Extracorporeal shock wave lithotripsy (SWL) is the most widely used procedure for comminution of urinary tract calculi, but after two decades of SWL, safety and efficiency appear to be declining, not improving. In some reports, clinically significant hemorrhaging within the kidney has increased tenfold, and the probability of successful treatment has been reduced by half. The effect on public health has been an increased risk/benefit ratio and cost of repeated treatments. In vitro and in vivo experimentation have shown that cavitation plays an important role in both the desired effect, stone comminution, and the undesired side effect, tissue injury, and that whereas some undefined number of bubbles is necessary in comminution, more bubbles, as can be produced by high shock wave delivery rates, inhibit comminution. Recent high-speed camera images indicate that the cavitation bubble cluster can grow to envelop the stone and that the cluster dynamics cannot be predicted by existing theories for single, isolated bubbles. Currently no model in SWL accounts for the dynamic coupling of bubbles to one another or to nearby tissue. The goal of this project and its relevance to public health is to develop accurate analytical models, tested and supported by experiment, to increase our understanding of cavitation clusters near kidney stones and tissue, and to provide guidance for improving the efficacy and safety of SWL. The project has three specific aims. (1) Develop a mathematical model for bubble cluster dynamics and use this model to understand and predict the growth, translation, collapse, and shock wave radiation associated with individual cavitation bubbles in the cluster, and to estimate the collective impact of these effects on the stone. Expand the model to account for solid particles interspersed among the bubbles. Calculate and compare pressures produced by the cluster and the shock wave produced by four clinical lithotripters. Ultimately, determine parameters and predict conditions for shock waveform, shock wave delivery rate, and lithotripter beam width that improve stone comminution. (2) Develop a model for individual and clustered bubble dynamics in urinary tubules, blood vessels, and other spaces confined by tissue. (3) Obtain pressure measurements within the cluster and 3D movies of cluster dynamics using piezoelectric sensors and two high speed cameras to compare to model simulations. Quantify numerically and experimentally the pressure on a stone or vessel wall as an effect of bubble number and therefore SW delivery rate. Simultaneously, characterize inhibitory clusters on B-mode ultrasound as a feedback to clinicians. Together, the model and experimental results may then guide monitoring, protocol, and lithotripter development.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Research Project (R01)
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Biomedical Computing and Health Informatics Study Section (BCHI)
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Kirkali, Ziya
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University of Texas Austin
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Ilinskii, Yurii A; Zabolotskaya, Evgenia A; Treweek, Benjamin C et al. (2018) Acoustic radiation force on an elastic sphere in a soft elastic medium. J Acoust Soc Am 144:568
Hsiao, C-T; Choi, J-K; Singh, S et al. (2013) Modelling single- and tandem-bubble dynamics between two parallel plates for biomedical applications. J Fluid Mech 716:
Hay, Todd A; Ilinskii, Yurii A; Zabolotskaya, Evgenia A et al. (2013) Model for the dynamics of a spherical bubble undergoing small shape oscillations between parallel soft elastic layers. J Acoust Soc Am 134:1454-62
Zabolotskaya, Evgenia A; Ilinskii, Yurii A; Hay, Todd A et al. (2012) Green's functions for a volume source in an elastic half-space. J Acoust Soc Am 131:1831-42
Simon, Julianna C; Sapozhnikov, Oleg A; Khokhlova, Vera A et al. (2012) Ultrasonic atomization of tissue and its role in tissue fractionation by high intensity focused ultrasound. Phys Med Biol 57:8061-78
Hay, Todd A; Ilinskii, Yurii A; Zabolotskaya, Evgenia A et al. (2012) Model for bubble pulsation in liquid between parallel viscoelastic layers. J Acoust Soc Am 132:124-37
Ilinskii, Yurii A; Zabolotskaya, Evgenia A; Hay, Todd A et al. (2012) Models of cylindrical bubble pulsation. J Acoust Soc Am 132:1346-57
Kreider, Wayne; Crum, Lawrence A; Bailey, Michael R et al. (2011) A reduced-order, single-bubble cavitation model with applications to therapeutic ultrasound. J Acoust Soc Am 130:3511-30
Yan, Xiang; Hamilton, Mark F (2011) Statistical model of clutter suppression in tissue harmonic imaging. J Acoust Soc Am 129:1193-208
Chen, Hong; Kreider, Wayne; Brayman, Andrew A et al. (2011) Blood vessel deformations on microsecond time scales by ultrasonic cavitation. Phys Rev Lett 106:034301

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