• Journal of Chest Surgery
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• v.32 no.5
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• pp.428-432
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• 1999

Background: It has been shown that low-grade electrical stimulus can transform fatigue resistant muscles which then can be used to protect the heart. The bulky and cumbersome power sources of the artificial heart or implantable ventricular assist devices are still in need of solution; however, on the other hand, the implantable ventricular assist devices using the resistant muscles as the power source have the advantages of using its own muscle contractions. The purpose of this study was to determine the possibility of a clinical application of the skeletal muscle ventricle. Material and Method: Latissimus dorsi muscles (LDM) of 8 canines were used for skeletal muscle ventricle. A latex chamber was wrapped one and a half times with LDM. The chamber was attached to a pressure transducer via Tygon tube. An electrode stimulator was placed around the thoracodorsal nerve and LDM was stimulated in cyclic bursts of 0.31 sec on time and 6.0 sec off time using 3.0 volt Itrel stimulator. The preload volume was added to the system in 25cc increments. Ejection volumes, pressures, and peak power outputs were measured. Result: Ejection volume was 76.3cc with 0cc of preload. Ejection volumes were less than 70ml with increments of preload over 75cc Pressures were more than 107 mmHg when the preloads were less than 75cc and less than 100 mmHg when the preloads were more than 100cc. Peak power output of 16.6 W/kg was observed at 50cc preload. Conclusion: Depending on the changes of preload, the volumes ejected from skeletal muscle ventricle and pressures from the skeletal muscle contraction surpassed those of the normal heart. These data suggest that there are clinical applications for skeletal muscle ventricular assist system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.94-99
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• 2007

Many cases of acute cardiac shock and cardiac arrest in emergency room and ICU have been increasing. In this case, ECMO with centrifugal pump has been used generally. However, due to the heavy weight and big size, the system is not adequate for emergency cases. And other defects of this system are that membrane oxygenator's pressure is high and blood are exposed to the air. There was some tries of ECMO using pulsatile pump, but it was found that the weak point of these system is high peak pressure and hemolysis. The mechanism of twin pulsatile pump is that Membrane oxygenator Outlet Pump(MOP) make negative pressure when Membrane oxygenator Inlet Pump(MIP) provides high positive pressure, and the negative pressure will decrease positive pressure of Membrane Oxygenator. Our group analyzed this advantage through In-Vitro and 12 Cases In-Vivo test.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.625-627
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• 2014

모바일 헬스케어의 기본 개념은 '치료'가 아닌 '관리'에 있다. 심박수 측정으로 내가 가진 운동 능력을 얼마나 사용하고 있는지 또는 얼마나 사용할 것인지 조절할 수 있고 자신에게 필요한 운동을 맞춤형식으로 조절이 가능하다. 선행연구에서 다뤘던 심박수 구간별 3대 영양소 연소 비율을 통해 다이어트를 목적으로 운동을 조절할 수도 있고 근력 강화를 위해 전문 트레이닝을 강행 할 수도 있다. 본 연구에서는 건강관리를 위한 생체신호 측정 센서 기반 스마트 기기로 심장수을 믈루투스를 사용하여 측정하고 이상을 예측 보고할 수 있는 프로토타입을 개발하고, 정성적, 정략정 평가를 설시하였다. 향후, 사용성 평가 결가를 기반으로 도출된 문제점의 수정 보완을 통해 최종 센서기반 스마트 심장박동 관리기를 구성하고자 한다.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.365-372
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• 1996

In an attempt to evaluate the effect of St. Thomas' hospital cardioplegic solution (STH) I and II on the cultured rat myocardial cells, beating rate, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (Irtrazolium MTT) and lactate dehydrogenase activity were investigated, and also light and electron microscopic studies were carried out. After rat myocardial cells were cultured for 72 hours, cells were treated with STH I or with STH H solution for 30 and 120 min. and thereafter myocardial cells were cultured in control medium for 24 hours. The results obtained were as follows : 1. Beating rate was 154 times per min. in control group, 141 times per min. in STH I solution(for 2. 120 min.)-treated group and 145 times in STH ll solution (for 120 min.)-treated group. MTT absorbances by MTT assay were 102% in STH I solution (for 120 min.)-treated group and 93% in STH ll solution (for 120 min.)-treated group compared with control group. 3. The amount of lactate dehydrogenase released into the medium were 123% in STH I solution (for 120 min.)-treated group and 109% in STH H solution (for 120 min.)-treated group compared with control group. 4. In the light microscopy examination, myocardial cells showed no differences between experimental and control groups in their number and shape. 5. In the electron microscopy examination, myocardial cells treated with STH I solution showed fewer destroyed mitochondria compared to STH ll solution-treated group. These results suggest that both 51. Thomas'cardioplegic solution STH 1 and STH H have no cytotoxicity on cultured rat myocardial cells, but STH H solution has more protective effect on myocardial cells compared to STH I solution.

• Broadcasting and Media Magazine
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• v.20 no.2
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• pp.64-71
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• 2015

웨어러블 디바이스 시장은 현재 스마트 워치를 중심으로 급속히 성장하고 있다. 웨어러블 디바이스는 심장 박동수 등 헬스케어 정보를 스마트워치나 스마트밴드의 헬스센서를 통해 얻고, 이 내용을 스마트 폰이나 서버로 전송하는 기능을 수행한다. 그리고 웨어러블 디바이스를 통해 자동차 또는 스마트폰의 메시지 통신과 통화기능까지 수행하고 있다. 현재 웨어러블 디바이스 중 하나인 스마트 글래스도 세계의 여러나라에서 개발을 시작했으며, 구글 글래스 출시 이후에 스마트 글래스의 일반인의 관심이 높아지기 시작했으며, 두 손이 자유로운 이동환경에서 동영상 촬영이나 인터넷이나 사물인터넷 통신이 가능케 하고 있다. 웨어러블 MPEG 국제표준기술은 웨어러블 기기의 가장 중요한 특징을 기초로 하고 있다. 그 중요한 특징은 웨어러블 기기에서 키보드를 사용할 수 없다는 것이다. 웨어러블 디바이스를 사용하는데 제스처, 보이스 명령어를 이용하게 되고, 이 명령어로 멀티미디어 콘텐츠를 제어하는 것이 중요한 요소기술이다. 전세계 웨어러블 디바이스 제조사 입장에서는 스마트폰 또는 다른 웨어러블 디바이스와 통신을 위해 멀티미디어 응용 어플리케이션에 대하여 상호 통신이 가능한 메타데이터 정합표준이 필요하다. 이와 관련된 파일포맷정보의 국제표준화가 시급한 상황이다. 상호 통신을 위해 웨어러블 디바이스에서 사용자로 전달되는 명령어체계는 크게 제스처 명령어, 보이스 명령어와 터치 명령어로 나눌 수 있다. 웨어러블 MPEG 국제표준기술 중에서 멀티미디어 통신과 제스처인식 분야에서는 세가지의 명령어 집합을 기준으로 웨어러블 디바이스의 멀티미디어 콘텐츠를 제어하는 것이 중요한 부분이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.104-105
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• 2021

Along with the rapid development of ICT, health management is continuing based on various smart healthcare devices in an aging society and non-face-to-face era caused by COVID-19. In this paper, a heart rate monitor was manufactured using the DF Robot SEN0203 heart rate sensor based on Arduino so that you can check your health and maintain a healthy life by measuring the heart rate per minute in real time to support personalized health management. The device manufactured through this thesis can be used in various ways, such as a wristband or a smart watch.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.9
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• pp.813-821
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• 2013

In this paper, a vital signal sensor based on impedance variation of resonator is presented. Proposed vital signal sensor can detect the vital signal, such as respiration and heart-beat signal. System is composed of resonator, oscillator, surface acoustic wave (SAW) filter, and power detector. The cyclical movement of a dielectric such as a human body, causes the impedance variation of resonator within the near-field range. So oscillator's oscillation frequency variation is effected on resonator's resonant frequency. SAW filter's skirt characteristic of frequency response can be transformed a small amount of frequency deviation to a large variation. Aim to enhance the existing sensor detection range, proposed sensor operates in 870 MHz ISM band, and detect respiration and heart-beat signal at distance of 120 mm.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.4
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• pp.53-60
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• 2010

Biometrics are methods of recognizing a person based on the physiological or behavioral characteristics of his of her body. They are highly secure with little risk of loss or falsification by others. This paper has designed and implemented a security system of biometrics by precisely measuring heartbeat signals at two fingertips and using a photoplethysmogram, which is applicable to biometrics. A performance evaluation has led to the following result. The security system of biometrics for personal authentication which has been designed and implemented by this study has achieved a recognition rate of 90.5%. The security system of biometrics suggested here has merits of time saving and easy accessibility. The system is touch-based and collects the necessary biometrics information by simply touching the machine with fingers, so anyone can utilize the system without any difficulty.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.593-598
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• 1996

The large number of past investigation on extended myocardial protection clearly indicates that cold potassium cardioplegia and topical cooling have limited capabilities. Accordingly, more recent experimen- tal approaches have focused on the modalities of reperfusion and their implication on postischemic myo- cardial recovery. Oxygen may play a crucial role in the development of ischemic and reperfusion injury. Reactive oxygen radicals may be produced during ischemia or reperfusion after incomplete reduction of molecular oxygen or from other pathway and then induce fatal injury of the heart. The important obser- vation of oxygen-induced myocardial damage during reperfusion has led to the concept of applying oxy- gen free radical scavengers. So, this study is on dietary vitamin C supplementation as antioxidant in rats to determine whether or not they have a higher tolerance against cardiac ischemia-reperf'usion injury under Langendorff system. Male or female Sprague-Dawley rats (190-33Og) were randomly separated into two groups. Group A was not treated(n=10). Group B received vitamin C supplement (n=10). Experiment was performed 24 hours after vitamin C 200mg fed orally as injectable ascorbic acid. There were significant differences in contractile parameters between control and vitamin C-treated group. The RLVP (r te of post/preischemic left ventricular pressure) and Rdp/dt (rate of post/preischemic dp/dt) were significant statistically between two groups (p<0.05). But, RHR (rate of post/preischemic heart rate), time to first beat and sta'utilization were not significant. In conclusion, pretreatment with the antioxidant, ascorbic acid, was found to preserve left ventricular contractile function. But the precise mechanism of action of ascorbic acid has not as yet been determined, so further study will be required.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.95-97
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• 2008

Ischemic ventricular rupture is one of the most fatal complications following myocardial infarction, and this requires prompt diagnosis and operation. A 75-year-old female was admitted to the ER in a semicomatous mentality with cyanotic extremities. Cardiac echography was carried out in the ER, and a $1.5{\sim}2\;cm$ thickness of effusion in the pericardium was seen. Because the patient's heart had declined to 35 times per min, an emergency operation was started while giving cardiac massage. After observing a 1 cm rupture on the right ventricular wall and a necrotic hemorrhagic scar with a rupture on the left ventricular apical wall, repair of the ruptured areas with a large Satinsky clamp was carried out to control bleeding without cardiopulmonary bypass. On the 28th day after surgery, she was discharged home with a minimal degree of dyspnea.