• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.411-417
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• 2000

This paper describes the analysis of the oscillometric method based on the shape of arterial pressure and proposal of a new algorithm for estimating the blood pressure by computer simulation. In the first step, the arterial pressure model which is able to control the shape of arterial pressure was designed and then we simulated the oscillometric model using both the existing exponential model showing the static arterial pressure-volume relation and the designed arterial pressure model. By analyzing the correlation of characteristic ratio based on the shape of arterial pressure, we could find that the characteristic ratio was not the only standard parameter for estimating systolic and diastolic pressure. We were able to estimate the shape of arterial pressure by computing the correlation of arterial pressure shape with oscillation shape. Finally, we proposed an algorithm which is able to estimate systolic and diastolic pressure according to pressure(Pp) table constructed from the relation of maximum amplitude of oscillation and arterial pressure shape. We tested 60 arterial pressure waveforms having various arterial pressure shape and pulse. As a results, the absolute deviation average values of the estimation of systolic, diastolic and mean pressure were 1.62%, 2.40% and 2.20%, respectively. In conclusions, the proposed algorithm showed the possibility of usefullness in estimating the blood pressure.

• Transactions on Electrical and Electronic Materials
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• v.9 no.1
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• pp.38-43
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• 2008

Using an arterial pressure-volume (APV) model, we performed an analysis of the conventional blood pressure estimation method using an oscillometric sphygmomanometer with computer simulation. Traditionally, the maximum amplitude algorithm (MAA) has been applied to the oscillation waveforms of the APV model to obtain the mean arterial pressure and the characteristic ratio. The estimation of mean arterial pressure and characteristic ratio was significantly affected by the shape of the blood pressure waveforms and the cutoff frequency of high-pass filter (HPF) circuitry. Experimental errors result from these effects when estimating blood pressure. To determine an algorithm independent of the influence of waveform shapes and parameters of HPF, the volume oscillation of the APV model and the phase shift of the oscillation with fast Fourier transform (FFT) were tested while increasing the cuff pressure from 1 mmHg to 200 mmHg (1 mmHg/s). The phase shift between ranges of volume oscillation was then only observed between the systolic and the diastolic blood pressures. The same results were obtained from simulations performed on two different arterial blood pressure waveforms and one hyperthermia waveform.

• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.38-43
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• 2013

In this study, the artery's compliance model and the pulsation waveform model was proposed to estimate blood pressure without applying HPF (High Pass Filter) on signal measured by the oscillometric method. The method proposed in the study considered two ways of estimating blood pressure. The first method of estimating blood pressure is by comparing and analyzing changes in pulsation waveform's dicrotic notch region during each cardiac period. The second method is by comparing and analyzing morphological changes in the pulsation waveform during each cardiac period, which occur in response to the change in pressure applied on the cuff. To implement these methods, we proposed the compliance model and the pulsation waveform model of the artery based on hemodynamic theory, and then conducted various simulations. The artery model presented in this study only took artery's compliance into account. Then, a pulsation waveform model was suggested, which uses characteristic changes in the pulsation waveform to estimate blood pressure. In addition, characteristic changes were observed in arterial volume by applying artery's pulsation waveform to the compliance model. The pulsation waveform model was suggested to estimate blood pressure using characteristic changes of the pulsation waveform in the arteries. This model was composed of the sum of sine waves and a Fourier's series in combination form up to 10th harmonics components of the sinusoidal waveform. Then characteristic of arterial volume change was observed by inputting pulsation waveform into the compliance model. The characteristic changes were also observed in the pulsation waveform by mapping the arterial volume change in accordance with applied cuff's pressure change to the pulsation waveform's change according to applied pressure changes by cuff. The systolic and diastolic blood pressures were estimated by applying positional change of pulsation waveform's dicrotic notch region.

• Journal of the Semiconductor & Display Technology
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• v.6 no.4
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• pp.43-47
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• 2007

In this paper, we propose a novel sensor system for measuring the arterial pulse in an oral cavity. In order to measure pulse wave in oral cavity, the proposed system is designed with reflection type arterial wave sensor, not by using transmission type arterial pulse wave sensor. Driving circuit through pulse current is designed for solving self-heating problem of LED. The effectiveness of the proposed sensor system is compared with pulse wave between pulse wave of oral cavity and other body parts as well as with characteristic measurements. The experiment shows that the proposed sensor system is adaptive to capturing consecutive and meaningful biometric signals through the variation of pulse wave changes in oral cavity when exercising. The study result expects to design and develop mobile sensors which could be adapted to healthcare devices.

• The Korean Journal of Nuclear Medicine
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• v.1 no.2
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• pp.1-25
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• 1967

In 20 normal cases and 39 pulmonary tuberculosis cases, regional pulmonary arterial blood flow measurements and lung perfusion scans by $^{131}I$-Macroaggregated albumin, lung inhalation scans by colloidal $^{198}Au$ and spirometries by respirometer were done at the Radiological Research Institute. The measured lung function tests were compared and the results were as the following: 1. The normal distribution of pulmonary blood flow was found to be $54.5{\pm}2.82%$ to the right lung and $45.5{\pm}2.39%$ to the left lung. The difference between the right and left pulmonary arterial blood flow was significant statistically (p<0.01). In the minimal pulmonary tuberculosis, the average distribution of pulmonary arterial blood flow was found to be $52.5{\pm}5.3%$ to the right lung and $47.5{\pm}1.0%$ to the left lung when the tuberculous lesion was in the right lung, and $56.2{\pm}4.4%$ to the right lung and $43.8{\pm}3.1%$ to the left lung when the tuberculous lesion was in the left lung. The difference of pulmonary arterial blood flow between the right and left lung was statistically not significant compared with the normal distribution. In the moderately advanced pulmonary tuberculosis, the average distripution of pulmonary arterial blood flow was found to be $26.9{\pm}13.9%$ to the right lung and $73.1{\pm}13.9%$ to the left lung when the tuberculous lesion was more severe in the right lung, and $79.6{\pm}12.8%$ to the right lung and $20.4{\pm}13.0%$ to the left lung when the tuberculous lesion was more severe in the left lung. These were found to be highly significant statistically compared with the normal distribution of pulmonary arterial blood flow (p<0.01). When both lungs were evenly involved, the average distribution of pulmonary arterial blood flow was found to be $49.5{\pm}8.01%$ to the right lung and $50.5{\pm}8.01%$ to the left lung. In the far advanced pulmonary tuberculosis, the average distribution of pulmonary arterial blood flow was found to be $18.5{\pm}11.6%$ to the right lung and $81.5{\pm}9.9%$ to the left lung when the tuberculous lesion was more severe in the right lung, and $78.2{\pm}8.9%$ to the right lung and $21.8{\pm}10.5%$ to the left lung when the tuberculous lesion was more severe in the left lung. These were found to be highly significant statistically compared with the normal distribution of pulmonary arterial blood flow (p<0.01). When both lungs were evenly involved the average distribution of pulmonary arterial blood flow was found to be $56.0{\pm}3.6%$ to the right lung and $44.0{\pm}3.2%$ to the left lung. 2. Lung perfusion scan by $^{131}I$-MAA in patients with pulmonary tuberculosis was as follows: a) In the pretreated minimal pulmonary tuberculosis, the decreased area of pulmonary arterial blood flow was corresponding to the chest roentgenogram, but the decrease of pulmonary arterial blood flow was more extensive than had been expected from the chest roentgenogram in the apparently healed minimal pulmonary tuberculosis. b) In the pretreated moderately advanced pulmonary tuberculosis, the decrease of pulmonary arterial blood flow to the diseased area was corresponding to the chest roentgenogram, but the decrease of pulmonary arterial blood flow was more extensive in the treated moderately advanced pulmonary tuberculosis as in the treated minimal pulmonary tuberculosis. c) Pulmonary arterial blood flow in the patients with far advanced pulmonary tuberculosis both before and after chemotherapy were almost similar to the chest roentgenogram. Especially the decrease of pulmonary arterial blood flow to the cavity was usually greater than had been expected from the chest roentgenogram. 3. Lung inhalation scan by colloidal $^{198}Au$ in patients with pulmonary tuberculosis was as follows: a) In the minimal pulmonary tuberculosis, lung inhalation scan showed almost similar decrease of radioactivity corresponding to the chest roentgenogram. b) In the moderately advanced pulmonary tuberculosis the decrease of radioactivity in the diseased area was partly corresponding to the chest roentgenogram in one hand and on the other hand the radioactivity was found to be normally distributed in stead of tuberculous lesion in the chest roentgenogram. c) In the far advanced pulmonary tuberculosis, lung inhalation scan showed almost similar decrease of radioactivity corresponding to the chest roentgenogram as in the minimal pulmonary tuberculosis. 4. From all these results, it was found that the characteristic finding in pulmonary tuberculosis was a decrease in pulmonary arterial blood flow to the diseased area and in general decrease of pulmonary arterial blood flow to the diseased area was more extensive than had been expected from the chest roentgenogram, especially in the treated group. Lung inhalation scan showed almost similar distribution of radioactivity corresponding to the chest roentgenogram in minimal and far advanced pulmonary tuberculosis, but there was a variability in the moderately advanced pulmonary tuberculosis. The measured values obtained from spirometry were parallel to the tuberculous lesion in chest roentgenogram.

• Tuberculosis and Respiratory Diseases
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• v.50 no.6
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• pp.710-717
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• 2001

Two cases of an anomalous systemic arterial supply to the basal segments of the left lower lobe without pulmonary sequestration are presented. In the first case, a preoperative diagnosis was made by chest CT, and confirmed by angiography, in a 22-year old man who had a recurrent hemoptysis. There was systemic arterial supply that originated from the thoracic descending aorta and no pulmonary arterial supply to the basilar segments of the left lower lobe. However, the pulmonary parenchyma was normal without sequestration. Ligation of the abnormal artery and a left lower lobectomy were performed without complications. In the second case, there were characteristic features of this anomaly on chest CT and the angiogram in a 31-year-old man with symptoms of hemoptysis. The patient refused surgery.

• Journal of the Korean Magnetics Society
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• v.27 no.4
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• pp.145-152
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• 2017

The arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) method that can evaluate tissue perfusion using blood in the body. The characteristic of non-invasive examinations without contrast agents and the quantitative measurement of perfusion volume is possible, which are increasingly being used for clinical and research purposes. Up to the present, The ASL method has lower SNR than the perfusion imaging method using contrast agent and because optimization of various parameter in the imaging process is difficult, Which may result in measurement errors. To improve this, ASL methods using various technologies are introduced. This paper briefly introduces the outline of ASL, its features in imaging process, various techniques, and clinical application.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.10
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• pp.894-900
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• 2000

The experimental study for performance improvement of aluminum/freon22 grooved heat pipe was carried out. Arterial wick was used for performance improvement of heat pipe. The experimental result was compared with screen covered grooved wick heat pipe. And also, performance test of grooved wick thermosyphon inserted straight wire in the center of grooved pipe was carried out. This result was compared with the performance test result of grooved wick thermosyphon. The operation limit of artery inserted grooved heat pipe was slightly extended, but thermal resistance of this heat pipe was twice as large as that of screen covered grooved heat pipe. In case of thermosyphon, the operation limit of grooved thermosyphon inserted straight wire in the center of grooved pipe was slightly extended, but thermal resistance was increased, comparing with that of the grooved thermosyphon.

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

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.1-9
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• 2009

Bus information system(BIS), as a part of the intelligent transportation system(ITS), is one of the most advanced public transportation systems which provide the real-time bus traffic information for the users waiting the buses at the bus stop. However, correct bus information data, such as the present bus location, the user waiting time, the bus arrival time, etc. are not provided for the bus users because the proper bus arrival time predictive models are not used yet in most of the cities operating the bus information system, including the metropolitan City of Ulsan. Thus, the purpose in this study is to investigate real-time bus traffic characteristic data for identifying the bus operation characteristics on the arterial under the study in the metropolitan City of Ulsan, analyze real-time bus traffic characteristic data on the ID locations of the arterial under the study, construct the optimal unit segment models for the unit segments which are the bus stop, node and travel section using the exponential smoothing, weighted smoothing and Kalman Filter methods, respectively, and finally suggest the optimal integrated model for predicting the real-time bus arrival time at the bus stop of the arterial under the study.