scholarly journals In Vivo Pulse Wave Measurement Through a Multimode Fiber Diffuse Speckle Analysis System

2021 ◽  
Vol 8 ◽  
Author(s):  
Zhongshuai Teng ◽  
Feng Gao ◽  
Hua Xia ◽  
Wenliang Chen ◽  
Chenxi Li
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Continuous Monitoring ◽  
Pulse Wave ◽  
Cost Effective ◽  
Multimode Fiber ◽  
Pulsatile Blood Flow

Continuous monitoring of in vivo pulsatile blood flow and pulse wave velocity (PWV) is important for clinical applications. These parameters are correlated with physiological parameters, such as blood pressure and elasticity of blood vessels. A multimode fiber diffuse speckle contrast analysis (MMF-DSCA) system was developed for fast measurement of in vivo pulsatile blood flow and pulse wave velocity. With MMF and CCD sensor, the diffuse speckle could be captured and processed with higher temporal resolution of 3 ms. We also induced for the first time an MMF-DSCA for evaluation of PWV, which allows estimation of the blood pressure continuously. To validate its performance, both phantom and in vivo experiments were conducted. The results demonstrate that MMF-DSCA could achieve fast pulsatile blood flow measurement with detailed information of the pulse wave profile and velocity. Taking the advantages of being simple and cost-effective, the flexible system can be easily adapted for continuous monitoring of vital biosigns, such as heart rate, pulse wave, and blood pressure.

scholarly journals Studying Peripheral Vascular Pulse Wave Velocity Using Bio-impedance Plethysmography and Regression Analysis

2017 ◽  
Vol 11 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Ji-Jer Huang ◽  
Yang-Min Huang ◽  
Aaron Raymond See
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Regression Analysis ◽  
Pulse Wave Velocity ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Wave Velocity ◽  
Radial Artery ◽  
Pulse Wave ◽  
Middle Finger

In this study, a simple bioimpedance plethysmography method was employed to measure the pulse wave velocity (PWV) from the radial artery in the wrist to the middle finger of a patient. Subsequently, electrocardiography was combined with a bioimpedance method to calculate the PWV from ECG and pulse waves to the middle finger. Experiments were conducted by employing cuffs that temporarily block blood flow to produce observable changes in the PWV. Statistical results indicated that temporary blockage of blood flow did not influence the PWV of typical healthy people. Moreover, multiple regression analysis was used to establish an equation for estimating two types of PWV and their relevance with other physiological parameters. Multiple regression analysis indicated that the abdomen circle and height are independent predictors of the PWV from the radial artery in the wrist to the middle finger (wfPWV) (r = 0.893). Systolic blood pressure (SBP) and diastolic blood pressure (DBP) are independent predictors of the PWV from the EGC T wave to the middle finger (tfPWV) (r = 0.898). Correlation analysis showed the wfPWV is significantly associated with tfPWV (r = 0.770, p < 0.01).

Abstract 543: Increased Aortic Pulse Wave Velocity in Type 2 Diabetic db/db Mice is Dependent on Blood Pressure

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Mircea Anghelescu ◽  
Keith J Gooch ◽  
Aaron J Trask
Keyword(s):  
Blood Pressure ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Aortic Stiffness ◽  
Pulse Wave ◽  
Ex Vivo ◽  
Aortic Pulse Wave Velocity ◽  
Type 2 Diabetic

Pulse wave velocity (PWV) is the gold standard for in vivo aortic stiffness measurements but can be dependent upon blood pressure and/or heart rate. Previous studies from our and other labs have shown increased aortic PWV in type 2 diabetic db/db mice. Moreover, preliminary ex vivo pressure myography data from our lab has also shown a lack of increase in passive aortic stiffness, suggesting that increased PWV in vivo , and therefore, increased stiffness in db/db mice may be dependent upon other mechanisms. In this study, we tested the hypothesis that increased aortic pulse wave velocity measured in db/db mice in vivo is blood pressure dependent under anesthesia. 16-wk old normal Db/db (n=9) and type 2 diabetic db/db (n=5) mice were anesthetized with 2% isoflurane and instrumented with two 1.2F pressure-tip catheters: one inserted in the left carotid artery and advanced to the thoracic aorta, the other inserted into the left femoral artery and advanced into the abdominal aorta. Blood pressure was continuously recorded and PWV was calculated using the foot-to-foot method. A microcannula was inserted into the right jugular vein for the administration of drugs. After a stabilization period of 25-30 mins, baseline BPs and PWVs were measured, after which mice were infused with increasing doses of phenylephrine (Phe, 100-500 nmol/kg/min) and sodium nitroprusside (SNP, 100-500 nmol/kg/min) to increase and decrease blood pressure, respectively. At baseline (prior to the infusion of any drugs), mean arterial pressure and aortic PWV were significantly elevated in db/db mice under anesthesia (MAP; Db/db: 77±5 vs. db/db: 100±4 mmHg, p <0.05; PWV; Db/db: 0.31±0.01 vs. db/db: 0.35±0.01 cm/ms, p <0.05). The increase in aortic PWV in db/db mice at baseline was completely abrogated when measured at equivalent MAPs ranging from 40-120 mmHg during the Phe and SNP infusions ( p >0.05). In both Db/db and db/db mice, aortic PWV was significantly correlated with MAP (Db/db: r=0.94, p <0.001; db/db: r=0.97, p <0.0001). These data show that increased aortic PWV, and therefore increased aortic stiffness in db/db mice in vivo is dependent upon blood pressure.

Pressure dependency of aortic pulse wave velocity in vivo is not affected by vasoactive substances that alter aortic wall tension ex vivo

2015 ◽  
Vol 308 (10) ◽  
pp. H1221-H1228 ◽  
Author(s):  
Mark Butlin ◽  
George Lindesay ◽  
Kayla D. Viegas ◽  
Alberto P. Avolio
Keyword(s):  
Blood Pressure ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Aortic Stiffness ◽  
Pulse Wave ◽  
Ex Vivo ◽  
Venous Occlusion ◽  
Aortic Pulse Wave Velocity ◽  
Wall Tension

Aortic stiffness, a predictive parameter in cardiovascular medicine, is blood pressure dependent and experimentally requires isobaric measurement for meaningful comparison. Vasoactive drug administration to change peripheral resistance and blood pressure allows such isobaric comparison but may alter large conduit artery wall tension, directly changing aortic stiffness. This study quantifies effects of sodium nitroprusside (SNP, vasodilator) and phenylephrine (PE, vasoconstrictor) on aortic stiffness measured by aortic pulse wave velocity (aPWV) assessed by invasive pressure catheterization in anaesthetized Sprague-Dawley rats ( n = 7). This was compared with nondrug-dependent alteration of blood pressure through reduced venous return induced by partial vena cava occlusion. In vivo drug concentration was estimated by modeling clearance rates. Ex vivo responses of excised thoracic and abdominal aortic rings to drugs was measured using myography. SNP administration did not alter aPWV compared with venous occlusion ( P = 0.21–0.87). There was a 5% difference in aPWV with PE administration compared with venous occlusion ( P < 0.05). The estimated in vivo maximum concentration of PE (7.0 ± 1.8 ×10−7 M) and SNP (4.2 ± 0.6 ×10−7 M) caused ex vivo equivalent contraction of 52 mmHg (thoracic) and 112 mmHg (abdominal) and relaxation of 96% (both abdominal and thoracic), respectively, despite having a negligible effect on aPWV in vivo. This study demonstrates that vasoactive drugs administered to alter systemic blood pressure have a negligible effect on aPWV and provide a useful tool to study pressure-normalized and pressure-dependent aPWV in large conduit arteries in vivo. However, similar drug concentrations affect aortic ring wall tension ex vivo. Future studies investigating in vivo and ex vivo kinetics will need to elucidate mechanisms for this marked difference.

THE ELASTICITY OF THE LARGE ARTERIES IN HYPERTENSION

1952 ◽  
Vol 30 (2) ◽  
pp. 125-129
Author(s):  
J. P. Adamson ◽  
J. Doupe
Keyword(s):  
Blood Pressure ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Diastolic Pressure ◽  
Arterial Elasticity ◽  
Large Arteries ◽  
Wave Velocities

Intra-arterial pressures and pulse wave velocities were measured in 18 subjects whose auscultatory diastolic pressures ranged from 45 to 120 mm. Hg. Various methods were used to lower the blood pressure in the hypertensive and to raise it in nonhypertensive subjects so that pulse wave velocities might be compared in all subjects at a common diastolic pressure. The pulse wave velocities were calculated for a diastolic pressure of 80 mm. Hg. No significant differences were found between hypertensive and nonhypertensive subjects. It was concluded that a defect of arterial elasticity as gauged by pulse wave velocity is not a factor in the pathogenesis of hypertension.

scholarly journals Normal and reference values for cardiovascular magnetic resonance-based pulse wave velocity in the middle-aged general population

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Max J. van Hout ◽  
Ilona A. Dekkers ◽  
Jos J. Westenberg ◽  
Martin J. Schalij ◽  
Ralph L. Widya ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
General Population ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Reference Values ◽  
Pulse Wave ◽  
Disease Risk ◽  
Cardiovascular Disease Risk

Abstract Background Aortic stiffness, assessed through pulse wave velocity (PWV), is an independent predictor for cardiovascular disease risk. However, the scarce availability of normal and reference values for cardiovascular magnetic resonance imaging (CMR) based PWV is limiting clinical implementation. The aim of this study was to determine normal and reference values for CMR assessed PWV in the general population. Methods From the 2,484 participants of the Netherlands Epidemiology of Obesity (NEO) study that have available CMR-PWV data, 1,394 participants free from cardiovasculard disease, smokers or treatment for diabetes, hypertension or dyslipidaemia were selected (45–65 years, 51% female). Participants were divided into sex, age and blood pressure (BP) subgroups. Normal values were specified for participants with a BP < 130/80 mmHg and reference values for elevated BP subgroups (≥ 130/80 and < 140/90 mmHg; and ≥ 140/90 mmHg). Differences between groups were tested with independent samples t-test or ANOVA. Due to an oversampling of obese individuals in this study, PWV values are based on a weighted analysis making them representative of the general population. Results Normal mean PWV was 6.0 m/s [95% CI 5.8–6.1]. PWV increased with advancing age and BP categories (both p < 0.001). There was no difference between sex in normal PWV, however in the BP > 140/90 mmHg women had a higher PWV (p = 0.005). The interpercentile ranges were smaller for participants < 55 years old compared to participants ≥ 55 years, indicating an increasing variability of PWV with age. PWV upper limits were particularly elevated in participants ≥ 55 years old in the high blood pressure subgroups. Conclusion This study provides normal and reference values for CMR-assessed PWV per sex, age and blood pressure category in the general population.

scholarly journals Effects of an Innovative Head-Up Tilt Protocol on Blood Pressure and Arterial Stiffness Changes

2021 ◽  
Vol 10 (6) ◽  
pp. 1198
Author(s):  
Victor N. Dorogovtsev ◽  
Dmitry S. Yankevich ◽  
Nandu Goswami
Keyword(s):  
Blood Pressure ◽  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Healthy Subjects ◽  
Pulse Wave ◽  
Task Force ◽  
Column Height ◽  
Tilt Test ◽  
Test Protocol ◽  
Head Up Tilt

The objective of our study was to identify blood pressure (BP) and pulse wave velocity (PWV) changes during orthostatic loading, using a new the head-up tilt test (HUTT), which incorporates the usage of a standardized hydrostatic column height. Methods: 40 healthy subjects 20–32 years performed HUTT, which was standardized to a height of the hydrostatic column at 133 cm. Exposure time was 10 min in each of 3 positions: horizontal supine 1, HUTT, and horizontal supine 2. The individual tilt up angle made it possible to set the standard value of the hydrostatic column. Hemodynamic parameters were recorded beat to beat using “Task Force Monitor 3040 i”, pulse-wave velocity (PWV) was measured with a sphygmograph–sphygmomanometer VaSera VS1500N. Results: Orthostatic loading caused a significant increase in heart rate (HR) and a decrease in stroke volume (SV) (p < 0.05) but no significant reductions in cardiac output, changes in total vascular resistance (TVR), or BP. An analysis of personalized data on systolic blood pressure (SBP) changes in tilt up position as compared to horizontal position (ΔSBP) revealed non-significant changes in this index in 48% of subjects (orthostatic normotension group), in 32% there was a significant decrease in it (orthostatic hypotension group) and in 20% there was a significant increase in it (orthostatic hypertension group). These orthostatic changes were not accompanied by any clinical symptoms and/or syncope. During HUTT, all subjects had in the PWV a significant increase of approximately 27% (p < 0.001). Conclusion: The new test protocol involving HUTT standardized to a height of hydrostatic column at 133 cm causes typical hemodynamics responses during orthostatic loading. Individual analysis of the subjects revealed subclinical orthostatic disorders (OSD) in up to 52% of the test persons. During HUTT, all test subjects showed a significant increase in PWV. The new innovative HUTT protocol can be applied in multi-center studies in healthy subjects to detect preclinical forms of orthostatic disorders under standard gravity load conditions.

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