• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.209-215
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• 2019

The most important personal health care in digital health care is a very important issue mainly for chronic diseases. Therefore, it is important to develop a simple wearable device for real-time health management. Existing blood pressure estimation wearable devices use PPG characteristics to analyze PTT and propose blood pressure estimation algorithms. However, the influencing factors of the algorithm such as the reproducibility of PPG, whether to apply various PTTs, and variables generated from the physical differences of the measurers are actually very complex. Therefore, in this study, the correlation between PTT, SBP, and DBP was analyzed, and it was designed to use PPG sensors for device miniaturization. The blood pressure estimation algorithm took into account differences in PPG, heart rate, and personal variables.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.22 no.4
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• pp.406-415
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• 2015

Purpose: This study was conducted to investigate the effects on problem solving ability and learning satisfaction in nursing students using a teaching method with a standardized patient (SP) receiving blood transfusion. Method: The research design was a quasi-experimental pre-and-post-test control and experimental group for the methodological comparison study. Participants were 43 (Exp.=22, Cont.=21) nursing students in G city. The experimental group participated in the teaching class using SP. The control group received conventional education using a simple model. Data were collected between June 5 and July 15, 2015, through self-report structured questionnaires and data were analyzed using the SPSS/WIN 21.0 program. Results: There were significant differences in the level of problem solving ability (t=-2.75, p=.009), and learning satisfaction (t=-2.53, p=.016) between the experimental and control groups. Conclusion: The research findings indicate that, the teaching method using an SP is more effective in improving nursing students' problem solving ability and learning satisfaction compared to conventional education using a simple model. In the future it is necessary to develop scenarios of various cases and content, and to test their effectiveness.

• Journal of Pharmaceutical Investigation
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• v.22 no.2
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• pp.133-137
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• 1992

A novel oral controlled release tablet which may offer more uniform drug level in the body than simple zero-order was developed. The tablet is composed of three layers; outer film layer, middle part compression-coated hydroxypropylmethylcellulose (HPMC) matrix layer, and inner core layer. Each layer contains nicardipine HCl as a model drug. In vitro dissolution test showed that the tablet released the drug in clear three steps; a rapid initial release, followed by a constant rate of release, and then a second phase of fast release of drug. The dissolution characteristics could be modified easily by changing the grade of HPMC, thickness of matrix layer, content of methylcellulose in matrix layer, content of active ingredient in each layer. The pH of dissolution medium did not affect the release profile. This three-step release system is expected to raise the blood concentration rapidly to effective level and to maintain effective blood level longer than simple slow-release systems.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.278-284
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• 2004

In order to determine the bioavailability of c1onazepam, an anxiolytic drug, a simple, rapid and sensitive HPLC analysis was developed in healthy Korean volunteers. The analysis system was validated in specificity, accuracy, precision and linearity. The analysis condition we established was 2.58 min and 5 ng/$m\ell$ in retention time and limit of quantitation of c1onazepam, respectively, using reverse-phase C18 column connected to UV detector. Quantitation was performed at 235 nm wave length with p-hydroxybenzoic acid ethyl ester as internal standard. The method involved a simple extraction. In order to study blood level profiles as a function of time, eight volunteers were enrolled and orally took 6 mg clonazepam once. The blood samples were collected from 0 to 120 h after the drug administration. Mean AUC and Cmax value were 1028.17$\pm$568.165 (ng/$m\ell$$.$hr) and 41.25$\pm$10.82 (ng/$m\ell$), respectively. And mean Tmax and T$_{1}$2/ value were 1.08$\pm$0.42 (hr) and 30.78$\pm$3.26 (hr). From the results we determine the pharmacokinetic characteristics of clonazepam in Korean people using a newly developed and useful HPLC method.

• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.338-343
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• 2007

BOLD T2*-weighted MR images reflects cortical blood flow and oxygenation alterations. fMRI study relies on the detection of localized changes in BOLD signal intensity. Since fMRI measures the very small modulations in BOLD signal intensity that occur during changes in brain activity, it is also very sensitive to small signal intensity variations caused by physiologic noise during the scan. Due to the complexity of movement of various organs associated with heart beat, it is important to reduce cardiac related noise rather than other physiological noise which could be required with relatively simple method. Therefore, a number of methods have been developed for the estimation and reduction of cardiac noise in fMRI study. But, each method has limitation. In this study, we proposed a new estimation method for brain activities influenced by blood pulsation effect using regression analysis with blood pulsation signal and the correspond slice of fMRI. We could find out that the right anterior cingulate cortex and right olfactory cortex and left olfactory cortex were largely influenced by blood pulsation effect for new method. These observed areas are mostly on the structure of anterior cerebral artery in the brain. That is convinced with that our method would be valid and our new method is easier to apply in practice and reduce computational burden than the retrospective method.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.1
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• pp.96-107
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• 1996

Automated blood pressure monitors have gained acceptance in many clinical settings with the increasing demand, the accurate BP measuring devices reguire the need for validation. We have evaluated the Dinamap 8100, an oscillometric automated blood pressure monitor, using the Mercury sphygmomanometer as a reference. Comparison of sphygmomanometers was conducted 60 patients (30-Normotensive group, 30-Hypertensive group at Seoul National University Hospital. Two trained observers took measure blood pressure(systolic/diastolic) at the same time using the Dinamap 8100 on one arm and the Mercury on the other. For each measurement, the device was randomly selected from a group of devices repetively used for the experiment. Mean readings for systolic pressure with the Dinamap 8100 in normotensive group were lower(mean difference ; 4.26mmHg) than the Mercury type. Mean readings for systolic pressure with the Dinamap 8100 in hypertensive group were lower(mean difference ; 9.05mmHg) than the Mercury type. Mean readings for diastolic pressure with the Dinamap 8100 in normotensive group were lower (mean difference ; 7.46mmHg) than the Mercury type. Mean readings for diastolic pressure with the Dinamap 8100 in hypertensive group were lower(mean difference ; 9.03mmHg) than the Mercury type. We have found that blood pressure readings with the Dinamap 8100 were lower than those with the Mercury type. we are using the Mercury type in clinics, although it has observer bias and terminal digit preference. But the Dinamap 8100 is readily portable, simple to use, and capable of preventing observer bias and terminal digit preference. The Dinamap 8100 is acceptable for blood pressure determination in subjects who are normotensive or hypertensive ones.

• Korean Journal of Computational Design and Engineering
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• v.22 no.1
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• pp.89-99
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• 2017

In order to make a virtual endoscopy system effective for exploring the interior of the 3D model of a human organ, it is necessary to generate an accurate navigation path located inside the 3D model and to obtain consistent camera position and pose estimation along the path. In this paper, we propose an approach to virtual navigation of blood vessels, which makes proper use of orthogonal contours and skeleton curves. The approach generates the orthogonal contours and the skeleton curves from the 3D mesh model and its voxel model, all of which represent the blood vessels. For a navigation zone specified by two nodes on the skeleton curves, it computes the shortest path between the two nodes, estimates the positions and poses of a virtual camera at the nodes in the navigation zone, and interpolates the positions and poses to make the camera move smoothly along the path. In addition to keyboard and mouse input, intuitive hand gestures determined by the Leap Motion SDK are used as user interface for virtual navigation of the blood vessels. The proposed approach provides easy and accurate means for the user to examine the interior of 3D blood vessels without any collisions between the camera and their surface. With a simple user study, we present illustrative examples of applying the approach to 3D mesh models of various blood vessels in order to show its quality and usefulness.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.2
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• pp.195-207
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• 2019

Objectives: This study was performed to confirm whether plasma lead can be used as a chronic biomarker for the biological monitoring of exposure to lead. Methods: Lead concentrations in 66 plasma samples from retired lead workers (G.M. 60.25 years, Median 61.00 years) and 42 plasma samples from the general population (G.M. 53.76 years, Median 56.50 years) were measured using ICP/Mass. Tibia, whole blood, hemoglobin, hematocrit, and blood zinc protophorphyrin (ZPP) concentrations and urinary ${\delta}$-aminolevulinic acid (${\delta}-ALA$) were measured for correlation analysis with plasma lead. Results: The geometric mean concentration of lead in plasma was $0.23{\mu}g/L$ for the retired lead workers and $0.10{\mu}g/L$ for the general population sample. A simple correlation analysis of biomarkers showed that plasma lead concentration among the retired lead workers was highly correlated with lead concentration in the tibia and with blood lead concentration, and the plasma lead concentration among the general population correlated with ZPP concentration in the blood. The lead concentration in the tibia and the lead concentration in the whole blood increased with length of working period. As the period in the lead workplace increased, the ratio of lead in plasma to lead concentration in whole blood decreased. Conclusion: This study confirmed the possibility of a chronic biomarker of lead concentration in blood plasma as a biomarker. In the future, comparative studies with specific indicators will lead to more fruitful results.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.724-728
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• 2004

Several studies have shown that a low frequency stimulation can depress blood pressure in hypertension. We had developed a new auriculoelectrostimulator as an electronic blood pressure regulator for simple and easy stimulation. The new auriculoelectrostimulator was employed in hypertensive rat model induced by immobilization stress, diabetic and essential hypertensive rat models. Rats were stimulated by auriculoelectrostimulator at ear acupoint (Ear point for hypertension) bilaterally. Ear stimulation by auriculoelectrostimulator significantly decreased blood pressure in all hypertensive rat models and inhibited the increase of heart rates in stressed and spontaneous hypertensive rats. The results showed that auriculoelectrostimulator had depressive effects on hypertension in rat hypertensive models, suggesting that it is useful in treatment of hypertension.

• KSBB Journal
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• v.14 no.5
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• pp.600-605
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• 1999

For the production of angiotensin I converting enzyme inhibitory peptides as a material for antihypertensive functional foods from animal blood produced in slaughterhouse, the optimum condition for enzymatic hydrolysis to yield a peptide fraction of the highest activity were investigated with a respect of industrial production. Among several industrially-usable enzymes tested, $Alcalase^？$ produced hydrolysates of the highest activity from total plasma and purified albumin. $IC_50$ values of albumin hydrolysate and its third fraction separated by gel chromatography were 0.5 and 0.02 mg/mL, respectively. The fraction was found to be obtained by a simple ultrafiltration using a membrane of MW cutoff 1,000. The possibility for the industrial production of antihypertensive peptides from animal blood plasma protein was suggested.