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Kalina Kaweckajaszcz - One of the best experts on this subject based on the ideXlab platform.
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comparison of aortic pulse Wave Velocity measured by three techniques complior sphygmocor and arteriograph
Journal of Hypertension, 2008Co-Authors: Marek Rajzer, Marek Klocek, Ilona Palka, Malgorzata Brzozowskakiszka, Wiktoria Wojciechowska, Kalina KaweckajaszczAbstract:Background New 2007 European Society of Hypertension guidelines recommend measuring arterial stiffness in patients with arterial hypertension, suggesting a carotid-femoral pulse Wave Velocity over 12 m/s as an estimate of subclinical organ damage. Considering this cutoff point, it is worth exploring whether or not there are significant differences in results obtained using various techniques for measuring aortic pulse Wave Velocity. The aim of the study was to compare aortic pulse Wave Velocity measurements using Complior, SphygmoCor, and Arteriograph devices, and to assess the effect of pulse Wave transit time and traveled distance on pulse Wave Velocity values. Methods Aortic pulse Wave Velocity was measured on a single visit, using these devices, in randomized order, in a group of 64 patients with grade 1 or 2 arterial hypertension. Results Aortic pulse Wave Velocity measured using Complior (10.1 ± 1.7 m/s) was significantly higher than that obtained using SphygmoCor (8.1 ±1.1 m/s) or Arteriograph (8.6 ± 1.3 m/s). No differences were noted between pulse Wave Velocity measurements using SphygmoCor and Arteriograph. Between-method comparison revealed that differences in traveled distance were significant: Complior versus Arteriograph [0.09m, Confidence interval (Cl): 0.08-0.12m, P<0.05], Complior versus SphygmoCor (0.15m, Cl: 0.13-0.16m, P<0.05), Arteriograph versus SphygmoCor (0.05m, Cl: 0.03-0.07m, P<0.05). No between-method differences were found for transit times. Conclusion Differences in pulse Wave Velocity obtained by compared devices resulted primarily from using various methods for measuring traveled distance. It appears reasonable to establish uniform principles for the measurement of traveled distance. Because a large number of prognosis/survival studies used direct distance between carotid and femoral sites of pulse Wave recording, this distance should be mostly recommended..
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comparison of aortic pulse Wave Velocity measured by three techniques complior sphygmocor and arteriograph
Journal of Hypertension, 2008Co-Authors: Marek Rajzer, Marek Klocek, Ilona Palka, Malgorzata Brzozowskakiszka, Wiktoria Wojciechowska, Kalina KaweckajaszczAbstract:Background New 2007 European Society of Hypertension guidelines recommend measuring arterial stiffness in patients with arterial hypertension, suggesting a carotid-femoral pulse Wave Velocity over 12 m/s as an estimate of subclinical organ damage. Considering this cutoff point, it is worth exploring whether or not there are significant differences in results obtained using various techniques for measuring aortic pulse Wave Velocity. The aim of the study was to compare aortic pulse Wave Velocity measurements using Complior, SphygmoCor, and Arteriograph devices, and to assess the effect of pulse Wave transit time and traveled distance on pulse Wave Velocity values. Methods Aortic pulse Wave Velocity was measured on a single visit, using these devices, in randomized order, in a group of 64 patients with grade 1 or 2 arterial hypertension. Results Aortic pulse Wave Velocity measured using Complior (10.1 ± 1.7 m/s) was significantly higher than that obtained using SphygmoCor (8.1 ±1.1 m/s) or Arteriograph (8.6 ± 1.3 m/s). No differences were noted between pulse Wave Velocity measurements using SphygmoCor and Arteriograph. Between-method comparison revealed that differences in traveled distance were significant: Complior versus Arteriograph [0.09m, Confidence interval (Cl): 0.08-0.12m, P<0.05], Complior versus SphygmoCor (0.15m, Cl: 0.13-0.16m, P<0.05), Arteriograph versus SphygmoCor (0.05m, Cl: 0.03-0.07m, P<0.05). No between-method differences were found for transit times. Conclusion Differences in pulse Wave Velocity obtained by compared devices resulted primarily from using various methods for measuring traveled distance. It appears reasonable to establish uniform principles for the measurement of traveled distance. Because a large number of prognosis/survival studies used direct distance between carotid and femoral sites of pulse Wave recording, this distance should be mostly recommended..
Yulong Chen - One of the best experts on this subject based on the ideXlab platform.
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estimation of elastic Wave Velocity through unsaturated soil slope as function of water content and shear deformation
Soils and Foundations, 2019Co-Authors: Yulong Chen, Muhammad Irfan, Taro UchimuraAbstract:Abstract The objective of this study was to estimate the elastic Wave Velocity of an unsaturated soil slope, and to verify its applicability. The elastic Wave Velocity in a silty sand was measured. The individual influence of the volumetric water content and the tilt angle on the normalized Wave Velocity through unsaturated soil were investigated through a series of varied slope model tests. The relationship function of the normalized Wave Velocity-volumetric water content-tilt angle was established. To verify the proposed estimation function, a series of fixed slope model tests was carried out. The relationship functions were used to estimate the behaviors of the Wave Velocity in rainfall-induced slope failure model tests. The applicability of the proposed relationship functions for the Wave Velocity behaviors was also presented. It was found that the estimation function is highly consistent with the measurements for the Wave Velocity behaviors through unsaturated soil slope in the presented test conditions. In addition, the effects of the rainfall duration/initial water content, density, slope angle and surface layer thickness on the decrease rate of the normalized Wave Velocity with the volumetric water content and the tilt angle within the test conditions in this study were seen to be small.
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elastic Wave Velocity monitoring as an emerging technique for rainfall induced landslide prediction
Landslides, 2018Co-Authors: Yulong Chen, Muhammad Irfan, Taro Uchimura, Guanwen Cheng, Wen NieAbstract:Landslides are recurring phenomena causing damages to private property, public facilities, and human lives. The need for an affordable instrumentation that can be used to provide an early warning of slope instability to enable the evacuation of vulnerable people, and timely repair and maintenance of critical infrastructure is self-evident. A new emerging technique that correlates soil moisture changes and deformations in slope surface by means of elastic Wave propagation in soil was developed. This approach quantifies elastic Wave propagation as Wave Velocity. To verify its applicability, a series of fixed and varied slope model tests, as well as a large scale model test, were conducted. Analysis of the results has established that the elastic Wave Velocity continuously decreases in response of moisture content and deformation, and there was a distinct surge in the decrease rate of Wave Velocity with failure initiation, soil deformation was thus envisaged to have more significant effect on elastic Wave Velocity than water content. It is proposed that a warning be issued at switch of Wave Velocity decrease rate. Based on these observations, expected operation of the elastic Wave Velocity monitoring system for landslide prediction in the field application is presented. Consequently, we conclude that the elastic Wave Velocity monitoring technique has the potential to contribute to landslide prediction.
Paolo Salvi - One of the best experts on this subject based on the ideXlab platform.
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reference values of pulse Wave Velocity in healthy children and teenagers
Hypertension, 2010Co-Authors: George S Reusz, Orsolya Cseprekal, Mohamed Temmar, Abdelghani Bachir Cherif, Abddelhalim Thaleb, Andrea Fekete, Paolo Salvi, Attila J. Szabó, Athanase BenetosAbstract:Carotid-femoral pulse Wave Velocity is an established method for characterizing aortic stiffness, an individual predictor of cardiovascular mortality in adults. Normal pulse Wave Velocity values for the pediatric population derived from a large data collection have yet to be available. The aim of this study was to create a reference database and to characterize the factors determining pulse Wave Velocity in children and teenagers. Carotid-femoral pulse Wave Velocity was measured by applanation tonometry. Reference tables from pulse Wave velocities obtained in 1008 healthy subjects (aged between 6 and 20 years; 495 males) were generated using a maximum-likelihood curve-fitting technique for calculating SD scores in accordance with the skewed distribution of the raw data. Effects of sex, age, height, weight, blood pressure, and heart rate on pulse Wave Velocity were assessed. Sex-specific reference tables and curves for age and height are presented. Pulse Wave Velocity correlated positively ( P 1000 children, is the first to provide reference values for pulse Wave Velocity in children and teenagers, thereby constituting a suitable tool for longitudinal clinical studies assessing subgroups of children who are at long-term risk of cardiovascular disease.
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reference values of pulse Wave Velocity in healthy children and teenagers
Hypertension, 2010Co-Authors: George S Reusz, Orsolya Cseprekal, Mohamed Temmar, Abdelghani Bachir Cherif, Abddelhalim Thaleb, Andrea Fekete, Paolo Salvi, Attila J. Szabó, Athanase BenetosAbstract:Carotid-femoral pulse Wave Velocity is an established method for characterizing aortic stiffness, an individual predictor of cardiovascular mortality in adults. Normal pulse Wave Velocity values fo...
Marek Rajzer - One of the best experts on this subject based on the ideXlab platform.
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comparison of aortic pulse Wave Velocity measured by three techniques complior sphygmocor and arteriograph
Journal of Hypertension, 2008Co-Authors: Marek Rajzer, Marek Klocek, Ilona Palka, Malgorzata Brzozowskakiszka, Wiktoria Wojciechowska, Kalina KaweckajaszczAbstract:Background New 2007 European Society of Hypertension guidelines recommend measuring arterial stiffness in patients with arterial hypertension, suggesting a carotid-femoral pulse Wave Velocity over 12 m/s as an estimate of subclinical organ damage. Considering this cutoff point, it is worth exploring whether or not there are significant differences in results obtained using various techniques for measuring aortic pulse Wave Velocity. The aim of the study was to compare aortic pulse Wave Velocity measurements using Complior, SphygmoCor, and Arteriograph devices, and to assess the effect of pulse Wave transit time and traveled distance on pulse Wave Velocity values. Methods Aortic pulse Wave Velocity was measured on a single visit, using these devices, in randomized order, in a group of 64 patients with grade 1 or 2 arterial hypertension. Results Aortic pulse Wave Velocity measured using Complior (10.1 ± 1.7 m/s) was significantly higher than that obtained using SphygmoCor (8.1 ±1.1 m/s) or Arteriograph (8.6 ± 1.3 m/s). No differences were noted between pulse Wave Velocity measurements using SphygmoCor and Arteriograph. Between-method comparison revealed that differences in traveled distance were significant: Complior versus Arteriograph [0.09m, Confidence interval (Cl): 0.08-0.12m, P<0.05], Complior versus SphygmoCor (0.15m, Cl: 0.13-0.16m, P<0.05), Arteriograph versus SphygmoCor (0.05m, Cl: 0.03-0.07m, P<0.05). No between-method differences were found for transit times. Conclusion Differences in pulse Wave Velocity obtained by compared devices resulted primarily from using various methods for measuring traveled distance. It appears reasonable to establish uniform principles for the measurement of traveled distance. Because a large number of prognosis/survival studies used direct distance between carotid and femoral sites of pulse Wave recording, this distance should be mostly recommended..
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comparison of aortic pulse Wave Velocity measured by three techniques complior sphygmocor and arteriograph
Journal of Hypertension, 2008Co-Authors: Marek Rajzer, Marek Klocek, Ilona Palka, Malgorzata Brzozowskakiszka, Wiktoria Wojciechowska, Kalina KaweckajaszczAbstract:Background New 2007 European Society of Hypertension guidelines recommend measuring arterial stiffness in patients with arterial hypertension, suggesting a carotid-femoral pulse Wave Velocity over 12 m/s as an estimate of subclinical organ damage. Considering this cutoff point, it is worth exploring whether or not there are significant differences in results obtained using various techniques for measuring aortic pulse Wave Velocity. The aim of the study was to compare aortic pulse Wave Velocity measurements using Complior, SphygmoCor, and Arteriograph devices, and to assess the effect of pulse Wave transit time and traveled distance on pulse Wave Velocity values. Methods Aortic pulse Wave Velocity was measured on a single visit, using these devices, in randomized order, in a group of 64 patients with grade 1 or 2 arterial hypertension. Results Aortic pulse Wave Velocity measured using Complior (10.1 ± 1.7 m/s) was significantly higher than that obtained using SphygmoCor (8.1 ±1.1 m/s) or Arteriograph (8.6 ± 1.3 m/s). No differences were noted between pulse Wave Velocity measurements using SphygmoCor and Arteriograph. Between-method comparison revealed that differences in traveled distance were significant: Complior versus Arteriograph [0.09m, Confidence interval (Cl): 0.08-0.12m, P<0.05], Complior versus SphygmoCor (0.15m, Cl: 0.13-0.16m, P<0.05), Arteriograph versus SphygmoCor (0.05m, Cl: 0.03-0.07m, P<0.05). No between-method differences were found for transit times. Conclusion Differences in pulse Wave Velocity obtained by compared devices resulted primarily from using various methods for measuring traveled distance. It appears reasonable to establish uniform principles for the measurement of traveled distance. Because a large number of prognosis/survival studies used direct distance between carotid and femoral sites of pulse Wave recording, this distance should be mostly recommended..
Ernest L Madsen - One of the best experts on this subject based on the ideXlab platform.
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shear Wave Velocity imaging using transient electrode perturbation phantom and ex vivo validation
IEEE Transactions on Medical Imaging, 2011Co-Authors: Ryan J Dewall, Tomy Varghese, Ernest L MadsenAbstract:This paper presents a new shear Wave Velocity imaging technique to monitor radio-frequency and microWave ablation procedures, coined electrode vibration elastography. A piezoelectric actuator attached to an ablation needle is transiently vibrated to generate shear Waves that are tracked at high frame rates. The time-to-peak algorithm is used to reconstruct the shear Wave Velocity and thereby the shear modulus variations. The feasibility of electrode vibration elastography is demonstrated using finite element models and ultrasound simulations, tissue-mimicking phantoms simulating fully (phantom 1) and partially ablated (phantom 2) regions, and an ex vivo bovine liver ablation experiment. In phantom experiments, good boundary delineation was observed. Shear Wave Velocity estimates were within 7% of mechanical measurements in phantom 1 and within 17% in phantom 2. Good boundary delineation was also demonstrated in the ex vivo experiment. The shear Wave Velocity estimates inside the ablated region were higher than mechanical testing estimates, but estimates in the untreated tissue were within 20% of mechanical measurements. A comparison of electrode vibration elastography and electrode displacement elastography showed the complementary information that they can provide. Electrode vibration elastography shows promise as an imaging modality that provides ablation boundary delineation and quantitative information during ablation procedures.
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shear Wave Velocity imaging using transient electrode perturbation a phantom study
Internaltional Ultrasonics Symposium, 2010Co-Authors: Ryan J Dewall, Tomy Varghese, Ernest L MadsenAbstract:A new shear Wave Velocity imaging technique to monitor radiofrequency and microWave ablation procedures is presented, coined electrode vibration elastography. A piezoelectric actuator is attached to the ablation needle and is transiently vibrated to generate shear Waves that are tracked at high frame rates. The time-to-peak algorithm is used to reconstruct the shear Wave Velocity and thereby the shear modulus variations. The feasibility of this approach is demonstrated in phantoms mimicking fully ablated (phantom 1) and partially ablated (phantom 2) regions. Shear Wave Velocity estimates in phantom 1 were within 7% of mechanical measurements and within 17% in phantom 2. Good boundary delineation was observed in both phantoms. No significant differences in ellipsoid area estimates between shear Wave Velocity and B-mode images were present in phantom 1. Shear Wave Velocity area estimates were significantly higher than B-mode area estimates in phantom 2. Electrode vibration elastography shows promise as an imaging modality that provides ablation boundary delineation and quantitative information during ablation procedures.
