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    Wyświetlanie 1-8 z 8
    Tytuł:
    Analysis for Improvement of Doppler Tomography Imaging of Objects Scattering Continuous Ultrasonic Waves
    Autorzy:
    Świetlik, Tomasz
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/176449.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    continuous wave ultrasonic tomography
    Doppler tomography
    image reconstruction
    Opis:
    The paper describes an innovative ultrasound imaging method called Doppler Tomography (DT), otherwise known as Continuous Wave Ultrasonic Tomography (CWUT). Thanks to this method, it is possible to image the tissue cross-section in vivo using a simple two-transducer ultrasonic probe and using the Doppler effect. It should be noted that DT significantly differs from the conventional ultrasound Doppler method of measuring blood flow velocity. The main difference is that when measuring blood flow, we receive information with an image of the velocity distribution in a given blood vessel (Nowicki, 1995), while DT allows us to obtain a cross-sectional image of stationary tissue structure. In the conventional method, the probe remains stationary, while in the DT method, the probe moves and the examined tissue remains stationary. This paper presents a method of image reconstruction using the DT method. First, the basic principle of correlation of generated Doppler frequencies with the location of inclusions from which they originate is explained. Then the exact process and algorithm in this method are presented. Finally, the impact of several key parameters on imaging quality is examined. As a result, the conclusions of the research allow to improve the image reconstruction process using the DT method.
    Źródło:
    Archives of Acoustics; 2020, 45, 2; 329-339
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of the Ultrasonic Ring Array Used in UTT for the Reflection Method Examinations of Structures
    Autorzy:
    Staszewski, Wiktor
    Gudra, Tadeusz
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1945647.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    ultrasonic reflection tomography
    dynamic focusing
    ultrasonic ring array
    Opis:
    The ultrasonic ring array, designed for examining the female breast with the use of ultrasonic transmission tomography (UTT), has been adapted for reflection method trials. By altering the activation time of ultrasonic elementary transducers, the parameters of the focus were changed with the aim at improving the quality of the obtained ultrasound image. For this purpose, a phantom consisting of rods having varying thicknesses was analyzed when moving the position of the focus with the use of dynamic focusing along the symmetry axis of the ring array ranging from 30 to 130 mm from central transducers. In previous trials, which applied an algorithm using the sum of all the acoustic fields, a series of simulations was performed in conditions identical to the phantom trial. This paper documents attempts at improving the parameters of the acoustic field distribution during unconventional focusing. The research here presented is a continuation of examinations focusing on the acoustic field distribution inside the ultrasonic ring array with the aim at finding the best possible cross-section of the female breast using the reflection method.
    Źródło:
    Archives of Acoustics; 2021, 46, 3; 427-434
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of Doppler tomography in circular geometry as a novel method of imaging tissue cross-sections in vivo
    Autorzy:
    Świetlik, Tomasz
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/128200.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    Doppler tomography
    Doppler signal
    continuous wave ultrasonic tomography
    image reconstruction
    tomografia dopplerowska
    sygnał Dopplera
    ultradźwiękowa tomografia fali ciągłej
    rekonstrukcja obrazów
    Opis:
    Currently, methods such as conventional ultrasound B-mode scanning (US), computerized X-ray tomography (CT), magnetic resonance imaging (MRI), standard X-ray diagnostics, radioisotope imaging and thermography are used to visualize the internal structure of tissue in vivo and to diagnose the patient. Doppler tomography (DT) is an innovative method of reconstructing the image of the tissue section using ultrasonic waves and Doppler effect. In contrast to the currently applied solutions (US), this method uses a continuous wave, which, in theory, allows one to operate with higher energy and to detect smaller inclusions within the examined tissue. This study focuses on the analysis of DT simulation in circular geometry, where a two-transducer ultrasonic probe circulating around the tested object is used to measure the useful signal. In this paper, the influence on the tested object’s cross-section imaging quality of both the simulated Doppler signal’s registration parameters, and the calculation algorithm’s parameters, were analyzed.
    Źródło:
    Vibrations in Physical Systems; 2019, 30, 1; 1-8
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Effect of Dynamic Beam Deflection and Focus Shift on the Acoustic Field Distribution Inside the Ultrasonic Ring Array
    Autorzy:
    Staszewski, Wiktor
    Gudra, Tadeusz
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/176553.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    ultrasonic ring array
    acoustic field distribution
    ultrasonic beam focusing
    ultrasound tomography
    Opis:
    This paper presents the results of acoustic field distribution simulations for the 1024-element ultrasonic ring array intended for the diagnosis of female breast tissue with the use of ultrasound tomography. For the purpose of analysing data, all acoustic fields created by each elementary transducer were combined. The natural position of the focus inside the ultrasonic ring array was changed by altering activation time of individual transducers in sectors consisting of 32, 64, and 128 ultrasonic transducers. Manipulating the position of the focus inside the array will allow to concentrate the ultrasonic beam in a chosen location in the interior space of the ring array. The goal of this research is to receive the best possible quality of images of cross-sections of the female breast. The study also analysed the influence of the acoustic field distribution on the inclination of the beam. The results will enable to choose an optimal focus and an optimal number of activated transducers.
    Źródło:
    Archives of Acoustics; 2019, 44, 4; 625-636
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of Using Multi-Angle Conventional Ultrasound Scanning for Efficient 3-D Object Imaging
    Autorzy:
    Sabiniok, Maciej
    Opieliński, Krzysztof J.
    Lis, Sylwia
    Powiązania:
    https://bibliotekanauki.pl/articles/176805.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    ultrasonic imaging
    multi-angle scanning
    efficient 3-D imaging
    ultrasound tomography
    Opis:
    The purpose of this work is to examine the possibility of using multi-angle conventional ultrasound B-mode scanning in efficient 3-D imaging. In the paper, the volume of an object is reconstructed from vertical projections registered at fixed angular positions of the multi-element linear ultrasonic probe rotated in relation to the object submerged in water. The possible configurations are: vertical lateral, vertical top or vertical bottom. In the vertical lateral configuration, the ultrasonic probe acquires 2-D images of object’s vertical cross-sections, turning around its lateral surface. In the vertical top or bottom configuration, the ultrasonic probe acquires 2-D images of the object’s vertical cross-sections, turning on the horizontal plane over the top or under the bottom surface of the object. The method of recording 3-D volume of an object’s structure and reconstruction algorithm have been designed. Studies show the method in the vertical top or bottom configuration could be successfully applied to the effective 3-D visualisation of the structure of the female breast in vivo as the new complement ultrasonic imaging modality in the prototype of the developed ultrasound tomography scanner.
    Źródło:
    Archives of Acoustics; 2019, 44, 4; 645-657
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ultrasound tomography imaging: results of breast phantom study and resolution estimation
    Autorzy:
    Opieliński, Krzysztof J.
    Wrzosek, Marcin
    Nicpoń, Józef
    Podgórski, Przemysław
    Świetlik, Tomasz
    Powiązania:
    https://bibliotekanauki.pl/articles/127988.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    ultrasound tomography
    breast phantom
    estimation of imaging resolution
    tomografia ultradźwiękowa
    fantom piersi
    rozdzielczość obrazowania
    Opis:
    In order to improve breast cancer detection rates, new and better imaging methods are required. Currently, the ultrasound tomography (UT) as non-invasive and safe hybrid method may contribute to achieving a new standard for breast cancer diagnostics. The aim of the paper was to analyse the imaging ability of tissue-like media structure found in female breast using the developed novel ultrasound computer-assisted tomographic scanner. Measurements was performed on commercial breast biopsy phantoms due to their well-defined structure with inclusions mimicking glandular tissue with lesions, as well as on the simple agar phantom. Obtained magnetic resonance images (MRI), conventional ultrasound images (US) or X-ray computed tomography (CT) images of the measured media sections were used for comparison. The analysis of the obtained results and carried out theoretical considerations have allowed to estimate the resolution of soft tissue UT imaging.
    Źródło:
    Vibrations in Physical Systems; 2019, 30, 1; 1-8
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A method of precise pulse onset determination using the Akaike Information Criterion for Ultrasound Transmission Tomography
    Autorzy:
    Pruchnicki, Piotr
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2146650.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    Akaike Information Criterion
    AIC
    pulse wave
    transmission method
    ultrasound tomography
    kryterium informacyjne Akaike
    fala tętna
    metoda transmisyjna
    tomografia ultradźwiękowa
    Opis:
    Information criteria used in statistics for model selection can be used to accurately determine pulse transition times in transmission methods. The most popular information criteria are the Akaike Information Criterion (AIC) and the Bayesian Schwartz Criterion (BIC). These criteria are considered the most reliable tests of model type and structure and are computationally simple. In this paper, an algorithm developed according to the AIC criterion is used to determine the transition time from transmission tomography measurements acquired with a multi-element ultrasonic ring array, which is the scanning element of the novel prototype of ultrasound tomography device for detecting and estimating the malignancy of female breast cancer in vivo. As a result, a new algorithm was developed to precise search for the onset of the recorded receiving pulse. The algorithm was tested in an aqueous environment using elementary pairs of transmitting and receiving ultrasonic transducers of a tomographic ring array.
    Źródło:
    Vibrations in Physical Systems; 2021, 32, 1; art. no. 2021115
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Model of multipath propagation of ultrasonic pulses in soft tissue using divergent beam tomography method
    Autorzy:
    Borowski, Jędrzej
    Opieliński, Krzysztof J.
    Powiązania:
    https://bibliotekanauki.pl/articles/127791.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    model of multipath propagation of ultrasonic pulses
    ultrasonic transducer ring array
    divergent wave beam
    soft tissue
    ultrasound tomography
    model wielościeżkowej propagacji impulsów ultradźwiękowych
    pierścieniowa głowica ultradźwiękowa
    rozbieżna wiązka fali
    tkanka miękka
    tomografia ultradźwiękowa
    Opis:
    The paper presents the model of calculating ultrasound waveform beam emitted inside the circular space of ultrasonic transducer ring array and propagated through a biological medium submerged in water. Each elementary transducer emits a burst signal, which then propagates through a medium and is received by a number of transducers on the opposite side of the ring array. The method allows for calculating runtime and amplitude of ultrasonic bursts while traveling from an emitter to a receiver through a specified soft tissue section geometry, having regard to the refraction and attenuation effects and directivity pattern of transducers. The soft tissue section geometry is constructed using circular shapes with given ultrasound speed and attenuation distribution. The elaborated software creates a set of received waveforms for each transmitting transducer. The presented results produced by the software can be used as a basis for further research on inverse problems in ultrasound waveform tomography.
    Źródło:
    Vibrations in Physical Systems; 2019, 30, 1; 1-8
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

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