Optimal synthesis of phased array field patterns in the presence of the ribcage

In this paper, hyperthermia treatment of liver tumors using a phased array applicator system is considered. This type of noninvasive surgical application is performed by focusing high intensity ultrasonic beam on the tumor through the ribcage. The ribcage acts as a strongly scattering inhomogeneity and focusing is achieved by directing the beam through the acoustical window of the intercostal spacings. The feed array is synthesized to efficiently focus the beam to the tumor location and achieve minimal power deposition over the solid rib surfaces. Single and multiple focusing examples with realistic geometrical and physical data are presented to validate the suggested analysis and synthesis approaches.