US Patent 11491353 Zero vergence ultrasound waves for sonodynamic therapy

Disclosed are methods of obtaining zero vergence ultrasound waves for providing sonodynamic therapy with ultrasound waves that do not converge and do not diverge. The method includes coupling a sonodynamic therapy device with an array of flat piezoelectric transducers to a skin surface. A controller is configured to generate an electrical drive signal at a frequency, modulate the drive signal, and drive the transducer with the modulated drive signal at the frequency to produce a zero vergence ultrasound wave to produce an average acoustic intensity sufficient to activate a sonosensitizer in a treatment region without damaging healthy cells in the treatment region.