| Autor: |
Pernot M; Laboratoire Ondes et Acoustique, ESPCI, Université Paris VII, UMR CNRS 7587, 10 rue Vauquelin, 75005 Paris, France., Aubry JF, Tanter M, Thomas JL, Fink M |
| Jazyk: |
angličtina |
| Zdroj: |
Physics in medicine and biology [Phys Med Biol] 2003 Aug 21; Vol. 48 (16), pp. 2577-89. |
| DOI: |
10.1088/0031-9155/48/16/301 |
| Abstrakt: |
A sparse phased array is specially designed for non-invasive ultrasound transskull brain therapy. The array is made of 200 single elements corresponding to a new generation of high power transducers developed in collaboration with Imasonic (Besançon, France). Each element has a surface of 0.5 cm2 and works at 0.9 MHz central frequency with a maximum 20 W cm(-2) intensity on the transducer surface. In order to optimize the steering capabilities of the array, several transducer distributions on a spherical surface are simulated: hexagonal, annular and quasi-random distributions. Using a quasi-random distribution significantly reduces the grating lobes. Furthermore, the simulations show the capability of the quasi-random array to electronically move the focal spot in the vicinity of the geometrical focus (up to +/- 15 mm). Based on the simulation study, the array is constructed and tested. The skull aberrations are corrected by using a time reversal mirror with amplitude correction achieved thanks to an implantable hydrophone, and a sharp focus is obtained through a human skull. Several lesions are induced in fresh liver and brain samples through human skulls, demonstrating the accuracy and the steering capabilities of the system. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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