The Acustic Field Regulation Research Of Ultrasonic Phased-Array Under The G-S Algorithm

Ultrasonic phased-array as a development of traditional ultrasound transducer has been used in medical imaging,nondestructive testing,ultrasonic therapy and so on. This paper will introduce some kind of ultrasonic phased-array used commonly and a series of calculation method in ultrasonic phased-array. In current calculation method the output acoustic field of phased-array could achieve focusing,deflection,deflection with focusing and multi-focus output model, however the whole acoustic field in output surface could not be controlled effectively.This paper is based on the basic theory of nowadays calculation way of ultrasonic phased-array, and brings in some excellent thoughts, so that we can design new calculation method, and under this way the acoustic field output model controlled relatively good, at last the output acoustic field of ultrasonic phased-array could service for the therapy.G-S algorithm and Y-G algorithm are both the common calculation way in design of diffractive optical. The results of Y-G algorithm is more accurate than G-S algorithm, but the process of Y-G algorithm is complicated and computation complexity. In some extent G-S algorithm is the specific of Y-G algorithm, but the process of G-S is more concise and realization. So this paper will design the new calculation method of ultrasonic phased-array under the G-S algorithm.The theory of G-S algorithm is design the phase of diffract optic elements through presetting the distribution of optic field in output plane. In order to control the whole output acoustic field of ultrasonic phased-array, this research based on the central idea of G-S algorithm. First, presupposition the model of acoustic field in the output surface of ultrasonic phased-array; Second, return to the surface of phased-array by the pseudo-inverse algorithm; Third, calculation the acoustic field in the output surface of ultrasonic phased-array through Rayleigh integral. At last we can achieve the driver of phased-array through the iterative transform between the ultrasonic phased-array and its'output surface. We simulated a series of different presupposition output acoustic field model and what we can achieve under this new calculation method, by this way the feasibility and effectively of the new calculation way are both proved. The final results show that this new calculation of ultrasonic phased-array is feasibility and effectively on the controlling of the phased-arrays'output acoustic field.