array model of HIFU treatment

We designed the three-dimensional spherical array of geometric model-spherical crown array  model. In other words, using the adjacent triangles as the modeling material, a finite shape is established.A geometric model of a spherical crown array is composed of planar regular hexagonal elements of the same size. The modeling process of piezoelectric ring crystal is shown in the figure.The specific modeling steps are expressed as follows (a) First, selecting five adjacent triangles , in particular, the geometric center point of the icosahedron is at the origin of the coordinate system; (b) then, it will be positive of the five adjacent triangles is divided into aliquots and each aliquot.Connected in the way of Figure (b), it is obtained that each A is divided into small triangles a; (c)After that, the six adjacent a on the five A are combined into a planar hexagon Hex; (d) Then,a model as shown in (d); (e) then, culling (d) the quadrilateral Quad of the edge, and five A's .

The non-planar Hex on the intersection line is transformed into a plane Hex by rotation; (f) next, each Hex,The geometric center point is the center of the rectangular piezoelectric sensor, which is translated and rotated radially along the spherical surface, and finally transformed into a radius.1 is the spherical surface s. (g) Finally, each Hex is translated radially along the spherical surface to a radius of curvature R.The crown surface 51 is enlarged, and side length of the regular hexagonal PzTEgdeL is enlarged to a specified size, most geometric model of the spherical crown array was finally obtained.

For a specific spherical crown array structure, a regular hexagon.The number is 130 pieces, and the side length of the regular hexagon is 2.5mm.In order to quickly predict the sound field characteristics of the probe, we have initially established a comparison using MATLAB.The ideal HIFU treatment array model is a spherical coronal ultrasound array model, the each piezoelectric disc generator is a regular hexagon with a side length of PzTEgdeL, and the properties of each piezoelectric element.What characteristics are consistent, the main vibration mode is thickness vibration mode, the resonance frequency is set to F its apodization.In addition, the far field of the regular hexagonal array element is approximated to a disk array with a radius of several .The far field of the piezoelectric sensor crystal, so it is using the polar coordinate system, the aperture function of the array element of the probe is defined as a few. (rl)=Circ(rl/a), where circ(rl/a)=1 when rl/a'1; when rl/a>1, circ(rl/a)=O;

The parameters of the high intensity focused piezo treatment array model includes the radius of curvature R, the element size PzTEgdeL,The component is related to the number of elements, it is effective spacing center of the operating frequency .