• The Journal of the Korea institute of electronic communication sciences
• /
• v.14 no.6
• /
• pp.1257-1264
• /
• 2019

The traditional cuff-based method for BP(Blood Pressure) measurement is not suitable for continuous real-time BP measurement techniques. For this reason, the previous studies estimated various blood pressures by fusion with the electrocardiography (ECG) and photoplethysmogram (PPG) sensor signals. However, conventional techniques based on PPG bio-sensing measurement face many challenging issues such as noisy supply fluctuation, small pulsation, and drifting non-pulsatile. This paper proposed a novel BP estimation methods using PPG and ECG sensors, which can be derived from the relationship between PPG and ECG using PTT(Pulse Transit Time) and PWV(Pulse Wave Velocity). Unlike conventional height ratio features, which are extracted on the basis of the peaks in the PPG and ECG waveform. The proposed method can be reliably obtained even if there are missing peaks among the sensed PPG signal. The increased reliability comes from periodical estimation of the peak-to-peak interval time using ECG and PPG. After 250,000 times trials of the blood pressure measurement, the proposed estimation technique was verified with the accuracy of ±28.5% error, compared to a commercialized BP device.

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.15 no.3
• /
• pp.245-260
• /
• 2011

Objectives: The aim of this experiment is to know the effect of Mountain Cultivated Ginseng Pharmacopuncture on Heart Rate Variability (HRV), Pulse wave velocity (PWV) in Middle Aged Women. Methods: We investigated on 40 women of breast cancer patients. First, we measured their Heart Rate Variability(HRV), Pulse wave velocity (PWV) and then Mountain Cultivated Ginseng Pharmacopuncture $20m{\ell}$ were injected on them. After 30 minutes, we measured Heart Rate Variability(HRV), Pulse wave velocity(PWV) again. As a result, method of non-equivalent control group non-synchronized design were used for evaluation. Results: In HRV, Mean HRV is significantly decreased from 69.15 to 63.34 after injection. Mean RR is significantly increased from 877.20 to 962.10 after injection. SDNN is significantly increased from 32.56 to 41.34 after injection. PNN50 is significantly decreased after injection. RNSSD, SDSD, TP, VLF is significantly increased after injection. Stress Resistance ability is significantly increased from 37.55 to 44.60 after injection. And In PWV, E-R, E-L, H-R, H-L is significantly decreased after injection. Conclusions: Effect of Mountain Cultivated Ginseng Pharmacopuncture on Heart Rate Variability (HRV) increased adaptability of autonomic nervous system and on Pulse wave velocity (PWV) decreased arterial stiffness.

• Journal of Oriental Medical Thermology
• /
• v.6 no.1
• /
• pp.23-31
• /
• 2008

Objective: The purpose of this study is to identify relationship between the PWV and the temperature difference. Methods: When it comes to senile patients who suffer from cold limbs, there is need to see whether or not the patient's low temperature of the limbs is do to arteriosclerosis. The Pulse Wave Velocity(PWV) is a non-invasive method measuring the artery's rigidness. And the Digital Infrared Thermal Imaging(D.I.T.I) is a non-invasive method to see the body's thermal change. Research on the interrelationship of the artery's rigidness and body's thermal distribution was done by using these two tests. The subjects of this research were patients between the age 40~65 who have done both the D.I.T.I and PWV in March 2005~ September 2005. They had to have no history of diabetes, coronary illnesses or cerebrovascular diseases which are diseases that can effect the outcome of the PVW, nor history of spondylopathy or dermatosis which can effect the outcome of the D.I.T.I. Results: The results were as follows. 1. There was a significant interrelationship between the right wrist-ankle PWV and the temperature difference of the right wrist-palm. 2. There was a significant interrelationship between the left wrist-ankle PWV and the temperature difference of the left wrist-palm. 3. There was no significant interrelationship between the right wrist-ankle PWV and the temperature difference of the right thigh-dorsum of foot. 4. There was no significant interrelationship between the left wrist-ankle PWV and the temperature difference of the left thigh-dorsum of foot. 5. The right ABI showed no significant interrelationship between the temperature difference of the right wrist-palm and the right thigh-dorsum of foot. 6. The left ABI showed no significant interrelationship between the temperature difference of the left wrist-palm and the left thigh-dorsum of foot. Conclusion: The study shows that there was a significant interrelationship between wrist-ankle PWV and the temperature difference of wrist-palm.

• Journal of Biomedical Engineering Research
• /
• v.30 no.5
• /
• pp.401-411
• /
• 2009

In this paper, we correct pulse wave velocity(PWV) with heart-rate and derive regression equations to estimate intima-media thickness(IMT). Widely used methods for diagnosis of arteriosclerosis are IMT and PWV. Arterial wall stiffness determines the degree of energy absorbed by the elastic aorta and its recoil in diastole but there is not correlation between sclerosis and IMT in an existing study. In this study, we will correct PWV with heart-rate and get regression equation to estimate IMT using heart-rate correction index(HCI). We executed experiments for this study. Made up question of physical condition and measured electrocardiogram(ECG), photoplethysmogram (PPG) of finger-tip and toe-tip and ultrasound image of carotid artery. Calculated PWV and IMT using ECG, PPG and ultrasound image. We found that every p-value between PWV and IMT is not significant(<0.05). But p-value between IMT and HCI which is a corrected PWV using heart-rate is significant(>0.01). We use HCI and various measured parameter for estimating regression equation and apply backward estimation to select parameters for regression analysis. Result of backward estimation, found that only HCI is possible to derive proper regression equation of IMT. Relationship between PWV and IMT is the second order. Result of regression equation of E-H PWV is $R^2$=0.735, adj $R^2$=0.711. This is the best correlation value. We calculate error of its analysis for verification of earlobe PWV regression equation. Its result is RMSEP=0.0328, MAPE(%) = 4.7622. Like this regression analysis, we know that HCI is useful parameter and relationship between PWV, HCI and IMT. In addition, we are able to suggest possibility which is that we can get different parameter of prediction throughout just one measurement.

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.9 no.1
• /
• pp.112-124
• /
• 2005

Background: PWV is determined by dividing the distance by the time taken for the pulses traveling between two measuring sites, used as a marker of arterial stiffness and an important indicator for cardiovascular disease. Methods: A PWV measurement system, which offers a non-invasive, simple method of measurement, and simultaneous recording of six signlas(ECG, PCG and four pulse waves from carotid, femoral, radial and dorsalis pedis arteries) was developed. Seventeen healthy subjects with a mean age of 33 years(22 to 52) without any cardiovascular disease were participated for the experiment. Two observers(A and B) performed two consecutive measurements from the same subject in a random order. For the evaluation of stability and accuracy of the PWV measurement system, reproducibility of PWV from between-observer were also evaluated. Results: PWV $values(Mean{\pm}SD)$ measured by A were $7.07{\pm}1.48m/s$, $8.43{\pm}1.14m/s$ , $8.09{\pm}0.98m/s$ for aorta, arm, and leg, respectively. The values obtained from B were $6.76{\pm}1.00m/s$, $7.97{\pm}0.80m/s$, and $7.97{\pm}0.72m/s$ for aorta, arm, and leg, respectively. Between-observer $differences(mean{\pm}SEM)$ from the aorta, arm and leg were $0.14{\pm}0.15m/s$, $0.18{\pm}0.10m/s$ and $0.07{\pm}0.10m/s$. Reproducibility coefficients(2SD) from the aorta, arm, and leg were 0.62m/s, 0.84m/s and 0.86m/s. Correlation coefficients were significantly higher in aortic PWV, 0.93, compared to the coefficients for arm and leg. Coefficient of variance which reflects the reproducibility of the system ranged from $4.4{\sim}5.8%$ in all regional PWV. , Conclusion: Reproducibility of PWV in the study shows that the developed system has reliable and reproducible characteristics. The PWV measurement system used for the study offers comfortable and simple operation and provides accurate analysis and results with high reproducibility. Results of the PWV measurement system could contribute to various clinical applications in the future.

• Journal of Sensor Science and Technology
• /
• v.20 no.5
• /
• pp.343-350
• /
• 2011

The compliance and stiffness of artery are closely related with disease of arteries. Pulse wave velocity(PWV) in the blood vessel is a basic and common parameter in the hemodynamics of blood pressure and blood flow wave traveling in arteries because the PWV is affected directly by the conditions of blood vessels. However, there is no standardized method to measure the PWV and it is difficult to measure. The conventional PWV measurement has being done by manual calculation of the pulse wave transmission time between coronary arterial proximal and distal points on a strip chart on which the pulse wave and ECG signal are recorded. In this study, a pressure sensor consisting of strain gauges is used to measure the blood pressure of arteries in invasive method and regular ECG electrodes are used to record the ECG signal. The R-peak point of ECG is extracted by using a reference level and time windowing technique and the ascending starting point of blood pressure is determined by using differentiation of the blood pressure signal and time windowing technique. The algorithm proposed in this study, which can measure PWV automatically, shows robust and good results in the extraction of feature points and calculation of PWV.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.23 no.1
• /
• pp.53-64
• /
• 2010

Purpose: This study was performed to observe the correlation between Hot flush and pulse wave velocity(PWV), ankle brachial index(ABI) in the Climacteric women. Methods: We studied 63 climacteric women visiting OO hospital from 8th January 2007 to 22nd April 2009. The subjects were categorized in two groups, the hot flush group(37) and normal group(26). For the study, the subjects were selected by excluding the patients who receive treatment affect hot flush or have disease affect arterial states. We assessed PWV and ABI of two groups by Oscillometric method using VS-1000(Form PWV/ABI; Fukuda Denshi, Co., Ltd., Japan). From these results, we studied the correlation between hot flush and PWV/ABI by Wilcoxon Mann Whitney Test. Results: 1. It is shown that hot flush group was no significant correlation with normal group. There is no significant factor among R-PWV, L-PWV, R-ABI, L-ABI. However, L-ABI have shown relatively higher correlation with comparison to the other factors.(p-value<0.05) 2. R-PWV, L-PWV significantly increased in menopause group than in premenopause group though there is no relation to the hot flush. (p-value<0.01) Conclusion: Though the results showed no correlations between Hot flush and PWV/ABI in the Climacteric women, L-ABI showed relatively higher correlation with hot flush than others. R-PWV, L-PWV showed significant correlation between premenopause and menopause.

• Journal of Korean Academy of Nursing
• /
• v.40 no.5
• /
• pp.705-713
• /
• 2010

Purpose: To investigate the effectiveness of aromatherapy on blood pressure, heart rate variability, aortic pulse wave velocity and the aortic augmentation index of essential hypertensive patients. Methods: Using a coin toss, 22 participants were assigned to the experimental group and 20 to the control. The experimental group was given a blend of oils of lemon (Citrus limonum), lavender (Lavandula angustifolia), and ylang ylang (Cananga odorata) which were prepared in the ratio of 2:2:1, respectively. The control group was given an artificial lemon fragrance of Limonene (35 cc) and Citral (15 cc) mixture. The experiment, inhalation, was conducted for 3 weeks (2 min per inhalation, 2 times per day) to both groups. Results: There was a noticeable difference in systolic blood pressure between the groups (p=.001), however the difference in diastolic blood pressure between the two groups was not significant. There was a notable difference in sympathetic nerve system activity of heart rate variability (p=.047). However, the differences in aortic pulse wave velocity or the aortic augmentation index were not significant. Conclusion: Aromatherapy is effective in lowering systolic blood pressure and sympathetic nerve system activity.

• Journal of Sensor Science and Technology
• /
• v.21 no.2
• /
• pp.135-143
• /
• 2012

Arterial stiffness is causing the serious problems for human who is suffered from hypertension and metabolic syndrome. So it is important that measure the arterial stiffness for early prevention. Many researches point out that pulse wave velocity(PWV) is the reliable and simple method to predict arterial stiffness. In this paper, we developed the sensing parts that detect the pulse wave and ECG by using piezoelectric film and conductive textile with elastic band. Our system could detect 3ch pulse wave and ECG. Simultaneously, our algorithm extracts the features for calculating the delays among pulse waves. The delays are the significant parameter to estimate PWV, thus we design the experiment for evaluating the performance of our sensing parts. The reference is PP-1000(HanByul Meditech, Korea) that is good for performance evaluation. As a result, the start point of the pulse wave was the most reliable feature for comparing with PP-1000(r=0.691, P=0.00). The results between two operators showed that there is only a slight difference in the reproducibility of the devices. In conclusion, we assume that the suggested sensor could be more comfortable and faithful method for arterial stiffness.

• Journal of Life Science
• /
• v.17 no.2 s.82
• /
• pp.218-222
• /
• 2007

The purpose of this study is to evaluate the relationship between high sensitive C-reactive protein (hsCRP) and pulse transit time (PPT). Apparently healthy 233 subjects had been enrolled in the health promotion center of the Pusan National University Hospital from Jan. 29 to Feb. 26, 2004. They had no previous history of diabetes, hypertension and hyperlipidemia. Subjects were categorized according to tertiles of hsCRP level [Group 1: first tertile $(0.01\;{\sim}\;0.02\;mg/dl)$, Group 2: second tertile $(0.03\;{\sim}\;0.05\;mg/dl)$, Group 3: third tertile $(0.06\;{\sim}\;0.12\;mg/dl)$, and Group 4: Fourth tertile $(0.13\;{\sim}\;16.8\;mg/dl)$]. PTT body mass index (BMI), total cholesterol (T-C), LDL-cholesterol(LDL-C), blood sugar (BS), systolic blood pressure (sBP) and diastolic blood pressure (dBP) were significantly different among hsCRP groups (p<0.05). HsCRP is positively related with BMI, tryglyceride (TG), LDL, sBP and dBP (p<0.05), and negatively related with PTT and HDL-cholesterol (HDL-C) (p<0.05). PTT is significantly negatively related with hsCRP, T-C, TG, LDL-C, BS, dBP and sBP (p<0.05). The hsCRP and PTT were related before controlling BMI, T-C, LDL-C, sBP, and dBP, but not related after conkolling. The relationship between hsCRP and PTT depends on cardiovascular disease risk factors.