High-intensity focused ultrasound spherical phased array with array elements annually and intensively distributed

Abstract

The invention relates to a high-intensity focused ultrasound spherical phased array with array elements annually and intensively distributed, comprising a rigid spherical crown body and a plurality of array elements, wherein one array element is independently arranged in the center of the spherical crown body, and the other array elements are evenly and dispersedly distributed on a plurality of layers of concentric rings which take the center of the spherical crown body as an original point; the angular spacings among all ring layers are not equal, and the spacings among all ring layers and the spacing between adjacent array elements in the same ring are set according to an array element intensive distribution principle; the position of the original array element of each layer of concentric rings is randomly set, the other array elements are subsequently, intensively and evenly distributed on the concentric rings according to equiangular spacing, and each array element has independent electric excitation signal feeder lines which are respectively connected to a phased signal excitation system. The invention calculates the phase position and the voltage amplitude distribution of the array elements by adopting a focus model synthesis method based on a pseudo-inverse matrix theory, realizes acoustic beam electron focusing and scanning, generates required single-focus or multi-focus sound field control modes, and the like and is applied to heating and fusing target tumor focuses in the human body.

Description

technical field [0001] The present invention relates to an ultrasonic phased array, in particular to a high-intensity focused ultrasonic spherical phased array in which array elements are densely distributed in a ring shape, which is applied to a phased-controlled high-intensity focused ultrasonic (P- A HIFU) tumor treatment system belongs to the technical field of biomedical engineering. Background technique [0002] High-intensity focused ultrasound phased array is one of the key components of phased high-intensity focused ultrasound tumor therapy system. It is electronically controlled focus and variable focal length, which can produce a variety of sound field control modes such as single focus or multiple focus. By adjusting the excitation phase and amplitude of any array element, it can realize the convergence of external ultrasound in the human body. This point (that is, the focal point) has the characteristics of the largest sound pressure amplitude in the entire sou...

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Problems solved by technology

"This technology has obvious shortcomings: since each partition is controlled by an independent power supply, that is, all array elements in the partition will be excited by the same power and phase of the same driving power supply, so each partition can be viewed equivalently. As a "big" array element, the multivariate high-intensity focused ultrasound transducer is only composed of 4N "big" array elements, and the reduction in the number of equivalent array elements will limit the focus scanning range of the transducer, and at the same time due to the adjacent The distance between "large" array elements is much larger than the original spacing between adjacent array elements, that is, the spatial distribution of "large" array elements is not compact, and large side lobes are likely to be generated during electronic focusing and scanning, which may lead to abnormalities outside the target area. Tissue is overheated, endangering the patient

"This technology has the following two disadvantages: First, because the detection probe of the ultrasonic positioning device is installed in the central hole of the spherical crown, the transducer structure of the central opening will make the sound beam focus on the axis of the sound beam. The focal point energy is not concentrated, and the advantage of geometric focusing of the spherical phased array itself cannot be brought into play. At the same time, the distance between the focal point position and the axis of the sound beam (that is, the focus scanning range) is limited, which affects the therapeutic range of the transducer; second, "The angular spacing between each ring layer is equal" makes the spacing between adjacent array element rings in the inner ring layer larger than that in the outer ring layer. Due to the spacing between adjacent array elements in the phased array and the focusing of the phased array The size of the side lobe generated when the array elements are not densely arranged is proportional to the size of the side lobe, so the side lobe generated by the phased array in which the array elements are not densely arranged is larger than that of the phased array with densely arranged array elements under the same conditions, which will affect the phased array. Array focus effect

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