Fresnel Zone Focusing of Linear Arrays Applied to B and C Echography
For a long time, physicists have tried to get acoustical pictures like. ordinary X rays pictures. The through imaging techniques, holographic or ordinary imaging ones, have not yet proved to be of the same interest for medical use as echographic techniques. On the other hand, these later techniques give essentially cross-sectional B echograms, while the C echographic techniques remain quite limited due to the time required by X Y mechanical scanning. It is possible to run faster using an electronically X scanned one dimensional array, but the lateral resolution of such a device must be higher both in X and Y directicnsthan for B echography. Electronic focusing by delay lines may be combined to an X or θ scanner (1, 2) this technique requires high performance circuits able to handle the greatdynemic range of ultrasonic echoes. We want to present here a relatively simpler technique using holographic focusing useful for boti. B and C echography.
KeywordsExpense Nylon Convolution Lution Acoustics
Unable to display preview. Download preview PDF.
- 1.F.L. THURSTONE, O.T. RAMM, Acoustical holography, Vol. 5, (1974) pp. 249–259.Google Scholar
- 2.L. POURCELOT, J.M. POTTIER, M, BERSON, Th. PLANIOL, Proceeding of the 2nd European Congress on Ultrasonics in Medicine, Munich, May 1975.Google Scholar
- 3.B.A. AULD and S.A. FARNOW, Acoustical Holography, Vol. 6, (1975) pp. 259–274.Google Scholar
- 4.M. LAGREVE, 1976 Thesis, Université Pierre et Marie Curie, Paris, France.Google Scholar
- 5.P. ALAIS, M. FINK, Proceedings of the 2nd European Congress on Ultrasonics in Medicine, Munich, May 1975.Google Scholar
- 6.P. ALAIS, M. ‘FINK, B. RICHARD, J. PERRIN, 1st meeting of the world federation olf Ultrasound in Medicine and Biology, San Francisco (August 1976)® Google Scholar
- 7.A. NIGAM, Acoustical Holography, Vol. 6, (1975), pp. 669–710.Google Scholar