• Journal of Biomedical Engineering Research
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• v.38 no.3
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• pp.111-115
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• 2017

Blood pressure is one of the important vital signs for monitoring the medical condition of a patient. Automated NIBP(non-invasive blood pressure) monitoring devices calculate systolic and diastolic blood pressures from the oscillation in cuff pressure caused by a pulsation of an artery. To validate the NIBP devices, we developed a simulator to supply the oscillometric waveforms obtained from human subjects. The simulator provided pressure pulses to device-under-test and device readings were compared to the auscultatory references. Fully automated simulation system including OCR(optical character recognition) were developed and used for NIBP monitoring devices. The validation results using the simulator agreed well with previous clinical validation. More validation studies using the standardized oscillometric waveforms would be required for the replacement of clinical trials to validate a new automated NIBP monitoring device.

• Journal of Sensor Science and Technology
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• v.24 no.4
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• pp.239-246
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• 2015

Blood pressure is possible to diagnose a disease associated with blood pressure and judgment the current health of patients. Automatic blood pressure monitor capable of measuring a blood pressure easily in hospital and at home have become spread. In this study, we developed the blood pressure simulator (BPS) that can test the arm-type automatic blood pressure monitor that is commonly used in hospital. BPS is to produce a pressure similar to the pressure wave generated in the human blood using a servo disk motor. Then, using the silicon tube, it implements the situations such as human blood vessels, and to output the generated pressure waveform. Simply the BPS's phantom put on the cuff and it is able to simulate blood pressure. So anyone can quickly test the blood pressure monitor within one minute and it is possible to shorten the test time required for the automatic blood pressure monitor. In Performance test, the trends and the standard deviation of the values measured in the BPS is similar to the value of the measured pressure from people with normal blood pressure. Thus, the development BPS showed a possibility of taking into account the actual blood pressure measurement environment simulator.

• Journal of Biomedical Engineering Research
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• v.45 no.1
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• pp.49-55
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• 2024

Accurate measurement of blood pressure is essential for classifying an individual's disease, identifying blood pressure-related risks, and managing health. Due to the environmental and health hazards of mercury sphygmomanometers, automatic sphygmomanometers using the oscillometric method are widely used in hospitals as well as in general homes, and have established themselves as a practical standard sphygmomanometer. In this study, we developed a blood pressure simulator using an actuator that provides simulated pressure to an automatic blood pressure cuff. The developed blood pressure simulator adopts an arm-shaped cylindrical shape similar to the situation in which a person measures blood pressure with an automatic blood pressure monitor, and implements a method of transmitting pressure to the cuff using a pressure plate. Accuracy was evaluated through the mean and standard deviation of the difference with the commercialized blood pressure simulator BP PUMP 2, and reproducibility was confirmed using two automatic blood pressure monitors. The developed blood pressure simulator enables automatic blood pressure monitoring in a simple manner and also meets the evaluation standards for accuracy and reproducibility. In the future, as a standardized blood pressure simulator, it is expected to be of great help in evaluating and verifying the performance of automatic blood pressure monitors by supplementing precise hardware and software and building a blood pressure database.

• Journal of Life Science
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• v.13 no.5
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• pp.634-641
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• 2003

In order to examine whether arsenic, one of environmental stress, contribute to augumentation and relaxation of rat aorta, this study was performed in vivo and in vitro, using intacted or denuded rats aorta ring preparation, respectively. The carotid arterial pressure was recorded on an ink-writing physiograph(Grass Co. 79E) connected to strain gauge. The contractile response of vascular ring with or without endothelium preparation isolated from rat were determined in organ bath and was recorded on physiograph connected to isometric transducer. Vasopressin-,and phenylephrine- induced increase in arterial pressure significantly enhanced in arsenic-treated rats; increase of 19.1%, and 46.6%, respectively. Vascular contractile response was measured in vitro preparations exposed to 0, 0.5, 1, 2 and 4 mM of arsenic for 1, 3, 5 and 8 hours. The dose-vascular responses of phenylephrine augmented by increasing dose of arsenic in the strips exposed to arsenic for 8 hours, and did not augmented for 1, 3, 5 hours. The phenomenon was not affected by strips denuded endothelium. And the response of relaxation of rat aorta induced by nitroprusside was not influenced by arsenic stress, but acetylcholine was a little increased. compared to that of control. There were no significant difference in relaxation between control and arsenic treated rings with endothelium or denuded. All of the results, phenyleprine-induced vascular contraction was significantly enhanced in 4 mM arsenic-treated rat aortic rings compared with control, whether endothelium was present or denuded at 8 hours after arsenic treatment. It may be a mechanism by which long-term arsenic stresses play a role in development of hypertension.

• Tuberculosis and Respiratory Diseases
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• v.52 no.2
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• pp.156-165
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• 2002

Background: A tracheal stenosis is caused by mucosal ischemic injury related to a high cuff pressure ($P_{cuff}$) of the endotracheal tube. In contrast, aspiration of the upper airway secretion and impaired gas exchange due to cuff leakage is related to a low $P_{cuff}$. To prevent these complications, the $P_{cuff}$ should be kept appropriately because the appropriate $P_{cuff}$ appears to change according to the patient's daily respiratory mechanics. However, the constant cuff volume($V_{cuff}$) has frequently been instilled to the cuff balloon on a daily basis to maintain the optimal $P_{cuff}$ instead of monitoring the $P_{cuff}$ directly at the patients' bedside. To address the necessity of continuous $P_{cuff}$ monitoring, the change in the $P_{cuff}$ was evaluated at various $V_{cuff}$ levels on a daily basis in patients with long-term mechanical ventilation. The utility of mercury column sphygmomanometer for the continuous monitoring $P_{cuff}$ was also investigated. Method: The change in $P_{cuff}$ according to the increase in $V_{cuff}$ was observed in 17 patients with prolonged endotracheal intubation for mechanical ventilation for 2 week or more. This maneuver measured the change in $P_{cuff}$ daily during the mechanical ventilation days. In addition, the $P_{cuff}$ measured by mercury column sphygmomanometer was compared with the $P_{cuff}$ measured by an automatic cuff pressure manager. Results : There were no statistically significant changes of $P_{cuff}$ during more than 14 days of intubation for mechanical ventilation. However the $V_{cuff}$ required to maintain the appropriate $P_{cuff}$ varied from 1.9 cc to 9.6 cc. In addition, the intra-individual variation of the $P_{cuff}$ was observed from 10 $cmH_2O$ to 46 $cmH_2O$ at constant 3 cc $V_{cuff}$. The $P_{cuff}$ measured by the bedside mercury column sphygmomanometer is well coincident with that measured by the automatic cuff pressure manager. Conclusion: Continuous monitoring and management of the $P_{cuff}$ to maintain the appropriate $P_{cuff}$ level in order to prevent cuff related problems during long-term mechanical ventilation is recommended. For this purpose, mercury column sphygmomanometer may replace the specific cuff pressure monitoring equipment.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.1012-1017
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• 2008

Purpose : This study aimed to assess the mechanical properties of the abdominal aorta in school-aged patients treated for Kawasaki disease and in normal, healthy children. Methods : This study examined 28 children with Kawasaki disease who had been followed up on and 30 healthy subjects of the same age and gender. We recorded systolic (Ps) and diastolic (Pd) blood pressure values and the aortic diameter at both minimum diastolic (Dd) and maximum systolic (Ds) expansion using two-dimensional echocardiography. These measurements were used to determine 1) aortic strain: S=(Ds-Dd)/Dd; 2) pressure strain elastic modulus: Ep=(Ps-Pd)/S; and 3) normalized Ep: $Ep^*=Ep/Pd$. Results : Ep (P=0.008) and $Ep^*$ (P=0.043) of the Kawasaki disease group were relatively high compared to those of the control group. Ep (P=0.002) and $Ep^*$ (P=0.015) of patients with coronary aneurysm were also relatively high compared with those of patients without coronary aneurysm, but lipid profiles did not differ, except for homocysteine (P=0.008). Therefore, in patients with coronary aneurysm, aortic stiffness was higher, compared to not only the control group but also patients without coronary aneurysm. However, in patients without coronary aneurysm, aortic stiffness was not significant, different compared to the control group. Conclusion : Measuring aortic distensibility may be helpful in assessing the risk of early atheroscletic change in the long-term management of Kawasaki disease.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.3
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• pp.441-446
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• 2001

Flumazenil is a competitive antagonist of benzodiazepines. It is usually administered intravenously. However, if the intravenous route is not available then other routes of drug administration should be considered. This study was designed to evaluate the reversal effects of flumazenil after nasal administration. Twenty-five young, healthy adult volunteers participated in this clinical trial. The dosage of 0.08mg/kg midazolam was administered intravenously to induce deep sedation. Ten minutes after midazolam administration, 0.5mg of flumazenil was dropped nasally, over a period of one minute. Blood samples were taken to measure the concentration of midazolam and flumazenil at 0, 5, 10, and 20min after nasal administration of flumazenil, using High Performance Liquid Chromatography. The degree of sedation was evaluated with sedation score and bispectral index (BIS), Statistical analysis was performed by multivariate ANOVA and correlation analysis (P<0.05). Peak serum flumazenil concentration was reached in 10min. Sedation score decreased after midazolam administration and showed a significant increase after flumazenil administration. However, BIS decreased during the first 10min after midazolam administration and then no significant changes after flumazenil administration. There were two instances representing rapid and complete reversal of midazolam after intranasal administration of flumazenil. In conclusion, intranasal flumazenil administration may be effective in some patients when intravenous route is not available in condition of benzodiazepine overdose.