Multi-frequency partition excitation method based on random distribution 82 array element phase-controlled ultrasonic transducer

Abstract

The invention discloses a multi-frequency partition excitation method based on a 82 array element random distribution phased array ultrasonic transducer, which comprises the following steps: each array element is divided into different excitation regions according to the three-dimensional space coordinates of the array elements; sine waves of different working frequencies are applied to for the array elements of different partitions under the condition that the excitation areas of each partition are equal; In the numerical simulation model of craniotomy, the influence of frequency partitionsand frequency difference between different partitions on the HIFU focusing performance is studied, and the frequency partition number and the corresponding frequency combination are obtained when thefocusing effect is best. Based on the number of frequency partitions obtained by frequency partitions obtained by the craniotomy numerical simulation model, the two-zone excitation of the 82 array element phase-controlled transducer in the skull model is performed to study the influence of frequency difference between different partitions on the focusing performance of the skull HIFU, the frequency combination when the focus performance is optimal is determined. The invention reduces the required temperature and treatable focal volume while reducing the input power and treatment time requiredfor tissue ablation.

Description

technical field [0001] The invention relates to the technical field of high-intensity focused ultrasound, in particular to a multi-frequency partition excitation method based on an 82-element randomly distributed phased array ultrasonic transducer. Background technique [0002] High-Intensity Focused Ultrasound (HIFU) has been used in the clinical treatment of solid soft tissue tumors such as breast cancer, prostate cancer, and uterine fibroids due to its advantages of non-invasive / minimally invasive and repeatable treatment. In the process of transcranial treatment, due to the strong attenuation of the skull to ultrasonic waves and the highly heterogeneous structure and density of the skull, the ultrasonic beams emitted by the transducers in different directions have different attenuation degrees after propagating through the skull. The difference in the energy of the beam reaching the focal area is relatively large, which eventually leads to a lower temperature in the foca...

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Problems solved by technology

In 2010, McDannold et al. used ExAblate 3000 transcranial magnetic resonance-guided focused ultrasound system to treat three patients with glioblastoma (47 years old, 23 years old, and 34 years old). The highest temperature in the region only reached 42°C, 51°C, and 48°C respectively, failing to reach the target focal region temperature set at 55°C, and did not form a lethal therapeutic effect on target tissue; in 2014, Chang et al. used the ExAblate 4000 treatment system Defibrillation therapy was performed on 11 tremor patients, and the trial results showed that three of them failed due to the low temperature of the target area

The above-mentioned experts have conducted research on multi-frequency ultrasound excitation based on single-array focused transducers, but they did not involve the phase-controlled transducers used in transcranial therapy, and did not discuss in detail the effect of the number of frequency partitions and the frequency difference between adjacent intervals on HIFU. Focus performance impact

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