Waveform Diversity Method Based on Single Focus Spot Scanning for Ultrasound Hyperthermia

Waveform diversity can be employed for optimizing acoustic power depositions generated by ultrasound array. Here based on single focus spot scanning we propose a new waveform diversity method for ultrasound hyperthermia technique. This method stems from the idea that the acoustic power depositions in the entire treatment time can be equal to the summation of power distributions for multiple single foci at different location. Consequently, the problem of optimizing acoustic power depositions can be transformed into a linear programming problem to find an optimal dwell schedule for each single focal point. Compared with the existing waveform diversity method, our method can be exploited directly to design the uniform amplitude waveform and leads to lower computation cost, and besides, it has an explicit physical background. We carried out a numerical simulation to demonstrate the validity of our method. As expected, the simulation results show that the acoustic power uniformly focuses onto the predetermined region while maintaining a low level in the surrounding region.