Image Based Renal Stone Tracking to Improve Efficacy in Extracorporeal Lithotripsy

Orkisz, Maciej; Farchtchian, T.; Saighi, D.; Bourlion, Maurice; Thiounn, Nicolas; Gimenez, G.; Debré, B; Flam, T.

doi:10.1097/00005392-199810000-00008

Cited by 13 publications

(12 citation statements)

References 2 publications

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“…The results confirm previous observations that translational motion negatively affects stone fragmentation in the absence of renal stone tracking systems (Orkisz et al, 1998;Chang et al, 2001), especially for high peak pressure, narrow focus lithotripters (Cleveland et al, 2004). Furthermore, the simulated motion histograms are utilized for the prediction of stone comminution efficiencies from both lenses through the heuristic model.…”

Section: Discussionsupporting

confidence: 84%

A heuristic model of stone comminution in shock wave lithotripsy

Smith

Zhong

2013

The Journal of the Acoustical Society of America

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A heuristic model is presented to describe the overall progression of stone comminution in shock wave lithotripsy (SWL), accounting for the effects of shock wave dose and the average peak pressure, P þ(avg) , incident on the stone during the treatment. The model is developed through adaptation of the Weibull theory for brittle fracture, incorporating threshold values in dose and P þ(avg) that are required to initiate fragmentation. The model is validated against experimental data of stone comminution from two stone types (hard and soft BegoStone) obtained at various positions in lithotripter fields produced by two shock wave sources of different beam width and pulse profile both in water and in 1,3-butanediol (which suppresses cavitation). Subsequently, the model is used to assess the performance of a newly developed acoustic lens for electromagnetic lithotripters in comparison with its original counterpart both under static and simulated respiratory motion. The results have demonstrated the predictive value of this heuristic model in elucidating the physical basis for improved performance of the new lens. The model also provides a rationale for the selection of SWL treatment protocols to achieve effective stone comminution without elevating the risk of tissue injury.

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Section: Discussionsupporting

confidence: 84%

A heuristic model of stone comminution in shock wave lithotripsy

Smith

Zhong

2013

The Journal of the Acoustical Society of America

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“…22 Prototype targeting and tracking systems have demonstrated improvements in in vitro hit rates and stone breakage of 1.5-to 2-fold. [23][24][25][26] By eliminating or reducing the shockwaves that likely only contribute to injury, this could potentially decrease the total number of shockwaves delivered.…”

Section: Sorensen Et Almentioning

confidence: 99%

Quantitative Assessment of Shockwave Lithotripsy Accuracy and the Effect of Respiratory Motion

Sorensen

Bailey

Shah

et al. 2012

Journal of Endourology

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Background and Purpose: Effective stone comminution during shockwave lithotripsy (SWL) is dependent on precise three-dimensional targeting of the shockwave. Respiratory motion, imprecise targeting or shockwave alignment, and stone movement may compromise treatment efficacy. The purpose of this study was to evaluate the accuracy of shockwave targeting during SWL treatment and the effect of motion from respiration. Patients and Methods: Ten patients underwent SWL for the treatment of 13 renal stones. Stones were targeted fluoroscopically using a Healthtronics Lithotron (five cases) or Dornier Compact Delta II (five cases) shockwave lithotripter. Shocks were delivered at a rate of 1 to 2 Hz with ramping shockwave energy settings of 14 to 26 kV or level 1 to 5. After the low energy pretreatment and protective pause, a commercial diagnostic ultrasound (US) imaging system was used to record images of the stone during active SWL treatment. Shockwave accuracy, defined as the proportion of shockwaves that resulted in stone motion with shockwave delivery, and respiratory stone motion were determined by two independent observers who reviewed the ultrasonographic videos. Results: Mean age was 51 -15 years with 60% men, and mean stone size was 10.5 -3.7 mm (range 5-18 mm). A mean of 2675 -303 shocks was delivered. Shockwave-induced stone motion was observed with every stone. Accurate targeting of the stone occurred in 60% -15% of shockwaves. Conclusions: US imaging during SWL revealed that 40% of shockwaves miss the stone and contribute solely to tissue injury, primarily from movement with respiration. These data support the need for a device to deliver shockwaves only when the stone is in target. US imaging provides real-time assessment of stone targeting and accuracy of shockwave delivery.

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“…Devices that exploit the time-reversal property of acoustic waves to focus them onto kidney stones automatically have been demonstrated in a laboratory setting. 8,9 Orkisz and associates 10,11 developed an ultrasound-based tracking system to determine stone motion during lithotripsy. The mean stone position was used to move the SW source (piezoelectric) automatically so that it tracked the stone.…”

Section: Introductionmentioning

confidence: 99%