records of 10 patients who experienced direct ICED exposure between January 2012 and December 2015 were retrospectively reviewed. The following surgical procedure was performed in all patients: removal of skin erosion and capsule, creation of a new pocket at least 1.0-1.5 cm inferior to its original position, migration of the ICED to the new pocket, and insertion of closed-suction drainage. Patients with gross local sepsis or septicemia were excluded from this study. Results Seven patients had cardiac pacemakers and the other 3 had implantable cardiac defibrillators. The time from primary ICED placement to exposure ranged from 0.3 to 151 months (mean, 29 months. Postoperative follow-up in this series ranged from 8 to 31 months (mean follow-up, 22 months). Among the 10 patients, none presented with any signs of overt infection or cutaneous lesions, except 1 patient with hematoma on postoperative day 5. The hematoma was successfully treated by surgical removal and repositioning of the closed-suction drainage. Conclusions Based on our experience, salvage of exposed ICEDs is possible without removing the device in selected patients.

• 대한의용생체공학회:의공학회지
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• 제26권3호
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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.

• 대한전자공학회논문지SD
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• 제45권1호
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• pp.28-36
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• 2008

이번 논문은 implantable cardiac 페이스메이커의 검출 단 로서 저전압, 저전력 단일-비트 삼차 델타-시그마 모듈레이터를 구현하였다. 1V이하의 전원 전압에서 효과적으로 동작하기 위하여 distributed feedforward구조와 벌크-드리븐 OTA를 활용하였다. 설계된 모듈레이터는 0.8V의 전원 전압에서 49dB의 dynamic range를 가지면서 816nW의 파워를 소모하였다. 파워 소모를 획기적으로 줄임으로서 페이스메이커뿐만 아니라 제한된 배터리에서 동작하는 implantable 의료 기기에서 다양한 활용이 가능할 것으로 생각된다. 본 모듈레이터의 칩 크기는 $1000{\mu}m{\times}500{\mu}m$로서 $0.18{\mu}m$ CMOS standard 공정으로 제작되었다.

• 센서학회지
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• 제14권5호
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• pp.322-330
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• 2005

A new type of transducer, piezoelectric floating mass transducer (PFMT) which has advantages of piezoelectric and electromagnetic transducer has been proposed and implemented for the implantable middle ear hearing devices. By the uneven bonding of piezoelectric material to the inner bottom of transducer case, the PFMT can vibrate back-and-forth along the longitudinal axis of the transducer even though the piezoelectric material within the cylindrical case produces only the bilateral expansion and contraction according to the applied electrical signal. To improve efficiency of the PFMT, the multi-layered piezoelectric material has been adapted. The small number of components in the PFMT enables the simple manufacturing and the easy implanting into the middle ear. In order to examine the characteristics of vibration, mechanical modeling and finite element analyses of the proposed transducer have been performed. From the result of theoretical analyses and the measured data from the experiment, it is verified that the implemented PFMT can be used in implantable middle ear hearing devices.

• ETRI Journal
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• 제37권2호
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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%.

• Archives of Plastic Surgery
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• 제46권6호
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• pp.594-598
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• 2019

Overall complication rates of 9.1% have been reported following implantable cardioverter defibrillator (ICD) placement. Brachial plexus injury is infrequently reported in the literature. We describe a 26-year-old female experiencing left arm nerve pain, a positive Tinel's sign, numbness in the median nerve distribution of the hand and biceps muscle weakness following revision ICD via subclavian vein approach. Nerve conduction studies identified severe partial left brachial plexopathy, which remained incompletely resolved with conservative management. Surgical exploration revealed lateral cord impingement by the ICD generator and a loop of the ICD lead, along with fibrosis, necessitating surgical neurolysis and ICD generator repositioning. As increasing numbers of patients undergo cardiac device implantation, it is incumbent on practitioners to be aware of potential increases in the prevalence of this complication.