• Journal of the Optical Society of Korea
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• v.10 no.2
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• pp.91-95
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• 2006

Blood pressure was predicted from photoplethysmography (PPG). To obtain PPG, backscattered light from a fingertip was measured and its waveform was analyzed. Systolic upstroke time and diastolic time in the pulse waveform were used as parameters to predict blood pressure. The experiment was carried out with five subjects on five different days. The systolic upstroke time had a correlation coefficient of -0.605 with respect to systolic blood pressure and the diastolic time had a correlation coefficients of -0.764 for diastolic pressure. This PPG method does not require an air-cuff installation on the arm and can predict blood pressure continuously. This simple LED/photo detector setup can be a good candidate for nonconstrained monitoring of blood pressure variations.

• Korean Journal of Acupuncture
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• v.27 no.1
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• pp.1-12
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• 2010

Objectives: The purpose of this study is to gain the objective indicators for the classification of hypertension by oriental medical pulse diagnosis, through finding out the parameters which can distinguish the pulse of hypertensive patient from that of normal subject, and characterizes the wiry pulse of hypertension. Methods: 30-59 yr, male, 946 healthy volunteers and 35 hypertensive patients were enrolled in this study. All the hypertensive patients were taking medicine to control the blood pressure and the blood pressure of the hypertension group was not statistically different from that of the normal healthy group. Data were acquired using 3 dimensional pulse imaging analyser(DMP-3000, DAEYOMEDI, KOREA) and analysed according to the age bands and the applied pressure levels. Results: 1. RAI/t, w/t and t2/t decreased with the levels of applied pressure and increased with age in the normal healthy group, not in the hypertension group. 2. RAI/t, w/t, t2/t were significantly higher in the hypertension group than the normal healthy group in the 30-age band, and elasticity coefficient was higher in the hypertension group than the normal healthy group in the 40-age band. 3. Researches on the patients without hypotensive agents are needed to figure out whether these parameters are the components of hypertensive wiry pulse. Conclusions: Analysing the radial pulse at 5 applied pressure levels using 3 dimensional pulse imaging analyser may be useful to differentiate the pulses of the hypertensive patients from those of the normal subjects, and characterize the hypertension.

• Journal of Magnetics
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• v.15 no.4
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• pp.209-212
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• 2010

Photoplethysmogram (PPG) and pressure pulse waveform (PPW) were compared and evaluated for the efficacy of stimulating knuckles by using the pulsed magnetic field. Both signals were observed simultaneously while the knuckles were exposed for 10 min to the pulsed magnetic field, with maximum field intensity of 0.8 T and transition time of 0.126 msec. After 5 min stimulation of the knuckles, the results showed that the aging indexes calculated from the second derivative of the PPG were increased from -1.913 to 0.072, and that of the PPW from -0.063 to 0.387. However, for the relatively long-term stimulation for 10 min, we found that the values of both the aging indexes of the second derivatives and augmentation index of the PPW returned to the starting level. The changes observed in characteristic factors such as the aging indexes of the second derivatives and augmentation index of the PPW indicate the potential of pulsed magnetic field stimulation as a therapeutic method for the treatment of patients with peripheral vascular disease.

• Korean Journal of Acupuncture
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• v.28 no.4
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• pp.79-89
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• 2011

Objectives : The aim of this study is to propose the W area of pulse (AW) as a new index which can confirm the arteriosclerosis by analyzing parameters of 5-level pressure pulse waveform measurement system for normotensive group according to aging. Methods : We measured radial pulse waveforms of normotensive group (20 to 60 years old) using 3-dimensional pulse imaging analyser (DMP-3000, DAEYOMEDI Co., Korea). And then we analyzed various parameters for sclerosis of the arteries such as Height (h1, h2, h3, h4, h5), Time (t1, t2, t3, t4, t5), AW, AW rate, Total area of pulse (At) and Augmentation Index (AIx). Results : As a result of analyzing parameters according to the aging, h2, h3, AS (systolic area rate to AT), AIx and AW were increased but t2/t, t3/t, t5/t and AD (diastolic area rate to AT) were decreased. Conclusions : We checked blood vessel conditions for normotensive group according to aging and confirmed various parameters. Also, we found that AW was analogous to AIx which has been used for diagnosing arteriosclerosis. Furthermore, we confirmed the usefulness of AW as a new parameter for checking vessel condition and characteristic compared with the AIx.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.1-10
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• 2002

Objective: There exist gender differences in pulsatile contour waveform. Women have a greater age-related increase in left ventricular mass than do men and more likely to experience symptomatic heart failure after infarction. SDPTG (the second derivative of photoplethysmogram waveform) is a noninvasive method for evaluating the pulse wave and is correlated with age and other risk factors for atherosclerosis. We studied the effect of gender on SDPTG and made clear why the gender differences appear. Methods: To study the effects of effect factors, including height and blood pressure, on SDPTG in the fourth decade, data on height, weight, PTD (pulse transit distance), blood pressure, serum lipid levels, and SDPTG were collected in 115 laboratory healthy men and women. SDPTG is derived from double-differential processing of fingertip photoplethysmography and consists of a, b, c, and d waves in systole and an e wave in diastole; SDPTG aging index (AI) was calculated as (b-c-d-e)/a. Results: There were significant gender-related differences of SDPTG AI, height, and blood pressure. Age, height, and mean blood pressure were respectively and significantly correlated with SDPTG AI. SDPTG is dependent upon age, height, and blood pressure. Restricting analysis to SDPTG AI, age, height, and mean blood pressure, yielded that there were gender-related differences in SDPTG AI (P<0.05) which were derived from those of height (F<0.001, df=l, P=0.994). Conclusions: These new data may help to explain previous findings about age-related differences in pulsatile contour waveforms and why gender differences of SDPTG appear. The results of this study suggest that SDPTG AI, used for evaluation of biological vascular aging, should be calibrated by height as well as age and blood pressure.

• Korean Journal of Acupuncture
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• v.27 no.2
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• pp.107-120
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• 2010

Objectives : The aim of this study is to measure pulse waveforms by applying 5-level graded pressure, and selecting optimum pulse waveforms. Also to proposing the possibility of using AW(Area of the 1/3 upper height of h1) rate in respect to AT(Total Area) for risk assessment of hypertension or arteriosclerosis is another aim of the study. Methods : Pulse waveforms of normotensive were measured by 5-level graded pressure. The pulse waveforms well reflecting properties of blood vessel(having the largest h1) were selected for optimum pulse waveforms. Various parameters(h-parameter, t-parameter, and others) of optimum pulse waveforms were analyzed. AIx(Augmentation index) was calculated by height-parameters to assess arterial stiffness. The area rate of the 1/3 upper height for h1 in respect to total area was analyzed according to aging. Results : According to aging 1. in height-parameter, h2 and h3 were increased but h5 was decreased. 2. In time-parameter, t2, t3, and t5 were getting short. 3. Area of systolic period was increased, and that of diastolic period decreased. 4. AIx rose by aging. 5. AW was significantly increased despite no changes in AT. Conclusions : By analyzing optimum pulse waveforms of 5-level graded pressure method, we could complement weakness of single graded pressure method. Also, possibility of applying the AW rate to risk assessment of hypertension or arteriosclerosis was confirmed in normotensive population which might not be assessed by AIx.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2351-2357
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• 2008

Noninvasive radial artery pulse wave has been widely used not only for the pulse wave analysis(PWA) itself but also for assessment of arterial stiffness with estimated aortic pulse wave from peripheral pulse wave. However, it has been found that the deformation of pulse shape can be caused readily by changing measuring position, indentation pressure, and so on. So, in this study, we have developed a system which can measure radial pulse wave and skin displacement simultaneously while the indentation body goes down to occlude subject's radial artery. This system can be divided into a measuring apparatus part, an indentation control hardware part, a data acquisition part and a control and computation part. And, the measuring apparatus consists of an arm-rest, a step motor, an indentation body, a laser displacement sensor(LK-G30, Keyence Co.) and pulse wave sensor. Under load-free condition and radial artery loaded condition, the evaluation of developed system has been performed. From these results, we can conclude: 1) The developed system can control the indentation body quantitatively and the adopted laser displacement sensor shows linear output characteristic even with skin as a reflector. 2) This system can measure the pulse wave and the displacement of indentation body, that is, skin displacement simultaneously at each specific level of indentation body. 3) This system can provide the number of motor steps used to get down the indentation body, the measured skin displacement, the calculated indentation pressure, the calculated pulse pressure and the pulse waveform as well as the information generated by combining these with each others. 4) This system can reveal the relationship between the morphological changes of pulse wave and the estimated displacement of radial artery wall by indentation. Consequently, the developed system can furnish more abundant information on radial artery than previous diagnosis systems based on tonometric measurement. In further study, we expect to setup the standard measuring process and to concrete the algorithm for the estimation of radial artery's diameter and of displacement of radial artery's wall. Furthermore, with well designed clinical studies, we hope to turn out the usefulness of developed system in the field of cardiovascular system evaluation.

• Journal of the Korean Magnetics Society
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• v.21 no.3
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• pp.104-107
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• 2011

We measured signals at the "Guan" region of a radially arterial pulse using the prototype of a clamping pulsimeter equipped with a Hall effect device, which is passed signals through the voltage detecting hard ware system. The important four different measuring times of the period, systolic, reflective, and notch peaks for a temporally pulse signal are obtained and compared each other from the analysis for an arbitrary pulse wave of one position of small size permanent magnet. It is possible to measure the reproducible pulse rate and blood pressure by using the cuffless clip type pulsimeter without an unpleasant oppressive feeling due to the use of pressurization.

• Progress in Superconductivity and Cryogenics
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• v.12 no.2
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• pp.29-33
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• 2010

The experimental results of the 2 stage Gifford-McMahon(GM) type pulse tube refrigerator (PTR) or cryopump are presented in this paper. The objectives of his study are to develop design technology of the integral type 2 stage PTR which rotary valve is directly connected to he hot end of the regenerator and acquire its improved performance. Design of the 2 stage PTR is conducted by FZKPTR(Forschungs Zentrum Karlsruhe Pulse Tube Refrigerator) program for the design of pulse tube refrigerators. The fabricated PTR has U-type configuration and incorporates orifice valve, double-inlet valve and reservoir as phase control mechanism. Rotary valve is used to make pulsating pressure and is directly connected to inlet of $1^{st}$ stage regenerator. From experiments, cooling performance map and pressure waveform at each point were measured for different operating frequencies. Experimental results show the best cooling performance with 2 Hz operation in spite of small pressure amplitude. The lowest temperatures of the 2 stage PTR were 16.9 K at the second stage and 58.0 K at the first stage. The cooling capacities achieved were 14.4 W at 79 K, the first stage and 3.6 W at 29 K, the second stage.

• Korean Journal of Acupuncture
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• v.33 no.4
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• pp.213-220
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• 2016

Objectives : The aim of this paper is to develop acupuncture needle heating system by utilizing the new method which uses high frequency(HF) time-varying magnetic field. Also, it is possible to make an assessment for reliability and clinical significance of the system. Methods : We designed the system with solenoid coils for generation of HF time-varying magnetic field that oscillates at 150 kHz. Acupuncture needles are quickly magnetized and heated by 150 kHz. We assessed clinical significance of system, such as body temperature, pressure pulse waveform. Results : Temperature of acupuncture needle increased up to 60 degree. In the result for clinical significance of system, in case of manual acupuncture stimulation(MAS), body temperature change was $0.373^{\circ}C{\pm}0.224$(p<0.05), rate of pulse energy change increased about 7.6%. In case of warm acupuncture stimulation(WAS), body temperature change was $0.645^{\circ}C{\pm}0.281$(p<0.05), rate of pulse energy change remarkably increased about 35.9%. Conclusions : We confirm that the system is able to be applied clinically to various warm acupuncture needle therapy in the area of oriental medicine.