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

Author(s):  
Jian James Zhang ◽  
Danop Rajabhandharaks ◽  
Jason Rongwei Xuan ◽  
Ray W. J. Chia ◽  
Tom Hasenberg
2017 ◽  
Vol 32 (5) ◽  
pp. 1017-1021 ◽  
Author(s):  
Jian James Zhang ◽  
Danop Rajabhandharaks ◽  
Jason Rongwei Xuan ◽  
Ray W. J. Chia ◽  
Thomas Hasenberg

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Jian J. Zhang ◽  
Jonathan Rutherford ◽  
Metasebya Solomon ◽  
Brian Cheng ◽  
Jason R. Xuan ◽  
...  

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.


2019 ◽  
Vol 87 (3) ◽  
pp. 30901
Author(s):  
Romaric Landfried ◽  
Mohamed Boukhlifa ◽  
Thierry Leblanc ◽  
Philippe Teste ◽  
Jonathan Andrea

This work deals with the characterization of DC electric arcs in aeronautical conditions of pressure (from 104 Pa to 105 Pa). Observations have been made with the help of a high speed camera and various characteristics of electric arc under 540 V DC have been studied: the stability arc length, the extinction gap, the arc duration and the mean energy dissipated in the arc. The arc current intensity range is 10–100 A. The obtained results show that the arc stability length, extinction electrode gap, arc duration and energy dissipation in the arc have a direct correlation with the pressure and the current in the circuit.


2005 ◽  
Vol 896 ◽  
Author(s):  
Louis Ferranti ◽  
Naresh N. Thadhani

AbstractReverse Taylor anvil-on-rod impact experiments were conducted on Al+Fe2O3+30% epoxy composites to measure their viscoelastic and fracture response to dynamic loading. Impact velocities ranged from 80 to 200 m/s. High-speed camera images capturing transient deformation reveal these materials exhibit significant elastic recovery in both the longitudinal and radial directions. Images were time synchronized with free surface velocity measurements, using VISAR, to track elastic/plastic wave interactions attributed to the material’s dynamic loading response. Some specimens underwent brittle fracture once a critical areal strain was exceeded while the axial strain response appeared unaltered.


2013 ◽  
Vol 10 (85) ◽  
pp. 20130227 ◽  
Author(s):  
Kyung-Ah Kwon ◽  
Rebecca J. Shipley ◽  
Mohan Edirisinghe ◽  
Daniel G. Ezra ◽  
Geoff Rose ◽  
...  

Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.


2018 ◽  
Vol 52 (6) ◽  
pp. 065201 ◽  
Author(s):  
Sven Gröger ◽  
Marleen Ramakers ◽  
Marc Hamme ◽  
Jose A Medrano ◽  
Nikita Bibinov ◽  
...  

Author(s):  
Amol Kulkarni ◽  
Amey Vidvans ◽  
Mustafa Rifat ◽  
Gregory Bicknell ◽  
Xi Gong ◽  
...  

The present work delineates a novel and scalable approach to characterization of defects in additively manufactured components. The approach is based on digital image correlation and involves characterization of surface speeds during rigid body rotation of the workpiece, followed by normalization with respect to rotation speed. Towards this, two different imaging sources were tested, viz. smartphone camera and sophisticated high-resolution/high-speed camera. The proposed approach successfully delineated horizontal and vertical notch defects in a simple FDM fabricated component. Accuracy of this approach was tested with concomitant laser based scanning. Some limitations of this approach were discussed.


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