Bubble cavitation generation near blood vessel walls using amplitude-modulated wave irradiation

Abstract

Abstract We propose an amplitude-modulated pump ultrasound irradiation sequence to generate bubble cavitation for efficient sonoporation. By matching the envelope wavelength of the modulated wave to four times the vessel diameter, we aimed to improve the efficiency of bubble collapse near the vessel wall and extend the duration of collapse during repeated application of the sequence. Using an agarose-based blood vessel phantom, we compared the effects of the amplitude-modulated sequence with those of the normal sinusoidal sequence in which the sound pressure was adjusted so that the acoustic energy in one burst length of each sequence was equal. Compared with the normal irradiation sequence, the amplitude-modulated sequence yielded 2.45- and 1.31-fold greater bubble collapse near the vessel walls proximal and distal, respectively, to the pump ultrasound source, a 1.59-fold longer duration of bubble collapse, and a 1.69-fold larger area of micropores on the channel wall.