• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.859-860
• /
• 2006

We developed a cuffless and noninvasive measurement technique of blood pressure using tonometric pressure sensor. With observation that the maximum value of pulse pressure is not obtained at mean arterial pressure(MAP), we have figured out MAP based on the physiological characteristic including the elasticity of wrist tisse. Detecting only one part of the body and using only one device are quite advantageous over other BP measurement techniques. Our technique makes new way for the cuffless BP measurement.

• Archives of Reconstructive Microsurgery
• /
• v.1 no.1
• /
• pp.51-55
• /
• 1992

Problems of composite tissue transfer commonly arise when a single indispensable recipient vessel receives the graft vssel, and the graft vessel must be sutured in end-to-side fashion so as not todisturb the vascularity of the recipient vessel. The triangular flap in the recipient vessel wall gives an intact endothelial surface when the flow of blood stream is presented and may reduce the chance of anastomosis. We selected mature Wistar rats weighing over 450 grams to compare the conventional longitudinal slit from the triangular flap in the recipient carotid artery over bloood pressure and blood flow when the donor carotid artery was anastomosed in end-to-side fashion. In 30 minutes after anastomosis, maximum blood pressure measured in the donor carotid arterial side when the recipient arterial wall was fasioned with the longitudinal slit was recorded 114 mmHg and with the triangular flap 100mmHg. Minimum blood pressure with the longitudinal slit was 98mmHg and with the triangular flap 88mmHg. The amount of blood collected for 30 seconds in the conventional longitudinal slit was 1.18mg and in the triangular flap 0.78mg. Histology study in 30 minutes, the conventional longitudinal slit demonstrated the more hemorrhagic features around the suture material compared to that of the triangular. flap and, in the 7th day, the conventional longitudinal slit demonstrated the more prominent granulomatous reactions and vascular proliferations around the suture material compared to that of the triangular flap.

• Biomolecules & Therapeutics
• /
• v.5 no.3
• /
• pp.299-305
• /
• 1997

In order to investigate the pharmacological properties of ι-muscone, effects of ι-muscone and musk were studied on the cardiovascular system with various experimental models. In isolated rat aorta, ι-muscone and musk made the relaxation of blood vessels in maximum contractile response to phenylephrine (10$^{-6}$ M) in endothelium-containing rings of the rat aorta, but not in endothelium-denuded rings. However, ι-muscone and musk in the presence of the inhibitor of NO synthase and guanylate cyclase did not make the relaxation of blood vessels. In spontaneously hypertensive rats (SHRs), ι-muscone and musk slightly reduced blood pressure but significantly decreased heart rate. In the isolated perfused rat hearts, ι-muscone and musk did not affect significantly on LVDP, contractile force, coronary flow and (-dp/dt)/(+dp/dt). These results suggest that ι-muscone and musk have weak cardiovascular effects with relaxation of blood vessel and decrease of heart rate, but without significant cardiac functions.

• Journal of Ginseng Research
• /
• v.23 no.2 s.54
• /
• pp.81-87
• /
• 1999

The effect of saponin and non-saponin of Panax Red Ginseng on the blood pressure and nitric oxide production were investigated in the conscious free moving one-kidney, one-clip Goldbaltt hypertensive (lK, 1C-GBH) rats. Mean blood pressure in the control and lK, 1C-GBH rats was decreased by the administration of ginseng saponin (100 mg/kg, i.v.). The hypotensive effect induced by ginseng saponin was reached maximum at 2-4 minutes and was slowly recovered to the initial level of blood pressure. Also ginseng saponin induced reflex tachycardia in the conscious both rats. Contrast to the response induced by ginseng saponin, hypotensive effect induced by non-saponin of panax ginseng is minimal. Plasma nitric oxide concentration was increased by the treatment of ginseng saponin (100 mg/kg, i.p for 5 days) in both rats. It has been shown by western blotting that the expression level of the protein for endothelial nitric oxide synthase (eNOS) in the aorta of rats was not increased by the treatment of ginseng saponin (100 mg/kg, i.p). However, eNOS activity in aortic homogenates of both rats were increased by the treatment of ginseng saponins. From the above results, the hypotensive effect of saponin was greater than that of non-saponin of Panax Red Ginseng. The lowering effect of blood pressure by ginseng saponin may be due to the increase of plasma nitric oxide concentration via the increase of endothelial nitric oxide synthase activity in the renovascular hypertensive and control rats.

• Journal of Biomedical Engineering Research
• /
• v.24 no.5
• /
• pp.381-389
• /
• 2003

Various adult diseases (cerebral apoplexy, athymiait, etc.) result from hypertension, blood circulation disturbance and increment of HBP. In early diagnosis of these diseases, MRI, X-ray and PET have been used rather aim for treatment than for a prevention of disease. Since. cerebral apoplexy and athymiait could appear to the regular/irregular persons, it is very important to measure HBP which has connection with cerebral blood flow state. HBP has more diagnosis elements than that of BP. So, we can diagnose accurate hypertension by measuring of HBP. But, existing sphygmomanometers and automatic BP monitors can not measure HBP, and can not execute complex function(measuring of BP/HBP, blood flow improvement). Purpose of this paper is to develop a system and algorithm which can measure BP/HBP for accurate diagnosis. Also, we extracted diagnosis factors by correlativity analysis of BP/HBP. Maximum pressure of HBP corresponds to 62% that of BP, Minimum pressure of HBP corresponds to 46% that of BP. Therefore, we developed the multi-function automatic blood pressure monitor which can measure BP/HBP and improve cerebral blood flow state.

• Journal of Chest Surgery
• /
• v.23 no.6
• /
• pp.1049-1056
• /
• 1990

The OXYREX hollow fiber membrane oxygenator developed by joint work of KIST and Green Cross Medical company has been evaluated by experimental investigation and clinical application, In this oxygenator gas exchanges occur through small pores of 0.1pm size which are distributed on 70% of surface of polypropylene hollow fiber. The Oxyrex membrane oxygenator consists of 36 thousand hollow fibers and it has 3.3m2 of gas exchange surface. The Oxyrex membrane oxygenator has unique blood flow path: blood enters the oxygenator passes between the hollow fibers and exits through outlet ports, that provides low transmembrane pressure drop. In the animal experiment and in vitro investigations of Oxyrex oxygenator, it showed low transmembrane pressure difference, effective heat exchanger performance, stable gas transfer function and less blood trauma. The Oxyrex oxygenator been used from March, 1990, to October, 1990, in 40 patients undergoing open heart operations. In the clinical applications of Oxyrex, adequate oxygenation[PaO2, 283$\pm$70mmHg] and carbon dioxide removal[PaCO2, 27\ulcorner6mmHg]were maintained under the condition of FiO2: below 0.6, Hct; 25%, perfusion flow; 2.4 L/min, gas flow: 2.1 L/min. During maximum 365 minutes of cardiopulmonary bypass[CPB] time period, the Oxyrex oxygenator maintained stable condition of PaO2, PaCO2 respectively and it also kept low plasma hemoglobin level. The complement proteins C3 and CH50 were not significantly changed pre to post CPB. There were no complications related to the oxygenator during and after the CPB.

• Journal of Biomedical Engineering Research
• /
• v.24 no.2
• /
• pp.113-119
• /
• 2003

In this paper we introduced optimized deformed shape to prevent the blood vessel disease caused by the discord of deformed shape in the end-to-end anastomosis. This study considered the preliminary deformed shape induced by suture in the anastomosis of artery and PTFE, artificial blood vessel, with different diameters. Then we analyzed the final deformed shape of the anastomotic part under the systolic blood pressure. 120mmHg(16.0kPa). The final deformed shape of the anstomotic part was analyzed with respect to the change of initial diameter ratio(R$_{I}$) and the PTFE thickness. Equivalent and circumferential stresses induced by the systolic blood pressure in the anastomosis were also analyzed with respect to the initial diameter ratio(R$_{I}$). The results obtained were as follows : 1. Considering the preliminary deformed shape induced by suture and the systolic pressure in the anastomosis, not intimal hyperplasia, the optimal initial diameter ratio(R$_{I}$) was 1.073. 2. As the initial diameter ratio(R$_{I}$) became larger, higher equivalent and circumferential stresses were induced. And all the maximum stresses occurred on the side of PTFE 0.4mm apart from the anastomosis.

• Korean Journal of Exercise Nutrition
• /
• v.23 no.1
• /
• pp.55-62
• /
• 2019

[Purpose] The effect of acute nitrate supplementation on muscle fatigue is largely unknown. This study aimed to evaluate the effect of acute nitrate supplementation on muscle fatigue. [Methods] Thirty-five recreationally active subjects consumed 140 ml of beetroot (BR) juice (nitrate: 8 mmol·d^-1) or placebo (PL) 12 and 2.5 hours before two exercise sessions. Peak torque was measured during 50 repetitions, at maximal effort, and during concentric knee extensions at 90°·s^-1. Blood pressure (BP) was recorded pre- and post-exercise. [Results] Peak torque, maximum work, rate of fatigue, and rate of work fatigue were similar between the BR and PL conditions. Post-exercise diastolic BP (BR: 67.2 ± 9.8 vs. PL: 64.5 ± 7.9 mmHg, p < 0.05) and mean arterial pressure (BR: 91.6 ± 9.3 vs. PL: 88.8 ± 8.2 mmHg, p < 0.05) were higher with BR supplementation. [Conclusion] These findings suggest that the acute intake of BR juice had no effect on knee extensor muscle strength or fatigue but increased BP in a healthy recreationally active population.

• Journal of Korean Academy of Nursing
• /
• v.36 no.5
• /
• pp.837-844
• /
• 2006

Purpose: This study was done to identify fat distribution and blood pressure according to anthropometric change patterns between NIDDM patients and control subjects. Methods: Cross-sectionally 167 NIDDM patients and 87 controls were studied. Previous maximal body weight and acute weight loss was obtained. Current height, body weight, BMI, waist-hip ratio(WHR), skinfold thicknesses(abdomen, subscapular & triceps), and blood pressure was measured. Three anthropometric change patterns were categorized by BMI changes from the maximum lifetim's BMI to the current time (obese-obese, obese-nonobese and nonobese-nonobese: obese: BMI$\geq$25kg/m$^2$, nonobese: BMI<25kg/m$^2$). The data was analyzed by $X^2$, t-test, age adjusted ANCOVA and Least Squares Means(LSM) for multiple comparison. Result: Acute body weight loss(p=0.01), anthropometric change types (p=0.001), WHR (p=0.05), and skinfold thickness (p=0.002) of NIDDM were significantly higher than those of the controls. The mean arterial pressure, WHR and skinfold thicknesses were greater in both obese-obese and obese-nonobese NIDDM and control subjects compared with both nonobese-nonobese NIDDM and control subjects. (all p's<0.05). Conclusion: NIDDM patients had more central and upper body adiposicity. Also both obese-obese and obese-nonobese NIDDM and control subjects had higher mean arterial pressures and central body obesity.

• The Korean Journal of Physiology and Pharmacology
• /
• v.26 no.2
• /
• pp.77-86
• /
• 2022

The effect of PHAR-DBH-Me, a cannabinoid receptor agonist, on different cardiovascular responses in adult male rats was analyzed. The blood pressure was measured directly and indirectly. The coronary flow was measured by Langendorff preparation, and vasomotor responses induced by PHAR-DBH-Me in aortic rings precontracted with phenylephrine (PHEN) were analyzed. The intravenous injection of the compound PHAR-DBH-Me (0.018-185 ㎍/kg) resulted in decreased blood pressure; maximum effect was observed at the dose of 1,850 ㎍/kg. A concentrationdependent increase in the coronary flow was observed in a Langendorff preparation. In the aortic rings, with and without endothelium, pre-contracted with PHEN (10^-6 M), the addition of PHAR-DBH-Me to the superfusion solution (10^-12-10^-5 M), produced a vasodilator response, which depends on the concentration and presence of the endothelium. L-NAME inhibited these effects. Addition of CB₁ receptor antagonist (AM 251) did not modify the response, while CB₂ receptor antagonist (AM630) decreased the potency of relaxation elicited by PHAR-DBH-Me. Indomethacin shifted the curve concentration-response to the left and produced an increase in the magnitude of the maximum endothelium dependent response to this compound. The maximum effect of PHAR-DBH-Me was observed with the concentration of 10^-5 M. These results show that PHAR-DBH-Me has a concentration-dependent and endothelium-dependent vasodilator effect through CB₂ receptor. This vasodilation is probably mediated by the synthesis/release of NO. On the other hand, it is suggested that PHAR-DBH-Me also induces the release of a vasoconstrictor prostanoid.