Numerical modeling of ultrasound-induced temperature fields in multilayer nonlinear attenuating media

• Autorzy: Kujawska T. , Wójcik J. , Nowicki A.
• Języki publikacji: EN

Abstrakty

EN

Ultrasound is a safe, convenient and inexpensive modality which may be useful for soft tissues treatment. A range of beneficial biological effects induced by ultrasound depends on the exposure levels used during treatment. At high intensities instantaneous tissue necrosis is desired, whereas at lower intensities remedial reversible cellular effects may be produced. For example, increasing of cells immunity against stress can be obtained through the heat shock proteins (Hsp) expression enhancement. The possibility of the Hsp expression enhancement in soft tissues in vivo by means of controlled exposure to ultrasound would allow to evaluate the treatment efficiency. Ultrasonic regimes can be controlled by adjusting the ultrasound intensity, frequency, pulse duration, duty cycle and exposure time. The goal of this work was to develop the numerical model capable of predicting in space and time the temperature fields induced by circular focused transducer generating tone bursts in multilayer nonlinear attenuating media, which is intended for the Hsp expression enhancement therapeutic application. The acoustic pulsed pressure field generated from the transducer was calculated using our original 3D numerical solver [1]. For prediction of the temperature distributions in multilayer biological media the Pennes bio-heat transfer equation was numerically solved. The 3D temperature fields induced in a rat liver in vitro by a 2 MHz transducer with 15 mm diameter and 25 mm focal length during ultrasonic Hsp expression enhancement treatment using various acoustic beam intensities and exposure time was predicted.

Słowa kluczowe

EN

numerical modelling; ultrasound; attenuating media

• Wydawca: Polskie Towarzystwo Akustyczne. Oddział Gdański
• Czasopismo: Hydroacoustics
• Rocznik: 2009
• Tom: Vol. 12
• Strony: 91--97
• Opis fizyczny: Bibliogr. 4 poz., rys.,wykr.

Twórcy

autor

Kujawska T.

autor

Wójcik J.

autor

Nowicki A.

• Institute of Fundamental Technological Research Polish Academy of Sciences, Świętokrzyska 21, 00-049 Warsaw, Poland,

Bibliografia

• [1] J. Wójcik, A. Nowicki, P.A. Lewin, P.E. Bloomfield, T. Kujawska, L. Filipczyński, Wave envelopes method for description of nonlinear acoustic wave propagation, Ultrasonics, 44, 310-329, 2006.
• [2] H.H. Pennes, Analysis of tissue and arterial blood temperatures in the resting human Forearm, J. Appl. Physiol., 1, 93-122, 1948.
• [3] T. Kujawska, J. Wójcik, L. Filipczyński, Possible temperature effects computed for acoustic microscopy used for living cells, Ultrasound in Medicine and Biology, 30, 1, 93-101, 2004.
• [4] T. Kujawska, J. Wójcik, Harmonic ultrasound beams forming by means of adjusting source operating regime parameters, Hydroacoustics, 7, 135-142, 2004.