Ellipsoidal-reflector high intensity focused ultrasound system with integrated safety monitoring

• Published in: The Journal of the Acoustical Society of America 2009-04, Vol.125 (4_Supplement), p.2622-2622
• Main Authors: Samuels, Joshua, Zderic, Vesna
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4783995

High intensity focused ultrasound (HIFU) transducers can be created using concave piezo elements, acoustic lenses, phased arrays, or ellipsoidal reflectors. By using a 2 MHz cylindrical piezoelectric crystal and a brass ellipsoidal reflector, it was possible to use the base of the transducer to house specific devices which can be integrated into a safety system for the device. This system assists in focal point positioning, ablation confirmation, as well as assuring proper flow of coolant through the attached water pillow to couple the device. These methods combine to protect the patient and the device itself from improper use or dangerous positioning of the focal point within the tissue. The proposed system utilizes an unfocused 3.5 MHz ultrasound transducer to act as a rangefinder, determining the distance of the tissue from the transducer. A simple graphical user interface allows the maximum allowed depth of ablation to be user defined and a warning displayed if needed. A water pillow with integrated flow meter is used to provide cooling and coupling to the tissue. There is also a housed video camera in the device which could provide visual confirmation of ablation if used laparoscopically or for superficial lesions.