TY - JOUR
T1 - Effect of annular focusing of ultrasound on rate of stone erosion using cavitation bubbles
AU - Yura, Toshiya
AU - Lafond, Maxime
AU - Yoshizawa, Shin
AU - Umemura, Shin Ichiro
N1 - Funding Information:
This work was partially supported by a Grant-in-Aid for Scientific Research (No. 16H03160) from the Japan Society for the Promotion of Science and by Keyence, Japan. We would like to thank everyone who supported the survey, which helped us obtain good-quality results. Maxime Lafond is an International Research Fellow of the Japan Society for the Promotion of Science (Postdoctoral Fellowships for Research in Japan PE16053).
Publisher Copyright:
© 2018 The Japan Society of Applied Physics
PY - 2018/7
Y1 - 2018/7
N2 - Shock wave lithotripsy has been one of the first-line treatments to fragment kidney stones. One disadvantage of this method is that some residual stone fragments can be too large to pass through the ureters. Stone fragments can be made small enough by ultrasonically induced cavitation erosion, but the erosion rate, with conventional single-spot focusing, tends to be low owing to ultrasound attenuation by excessively generated cavitation bubbles upstream of the stone surface. Sector vortex annular focusing can generate cavitation bubbles widely and thinly. We propose exposure sequences utilizing this focusing scheme and investigated their effect on erosion rate using a stone model. Sector vortex annular focusing showed an erosion rate significantly higher than that of single-spot focusing. Among them, switching between the two focusing schemes provided the highest rate, higher than the mathematical sum of those of the two schemes, and even higher than that of sector vortex focusing at the same pulse repetition.
AB - Shock wave lithotripsy has been one of the first-line treatments to fragment kidney stones. One disadvantage of this method is that some residual stone fragments can be too large to pass through the ureters. Stone fragments can be made small enough by ultrasonically induced cavitation erosion, but the erosion rate, with conventional single-spot focusing, tends to be low owing to ultrasound attenuation by excessively generated cavitation bubbles upstream of the stone surface. Sector vortex annular focusing can generate cavitation bubbles widely and thinly. We propose exposure sequences utilizing this focusing scheme and investigated their effect on erosion rate using a stone model. Sector vortex annular focusing showed an erosion rate significantly higher than that of single-spot focusing. Among them, switching between the two focusing schemes provided the highest rate, higher than the mathematical sum of those of the two schemes, and even higher than that of sector vortex focusing at the same pulse repetition.
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U2 - 10.7567/JJAP.57.07LB18
DO - 10.7567/JJAP.57.07LB18
M3 - Article
AN - SCOPUS:85049387033
SN - 0021-4922
VL - 57
JO - Japanese Journal of Applied Physics
JF - Japanese Journal of Applied Physics
IS - 7
M1 - 07LB18
ER -