Focused Transducer Design And Sound Field Simulation

The technology of High Intensity Focused Ultrasound (High Intensity Focused Ultrasound, ab. HIFU) is a surgical means without wound in recent years, which has been broad used and generalized. This technology attracts much attention of universities and institutes both abroad and home for it woundless, harmless, safety, efficiency and which may insure the safety and integrality of tissue in the course of treatment. Focused Ultrasound transducer is the hard-core of the technology and it include transducer type, sound material, shape and size of transducer. Now, focus transducers have three kinds of types: Focus transducer, acoustic lens, phased array focusing system. Focus transducer has the self-focusing curve surface, and this kind of transducer has the concave spherical surface transducer, the column transducer and so on. Manufactured this kind transducer with the piezoelectricity is complex in techniques, the shape restricted by material, and much fetter in it application. The phased array transducer through the electronic control line may the very convenient adjustment focal distance, the focal point size and the focal point intensity, has the very great practical value in the clinical treatment. However, the electronic control line is especially huge and complex, which limited the possibility of its application. The acoustic lens focus system has many strong points, such as: ease of operation, structure simple, diverse shape and cheap of sound material and widely applied in the clinical medicine. Many ultrasonic treatment systems produced by The Chongqing HIFU Company are acoustic lens focus system. A new acoustic lens focus transducer has designed in this paper, the change rule and the tendency of the focus sound field is obtained via numerical simulate compute.In detail, the article is mainly about:1. Simulated the sound pressure change near the focal point distribution of concave spherical surface self-focusing transducer in different condition via the software value, and some parameters of the sound filed is calculated by theoretical and numerical simulation.2.A new twin surface acoustic lens is designed, and some sound material be used in acoustic lens is studied. It is shown that the Plexiglas is first choose consider about acoustics characteristic, process, the economy and so on.3. A new lens sound pressure change function in the sound field distribution and some simple theory inferential are given, and some parameter values of sound field are computed. Sound field change situation of the new lens with different material parameter is studied and the numerical simulate and theoretical calculated values are obtained. The simple test installation and the equipment in sound field survey are given.The result of theoretical calculated and numerical simulation shown that, we may obtain sound field of the twin surface acoustic lens with thinner beam of sound, higher sound pressure, and moderate high side lobe at most along the axial direction when the lens parameter selection is suitable. This kind of sound field may effective enhance the focus effect of the lens, and play a major role in High Intensity Focused Ultrasound technology application.