• Tsysar, Sergey A.
• Cunitz, Bryan W.
• Maxwell, Adam D.
• Terzi, Marina
• Nikolaeva, Anastasia V.
• Sapozhnikov, Oleg A.
• Bailey, Michael R.

Abstract

<jats:p>A technology to reposition kidney stones with radiation force was recently proposed by our team and already used to transcutaneously facilitate passage of small stones. While successful, the trial revealed a need for optimization of the ultrasound beam structure, frequency, and intensity to make it more effective. In the current work, the effect of the ultrasonic beam diameter vs. stone size using a quasi-Gaussian beam model was numerically investigated. Radiation force on a kidney stone was found to be strongest when the beam width was slightly wider than the stone diameter. This can be explained by more effective generation of shear waves inside the stone resulting from their effective coupling with the acoustic waves in liquid at the stone edges. In another study, the possibility of using vortex beams to trap the stones in the lateral direction was investigated. Both theoretical modeling and experiments were performed using two systems: a single-element transducer combined with a sector-shaped phase plate and a 12-element sector array. Human stones approximately 3-5 mm, as well as glass and styrofoam beads, were controllably translated along the surface transverse to the beam. [This work was supported by RBBR 14-02-00426, NIH NIDDK DK43881, DK104854, and DK092197, and NSBRI through NASA NCC 9-58.]</jats:p>

Topics

• surface
• phase
• experiment
• glass
• glass
• ultrasonic