• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2702-2703
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• 2002

본 연구에서는 종래의 심박출량 및 일회 심박동량 측정장치를 휴대용 시스템으로 구현하기 위한 회로 설계방법을 연구하였다. 휴대용 시스템의 설계를 위한 아날로그 부분은 인체 안전을 위한 아이솔레이션 증폭기, 변복조기, 0.1Hz 고역통과 필터 및 잡음제거 회로로 구성되며, 연속 심박출량 모니터링 및 연산을 위한 디지탈 부분은 TMS32030C를 이용한 회로로 구성이 된다. 또한 기존의 방법에서의 문제점을 개선하기 위해 연속 심박출량 연산을 위한 새로운 알고리듬을 제안하였다. 제안된 방법은 앙상블 평균시에 기존의 심전도 R피이크 점을 기준으로 하지 않고, 임피던스 신호의 dZ/dt 최대점을 이용하는 방법을 적용하였다. 제안한 심박출량 신호처리 알고리듬을 이용하여 측정된 임피던스 신호를 분석한 결과 최대 25.5 %까지 개선됨을 확인하였다.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.384-390
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• 2012

Echocardiographic measurements of cardiac output, including the modified Simpson's method, Automated Contour Tracking(ACT) method, and left ventricular outflow method are well described methods of evaluating cardiac function due to its reliability and the benefits of its non-invasive technique in human medicine. The purpose of this study was to evaluate the accuracy of an echocardiography estimate of cardiac output in isoflurane-anesthetized beagle dogs and was to compare the ACT method to the other methods used in measurement of cardiac output. In healthy beagle dogs, cardiac output results by echocardiography estimate methods showed an excellent correlations with those by the thermodilution method (The modified Simpson's method : r = 0.815, $r^2=0.665$, y = 0.434x + 0.311 ; ACT method : r = 0.86, $r^2=0.748$, y = 0.391x + 0.242 ; ventricular outflow method : r = 0.691, $r^2=0.478$, y = 0.593x + 0.242). Among the results obtained, the ACT method showed the highest correlation coefficient. In conclusion, our study demonstrated that echocardiography estimate methods did not prove to be suitable in accurately measuring absolute cardiac output values but showed an excellent correlation with thermodilution method. Therefore, by using the measurement of cardiac output as supplemental data, echocardiography estimate methods can be used for detection and correction of hemodynamic disturbances during emergency and anesthesia in veterinary practice.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.194-197
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• 2012

The purpose of the thesis is to develop a module which can measure precise Continuous Cardiac Output(CCO) better than existing equipments for the critical cardiopulmonary patient diagnosis purpose. This module enables more precise and effective diagnosis and treatment for the patient by compensating old method which injected cold liquid to inside of heart to measure the CCO.

• 대한핵의학회:학술대회논문집
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• 1967.11a
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• pp.106.3-107
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• 1967

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.79-79
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• 2003

심실의 내부는 유두근이나 trabecular와 같은 해부학적 구조물들로 인해 복잡한 형태를 띄고 있다. 그러한 복잡한 구조는 MR 영상을 이용한 심박출량 측정시 오차를 유발시킬 수 있으며, 만약 오차를 줄이기 위해 수작업을 하게 된다면 많은 수고와 시간이 필요하게 될 것이다. 본 연구에서는 threshold 기법을 이용하여 짧은 시간동안에 정확하게 복잡한 구조를 가진 심실의 심박출량을 측정하고자 하였다. 7 명의 환자에 대해 l.5T 급 MR 장치 (INTERA, Philips, Netherlands)를 이용하여 short-axis cardiac MR 영상을 획득하였다. 한 환자에 대해서 8개에서 10개의 슬라이스 영상을 8-10 mm의 두께로, 하나의 심장주기(cardiac cycle)동안 일정한 시간간격으로 25 개의 영상을 획득하였으며, 펄스시퀀스로는 ECG-gated segmented balanced fast field echo (TR/TE = 3ms/1.56ms)를 사용하였다. 획득된 영상은 PC(threshold 기법)와 workstation (기존의 수동 및 자동 segmentation 기법)로 DICOM 형태로 전송되었다. 측정은 IDL을 이용하여 자체 제작된 소프트웨어와 상용화된 소프트웨어 (MASS 5.0, MEDIS, Netherlands)를 이용하여 분석되었다. MR 영상에서 심내벽 부위를 추출하기 위하여 자체제작된 소프트웨어로는 threshold 기법을, 상용 소프트웨어로는 기존의 수동 및 자동 기법을 이용하였다. 심박출량은 최대수축기와 이완기 사이의 용적 차이로써 계산되었으며, 좌심실 및 우심실 모두에 대해 수행되었다. 또한, 해부학적 구조의 복잡도에 따른 측정방법의 정확도를 확인하기 위해 유두근 및 trabecular의 hypertrophy의 정도를 3 단계로 구분하고 측정된 값들을 통계적으로 분석하였다. Hypertrophy가 약한 그룹에서는 기존의 수동방식과 threshold 기법간의 의미있는 차이가 없었으며 (p=0.372), 기존의 수동 및 자동방식 간에도 큰 차이가 없었다 (p=0.298). 그러나, hypertrophy가 심한 그룹에서는 수동방식 및 자동방식 측정치 사이에 통계적으로 유의한 차이를 보임을 알 수 있었다 (p=0.044). 그러나, threshold 기법과 수동방식 사이에는 유의한 차이가 없었다 (p=0.l94). 분석시간은 threshold 기법이 기존의 수동방식에 비해서 두배정도 빠르다는 것을 알 수 있었다, Threshold 기법은 심박출량 측정에 있어서 정확하면서도 빠른 결과의 도출이 가능했으며, 특히 심내벽의 구조가 복잡한 경우에 그 효과가 증대됨을 알 수 있었다.

• 전기의세계
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• v.28 no.12
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• pp.27-32
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• 1979

13명의 환자에 있어서 새로운 비관혈적 방법에 의한 심박출량을 계산하고, 열희석에 의한 방법으로 측정한 심박출량과 비교하였다. 본 논문에서 사용한 비관혈적 펄스 전달 방법은 대동맥 모델에서의 최적 매개변수 방법을 사용하였다. 모델의 최적 매개변수는 맥압의 첫번째 고주파 전달함수에서 측정치와 계산치의 차이를 최소화하는 조건에 의하여 계산하였다. 전달함수의 2개의 펄스는 각각 경동맥동과 대퇴동맥에서 Piezo-resistive Pulse Microphone을 사용하여 측정하였고, 대동맥의 직경은 초음파 방법을 사용하여 측정하였다. 13명의 환자에게서 16가지 측정을 해서 열희석과 비관혈적 방법은 0.89의 상관계수를 보여주었다.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.385-391
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• 1998

A new balancing method of atrial pressures balancing for the moving actuator total artificial heart(TAH) without an extra compliance chamber was developed. The asymmetric operation of the pendulous moving actuator have made it possible to compensate the left and right pump output difference by utilizing the interventricular air space as an internal compliance chamber in a pump housing. Furthermore, the balancing performance between left and right pump outputs is increased through the improvement of the flexibility of part of the polyurethane housing. However, the increase of the flexibility of the pump housing causes a little loss of the cardiac output due to the reduction of active filling property. In this paper., a good condition between the balance and pump output performance is evaluated by adjusting the air volume in the interventricular space through a series of in vitro experiments. This new pump was implanted in a sheep weighting 63kg, and it survived for 3 days and the average cardiac output during postoperative days was about 4.2 L/mim with the atrial pressures under 15 mmHg.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.959-964
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• 2013

This study materialized the new module which enables to measure more precise data than the existing modules in order to examine the cardiac disorder critical patient's state by using Swan-Ganz Catheter. There was bolus type CO(Cardiac Output) module which measured CO by measuring the blood changes in temperature and recovery time by injecting cold sap into the heart in the past, but recently, it is not used in most of hospitals due to limit of difficulty of continuous monitoring for the patients. To overcome this limit, the continuous cardiac output measurement platform was materialized to enable the continuous monitoring for patients. The wasted cost issues because of introducing the expensive imported equipment to observe the critical patient`s state with abnormal cardiopulmonary function in the hospitals can be solved by using this new module, and the problem of existing modules should be supplemented for more accurate diagnosis by collecting more precise data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1591-1597
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• 2011

In this paper, on cardiopulmonary function in the intensive care unit over the direction of the state to define the diagnostic or therapeutic cardiac output Study on Implementation of measures as a platform, Swan-Ganz Catheter with sensor inserted into the body by inserting a saline solution Using temperature change caused by using thermodilution be used to obtain cardiac output. Swan-Ganz Catheter with temperature sensors and pressure sensors and sensor value which is entered through the acquisition more closely if the cardiac output CO, systemic and pulmonary vascular resistance, oxygen consumption and may be able to more accurately calculate the patient's condition than accurate diagnosis and treatment is possible.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.206-215
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• 2007

Background : The prone position is often used for operations involving the spine and provides excellent surgical access. The complications associated with the prone position include ocular and auricular injuries, and musculoskeletal injuries. In particular, the prone position during general anesthesia causes hemodynamic changes. To evaluate the cardiovascular effects of the prone position in surgical patients during general anesthesia, we investigated the effects on hemodynamic change of the prone position with the Jackson spinal surgery table. Materials and Methods : Thirty patients undergoing spine surgery in the prone position were randomly selected. After induction of general anesthesia, intra-arterial and central venous pressures (CVP) were monitored and cardiac output was measured by $NICO^{(R)}$. We measured stroke volume, cardiac index, cardiac output, mean arterial pressure, heart rate, CVP and systemic vascular resistance (SVR) before changing the position. The same measurements were performed after changing to the prone position with the patient on the Jackson spinal surgery table. Results : In the prone position, there was a significant reduction in stroke volume, cardiac index and cardiac output. The heart rate, mean arterial pressure and CVP were also decreased in the prone position but not significantly. However, the SVR was increased significantly. Conclusion : The degree of a reduced cardiac index was less on the Jackson spinal surgery table than other conditions of the prone position. The reduced epidural pressure caused by free abdominal movement may decrease intraoperative blood loss. Therefore, the Jackson spinal surgery table provides a convenient and stable method for maintaining patients in the prone position during spinal surgery.