• Journal of Chest Surgery
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• 제17권3호
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• pp.409-417
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• 1984

In the early days of open heart surgery, acute respiratory failure following extracorporeal circulation was a significant deterrent to an uncomplicated recovery. Although a marked improvement in prevention and treatment of postoperative respiratory failure has been achieved, the problem has not been completely eliminated and continues to be a causative factor in morbidity and mortality Fates following open heart surgery. We have attempted to evaluate postoperative respiratory failure in patients undergoing cardiac operation with the aid of extracorporeal circulation. Our series comprised 92 patients who underwent elective open heart surgery at the Department of Thoracic and Cariodvascular Surgery, School of Medicine, Kyungpook National University, from January, 1980 to December, 1982. In our study, the overall incidence of acute respiratory failure following open heart surgery was 18.8 percent. The duration of extracorporeal circulation in a series of 18 patients who developed postoperative respiratory failure [Group B] was longer in the mean value [120.3 minutes] than the uncomplicated 74 patients [Group A] [85.8 minutes]. The duration of artificial ventilation after open heart surgery in Group A averaged 13.4 hours as contrasted with 76.5 hours in Group B. In Group B, the inspired oxygen concentration [FiO2] in artificial ventilation was continued in the higher level than Group A until 18 hours after operation. Upon pulmonary function test performed pre-and postoperatively, residual volume[RV], RV/TLC and FEV 1.0/FVC were remained essentially unchanged following extracorporeal circulation, whereas forced vital capacity [FVC], FEV 1.0 and FEF 25-75% were significantly decreased in the early postoperative days. The incidence of acute respiratory failure was significantly higher in a series of patients who developed postoperative complications, such as re- exploration due to massive bleeding, low cardiac output, acute renal failure and arrhythmias. A total of 9 patients died, giving an overall mortality was 33.3 percent whereas the mortality was only 1.1 percent for patients without respiratory failure.

• ETRI Journal
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• 제37권2호
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• pp.222-232
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• 2015

In this paper, we propose a dual-phase approach to improve the process of heart disease prediction in a mobile environment. Firstly, only the confident frequent rules are extracted from a patient's clinical information. These are then used to foretell the possibility of the presence of heart disease. However, in some cases, subjects cannot describe exactly what has happened to them or they may have a silent disease - in which case it won't be possible to detect any symptoms at this stage. To address these problems, data records collected over a long period of time of a patient's heart rate variability (HRV) are used to predict whether the patient is suffering from heart disease. By analyzing HRV patterns, doctors can determine whether a patient is suffering from heart disease. The task of collecting HRV patterns is done by an online artificial neural network, which as well as learning knew knowledge, is able to store and preserve all previously learned knowledge. An experiment is conducted to evaluate the performance of the proposed heart disease prediction process under different settings. The results show that the process's performance outperforms existing techniques such as that of the self-organizing map and gas neural growing in terms of classification and diagnostic accuracy, and network structure.

• Korea-Australia Rheology Journal
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• 제16권3호
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• pp.141-146
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• 2004

Shear-induced damage of Red Blood Cell (RBC) is an imminent problem to be solved for the practical application of artificial organs in extra corporeal circulation, as it often happens and affects physiological homeostasis of a patient. To design and operate artificial organs in a safe mode, many investigations have been set up to correlate shear and shear-induced cell damage. Most studies were focused on hemolysis i.e. the extreme case, however, it is important as well to obtain a clear understanding of pre-hemolytic mechanical damage. In this study, the change in deformability of RBC was measured by ektacytometry to investigate the damage of RBC caused by shear. To a small magnitude of pre-shear, there is little difference, but to a large magnitude of pre-shear, cell damage occurs and the effect of shear becomes significant depending on both the magnitude and imposed time of shearing. The threshold stress for cell damage was found to be approximately 30 Pa, which is much less than the threshold of mechanical hemolysis but is large enough to occur in vitro as in the extra corporeal circulation during open-heart surgery or artificial heart. In conclusion, it was found and suggested that the decrease of deformability can be used as an early indication of cell damage, in contrast to measuring plasma hemoglobin. As cell damage always occurs during flow in artificial organs, the results as well as the approach adopted here will be helpful in the design and operation of artificial organs.

• 패션비즈니스
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• 제8권3호
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• pp.10-19
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• 2004

The purpose of this research is to reveal the antimicrobial activity of pet-dog clothes by investigating the bacteria resistance of 4 kinds of pet-dog clothes materials. 1. Investigation Results of Pet-Dog Clothes 64.7% of 150 survey participants, revealed they had pet-dog clothes. Hand laundering was 67.0%, while the laundering of both human and animal clothes was 9.2%. The greatest washing frequency was once every 2 weeks. So, the subjects didn't seem to think high of hygienic matters. Even though no if any relations were reported by 34.7% of the subjects, there were some experiences like sneezing or coughing (41.3%), slight itching (20.7%), and acute skin allergies. There were such hugging methods as heart to heart to the center (22.7%), face to face and around the mouth (16.7%), and below the heart with the dog's face outward (15.3%). Thus, hugging the dog near the pet-lover's face seems to be the cause of respiratory diseases including sneezes and coughs. 2. Results of the Anti-Bacteria Experiment of Pet-Dog Clothes Materials According to the analysis of the germs collected and cultured in this study to reveal the properness of pet-dog clothes materials, they were bacteria or bacilli in shapes. Spore growth was active in the order of such experimental materials as artificial leather > cotton > cotton/ nylon > polyester (finest thread). In terms of germ groups, the order was polyester(finest thread) > cotton > cotton/ nylon > artificial leather.

• 한국인공지능학회지
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• 제8권1호
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• pp.1-6
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• 2020

The Recently there has been a growing interest in health care due to the COVID-19 situation. In this paper, we intend to develop a healthcare monitoring system to provide users with smart healthcare systems in line with the healthcare 3.0 era. The system consists of a wireless network between various sensors, Android smartphones, and OLEDs using Bluetooth, and through this, a health care monitoring system capable of collecting user's biometric information and managing health by receiving data values of sensors connected to Arduino. In conclusion, the user's BPM value was calculated using the heart rate sensor, and the exercise intensity can be adjusted through this. In addition, a step derivation algorithm is implemented using an acceleration sensor, and calorie consumption can be measured using the step and weight values. As such, the heart rate, step count, calorie consumption data can be transmitted to a smartphone application through a Bluetooth module and output, and can be output to an OLED for users who are not easy to access the smartphone. This healthcare monitoring system can be applied to various groups and technologies.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.287-288
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• 1998

The virtual surgery of Artificial Heart has focused on the simple fitting trial. But, as the processes of heart surgery being complex and detail, the requests of virtual surgery become more complex. One of the complex requests is volume editing. It may contain various editing functions: 3-dimensional cutting, registration, merging, splitting, inserting, deleting, translation and deformation. We have designed and implemented 3-dimensional volume editor that can be operated in Windows NT platform. With the results of this research, we can get convenient tools for the total virtual surgery system.

• 대한임베디드공학회논문지
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• 제18권6호
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• pp.277-283
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• 2023

Vital signals provide essential information regarding the health status of individuals, thereby contributing to health management and medical research. Present monitoring methods, such as ECGs (Electrocardiograms) and smartwatches, demand proximity and fixed postures, which limit their applicability. To address this, Non-contact vital signal measurement methods, such as CW (Continuous-Wave) radar, have emerged as a solution. However, unwanted signal components and a stepwise processing approach lead to errors and limitations in heart rate detection. To overcome these issues, this study introduces an integrated neural network approach that combines noise removal, demodulation, and dominant-frequency detection into a unified process. The neural network employed for signal processing in this research adopts a MLP (Multi-Layer Perceptron) architecture, which analyzes the in-phase and quadrature signals collected within a specified time window, using two distinct input layers. The training of the neural network utilizes CW radar signals and reference heart rates obtained from the ECG. In the experimental evaluation, networks trained on different datasets were compared, and their performance was assessed based on loss and frequency accuracy. The proposed methodology exhibits substantial potential for achieving precise vital signals through non-contact measurements, effectively mitigating the limitations of existing methodologies.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.161-162
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• 1997

It is very useful to perform the surgery simulation before implanting TAH(Total Artificial Heart} in a patient. The space of chest and the shape of vessels are different from patient to patient. So, It is desirable to customize a TAH design to the anatomy structure of a patient. Several studies are performed to visualize and explain the 3D structure of heart. These studies are performed using 2-dimensional ref or mated images and simple measurement. Anatomy structure of a human heart is not so simple. It is 4dimensional structure ; 3-dimensional plus time, heart beating. 3-dimensional reconstruction schemes of medical images developed for about 10 years are usually categorized into two types of rendering technique ; surface rendering and volume rendering. Volume rendering is preferable in medical image processing field because this technique can be applied without considering the complexity of geometry and change of field of interest. The usable space in the chest of patient can be measured by 3D volume matching of patient trunk and TAH model. This space changes with time. In this research we have developed the 4-dimensional volume match program of patient and TAH model. 3-dimensional rendered set of volumes along time were used to simulate TAH fitting trial. The quantitative measurement from this simulation could be applied to customize TAH design.

• Journal of Chest Surgery
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• 제19권4호
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• pp.644-662
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• 1986

Seventy cases of open heart surgery were performed in the department of Thoracic and Cardiovascular Surgery, Pusan Paik Hospital, Inje College, from Oct. 1985 to Oct. 1986. And the results were summarized as follows. 1. Among the 70 cases, there were 48 cases of congenital heart anomalies and 22 cases of acquired rheumatic valvular heart diseases. Age range of the congenital patients was 7 months to 31 years with the mean age of 10 years, and the acquired patients was 18 to 62 years with the mean age of 40 years. 2. The heart-lung machine used for cardiopulmonary bypass was Sarns 7000, 5-head roller pump, and the number and type of oxygenators were 5 of membrane type and 65 of bubble type. For all cases GIK [glucose-insulin-potassium] solution was used as cardioplegic solution for myocardial protection during operation. 3. Among the 48 congenital anomalies, there were 12 cases of ASD group, 29 of VSD group, 3 of ECD, 3 of TOF and one of PDA + MR, and to all of which the appropriate radical operations were applied. 4. Among the 22 acquired valvular diseases, there were 11 cases of mitral valve diseases [MS; 4, MSr; 3, MRs; 4], 3 cases of aortic valve diseases [AR:1, ARs;1, ASr;1], 4 cases of double valve diseases [MRs+TR; 3, MRs+ARs; 1] and 4 cases of triple valve diseases [MSr+ASr+TR; 3, MSr+Ar+TR; 1]. To all the diseased mitral and aortic valves, artificial valve replacement was applied except one [As], in which valve plication was applied. And to all the diseased tricuspid valve, DeVega annuloplasty was applied. 5. The number of replaced artificial valves were 29 in 25 patients [congenital; 3, acquire; 22]. In MVR, 6 of mechanical valves [St. Jude Medical valve; 6] and 15 of tissue valves [Carpentier-Edward valve; 11, lonescu-Shiley valve; 4] were used. In AVR, 6 of mechanical valves [St. Jude Medical valve; 6] and 2 of tissue valves [Carpentier-Edward valve; 2] were used. 6. Postoperative complications were occurred in 12 cases. Among them 11 cases were recovered with intensive cares, but one patient [VSD + Fistula of Valsalva sinus] was expired with low cardiac out put syndrome.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2000년도 춘계 학술대회논문집
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• pp.27-32
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• 2000

In this study, the three-dimensional blood flow within the sac of KTAH(Korean artificial heart) is simulated using fluid-structure interaction model. The numerical method employed in this study is the finite element commercial package ADINA. The thrombus formation is one of the most critical problems in KTAH. High fluid shear stress or stagnated flow are believed to be the main causes of these disastrous phenomenon. We solved the fluid-structure interaction between the 3D blood flow in the sac and the surrounding sac material. The sac material is assumed as linear elastic material and the blood as incompressible viscous fluid. Numerical solutions show that high shear stress region and stagnated flow are found near the upper part of the sac and near the comer of the outlet during diastole stage.