• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.801-805
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• 2009

This paper reports on a flexible flap valve actuated by electromagnetic force under a constant pressure source. The flexible flap valve consists of the three main components: a flexible flap with a steel disk embedded in PDMS, an electromagnetic actuator and two glass plates with inlet and outlet. The flap valve is fabricated by SU-8 mold process, the EDM process and oxygen plasma treatment. The dimension of an assembled flap valve is $12[mm]{\times}20[mm]{\times}28[mm]$. The stroke volume of the flap valve is measured for various pressures. And the time of the applied input voltage is varied to change the open time of the valve. When the input voltage of 30[V] is applied for 0.25[s], the minimum stroke volume of the flap valve is $40[{\mu}L]$ at 70 [kPa].

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2008.10a
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• pp.155-155
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• 2008

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.109-117
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• 2004

In this paper, we consider the aortic sinus baroreceptor, which is the most representative baroreceptor sensing the variance of pressure in the cardiovascular system, and propose heart activity control model to observe the effect of delay time in heart period and stroke volume under the regulation of baroreflex in the aortic sinus. The proposed heart activity baroreflex regulation model contains electric circuit sub-model. We constituted the time delay sub-model to observe sensitivity of heart activity baroreflex regulation model by using the variable value to represent the control signal transmission time from the output of baroreflex regulation model to efferent nerve through central nervous system. The simulation object of this model is to observe variability of the cardiovascular system by variable value in time delay sub-model. As simulation results, we observe three patterns of the cardiovascular system variability by the time delay, First, if the time delay over 2.5 second, aortic pressure and stroke volume and heart rate is observed nonperiodically and observed. Finally, if time delay under 0.1 second, then heart rate and aortic pressure-heart rate trajectory is maintained in stable state.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.730-734
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• 2006

Aqueous extracts of medicinal plants traditionally used in the East Asia such as China, Korea, and Japan were screened for inotropic activity using isolated rabbit atria. Among the twenty-one aqueous-extracts from medicinal plants, the aqueous extracts of Convallaria keiskei(ACK) and rhizome of Coptis chinesis (ACC) were found to exhibit distinctive positive inotropic activity. The aqueous extracts of C. keiskei and rhizome of C. chinensis significantly increased atrial stroke volume and pulse pressure in beating rabbit atria. These findings suggest that the aqueous extracts of C. keiskei and rhizome of C. chinensis enhance the cardiac muscle contractility and then could be useful for the treatment of cardiac failure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.8
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• pp.1251-1255
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• 2015

The purpose of this study is to measurement the cardiac output using hand to hand impedance method to provide convenience to user when measuring SV(stroke volume) with the use of ICG(Impedance Cardiography). We suggest the optimized modified formula, which can be applied when using impedance with the use of hand to hand Impedance. To verify this formula, a SV from transthoracic approach and hand to hand approach are compared for the 36 subjects, respectively. The acquired data was analyzed by using LabVIEW 8.6, analysis was implemented by SPSS 12.0. Fine difference was shown by individual. We showed that as a result of analyzing the ICG measurement value on thoracic and hand to hand, the correlation with SV was r=0.716, thereby having indicated the results of regression model in relatively high correlation.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.4
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• pp.47-61
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• 1983

In this paper the simulation of a thermodynamic power cycle for a 4-stroke, single-cylinder, spark-ignition engine was studied. In this simulation the cylinder volume was restricted to two zones, a burnt and an unburnt zone, and the convective heat transfer from cylinder contents to surroundings was considered. The chemical species in burnt gas considered was 12 species including H$_{2}$O, H$_{2}$, OH, H, N$_{2}$, NO, N, CO$_{2}$, CO, $O_{2}$, O and Ar. Using this model, computer program for compression, ignition and expansion processes was composed and pressure, temperature and composition of cylinder gas at each crank angle were computed. The composition of CO$_{2}$, CO, $O_{2}$ in the burnt gas when exhaust valve opens, the maximum temperature, the maximum flame speed and the combustion duration were also computed as a function of equivalence ratio. The relation between burnt mass fraction and burnt volume fraction was also computed.

• The Journal of the Society of Stroke on Korean Medicine
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• v.7 no.1
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• pp.1-10
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• 2006

Objectives : Yanggyuksanhwa-tang is a prescription used for cerebral infarction clinically. Methods : According to previous research data, the effect of Yanggyuksanhwa-tang on cerebral infarction, we induced cerebral infarction by middle cerebral artery occlusion(MCAO) in rats, and the rats were administered Yanggyuksanhwa-tang. Results: Infarct area, infarct volume were measured, and the level of elements such as c-Fos, Bax and caspase-3 in penumbra of infarct were expressed by immunohistochemical staining. Conclusion : Yanggyuksanhwa-tang showed neuroprotective effect through preventing neuronal cell apoptosis.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.340-347
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• 2012

Purpose: This study was conducted in order to investigate the effect on respiratory function, trunk control, and functional activities of daily living (ADL) through respiratory muscle strength training in patients with chronic stroke. Methods: Eighteen subjects who were six months post stroke participated in this study. The subjects were randomly allocated to two groups: experimental (n=10) and control (n=8). Both groups received physical therapy for five sessions, 30 minutes per week, during a period of six weeks. Subjects in the experimental group participated in an additional respiratory muscle strength training program, in which the threshold PEP device was used for 30 minutes per day, three days per week, during a period of six weeks. Results from pretest-posttest control were evaluated by pulmonary function forced vital capacity (FVC), forced expiratory volume at one second (FEV1), FEV1/FVC, peak expiratory flow (PEF), capacity of cough, trunk control, and functional ADL. Results: Significant improvement in the FEV1, PEF of pulmonary function (p<0.05), cough function (p<0.05), and trunk control (p<0.05) was observed among the groups. Conclusion: Respiratory muscle strength training improves pulmonary function, capacity of cough, and trunk control. These results suggest that respiratory muscle strength training is feasible and suitable for individuals with chronic stroke.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.1-8
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• 2022

Erythrocyte sedimentation rate (ESR) evaluation is a useful tool for monitoring disease activity in various inflammatory and non-inflammatory conditions. ESR is known to be influenced by a multitude of confounding factors. The present study aimed to assess the possible determinants of the ESR and its relationship with various risk factors involved in ischemic stroke. ESR and other hematological and biochemical parameters were investigated in 163 ischemic stroke patients (107 males and 56 females) selected based on imaging techniques including magnetic resonance imaging (MRI) or computed tomography (CT) scans. Statistical analysis was performed using the SPSS 16.0 software. Linear regression analysis showed a significant inverse relationship of hemoglobin (Hb) and hematocrit or packed cell volume (PCV) (P<0.001 for females; P<0.01 for males) with the ESR. It was observed that the red blood cell (RBC) count was not strongly correlated with the ESR (P<0.05 for both males and females). It was also observed that sex significantly affected the variables determining the ESR levels, whereas age had no effect. Gender differences were also observed with respect to Hb, RBC, PCV, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and ESR. The possible determinants of higher ESR levels in ischemic stroke may be sex, Hb, hematocrit, and RBC count, but the role of other clinical and laboratory parameters cannot be underestimated.

• Journal of Yeungnam Medical Science
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• v.39 no.2
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• pp.98-107
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• 2022

Background: Stroke patients usually experience damage to multiple functions and a long rehabilitation period. Hence, there is a large volume of patient clinical information. It thus takes a long time for clinicians to identify the patient's information and essential pieces of information may be overlooked. To solve this, we stored the essential clinical information of stroke patients in a blockchain and implemented the blockchain technology using the Java programming language. Methods: We created a mini blockchain to store the medical information of patients using the Java programming language. Results: After generating a unique pair of public/private keys for identity verification, a patient's identity is verified by applying the Elliptic Curve Digital Signature Algorithm based on the generated keys. When the identity verification is complete, new medical data are stored in the transaction list and the generated transaction is verified. When verification is completed normally, the block hash value is derived using the transaction value and the hash value of the previous block. The hash value of the previous block is then stored in the generated block to interconnect the blocks. Conclusion: We demonstrated that blockchain can be used to store and deliver the patient information of stroke patients. It may be difficult to directly implement the code that we developed in the medical field, but it can serve as a starting point for the creation of a blockchain system to be used in the field.