title: A 3D time reversal cavity for the focusing of high-intensity ultrasound pulses over a large volume.
abstract: Shock wave ultrasound therapy techniques, increasingly used for non-invasive surgery, require extremely high pressure amplitudes in precise focal spots, and large high-power transducers arranged on a spherical shell are usually used to achieve that. This solution allows limited steering of the beam around the geometrical focus of the device at the cost of a large number of transducer elements, and the treatment of large and moving organs like the heart is challenging or impossible. This paper validates numerically and experimentally the possibility of using a time reversal cavity (TRC) for the same purpose. A 128-element, 1 MHz power transducer combined with different multiple scattering media in a TRC was used. We were able to focus high-power ultrasound pulses over a large volume in a controlled manner, with a limited number of transducer elements. We reached sufficiently high pressure amplitudes to erode an Ultracal®target over a 10 cm2area.
authors.forename: J
authors.initials: J
authors.lastname: Robin
authors.forename: B
authors.initials: B
authors.lastname: Arnal
authors.forename: M
authors.initials: M
authors.lastname: Tanter
authors.forename: M
authors.initials: M
authors.lastname: Pernot
mesh_terms: D057086:High-Intensity Focused Ultrasound Ablation / Q000295:instrumentation*; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000528:radiation effects / Q000601:surgery; D008096:Lithotripsy; D019047:Phantoms, Imaging; D011312:Pressure; D014159:Transducers