Optimal focusing through aberrating media: a comparison between time reversal mirror and time delay correction techniques
- 9 December 2002
- proceedings article
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 1195-1199
- https://doi.org/10.1109/ultsym.1991.234304
Abstract
The problem of focusing an ultrasonic beam through an inhomogeneous medium was investigated experimentally for conventional time delay focusing, adaptive time delay focusing, and time reversal focusing. It is shown that neither time delay based technique gives a properly focused beam for all aberrator locations. Only time reversal focusing allows a robust focusing regardless of the aberrator location. The matched filter theory of signal processing allows an interpretation of this result: time reversal focusing provides the optimal input to the linear system consisting of the acousto-electric and diffraction impulse response Author(s) Wu, F. Lab. Ondes et Acoust., Paris Univ., France Fink, M. ; Mallart, R. ; Thomas, J.L. ; Chakroun, N. ; Cassereau, D. ; Prada, C.Keywords
This publication has 6 references indexed in Scilit:
- The iterative time reversal mirror: A solution to self-focusing in the pulse echo modeThe Journal of the Acoustical Society of America, 1991
- The random phase transducer: a new technique for incoherent processing-basic principles and theoryIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1990
- Phase aberration correction in medical ultrasound using speckle brightness as a quality factorThe Journal of the Acoustical Society of America, 1989
- Phase-aberration correction using signals from point reflectors and diffuse scatterers: basic principlesIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1988
- In vivo and in vitro ultrasound beam distortion measurements of a large aperture and a conventional aperture focussed transducerUltrasound in Medicine & Biology, 1987
- Diffraction Effects in Pulse-Echo MeasurementIEEE Transactions on Sonics and Ultrasonics, 1984