Development of an Automated Framework for High Intensity Focused Ultrasound Simulations

High Intensity Focused Ultrasound (HIFU) technique is a noninvasive medical method for localized tissue heating, used mostly in treatment of tumors. The modality of HIFU utilizes focused ultrasound to raise the temperature of the tumor tissue in small localized volumes, resulting in necrosis. The ablation of the whole tumor, while taking into consideration all safety aspects of the treatment, is a time consuming, but requires at the same time expertise and accuracy. Treatment with reduced time as well as enhanced safety need fundamental innovations on HIFU technologies like transducer architecture and beam focusing to enable fast ablation of large tumors. Therefore, it is favorable to use computer models and simulation for therapy planning. HIFU simulations are required to support the development of the HIFU device as well as the planning of noninvasive treatments. This paper presents the automated optimization framework to seamlessly integrate simulation process which performs from the device design to therapy planning. It consists of three processes: a) design of a random transducer array, b) design of both multi-focus patterns and a sparse array, and c) treatment planning of scanning time and path. Overall procedure of the optimization framework is shown in Figure 1. In the framework, the 3D acoustic pressure field is calculated by using the Rayleigh-Sommerfeld diffraction integral [5] and the 3D temperature distribution in tissue is modeled by using the Pennes’ bioheat transfer equation (BHTE) [2]. For the optimization, Genetic Algorithms (GAs) [1] are entirely used from the 1 process to the 3 process.