• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1903-1907
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• 2013

Heart condition should be observed for long periods of time because it does not appear abnormal all the time. However, there are many difficulties checking our health for a long time due to its size, operation of equipment, and cost. To solve these problems, an electrocardiograms(ECG), specially interfacing three gel-less metal electrodes for low cost portable applications, is designed and implemented. Gel-less metal electrodes are used for ECG monitoring system instead of gel-type electrodes that can cause skin rashes and itching problem. The whole ECG system consists of two parts-analog and digital circuits. The analog measurement circuit that has a 18*25mm size is made up of op-amps maintaining a sufficiently high common-mode noise rejection and passive elements of SMD type. Analog heart signal is converted to digital stream suitable for display on a TFT-LCD by an 8-bit microcontroller. The size of the completed ECG system is 25*80*50mm and its weighing is about 150g, which is small enough to be easily used. Therefore, the implemented ECG system can be used as a portable one.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.725-728
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• 2010

Rhabdomyoma is the most common benign cardiac neoplasm in neonates. Most patients with rhabdomyoma experienced spontaneous regression. Yet some of them need surgical therapy because of hemodynamic problems of the heart such as arrhythmia, outflow tract obstruction and valvular dysfunction. We found multiple masses in both ventricles on the patient's fetal echocardiogram. Heart failure caused by severe left ventricular outflow tract obstruction quickly presented after birth. The mass interfering with the outflow tract was resected via the transaortic approach at the first day of birth. Postoperative echocardiography showed complete release of the outflow tract obstruction. He was discharged on the postoperative day 8. During the 3 years of follow up, we found that the sizes of the remnant masses had gradually decreased.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.766-770
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• 2008

Primary tumors of the heart are uncommon among pediatric patients. Rhabdomyoma is the most frequent cardiac tumor in infants and children, which is commonly associated with tuberous sclerosis. Tuberous sclerosis is a neurocutaneous syndrome affecting the brain, heart, skin, and other organs. Cardiac rhadomyomas are reported in 50-64% of infants with tuberous sclerosis. Tuberous sclerosis involves multiple locations in the atrium, ventricle and septum, and may induce mechanical obstruction of the outflow tract and heart failure depending on the location, number, size, and degree of invasion of tumors. Arrhythmias may also develop in infants with cardiac rhadomyomas, but only a few of these patients require prolonged anti-arrhythmic therapy because arrhythmia often disappears with spontaneous regression of the tumors, and the ultimate prognosis may be decided by the cerebral manifestations.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.988-993
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• 2021

Cardiac papillary fibroelastoma (CPF) is the second or third most common primary cardiac tumor. Although histologically benign, it can cause serious symptoms depending on its location of occurrence, size, and motility. Herein, we report CPF in the left ventricular trabeculation as a potential cause of cerebral infarction.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.165-169
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• 2011

Cardiac myxoma is the most common benign tumor of the heart. However, low incidence of recurrence and metastasis has been reported. A 49-year-old female patient was admitted in the hospital due to sudden onset of left side weakness. Magnetic resonance imaging (MRI) of brain showed multifocal areas of diffusion restriction on diffusion weighted images. Echocardiography was performed to evaluate the cause of embolic brain infarction and cardiac myxoma was found in the left atrium. The patient underwent complete excision of the mass. One year later, the patient was readmitted with symptoms of dysarthria. Brain MRI showed newly developed multiple hemorrhagic metastatic lesions. The patient underwent radiotherapy of the metastatic lesions. Although rare, cardiac myxoma can cause delayed metastasis. We report a rare case of delayed multiple cerebral metastases from the completely resected cardiac myxoma.

• Journal of Sensor Science and Technology
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• v.6 no.3
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• pp.245-251
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• 1997

In designing defibrillator, several parameters such as patient's transthoracic impedance, output energy level, peak current, and time duration of current waveform must be considered to generate optimum electrical shocks on the heart. Patient's transthoracic impendence depends on the physical and health condition of patient. In this study, before the development of a defibrillator, the range of above parameters value as circuit elements was determined to derive optimal waveform by predicting and analyzing the performance of designed circuit by means of simulation with the software, P-Spice. The efficiency of parameter design was verified through the performance test with the developed defibrillator.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.205-208
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• 1997

Cardiac rhabdomyomas are the moil common primary tumor in infancy and childhood and are frequently associated with tuberous sclerosis. Although spontaneous regression of cardiac rhabdomyoma has been reported, prognosis of this tumor associated with subaortic stenosis is still considered to be poor and surgery continues to be indicated. A 4-day-old female was admitted due to tachypnea and cyanosis. Single rhabdomyoma arising from the interventricular septum associated with severe subaortic stcnosls as partially removed under cardiopulmonary bypass. Excised tumor sizc was 0.7$\times$0.9$\times$0.4cm in dimension. The postoperative course was uneventful and the infant discharged on the 14th postoperative day.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.637-639
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• 2006

Cardiac myxoma is the most common primary tumor of the heart, but right ventricular myxoma causing outflow obstruction is relatively rare. A 15 years old girl developed dyspnea on exertion and intermittent syncope caused by a right ventricular mass obstructing the right ventricle outflow tract. Transthoracic echocardiography revealed $3.6{\times}3.0\;cm$ sized pedunculated subpumonic mass originating from the right ventricular anterior free wall. The patient underwent an emergency operation, consisting of the removal of the mass by wide excision of the tumor base and PTFE (polytetrafluoroethylene) patching of the right ventricular anterior free wall defect. Pathological findings of the mass were compatible with myxoma, and the patient was discharged uneventfully 7 days after the operation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1213-1217
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• 2011

Electric stimulators are used for various treatments, such as for pain relief and to improve rehabilitation in and out of the hospital. However, if the stimulation pulse affects the patient's heart, it can cause critical cardiac disorders such as arrhythmia or ventricular fibrillation. As a result, it must be ensured that the transmission length of the stimulation pulse does not exceed the proper range in the design of an electric stimulator. Furthermore, every anticipated risk factor must be monitored in in-vitro and in-vivo experiments. A new stimulator was designed to supply continuous 0.001 J stimulation pulses at a rate of 60 pulses per second. To evaluate the safety of the new electric stimulator and to measure its energy transfer and pulse transmission length, we built a conduction model that was filled with saline and measured the electric field at various positions in response to real stimulations. In an animal experiment with two pigs, heart disorders were induced by applying electric stimulation to tissues near the heart. These heart disorders were different from the result obtained with 9 V DC stimulation.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1086-1089
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• 2011

현대 사회의 의학기술과 대체의학은 IT 기술과의 융합적 개발로 점차 발전하고 있다. 동양의학 이론을 통해 인체 중 손, 발, 얼굴 등이 오장육부와 관련이 있다는 학설이 널리 알려져 있다. 이 중 발은 '제2의 심장'이라고까지 불려지고 있다. 즉, 발이 건강해야 전신 건강을 유지할 수 있다는 의미도 있지만 실제로 혈액 순환에도 중요하다는 의미도 있다. 따라서, 본 논문에서는 심장과 관련된 발 영역인 왼쪽발바닥 네번째와 다섯 번째 발가락 사이에서 3cm정도 내려간 부위를 지압하여 심장 관련 얼굴 영역의 색상 변화를 측정하는 실험을 수행하였다. 지압에 쓰이는 지압봉은 일반 가정용으로 사용되는 150x10mm 크기의 지압봉이며 지압법으로는 뒤꿈치 방향에서 심장 지압점까지 누르면서하는 방법을 사용하였다. 이와 같은 발지압법을 수행한 후 심장과 관련된 얼굴 영역인 천정과 입술 부위의 붉은 정도를 Lab색체계로 측정하여 a*값 색상의 변화를 분석하였다.