Study of cavitation bubble dynamics during Ho:YAG laser lithotripsy by high-speed camera

2016 ◽  
Author(s):  
Jian J. Zhang ◽  
Jason R. Xuan ◽  
Honggang Yu ◽  
Dennis Devincentis
Keyword(s):  
Cavitation Bubble ◽  
High Speed ◽  
Bubble Dynamics ◽  
Laser Lithotripsy ◽  
High Speed Camera ◽  
Ho:Yag Laser

Calculus migration characterization during Ho:YAG laser lithotripsy by high-speed camera using suspended pendulum method

2017 ◽  
Vol 32 (5) ◽  
pp. 1017-1021 ◽  
Author(s):  
Jian James Zhang ◽  
Danop Rajabhandharaks ◽  
Jason Rongwei Xuan ◽  
Ray W. J. Chia ◽  
Thomas Hasenberg
Keyword(s):  
High Speed ◽  
Laser Lithotripsy ◽  
High Speed Camera ◽  
Ho:Yag Laser

Characterization of calculus migration during Ho:YAG laser lithotripsy by high speed camera using suspended pendulum method

2014 ◽  
Author(s):  
Jian James Zhang ◽  
Danop Rajabhandharaks ◽  
Jason Rongwei Xuan ◽  
Ray W. J. Chia ◽  
Tom Hasenberg
Keyword(s):  
High Speed ◽  
Laser Lithotripsy ◽  
High Speed Camera ◽  
Ho:Yag Laser

scholarly journals Numerical Response Surfaces of Volume of Ablation and Retropulsion Amplitude by Settings of Ho:YAG Laser Lithotripter

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Jian J. Zhang ◽  
Jonathan Rutherford ◽  
Metasebya Solomon ◽  
Brian Cheng ◽  
Jason R. Xuan ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Pulse Width ◽  
High Speed ◽  
Operation Time ◽  
Laser Lithotripsy ◽  
Pulse Number ◽  
Response Surfaces ◽  
Ho:Yag Laser ◽  
Energy Pulse ◽  
Best Fit

Objectives.Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate, the optimal laser settings for URS (ureteroscopic lithotripsy) for less operation time remain unclear. The aim of this study was to look for quantitative responses of calculus ablation and retropulsion by performing operator-independent experiments to determine the best fit versus the pulse energy, pulse width, and the number of pulses.Methods.A lab-built Ho:YAG laser was used as the laser pulse source, with a pulse energy from 0.2 J up to 3.0 J and a pulse width of 150 μs up to 1000 μs. The retropulsion was monitored using a high-speed camera, and the laser-induced craters were evaluated with a 3-D digital microscope. The best fit to the experimental data is done by a design of experiment software.Results.The numerical formulas for the response surfaces of ablation speed and retropulsion amplitude are generated.Conclusions.The longer the pulse, the less the ablation or retropulsion, while the longer pulse makes the ablation decrease faster than the retropulsion. The best quadratic fit of the response surface for the volume of ablation varied nonlinearly with pulse duration and pulse number.

Investigation on cavitation bubble dynamics induced by clinically available Ho:YAG lasers

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Karl Stock ◽  
Daniel Steigenhöfer ◽  
Thomas Pongratz ◽  
Rainer Graser ◽  
Ronald Sroka
Keyword(s):  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Laser Energy ◽  
Bubble Collapse ◽  
High Contrast ◽  
Core Diameter ◽  
Ho:Yag Laser ◽  
Fiber Core ◽  
Set Up ◽  
Short Time

AbstractEndoscopic laser lithotripsy is the preferred technique for minimally invasive destruction of ureteral and kidney stones, and is mostly performed by pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser irradiation. The absorbed laser energy heats the water creating a vapor bubble which collapses after the laser pulse, thus producing a shock wave. Part of the laser energy strikes the stone through the vapor bubble and induces thermomechanical material removal. Aim of the present study was to visualize the behavior and the dynamics of the cavitation bubble using a specially developed ultra-short-time illumination system and then to determine important characteristics related to clinically used laser and application parameters for a more detailed investigation in the future.In accordance with Toepler’s Schlieren technique, in the ultra-short-time-illumination set-up the cavitation bubble which had been induced by Ho:YAG laser irradiation at the fiber end, was illuminated by two Q-switched lasers and the process was imaged in high contrast on a video camera. Cavitation bubbles were induced using different pulse energies (500 mJ/pulse and 2000 mJ/pulse) and fiber core diameters (230 μm and 600 μm) and the bubble dynamics were recorded at different times relative to the Ho:YAG laser pulse. The time-dependent development of the bubble formation was determined from the recordings by measuring the bubble diameter in horizontal and vertical directions, together with the volume and localization of the center of the bubble collapse.The results show that the bubble dynamics can be visualized and studied with both high contrast and high temporal resolution. The bubble volume increases with pulse energy and with fiber diameter. The bubble shape is almost round when a larger fiber core diameter is used, and elliptical when using a fiber of smaller core diameter. Moreover, the center of the resulting bubble is slightly further away from the fiber end and the center of the bubble collapse for a smaller fiber core diameter.The experimental set-up developed gives a better understanding of the bubble dynamics. The experiments indicate that the distance between fiber tip and target surface, as well as the laser parameters used have considerable impact on the cavitation bubble dynamics. Both the bubble dynamics and their influence on the stone fragmentation process require further investigation.

Chromatically encoded high-speed photography of cavitation bubble dynamics inside inhomogeneous ophthalmic tissue

2016 ◽  
Author(s):  
N. Tinne ◽  
B. Matthias ◽  
F. Kranert ◽  
C. Wetzel ◽  
A. Krüger ◽  
...  
Keyword(s):  
Cavitation Bubble ◽  
High Speed ◽  
Bubble Dynamics ◽  
High Speed Photography

scholarly journals Cavitation and bubble dynamics: the Kelvin impulse and its applications

2015 ◽  
Vol 5 (5) ◽  
pp. 20150017 ◽  
Author(s):  
John R. Blake ◽  
David M. Leppinen ◽  
Qianxi Wang
Keyword(s):  
Cavitation Bubble ◽  
High Speed ◽  
Bubble Dynamics ◽  
Clinical Medicine ◽  
Bubble Collapse ◽  
Rigid Boundary ◽  
Design Problems ◽  
Practical Applications ◽  
Wide Range ◽  
Naval Engineering

Cavitation and bubble dynamics have a wide range of practical applications in a range of disciplines, including hydraulic, mechanical and naval engineering, oil exploration, clinical medicine and sonochemistry. However, this paper focuses on how a fundamental concept, the Kelvin impulse, can provide practical insights into engineering and industrial design problems. The pathway is provided through physical insight, idealized experiments and enhancing the accuracy and interpretation of the computation. In 1966, Benjamin and Ellis made a number of important statements relating to the use of the Kelvin impulse in cavitation and bubble dynamics, one of these being ‘One should always reason in terms of the Kelvin impulse, not in terms of the fluid momentum…’. We revisit part of this paper, developing the Kelvin impulse from first principles, using it, not only as a check on advanced computations (for which it was first used!), but also to provide greater physical insights into cavitation bubble dynamics near boundaries (rigid, potential free surface, two-fluid interface, flexible surface and axisymmetric stagnation point flow) and to provide predictions on different types of bubble collapse behaviour, later compared against experiments. The paper concludes with two recent studies involving (i) the direction of the jet formation in a cavitation bubble close to a rigid boundary in the presence of high-intensity ultrasound propagated parallel to the surface and (ii) the study of a ‘paradigm bubble model’ for the collapse of a translating spherical bubble, sometimes leading to a constant velocity high-speed jet, known as the Longuet-Higgins jet.

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