• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.387-391
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• 2007

An oxygenator is a very important artificial organ and widely used for patients with lung failure or during open heart surgery. Although an oxygenator has been widely studied worldwide to enhance its efficiency, studies on oxygenators, in particular when using a pulsatile blood flow, are domestically limited. Therefore, a new oxygenator was developed in the lab and animal experimental results are described in the paper. The oxygenator is composed of polycarbonate housing and polypropylene hollow fibers. It has a total length of 400 mm and a surface area of $1.7 m^2$. The animal experiment lasted for 4 hours. The blood flow rate was set to 2 L/min and a pulsatile blood pump, T-PLS (Twin-Pulse Life Support), was used. Samples were drawn at the oxygenator's inlet and outlet. The total hemoglobin (Hb), saturation oxygen ($sO_2$), and partial oxygen pressure ($pO_2$), partial $CO_2$ pressure ($pCO_2$), and plasma bicarbonate ion concentration ($HCO_3^-$) were measured. The oxygen and carbon dioxide transfer rates were also calculated based on the experimental data in order to estimate the oxygenator's gas transfer efficiency. The oxygen and carbon dioxide transfer rates were $16.4{\pm}1.58$ and $165.7{\pm}10.96 mL/min$, respectively. The results showed a higher carbon dioxide transfer rate was achieved with the oxygenator. Also, the mean inlet and outlet blood pressures were 162.79 and 137.92 mmHg, respectively. The oxygenator has a low pressure drop between its inlet and outlet. The aim of own preliminary study was to make a new oxygenator and review its performance when applying a pulsatile blood pump thus, confirming the possibility of a new oxygenator suitable for pulsatile flow.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.12
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• pp.491-498
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• 2019

Digital twin is a technology that virtualizes physical objects of the real world on a computer. It is used by collecting sensor data through IoT, and using the collected data to connect physical objects and virtual objects in both directions. It has an advantage of minimizing risk by tuning an operation of virtual model through simulation and responding to varying environment by exploiting experiments in advance. Recently, artificial intelligence and machine learning technologies have been attracting attention, so that tendency to virtualize a behavior of physical objects, observe virtual models, and apply various scenarios is increasing. In particular, recognition of each robot's motion is needed to build digital twin for co-robot which is a heart of industry 4.0 factory automation. Compared with modeling based research for recognizing motion of co-robot, there are few attempts to predict motion based on sensor data. Therefore, in this paper, an experimental environment for collecting current and inertia data in co-robot to detect the motion of the robot is built, and a motion prediction model based on the collected sensor data is proposed. The proposed method classifies the co-robot's motion commands into 9 types based on joint position and uses current and inertial sensor values to predict them by accumulated learning. The data used for accumulating learning is the sensor values that are collected when the co-robot operates with margin in input parameters of the motion commands. Through this, the model is constructed to predict not only the nine movements along the same path but also the movements along the similar path. As a result of learning using SVM, the accuracy, precision, and recall factors of the model were evaluated as 97% on average.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.57-64
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• 2004

The non pulsation blood pump is divided into axial flow and centrifugal style according to the direction of inlet and outlet flow. An axial flow blood pump can be made smaller than a centrifugal blood pump because centrifugal pump's rpm is fewer than axial flow pump. Hemolysis is an important factor for the development of an axial flow blood pump. It is difficult to identify the areas where hemolysis occurs. Evaluation of hemolysis both in in-vitro and in-vivo test requires a long-time and more expensive. Computational fluid dynamics(CFD) analysis enables the engineer to predict hemolysis on a computer which just can get not only amount of htmolysis but also location of hemolysis. It takes shorter time and less expensive than in-vitro test. The purpose of this study is to git Computational fluid dynamics in axial flow pump and to verify the accuracy of prediction by the possibility of design comparing CFD results with in-vitro experimental results. Also, wish to figure out the correction method that can bring improvement in shape of axial flow blood pump using CFD analysis.

• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.336-340
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• 2015

Background: Potentially harmful unplanned extubation (UE) may occur in patients on mechanical ventilation (MV) in an intensive care unit (ICU) setting. This study aimed to evaluate the clinical characteristics of UE and its impact on clinical outcomes in patients with MV in a medical ICU (MICU). Methods: We retrospectively evaluated MICU data prospectively collected between December 2011 and May 2014. Results: A total of 468 patients were admitted to the MICU, of whom 450 were on MV. Of the patients on MV, 30 (6.7%) experienced UE; 13 (43.3%) required reintubation after UE, whereas 17 (56.7%) did not require reintubation. Patients who required reintubation had a significantly longer MV duration and ICU stay than did those not requiring reintubation ($19.4{\pm}15.1days$ vs. $5.9{\pm}5.9days$ days and $18.1{\pm}14.2days$ vs. $7.1{\pm}6.5days$, respectively; p<0.05). In addition, mortality rate was significantly higher among patients requiring reintubation than among those not requiring reintubation (54.5% vs. 5.9%; p=0.007). These two groups of patients exhibited no significant differences, within 2 hours after UE, in the fraction of inspired oxygen, blood pressure, heart rate, respiratory rate, and pH. Conclusion: Although reintubation may not always be required in patients with UE, it is associated with a poor outcome after UE.

• Journal of Haehwa Medicine
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• v.12 no.1
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• pp.103-121
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• 2003

Human being can't live without nature, then the changes of nature affect human body. It means that human body has corresponding changes to the KI(vital energy) of nature. There is a stream of changes in human body which circulate mysteriously and punctually by the laws of nature. If this stream of changes fits into human's life style, it would be most effective. It has a certain mode continuously. So if a person has a habit fitting into it, he will get the healthiest body. Then the researcher tries to explain the changes in human body by the time, mainly focused on within 24 hours. it is showing not only the oriental view, but also the western's. The researcher can find the coincidence as followings. At In-Si(3-5 am), the body function and the body temperature get to the bottom, therefore it's good for him to wake up and to run the vital energy. At Sa-Si(9-11 am), the patience on pain anxiety and the psychic concentration get to the top, he'd better start the work. At O-Si(11am-1pm), the heart energy has a vital move, then the blood concentration of Hb(hemoglobin) gets to the top. At Mi-Si(1-3 pm), the muscle strength, the squeeze, and the breathing rate increase. The reflex nerve sensitivity gets to the top. Creativity, observation, and working efficiency go high, so it's time to work hard. At Hae-Si(9pm-1am), the body function falls, sleeping is needed. At Chuck-Si(1-3 am), the cell spontaneity gets to the top, immune lymphocyte moves actively, and the blood concentration of growth hormone gets to the top. These are liver's work. In west, there has been active studies on how to reduce the side effect by using a person's bio-rhythm based on the 'time treatment', and how to reorganize the bio-rhythm by using the machine and the age resistance based on the 'bio-watch'. Though the 'time treatment' means something, the artificial resistance on bio-rhythm seems to give bad effects to human body. If a person lives by regimen of oriental medicine, he will maintain the healthiest body. Regimen is that human body follows the laws of nature, and moves its mysterious, Punctual and periodical changes.

• Journal of Hospice and Palliative Care
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• v.18 no.3
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• pp.179-187
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• 2015

For patients who are near the end of life, an inevitable step is discussion of a do-not-resuscitate (DNR) order, which involves patients, their family members and physicians. To discuss DNR orders, patients and family members should know the meaning of the order and cardiopulmonary resuscitation (CPR) which includes chest compression, defibrillation, medication to restart the heart, artificial ventilation, and tube insertion in the respiratory tract. And the following issues should be considered as well: patients' and their families' autonomy, futility of treatment, and the right for death with dignity. Terminal cancer patients should be informed of what futility of treatment is, such as a low survival rate of CPR, unacceptable quality of life after CPR, and an irremediable disease status. In Korea, two different law suits related to life supporting treatments had been filed, which in turn raised public interest in death with dignity. Since the 1980s, knowledge of and attitude toward DNR among physicians and the public have been improved. However, most patients are still alienated from the decision making process, and the decision is often made less than a week before death. Thus, the DNR discussion process should be improved. Early palliative care should be adopted more widely.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.487-492
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• 2002

Low-fat and sugar-free (LFSF) cookies were developed for patients with metabolic syndrome X, such as obesity, diabetes, coronary heart disease, and hypertention, using artificial sweeteners (mixture of aspartame and saccharin), pectin and herb extracts such as Polygonatum Odoratum (Mill) Druce, Schizandrae Fructus and Lycii Fructus, without sugar and fats. LFSF cookies were composed of 7.5 : 1 of aspartame and saccharin, 5% pectin, 49% protein, and 5% herb extracts, with reduced fat level. The values for area under the curve in oral glucose tolerance tests were significantly lower in 90% pancreatomized-(Px, n = 8) and sham - operated (Sham, n = 8) rats which consumed LFSF cookies, than the control, which consumed regular cookies. Blood glucose levels were higher and the peak levels were significantly lower in the LFSF cookies group than the control group of Px and Sham rats. Blood glucose levels of healthy female college students (n = 10) at 30 and 60 min after the consumption of 30 g LFSF and regular cookies were not different, but they were significantly lower in the LFSF-cookies group in diabetes patients (n = 10). In conclusions, LFSF cookies was considered as a good snack for diabetic patients.

• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.197-205
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• 2019

The existing Extracorporeal membrane oxygenation(ECMO) and Cardiopulmonary bypass system(CPB) have been developed and applied to various devices according to their respective indications. However, due to the complicated configuration and difficult usage method, it causes inconvenience to users and there is a risk of an accident. Therefore, smart all-in-one cardiopulmonary circulation device is being developed recently. The smart all-in-one cardiopulmonary assist device consists of a blood pump for cardiopulmonary bypass, a blood oxidizer for cardiopulmonary bypass, a blood circuit for cardiopulmonary bypass, and an artificial cardiopulmonary device. It is an integrated cardiopulmonary bypass device that can be used for a variety of purposes such as emergency, intraoperative, post-operative intensive care, and long-term cardiopulmonary assist, combined with CPB used in open heart surgery and ECMO used when patient's cardiopulmonary function does not work normally. The smart all-in-one cardiopulmonary assist device does not exist as a standard and international standard applicable to advanced medical devices. Therefore, in this study, we will refer to the International Standard for Blood Components, the International Standard for Blood, the Guideline for Blood Products, and prepare applicable performance and safety guidelines to help quality control of medical devices, and contribute to the improvement of the health of people. The guideline, which is the result of conducted a survey of the method of safety and performance test, is based on the principle of all-in-one cardiopulmonary aiding device, related domestic foreign standards, the status of domestic and foreign patents, related literature, blood pump(ISO 18242), blood oxygenator (ISO 7199), and blood circuit (ISO 15676) for cardiopulmonary bypass.The items on blood safety are as follows: American Society for Testing and Materials ASTM F1841-97R17), and in the 2010 Food and Drug Administration's Safety Assessment Guidelines for Medical Assisted Circulatory Devices. In addition, after reviewing the guidelines drawn up through expert consultation bodies including manufacturers / importers, testing inspectors, academia, etc. the final guideline was established through revision and supplementation process. Therefore, we propose guidelines for evaluating the safety and performance of smart all-in-one cardiopulmonary assist devices in line with growing technology.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.1
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• pp.77-84
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• 2024

Objectives: Interventions promoting physical exercise and healthy habits in workplaces have been shown to be effective in reducing risk factors for metabolic syndrome. This study was conducted to examine the effects of an individualized conditioning exercise program of IT company office workers with or at higher risk of metabolic syndrome. Methods: A total of 444 IT company office workers with or at higher risk of metabolic syndrome participated in a 3-month conditioning exercise program. Body composition data using bioelectrical impedance analysis and cardiopulmonary data using cardiopulmonary exercise testing from 53 individuals (mean age: 34.8 ± 7.1 years, sex : 21% female, height : 170.4 ± 6.8 cm, weight : 75.2±12.2 kg, body mass index : 25.8±3.3 kg/m²) who have successfully completed pre-test, intervention, and post-test were analyzed. The 12 weeks intervention encompassed: (1) health counseling (2) supervised exercise(endurance-based, aerobic exercise, or circuit training once a week for 50 minutes at heart rate reserve(HRR) of 77-95%) (3) self-directed exercise and biweekly health screening checks. Results: The results indicated a significant decrease in body weight, body fat mass and body mass index, respectively. Moreover, VO₂peak, AT VO₂ and AT Time significantly improved, respectively. Resting blood pressure(SBP/DBP) showed positive changes but were not statistically significant. We observed the correlation between characteristics of participants and rate of changes in cardiopulmonary outcomes of participants, there are no significant correlation. These results indicate positive changes in body composition and cardiorespiratory fitness parameters following individualized conditioning exercise program. Conclusions: Individualized workplace exercise program for preventing metabolic syndrome can lead to improvements in body composition and cardiorespiratory fitness.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.292-298
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• 2009

Background: Surgery for mitral valve disease in children carries both technical and clinical difficulties that are due to both the wide spectrum of morphologic abnormalities and the high incidence of associated cardiac anomalies. The purpose of this study is to assess the outcome of mitral valve surgery for treating congenital mitral regurgitation in children. Material and Method: From 1997 to 2007, 22 children (mean age: 5.4 years) who had congenital mitral regurgitation underwent mitral valve repair. The median age of the patients was 5.4 years old and four patients (18%) were under 12 months of age. 15 patients (68%) had cardiac anomalies. There were 13 cases of ventricular septal defect, 1 case of atrial septal defect and 1 case of supravalvar aortic stenosis. The grade of the preoperative mitral valve regurgitation was II in 4 patients, III in 15 patients and IV in 3. The regurgitation was due to leaflet prolapse in 12 patients, annular dilatation in 4 patients and restrictive leaflet motion in 5 patients. The preoperative MV Z-value and the regurgitation grade were compared with those obtained at follow-up. Result: MV repair was possible in all the patients. 19 patients required reduction annuloplasty and 18 patients required valvuloplasty that included shortening of the chordae, papillary muscle splitting, artificial chordae insertion and cleft closure. There were no early or late deaths. The mitral valve regurgitation after surgery was improved in all patients (absent=10, grade I=5, II=5, III=2). MV repair resulted in reduction of the mitral valve Z-value ($2.2{\pm}2.1$ vs. $0.7{\pm}2.3$, respectively, p<0.01). During the mid-term follow-up period of 3.68 years, reoperation was done in three patients (one with repair and two with replacement) and three patients showed mild progression of their mitral reguration. Conclusion: our experience indicates that mitral valve repair in children with congenital mitral valve regurgitation is an effective and reliable surgical method with a low reoperation rate. A good postoperative outcome can be obtained by preoperatively recognizing the intrinsic mitral valve pathophysiology detected on echocardiography and with the well-designed, aggressive application of the various reconstruction techniques.