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1
New method for measure regional pulse wave velocity by means of RF ultrasonic signals
100%
Trawiński Z.
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tom Vol. 29
163-169
EN
The aim of this paper is to describe a non-invasive method of examination of the local pulse wave velocity. The measurements were carried out in the elastic silicon model of the artery immersed in water tank. Two synchronized ultrasonic apparatus VED with the ultrasonic radio frequency echoes acquisition for evaluation of the arterial elasticity, developed by the author, were used. The zerocrossing method was used for evaluating the pulse wave by measurements of the diameter changes of the model of the artery. The transit time between the waveforms of instant artery diameter at two measurement points, 5cm along the model of the artery was measured. The transit time was determined using the criteria of similarity of the first derivatives of the raising slopes of curves describing the instant vessel’s diameter changes in two measurement points of the model of the artery. The pulse wave velocity obtained by proposed two-point method was referred to the one-point method based of the modified Bramwell-Hill relation.
2
Content available remote Ultrasonic examination of common carotid artery wall elasticity of persons with different stages of internal carotid artery atherosclerosis
51%
Powałowski T. , Trawiński Z. , Hilgertner R.
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tom Vol. 28, no. 4
325-337
EN
Ultrasonic methods were used in this study to examine the association between the common carotid artery (CCA) wall elasticity and the atherosclerosis stage in the internal carotid artery (ICA). The degree of stenosis determined ultrasongraphically was used as an indicator of the atherosclerosis stage in the ICA. The examined persons were 45 to 80 years old. They had no arterial hypertension, diabetes mellitus and were not smokers. A comparative study was carried out for cases with ICA atherosclerosis (66 arteries) and without ICA atherosclerosis (61 arteries). In both groups there were persons without and with hypercholesterolemia, which according to our studies had no significant influence on CCA wall elasticity. The CCA wall elasticity was determined by the stiffness coefficient alpha and the distensibility coefficient DC based on ultrasonic measurements. The influences of age and arterial blood pressure on the CCA wall elasticity were taken into account in the analysis. The study revealed a significant decrease of the CCA wall elasticity in the case of patients with atherosclerosis compared with persons without atherosclerosis, and showed a significant correlation between the increase of the ICA stenosis degree and the decrease of CCA wall elasticity.
3
Content available Numerical solver of acoustic field in simulation of artery wall thickness examinations
51%
Powałowski T. , Wójcik J. , Trawiński Z.
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tom Vol. 10
163-168
EN
The aim of the study was the elaboration of a mathematical model to describe the process of acoustic wave propagation, generated by an ultrasonic probe in a inhomogenous loosing medium. Numerical calculations make it possible to define waveforms for electric signals that are generated when ultrasonic waves, being reflected and backscattered by an artery model, are then received by the ultrasonic probe. It is the signal that pretty well corresponds with the actual RF signal that is obtained during measurements at the output of the ultrasonic apparatus. The developed solver of acoustic field was used for simulation of the artery wall thickness examination. The theoretical model of the artery for the creating the simulated ultrasonic reflected echoes was used. The internal radius of the artery model was 3 mm for the diastolic pressure and 3.3 mm for the systolic pressure. The intima-media thickness (IMT) of the artery wall was changed from 0.48 mm to 0,44 mm respectively. The solver based on zero-crossing method was used for detecting changes of the IMT.
4
Content available remote Common carotid wall elasticity and intima-media thickness examinations by means of ultrasound
51%
Powałowski T. , Hilgertner R. , Trawiński Z.
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tom Vol. 25, no. 2
205-212
EN
The aim of this study was to examine the relation between the intima-media thickness and the wall elasticity measured simultaneously in the same cross-section of the common carotid artery. A group of 40 persons (19 healthy and 21 with hypertension and/or atherosclerosis) aged 22 to 81 were diagnosed by means of ultrasound. A high correlation occurred between the wall stiffness coefficient [alpha] and the intima-media thickness (r=0.950, p<0.00001)
5
Content available Common carotid wall elasticity and intima-media thickness examinations by means of ultrasound
51%
Powałowski T. , Hilgertner L. , Trawiński Z.
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tom Vol. 1
343--346
EN
The aim of this study was to examine the relation between the intima-media thickness and the wall elasticity in the common carotid artery. A group of 40 persons (19 healthy and 21 with hypertension and/or atherosclerosis) aged 22 to 81 were diagnosed by means of ultrasound. A high correlation occurred between the wall stiffness coefficient α and the intima-media thickness (r = 0.950, p<0.001).
6
Content available Mathematical and Ultrasonographic Model of the Left Ventricle : in Vitro Studies
51%
Olszewski R. , Trawiński Z. , Wójcik J. , Nowicki A.
Archives of Acoustics
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2012
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tom Vol. 37, No. 4
583-595
EN
The main objective of this study is to develop an echocardiographic model of the left ventricular and numerical modeling of the speckles- markers tracking in the ultrasound (ultrasonographic) imaging of the left ventricle. The work is aimed at the creation of controlled and mobile environment that enables to examine the relationships between left ventricular wall deformations and visualizations of these states in the form of echocardiographic imaging and relations between the dynamically changing distributions of tissue markers of studied structures.
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Ultradźwiękowe badanie wejściowej impedancji w modelach rozgałęzienia tętnicy szyjnej wspólnej
51%
Powałowski T. , Kałużyński K. , Trawiński Z. , Leśniak B.
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tom Vol. 83, nr 27
355-360
EN
The paper presents the setup and the results of examinations of the input impedance in the silicon models of the common carotid artery bifurcation without stenosis and with 90 % stenosis of the internal carotid artery branch. The input impedance measured in the models is compared with impedance calculated on the base of the values of the hydraulic model elements and of the model load. As a criterion of determination is used the difference between the measured flow and the flow evaluated on the basis on the calculated impedance in the carotid artery bifurcation models. There was no significant difference between the measured and calculated input impedances in the ease of the non-stenosed internal carotid artery. A significant difference between measured and calculated impedances was found for the model of bifurcation with the stenosis of the internal carotid artery. Reflections of pressure wave from the stenosis are expected to be the reason of this effect.
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Content available remote Strain examinations of the left ventricle phantom by ultrasound and multislices computed tomography imaging
32%
Trawiński Z. , Wójcik J. , Nowicki A. , Olszewski R. , Balcerzak A. , Frankowska E. , Zegadło A. , Rydzyński P.
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2015
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tom Vol. 35, no. 4
255--263
EN
The main aim of this study was to verify the suitability of the hydrogel sonographic model of the left ventricle (LV) in the computed tomography (CT) environment and echocardiography and compare the radial strain calculations obtained by two different techniques: the speckle tracking ultrasonography and the multislices computed tomography (MSCT). The measurement setup consists of the LV model immersed in a cylindrical tank filled with water, hydraulic pump, the ultrasound scanner, hydraulic pump controller, pressure measurement system of water inside the LV model, and iMac workstation. The phantom was scanned using a 3.5 MHz Artida Toshiba ultrasound scanner unit at two angle positions: 0° and 25°. In this work a new method of assessment of RF speckles' tracking. LV phantom was also examined using the CT 750 HD 64-slice MSCT machine (GE Healthcare). The results showed that the radial strain (RS) was independent on the insonifying angle or the pump rate. The results showed a very good agreement, at the level of 0.9%, in the radial strain assessment between the ultrasound M-mode technique and multislice CT examination. The study indicates the usefulness of the ultrasonographic LV model in the CT technique. The presented ultrasonographic LV phantom may be used to analyze left ventricle wall strains in physiological as well as pathological conditions. CT, ultrasound M-mode techniques, and author's speckle tracking algorithm, can be used as reference methods in conducting comparative studies using ultrasound scanners of various manufacturers.
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