Pulsed nonlinear acoustic fields from clinically relevant sources: numerical calculations and experiments results

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

Abstrakty

EN

The goal of this work was to verify experimentally the applicability of the recently developed Time-Averaged Wave Envelope (TAWE) method [1] as a tool for fast prediction of pulsed nonlinear pressure fields from focused nonaxisymmetric acoustic sources in attenuating media. The experiments were performed in water at the fundamental frequency of 2.8 MHz for spherically focused (focal length F = 80 mm) square (20x20 mm) and rectangular (10x25 mm) sources similar to those used in the design of 1D linear arrays operating with ultrasonic imaging systems. The experimental results obtained with 10-cycle tone bursts at three different excitation levels corresponding to linear, moderately nonlinear and highly nonlinear propagation conditions (0.045, 0.225 and 0.45 MPa on-source pressure amplitude, respectively) were compared with those yielded using the TAWE approach. Comparison of the experimental and numerical calculations results has shown that the TAWE approach is well suited to predict (to within ±1 dB) both the spatial-temporal and spatial-spectral pressure variations in the pulsed nonlinear acoustic beams.

Słowa kluczowe

EN

rectangular focused apertures; pulsed acoustic fields; nonlinear distortion; numerical modelling and experiments

• Wydawca: Instytut Podstawowych Problemów Techniki PAN ; Komitet Akustyki PAN ; Polskie Towarzystwo Akustyczne
• Czasopismo: Archives of Acoustics
• Rocznik: 2008
• Tom: Vol. 33, No. 4
• Strony: 565--571
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Wójcik J.

autor

Kujawska T.

autor

Nowicki A.

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

Bibliografia

• [1] WÓJCIK J., NOWICKI A., LEWIN P.A., BLOOMFIELD P.E., KUJAWSKA T., FILIPCZY´N SKI L., Wave envelopes method for description of nonlinear acoustic wave propagation, Ultrasonics, 44, 310–329 (2006).
• [2] CHRISTOPHER P.T., PARKER K.J., New approaches to nonlinear diffractive field propagation, J. Acoust. Soc. Am., 90, 1, 488–499 (1991).
• [3] KAMAKURA T., TANI M., KUMAMOTO Y., Harmonic generation in finite amplitude sound beams from a rectangular aperture source, J. Acoust. Soc. Am., 91, 6, 3144–3151 (1992).
• [4] BAKER A.C., BERG A.M., SAHIN A., NAZE TJØTTA J., The nonlinear pressure field of plane, rectangular apertures. Experimental and theoretical results, J. Acoust. Soc. Am., 97, 6, 3510–3517 (1995).
• [5] NACHEF S., CATHIGNOL D., NAZE TJØTTA J., BERG A.M., TJØTTA S., Investigation of a high intensity sound beam from a plane transducer. Experimental and theoretical results, J. Acoust. Soc. Am., 98, 4, 2303–2323 (1995).
• [6] CAHILL M.D., BAKER A.C., Increased off-axis energy deposition due to diffraction and nonlinear propagation of ultrasound from rectangular sources, J. Acoust. Soc. Am., 102, 1, 199–203 (1997).
• [7] CAHILL M.D., BAKER A.C., Numerical simulation of the acoustic field of a phased-array medical ultrasound scanner, J. Acoust. Soc. Am., 104, 3, 1274–1283 (1998).
• [8] ZEMP R.J., TAVAKKOLI J., COBBOLD R.S.C., Modeling of nonlinear ultrasound propagation in tissue from array transducers, J. Acoust. Soc. Am., 113, 1, 139–152 (2003).