• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.643-646
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• 2001

This paper investigates the structural analysis and design of mechanical heart valve through the numerical analysis methodology. In a numerical analysis methodology application to the thickness minimization structural design of mechanical heart valve, structural analysis is performed for the blood flow through a bileaflet mechanical heart valve. The structural static analysis is carried out to confirm the thickness minimization structural condition (minimum thickness shape of leaflet).

• Journal of Industrial Technology
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• v.32 no.A
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• pp.15-20
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• 2012

For emergency patients as heart disease, fast treatment is very important. This paper describes a smart phone software to detect emergency circumstance and request rescue. Detection of emergency condition of heart disease patients is based on physical motion and biological heart signals as electrocardiogram. Most smart phones have three axis acceleration sensor. On emergency condition, patients remain stationary. Thus the software detect stationary condition by using acceleration sensor data. For more precise detection, it combines electrocardiogram of patients. To request rescue, it sends help messages to designated persons. In addition, it generates emergency sound to surrounding people and plays a video of emergency measure that any person on the place can help the patient temporarily.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.126-130
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• 1997

In the development of the totally implantable artificial heart (TAH), the information of the preload condition is important to ind appropriate condition or the automatic control of the heart. Our TAH configuration consists of two artificial ventricles, and brushless DC motor within actuator. The pressure between ventricles could indicate the preload condition during the TAH operation. If we can measure accurately inspite of the noise induced from TAH and environmental condition. We suggested integrating a feedback loop to remove an unexpected DC drift. NPI 19-series Nova sensor was used which could measure pressure in gas and liquid. This method and sensor enabled us to develop the pressure transducer compact so (that) the systems can be implanted with TAH into patient. This system has been verified in vitro and in vivo test. This results showed that the output waveform of this system was stable irrespective of animal condition.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.9-10
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• 2002

Human circulatory system between heart and tissue is not directly connected in normal condition but mandatory to go through the capillary system in order to fulfill its physiologic aim to deliver oxygen and nutrients, etc. to the tissue and retrieve used blood together with waste products from the tissue properly. When abnormal connection between arterial and venous system (AV fistula), these two circulatory systems respond differently to the hemodynamic impact of this abnormal connection between high pressure (artery) and low pressure (vein) system. Depending upon the location and/or degree (e.g. size and flow) of fistulous condition, each circulatory system exerts different compensatory hemodynamic response to this newly developed abnormal inter-relationship between two systems in order to minimize its hemodynamic impact to own system of different hemodynamic characteristics. Pump action of the heart can assist the failing arterial system directly to maintain arterial circulation against newly established low peripheral resistance by the AV fistula during the compensation period, while it affects venous system in negative way with increased venous loading. However, the negative impact of increased heart action to the venous system is partly compensated by the lymphatic system which is the third circulatory system to assist venous system independently with different hemodynamics. The lymphatic system with own unique Iymphodynamics based on peristaltic circulation from low resistance to high resistance condition, also increases its circulation to assist the compensation of overloaded venous system. Once these compensation mechanisms should fail to fight to newly established hemodynamic condition due to this abnormal AV connection, each system start to show different physiologic ${\underline{de}compensation}$ including heart and lymphatic system. The vicious cycle of decompensation between arterial and vein, two circulatory system affecting each other by mutually negative way steadily progresses to show series of hemodynamic change throughout entire circulation system altogether including heart. Clinical outcome of AV fistula from the compensated status to decompensated status is closely affected by various biological and mechanical factors to make the hemodynmic status more complicated. Proper understanding of these crucial biomechanical factors iii particular on hemodyanmic point of view is mandatory for the advanced assessment of biomechanical impact of AV fistula, since this new advanced concept of AY fistula based on blomechanical information will be able to improve clinical control of the complicated AV fistula, either congenital or acquired.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.24-28
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• 1995

Exercise physiology of fish was studied by means of Electro-cardio-gram(ECG) technique with wired electrode system. Effects of swimming activity on the heart rate change for carp Cyprinus carpio was observed and analysed under swimming speeds among 1~3 Body Length/s and swimming durations of 10 and 60 minutes in the flume tank. The heart rate increase during swimming activity was observed in higher speed and longer duration conditions. The exercise effect on the heart rate continued even after fish stopped swimming. The time for recovery after exercise was tended to be elongated with the higher exercise condition.

• Journal of Chest Surgery
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• v.27 no.4
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• pp.310-312
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• 1994

Primary cardiac lipoma is an extremely rare condition. We reports a case of primary lipoma located mainly in the right atrium of the heart in a 58-year-old male patient. The initial presenting symptoms were dyspnea followed by rapidly progress!ve congestive heart failure. Echocardiogram revealed huge mass on right atrium with stalk arising from septum. Under cardiopulmonary bypass the mass was removed and revealed characteristic findings of lipoma on microscope. The patient was recovered without any problem. We would like to describe this case of rare tumor with the review of literatures.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.237-243
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• 2014

Heart sounds of patient's chest could be heard using an analog stethoscope. However, auscultation of a heart sound can be diagnosed differently by each doctor hearing it. Therefore the condition of each patient is determined by the subjective comments based on the hearing ability of a physician who has years of experience. In this paper, through analysis of heart sound and heart rate of the patient's condition, we will define minutely how to diagnose the condition of patient using a wireless digital stethoscope diagnostic system. And it is possible to perform an objective medical diagnosis by applying LCR (Level Crossing Rate) and to show the relationship of a disease using this system.

• Advances in nano research
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• v.15 no.2
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• pp.155-163
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• 2023

Exercise is beneficial to the body in some ways. It is vital for people who have heart problems to perform exercise according to their condition. This paper describes how an Android platform can provide early warnings of fatigue during wushu exercise using Photoplethysmography (PPG) signals. Using the data from a micro-electro-mechanical system (MEMS) gyroscope to detect heart rate, this study contributes an algorithm to determine a user's fatigue during wushu exercise. It sends vibration messages to the user's smartphone device when the heart rate exceeds the limit or is too fast during exercise. The heart rate monitoring system in the app records heart rate data in real-time while exercising. A simple pulse sensor and Android app can be used to monitor heart rate. This plug-in sensor measures heart rate based on photoplethysmography (PPG) signals during exercise. Pulse sensors can be easily inserted into the fingertip of the user. An embedded microcontroller detects the heart rate by connecting a pulse sensor transmitted via Bluetooth to the smartphone. In order to measure the impact of physical activity on heart rate, Wushu System tests are conducted using various factors, such as age, exercise speed, and duration. During testing, the Android app was found to detect heart rate with an accuracy of 95.3% and to warn the user when their heart rate rises to an abnormal level.

• The Journal of Internal Korean Medicine
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• v.13 no.1
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• pp.61-69
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• 1992

In Nan-Gyung, showed that could know the lung condition taking pulse with the weight of three beans, the heart condition taking pulse with the weight of six beans, the spleen condition taking pulse with the weight of nine beans, the liver condition taking pulse with the weight of twelve beans, the kidney condition pressing to bone(骨). This theory is first suggested in Nan-Gyung(難經). In those case, the weight of three, six, nine, twelve beans and pressing to bone don't mean not the real weight but the relative weight(輕重) of taking pulse(按脈). In other words, those represent Boo Jung Chin(浮中沈), which are the conception of the upper, the meddle, the lower part(上中下). So, we could take pulse of the heart and the lung condition in Boo(浮), the spleen condition in Jung(中), and the liver and the kidney condition in Chim(沈). The heart and the lung pulse showed in the Boo(float level) must be seen with Boo-Mack(부맥 : float pulse), the liver and the kidney pulse showed in Chim (sinklevel) must be seen also with Chin-Mack(沈脈 : sink pulse). The result of the method of taking pulse of viscera with relative weight focused on the as pect of mornal pulse(平脈) and disease pulse(病脈) of five viscera in Mack-Gyung publeshed later than Nan-Gyung and special works which made a comprehensive survey the result is as follow. 1. In normal pulse of five viscera, the heart and the lunk pulse were shown with Boo-Mack(浮脈:float pulse) as the central figure, the liver's and the kidney's pulse were shown centering around Chim-Mack(沈脈: sink pulse) and the spleen's pulse was shown with Wan-Mack(緩脈) which is vital force of stomach(胃氣) and seen in only middle part. 2. In disease pulse of five viscera, frequently, the heart and the lung pulse was shown as Chim-Mack(sink pulse), the liver and the kidney pulse was seen as Boo-Mack (float pulse). 3. In the case of normal pulse. the method of taking pulse with relative weight in Nan-Gyung agree with the normal pulse of five viscera in Mack-Gyung. But in the case of disease pulse, they didn't correspond with the other. 4. So the method of taking pulse with relative weight in Nan-Gyung is not the exam pulse which ca be used in the clinical diagnosis but one of the feeling pulse way to bring in the conception of location of the visceras. 5. From now on, the method of taking pulse rdlated to relative weight need to be looked into minutely compared with later physician's theory than Mack-Gyung.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.191-193
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• 2010

Unexplained hypotension during a stay in the ICU is not uncommon in patients who underwent major surgery such as open heart surgery. When the cardiac output of patients is low, the heart may be the origin of this problem. If the heart function is normal, then we have to consider adrenal insufficiency as a possible cause of this hypotension. Adrenal insufficiency is a rare condition in the general population, yet patients who are under a stressful condition might experience adrenal insufficiency more frequently. We report here on a case of a patient who was in an unstable postoperative state with adrenal insufficiency after surgery and the patient dramatically recovered after the replacement of hydrocortisone.