• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.199-208
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• 2017

Both cardiovascular diseases caused by decreased body composition and arterial compliance and falling induced by loss of muscle mass are frequent occurrences in the elderly. Therefore, elderly people are advised to perform elastic band resistance exercises to improve their body composition and arterial compliance. Thus, the purpose of this study was to examine the effects of 12 weeks of elastic band resistance training on the body composition, arterial compliance and falling index in elderly females (> 65 years). The elastic band resistance exercise program was administered 3 times per week for 60 minutes each time for 12 weeks. In addition, the exercise intensity was set to 11-14 on the Borg scale (6-20). Before and after the training period, the body composition (body weight (BW), muscle mass, % body fat, body mass index (BMI)), arterial compliance (ankle brachial index (ABI) and pulse wave velocity (PWV)) and risk of falling index were determined. (After the program?), the BW (p=.003), BMI (p=.002), PWV (p=.017) and risk of falling (p=.037) in the exercise group were significantly reduced, whereas the BW (p=.009) and BMI (p=.009) in the control group were significantly increased. In conclusion, the body weight, BMI and arterial compliance of elderly females were positively changed by the elastic band resistance training. Thus, the elastic band resistance exercise may be useful for elderly people to prevent metabolic syndrome and cardiovascular diseases and to reduce their risk of falling.

• Korean Journal of Exercise Nutrition
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• v.23 no.3
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• pp.39-44
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• 2019

[Purpose] Weight loss can reduce obesity-induced arterial stiffening that is attributed to decreased inflammation. Angiopoietin-like protein 2 (ANGPTL2) is a pro-inflammatory adipokine that is upregulated in obesity and is important in the progression of atherosclerosis and cardiovascular disease. The purpose of this study is to investigate the effects of dietary modification on circulating ANGPTL2 levels and arterial stiffness in overweight and obese men. [Methods] Twenty-two overweight and obese men (with mean age of 56 ± 2 years and body mass index of 28.6 ± 2.6 kg/m²) completed a 12-week dietary modification program. We measured the arterial compliance and β-stiffness index (as the indices of arterial stiffness) and serum ANGPTL2 levels before and after the program. [Results] After the 12-week dietary modification, body mass and daily energy intake were significantly reduced. Arterial compliance was significantly increased and β-stiffness index was significantly decreased after the 12-week dietary modification program. Serum ANGPTL2 levels were significantly decreased. Also, the changes in arterial compliance were negatively correlated with the changes in serum ANGPTL2 levels, whereas the changes in β-stiffness index were positively correlated with the changes in serum ANGPTL2 levels. [Conclusion] These results suggest that the decrease in circulating ANGPTL2 levels can be attributed to the dietary modification-induced reduction of arterial stiffness in overweight and obese men.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.243-250
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• 2016

The body composition and arterial compliance with advanced age increase the risks of cardiovascular diseases, but the elderly can perform rhythm exercise easily, which may positively influence their body composition and arterial compliance. Therefore, this study examined the effects of rhythm exercise training on the body composition and arterial compliance in elderly females. The subjects (n=20) were assigned randomly to either an exercise group (n=10, EX) or non-exercise control group (n=10, CON). The rhythm exercise training for 12 weeks consisted of 3 sessions per week with 60 minutes per session. In addition, the intensity was set to 11-14 of the Borg scale (6-20). The body composition and arterial compliance (pulse wave velocity (PWV)) were measured before and after training. The skeletal muscle mass in the EX was increased significantly (p=0.04) and the right (p=0.002) and left side (p=0.02) of the PWV in the EX were decreased significantly, but the skeletal muscle and both sides of the PWV in the CON were not changed. Elderly females could easily perform rhythm exercise training, which resulted in improvements of the skeletal muscle mass and arterial compliance. Therefore, rhythm exercise training may prevent or delay sarcopenia and reduce the risk of cardiovascular diseases.

• 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 Biomedical Engineering Research
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• v.13 no.2
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• pp.165-174
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• 1992

Compliance mismatch across an end-to-end anastomosis was measured In the In vitro experimental setup. A 35mm camera was used and Image process was done in Gould/ DeAnza Image processor. The results showed that compliances of Penrose tubing and synthetic PTFE grafts were In good agreement with the previously reported In vivo data. PTFE grafts exhibited a nonlinear behavior with compliance decreasing with Increasing transmural pressure, whereas the compliance of the Penrose tubing remained relatively constant within the range of the pressures in which data were obtained. The lumen cross sections at the anastomosis were affected by the suture and the mismatch In compliance between the Penrose tubing and vascular grafts. The varla~lons In the lumen dtameter at the anastomosis was more pronounced with increasing transmural pressures. From the present study, it was clearly demonstrated that the compliance of prosthetic grafts Is much lower than that of the arteries. In addition to the hemodynamlc consequences, compliance mismatch across the anastomosis has been known to lead to Increased anastomotlc and suture stresses with resultant suture line dehlscence and false aneurysm formation. Thus, there are good hemodynamic reasons to suppose that Introduction of a less compliant arterial graft Into the arterial circulation wlll be damaging and that grafts should be made to match the elastic behavior of their host arteries as closely possible.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.183-190
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• 2015

Invasive blood pressure (IBP) is measured for the patient's real time arterial pressure (ABP) to monitor the critical abrupt disorders of the cardiovascular system. It can be used for the estimation of cardiac output and the opening and closing time detection of the aortic valve. Although the unexplained inflections on ABP make it difficult to find the mathematical relations with other cardiovascular parameters, the estimations based on ABP for other data have been accepted as useful methods as they had been verified with the statistical results among vast patient data. Previous windkessel models were composed with systemic resistance and vascular compliance and they were successful at explaining the average systolic and diastolic values of ABP simply. Although it is well-known that the blood pressure reflection from peripheral arteries causes complex inflection on ABP, previous models do not contain any elements of the reflections because of the complexity of peripheral arteries' shapes. In this study, to simulate a reflection wave of blood pressure, a new mathematical model was designed with four elements that were the impedance of aorta, the compliance of aortic arch, the peripheral resistance, and the compliance of peripheral arteries. The parameters of the new model were adjusted to have three types of arterial blood pressure waveform that were measured from a patient. It was used to find the relations between the inflections and other cardiovascular parameters such as the opening-closing time of aortic valve and the cardiac output. It showed that the blood pressure reflection can bring wide range errors to the closing time of aortic valve and cardiac output with the conventional estimation based on ABP and that the changes of one-stroke volumes can be easily detected with previous estimation while the changes of heart rate can bring some error caused by unexpected reflections.

• International Journal of Vascular Biomedical Engineering
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• v.1 no.1
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• pp.41-47
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• 2003

The patency rates of small diameter vascular grafts are disappointing because of the formation of thrombus and intimal hyperplasia. Among the various factors influencing the success of graft surgery, the compliance and the size of a graft are believed to be the most important physical properties of a vascular graft. Mismatch of compliance and size between an artery and a graft alters anastomotic flow characteristics, which may affect the formation of intimal hyperplasia. Among the hemodynamic factors influencing the development of intimal hyperplasia, the wall shear stress is suspected as the most important one. The wall shear stress distributions are experimentally measured near the end-to-end anastomosis models in order to clarify the effects of compliance and diameter mismatch on the hemodynamics near the anastomosis. The effects of radial wall motion, diameter mismatch and impedance phase angle on the wall shear rate distributions near the anastomosis are considered. Compliance mismatch generates both different radial wall motion and instantaneous diameter mismatch between the arterial portion and the graft portion during a flow cycle. Mismatch in diameter seems to be affecting the wall shear rate distribution more significantly compared to radial wall motion. The impedance phase angle also affects the wall shear rate distribution.

• Journal of Biomedical Engineering Research
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• v.13 no.3
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• pp.189-194
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• 1992

As people's income and intake of animal fat rapidly increase, so does choresterol concentration in blood. Thus diseases such as non-insulin-dependent diabetes mellitus(NIDDM)myocardial infraction, high blood pressure, cerebral stroke resulting from atherosclerosis rapidly increase recently. It is very difficult to diagnose atherosclerosis early since its progress is so slow and there is no sypmtoms in the beginning of the disease. In this study a mechanical characteristic, compliance, of the lower leg arteries was measured noninvasively. Changes of blood volume and pressure were measured using impedance plethysmgraphy and mercury sphygmomanometer, respectively. The compliance was calculated by dividing the change of blood volume by the change of pulse pressure ( systolic-diastolic pressure ) . Subjects were 24 asymptomatic persons ranging (rom 30 Ic 58yeras and 14 diabetics from 41 to 59years. The compliances, mean, and systolic pressures were statistically analyzed using a t-test be- tween the healthy and diabetic groups. The average compliance of the healthy and diabetic group was measured 2.79 and 1.82U1/mmHg/cm, respectively and these were significantly different(p<0.01). It was also found that the compliance is a better parameter in differentiating the vascular disease than mean or systolic blood pressure.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2745-2748
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• 2003

In this paper, we implement the photoplethysmo-graphy system that have three channel pulse wave detects and one channel ECG amplifier. In order to detect the artery state, we measured the pulse waves at different positions, simultaneously. In general, arterial vascular system suffers the decrease of compliance, increase of resistance, and decrease of distensibility through aging. Therefore, we compared and analyzed variation of tile Pulse waves parameter both in time and frequency domains that is concerned with the changes of arterial characteries. And then evaluated the correlation coefficients between the parameters variation and the age group. As the result of experiment, we found that the Parameters have a significant correlation about aging.

• Current Optics and Photonics
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• v.1 no.5
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• pp.529-537
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• 2017

We explored how changes in blood vessel compliance affected the systolic rise time (SRT) of the maximum blood pressure (BP) peak wave and the diastolic fall time (DFT) of the minimal BP peak wave, compared to photoplethysmograpic (PPG) parameters, using a two-compartment, second-order, arterial Windkessel model. We employed earlier two-compartment Windkessel models and the components thereof to construct equivalent blood vessel circuits, and reproduced BP waveforms using PSpice technology. The SRT and DFT values were obtained via circuit simulation, considering variations in compliance (the dominant influence on blood vessel parameters attributable to BP changes). And then performed regression analysis to identify how compliance affected the SRT and DFT. We compared the SRTs and DFTs of BP waves to the PPG values by reference to BP changes in each subject. We confirmed that the time-shift propensities of BP waves and the PPG data were highly consistent. However, the time shifts differed significantly among subjects. These simulation and experimental results allowed us to construct an initial trend curve of individual BP peak time (measured via wrist PPG evaluations at three arm positions) that facilitated accurate individual BP estimations.