This paper presents a new focusing and scanning method which focuses multiple waves on a target. The key of the method is to control excitation pulses for each element of the transducer array. The excitation pulse on ...This paper presents a new focusing and scanning method which focuses multiple waves on a target. The key of the method is to control excitation pulses for each element of the transducer array. The excitation pulse on each array element is obtained by time reversing the signal received by the same element, which is generated by an imaginary source at the target. The excitation pulses from all array elements are transmitted and arrive at the target simultaneously, and focusing is achieved. The performance of the two methods is compared in numerical examples, and it is demonstrated that the proposed method achieves a satisfactory focusing and a good signal-to-noise ratio no matter where the target location is.展开更多
The shape and size of the energy transducer’s focus decide the constitution of the cure project using HIFU (High intensity focused ultrasound). The parameter of the focus will be different when the structure of the t...The shape and size of the energy transducer’s focus decide the constitution of the cure project using HIFU (High intensity focused ultrasound). The parameter of the focus will be different when the structure of the transducer is different, so we must calibrate each of them. This paper represents calibration principle and method of focal territory in a high-power ultrasonic focus transducer. The experiment is performed on our designed multiple wafer concave focus probe and HIFU apparatus, using 1010 nylon and pork as the target range. It can be seen that the geometric center and focal territory acoustic field center cannot match together. When using nylon as the target, the distributed curves and theoretical curves are a better match. Therefore, the method and principle of calibration here is constructive for the calibration on pictures of other types of HIFU apparatus.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11174322 and 11074273)the Research Council of Norway (GrantNo. 186923/I30)
文摘This paper presents a new focusing and scanning method which focuses multiple waves on a target. The key of the method is to control excitation pulses for each element of the transducer array. The excitation pulse on each array element is obtained by time reversing the signal received by the same element, which is generated by an imaginary source at the target. The excitation pulses from all array elements are transmitted and arrive at the target simultaneously, and focusing is achieved. The performance of the two methods is compared in numerical examples, and it is demonstrated that the proposed method achieves a satisfactory focusing and a good signal-to-noise ratio no matter where the target location is.
文摘The shape and size of the energy transducer’s focus decide the constitution of the cure project using HIFU (High intensity focused ultrasound). The parameter of the focus will be different when the structure of the transducer is different, so we must calibrate each of them. This paper represents calibration principle and method of focal territory in a high-power ultrasonic focus transducer. The experiment is performed on our designed multiple wafer concave focus probe and HIFU apparatus, using 1010 nylon and pork as the target range. It can be seen that the geometric center and focal territory acoustic field center cannot match together. When using nylon as the target, the distributed curves and theoretical curves are a better match. Therefore, the method and principle of calibration here is constructive for the calibration on pictures of other types of HIFU apparatus.
