Free-Lagrange Simulations of Shock/Bubble Interaction in Shock Wave Lithotripsy

Jamaluddin, A. R.; Ball, G. J.; Leighton, T.G.

doi:10.1007/978-3-642-59334-5_81

Cited by 13 publications

(34 citation statements)

References 9 publications

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“…Pressures at such distances for propagation through water can readily be calculated using the Gilmore model [40], although this study highlights that, when doing so, it is important to assess whether the assumptions inherent in the Gilmore model are germane to the scenario being simulated (see §4). Even for propagation in water, if the bubble collapses asymmetrically as in this study, the source of the pressure wave is incorrectly modelled by the Gilmore model as being the spherically compressed gas, rather than the blast wave [15,41]. Furthermore, propagation through tissue generates higher absorption than occurs in water.…”

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 77%

“…Furthermore, propagation through tissue generates higher absorption than occurs in water. There are standard methods for derating predictions made for propagation in water to give estimates of what form the pulse would take if it propagated through tissue, and these have been applied to this problem [15,41]. However, the appropriateness of using the standard method to correct for absorption by the intervening tissue has not been addressed for cases such as the shocks presented here, and this will be also discussed in §4.…”

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 99%

“…However, account must be taken of absorption in the tissue and the effect of neglecting any nonlinear propagation in this way. Providentially, tissue absorption is the simpler feature to include if standard techniques are followed and are valid (a question discussed further in §4), and its inclusion reduces the importance of nonlinear propagation because high absorption rapidly attenuates the amplitude of the wave [15,41].…”

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 99%

“…There are two methods for estimating the far-field emissions following linear propagation outside the control surface, and previously two numerical schemes based on the Kirchhoff and Ffowcs William-Hawkings formulations were developed and tested for this SWL problem [15,41]. The Kirchhoff method assumes that nonlinear waves are confined within the control surface, and the input parameters for the calculation of far-field acoustic emissions are compatible with linear wave propagation.…”

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 99%

“…The first stage of the work developed a free-Lagrange simulation for single bubbles, which offered advantages over the existing boundary-element method of capturing blast waves, and over the Eulerian methods, in that it could follow the bubble collapse after the moment when the liquid jet formed by bubble involution impacts the downstream bubble wall [14,20,21]. Inclusion of the events after this moment into the simulation is critical because the evolution and detection of the blast wave generated by that impact (and its subsequent interaction with the kidney stone and tissue) is important both to kidney stone fracture and also to the operation of the device, which detects this blast wave in the far field via a receiver placed on the patient's torso.…”

Section: Introductionmentioning

confidence: 99%

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Prediction of far-field acoustic emissions from cavitation clouds during shock wave lithotripsy for development of a clinical device

et al. 2013

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This study presents the key simulation and decision stage of a multi-disciplinary project to develop a hospital device for monitoring the effectiveness of kidney stone fragmentation by shock wave lithotripsy (SWL). The device analyses, in real time, the pressure fields detected by sensors placed on the patient's torso, fields generated by the interaction of the incident shock wave, cavitation, kidney stone and soft tissue. Earlier free-Lagrange simulations of those interactions were restricted (by limited computational resources) to computational domains within a few centimetres of the stone. Later studies estimated the far-field pressures generated when those interactions involved only single bubbles. This study extends the free-Lagrange method to quantify the bubblebubble interaction as a function of their separation. This, in turn, allowed identification of the validity of using a model of non-interacting bubbles to obtain estimations of the far-field pressures from 1000 bubbles distributed within the focus of the SWL field. Up to this point in the multi-disciplinary project, the design of the clinical device had been led by the simulations. This study records the decision point when the project's direction had to be led by far more costly clinical trials instead of the relatively inexpensive simulations.

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Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 77%

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 99%

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 99%

Section: (B) the Kirchhoff Acoustic Emission Schemementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Prediction of far-field acoustic emissions from cavitation clouds during shock wave lithotripsy for development of a clinical device

et al. 2013

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Simulations of pressure pulse–bubble interaction using boundary element method

Klaseboer

Turangan

Fong

et al. 2006

Computer Methods in Applied Mechanics and Engineering

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The collapse of single bubbles and approximation of the far-field acoustic emissions for cavitation induced by shock wave lithotripsy

et al. 2011

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Recent clinical trials have shown the efficacy of a passive acoustic device used during shock wave lithotripsy (SWL) treatment. The device uses the far-field acoustic emissions resulting from the interaction of the therapeutic shock waves with the tissue and kidney stone to diagnose the effectiveness of each shock in contributing to stone fragmentation. This paper details simulations that supported the development of that device by extending computational fluid dynamics (CFD) simulations of the flow and near-field pressures associated with shock-induced bubble collapse to allow estimation of those far-field acoustic emissions. This is a required stage in the development of the device, because current computational resources are not sufficient to simulate the far-field emissions to ranges of O(10 cm) using CFD. Similarly, they are insufficient to cover the duration of the entire cavitation event, and here simulate only the first part of the interaction of the bubble with the lithotripter shock wave in order to demonstrate the methods by which the far-field acoustic emissions resulting from the interaction can be estimated. A free-Lagrange method (FLM) is used to simulate the collapse of initially stable air bubbles in water as a result of their interaction with a planar lithotripter shock. To estimate the far-field acoustic emissions from the interaction, this paper developed two numerical codes using the Kirchhoff and Ffowcs William-Hawkings (FW-H) formulations. When coupled to the FLM code, they can be used to estimate the far-field acoustic emissions of cavitation events. The limitation of the technique is that it assumes that no significant nonlinear acoustic propagation occurs outside the control surface. Methods are outlined for ameliorating this problem if, as here, computational resources cannot compute the flow field to sufficient distance, although for the clinical situation discussed, this limitation is tempered by the effect of tissue absorption, which here is incorporated through the standard derating procedure. This approach allowed identification of the sources of, and explanation of trends seen in, the characteristics of the far-field emissions observed in clinic, to an extent that was sufficient for the development of this clinical device.

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Free-Lagrange Simulations of Shock/Bubble Interaction in Shock Wave Lithotripsy

Cited by 13 publications

References 9 publications

Prediction of far-field acoustic emissions from cavitation clouds during shock wave lithotripsy for development of a clinical device

Prediction of far-field acoustic emissions from cavitation clouds during shock wave lithotripsy for development of a clinical device

Simulations of pressure pulse–bubble interaction using boundary element method

The collapse of single bubbles and approximation of the far-field acoustic emissions for cavitation induced by shock wave lithotripsy

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