Analysis of cavitation bubble dynamics by optical online monitoring

1998 ◽  
Author(s):  
Ralf Brinkmann ◽  
Christoph Hansen
Keyword(s):  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Online Monitoring

Data assimilation for modeling cavitation bubble dynamics

2021 ◽  
Vol 62 (5) ◽  
Author(s):  
Javad Eshraghi ◽  
Arezoo M. Ardekani ◽  
Pavlos P. Vlachos
Keyword(s):  
Data Assimilation ◽  
Cavitation Bubble ◽  
Bubble Dynamics

scholarly journals Intraocular Pressure Study in Ex Vivo Pig Eyes by the Laser-Induced Cavitation Technique: Toward a Non-Contact Intraocular Pressure Sensor

2020 ◽  
Vol 10 (7) ◽  
pp. 2281
Author(s):  
Santiago Camacho-Lopez ◽  
Carlos Andrés Zuñiga-Romero ◽  
Luis Felipe Devia-Cruz ◽  
Carolina Alvarez-Delgado ◽  
Marcos Antonio Plata-Sanchez ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Continuous Wave ◽  
Ex Vivo ◽  
Applanation Tonometry ◽  
Reliable Technique ◽  
Measurement Resolution ◽  
In Vivo Diagnosis

Traditional applanation tonometry techniques lack the necessary accuracy and reliability for measuring the intraocular pressure (IOP), and there is still a need for a reliable technique for in vivo diagnosis. A single laser-induced cavitation bubble event was optically monitored in order to precisely measure the first collapse time of the cavitation bubble, which presents a direct dependence on the liquid pressure. This can certainly be done within the IOP range. We now extend the partial transmittance modulation (STM) technique to determine its feasibility for directly measuring the IOP by studying the nanosecond (ns) pulsed laser-induced cavitation bubble dynamics for an externally pressurized fresh ex vivo porcine eye. The results demonstrate that it is possible to monitor the IOP by detecting the light of a continuous-wave (CW) laser beam which is intensity modulated by the bubble itself. This technique currently presents a measurement resolution of about 4 mmHg in the 5 to 50 mmHg pressure range, indicating the feasibility of this approach for measuring IOP. This technique provides a direct measurement within the anterior eye chamber, avoiding common pitfalls in IOP diagnosis, such as errors due to patient movement, varying physical properties of the eye globe, or central cornea thickness (CCT) effects.

scholarly journals Cavitation bubble dynamics

1997 ◽  
Vol 4 (2) ◽  
pp. 65-75 ◽  
Author(s):  
Werner Lauterborn ◽  
Claus-Dieter Ohl
Keyword(s):  
Cavitation Bubble ◽  
Bubble Dynamics

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.

Sign in / Sign up

Export Citation Format

Share Document