Compensation for Aberrations Using High-Intensity Focused Ultrasound for Destruction of Uterine Fibroids

Abstract— In a numerical experiment, we analyzed the distortion of an ultrasound beam when focusing through the abdominal wall into the area of uterine fibroids and assessed the possibility of compensation for aberrations caused by inhomogeneities of human body tissues. A three-dimensional acoustic model of the female pelvic organs was constructed based on anonymized CT data. The field was calculated by combining the analytical method for calculating the Rayleigh integral and the pseudospectral method for solving the wave equation in an inhomogeneous medium (k-Wave software package). The diffraction algorithm for aberration compensation was based on modeling the propagation of a spherical wave from the focal point to the surface of an ultrasound phased array and optimizing the selection of phases on its elements using the least squares method. A model of a 256-element compact array with an operating frequency of f = 1.2 MHz and an aperture number of F# = 0.75 was used. Significant field distortions and the occurrence of side maxima comparable in amplitude to the main one are demonstrated in the absence of aberration compensation. Compensation for aberrations made it possible to ensure precise focusing in the target area and increase the pressure amplitude at the focus by 3.2 times.