Numerical simulation of HIFU with dual transducers: The implementation of dual-phase lag bioheat and non-linear Westervelt equations

The high intensity focused ultrasound (HIFU) has been proved to be effective and promising in local tumor treatment. Although HIFU utilization with multi transducers goes back several decades, the procedure numerical simulation, to the best of author knowledge, has not been conducted. In the present study, computational modeling of the HIFU with two crossing transducers at various arrangements was carried out to determine the treatment effectiveness. The coupled dual-phase bioheat transfer and non-linear Westervelt equations were solved to determine the acoustic and temperature fields, respectively. Moreover, the thermal dosage criteria were applied to obtain an effective thermo-ablated area in the targeted tumor. The developed model included the nonFourier heat transfer law, and the scattering and absorption of acoustic waves at higher harmonics. The effect of transducers position and orientation, and the acoustic power level on the produced pressure and thermal fields, were investigated. The presented results showed that by increasing the sonication amplitude, the effective area has an average enhancement of about 0.27, 7.08 and 27.9% for 3, 5 and 7 W power levels, respectively. Moreover, based on the tumor shape, a suitable combination of transducer location, orientation, and power level can be selected to achieve optimum treatment.