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Bailey MR, Maxwell AD, Cao S, Ramesh S, Liu Z, Williams JC, Thiel J, Dunmire B, Colonius T, Kuznetsova E, Kreider W, Sorensen MD, Lingeman JE, Sapozhnikov OA. Improving burst wave lithotripsy effectiveness for small stones and fragments by increasing frequency: theoretical modeling and ex vivo study. J Endourol 2022; 36:996-1003. [PMID: 35229652 DOI: 10.1089/end.2021.0714] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION AND OBJECTIVE In clinical trial NCT03873259, a 2.6-mm lower pole stone was treated transcutaneously and ex vivo with 390-kHz burst wave lithotripsy (BWL) for 40 minutes and failed to break. The stone was subsequently fragmented with 650-kHz BWL after a 4-minute exposure. This study investigated how to fragment small stones and why varying BWL frequency may more effectively fragment stones to dust. METHODS A linear elastic model was used to calculate the stress created inside stones from shock wave lithotripsy (SWL) and different BWL frequencies mimicking the stone's size, shape, lamellar structure, and composition. To test model predictions about the impact of BWL frequency, matched pairs of stones (1-5 mm) were treated at 1) 390 kHz, 2) 830 kHz, and 3) 390 kHz followed by 830 kHz. The mass of fragments greater than 1 and 2 mm was measured over 10 minutes of exposure. RESULTS The linear elastic model predicts that the maximum principal stress inside a stone increases to more than 5.5 times the pressure applied by the ultrasound wave as frequency is increased, regardless of composition tested. The threshold frequency for stress amplification is proportionate to the wave speed divided by the stone diameter. Thus, smaller stones may be likely to fragment at higher frequency, but not lower frequency below a limit. Unlike with SWL, this amplification in BWL occurs consistently with spherical and irregularly shaped stones. In water tank experiments, stones smaller than the threshold size broke fastest at high frequency (p=0.0003), whereas larger stones broke equally well to sub-millimeter dust at high, low, or mixed frequency. CONCLUSIONS For small stones and fragments, increasing frequency of BWL may produce amplified stress in the stone causing the stone to break. Using the strategies outlined here, stones of all sizes may be turned to dust efficiently with BWL.
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Affiliation(s)
- Michael R Bailey
- University of Washington, Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, 1013 NE 40th St., Seattle, Washington, United States, 98105;
| | - Adam D Maxwell
- University of Washington School of Medicine, 12353, Department of Urology, 1013 NE 40th St, Seattle, Washington, United States, 98105;
| | - Shunxiang Cao
- California Institute of Technology, Dept. of Mechanical Engineering, Pasadena, California, United States;
| | - Shivani Ramesh
- University of Washington Applied Physics Lab, Center for Industrial and Medical Ultrasound, Seattle, Washington, United States;
| | - Ziyue Liu
- Indiana University School of Medicine, Biostatistics, Indianapolis, Indiana, United States;
| | - James Caldwell Williams
- Indiana Univ Sch Med, Anatomy & Cell Biology, 635 Barnhill Dr MS5035, Department of Anatomy & Cell Biology, Indianapolis, Indiana, United States, 46202-5120.,United States;
| | - Jeff Thiel
- University of Washington School of Medicine, Radiology, Seattle, Washington, United States;
| | - Barbrina Dunmire
- University of Washington, Applied Physics Lab, 1013 NE 40th St, Seattle, Washington, United States, 98105;
| | - Tim Colonius
- California Institute of Technology, Dept. of Mechanical Engineering, Pasadena, California, United States;
| | - Ekaterina Kuznetsova
- University of Washington Applied Physics Lab, Center for Industrial and Medical Ultrasound, Seattle, Washington, United States;
| | - Wayne Kreider
- University of Washington Applied Physics Lab, Center for Industrial and Medical Ultrasound, Seattle, Washington, United States;
| | - Mathew D Sorensen
- University of Washington, Department of Urology, 1959 NE Pacific Street, Box 356510, Seattle, Washington, United States, 98195;
| | - James E Lingeman
- Indiana University School of Medicine, Dept. of Urology, 1801 North Senate Blvd., Suite 220, Indianapolis, Indiana, United States, 46202;
| | - Oleg A Sapozhnikov
- University of Washington Applied Physics Lab, Center for Industrial and Medical Ultrasound, Seattle, Washington, United States.,Moscow State University, 64935, Department of Acoustics, Physics Faculty, Moskva, Moskva, Russian Federation;
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Moghimnezhad M, Shahidian A, Andayesh M. Multiphysics Analysis of Ultrasonic Shock Wave Lithotripsy and Side Effects on Surrounding Tissues. J Biomed Phys Eng 2021; 11:701-712. [PMID: 34904067 PMCID: PMC8649164 DOI: 10.31661/jbpe.v0i0.1182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 07/08/2019] [Indexed: 11/16/2022]
Abstract
Background: Today, the most common method for kidney stone therapy is extracorporeal shock wave lithotripsy. Current research is a numerical simulation of kidney stone fragmentation via ultrasonic shock waves.
Most numerical studies in lithotripsy have been carried out using the elasticity or energy method and neglected the dissipation phenomenon. In the current study,
it is solved by not only the linear acoustics equation, but also the Westervelt acoustics equation which nonlinearity and dissipation are involved. Objective: This study is to compare two methods for simulation of shock wave lithotripsy, clarifying the effect of shock wave profiles and stones’ material, and investigating side effects on surrounding tissues Material and Methods: Computational study is done using COMSOL Multiphysics, commercial software based on the finite element method. Nonlinear governing equations of acoustics,
elasticity and bioheat-transfer are coupled and solved. Results: A decrease in the rise time of shock wave leads to increase the produced acoustic pressure and enlarge focus region. The shock wave damages kidney tissues in both linear and nonlinear
simulation but the damage due to high temperature is very negligible compared to the High Intensity Focused Ultrasound (HIFU). Conclusion: Disaffiliation of wave nonlinearity causes a high incompatibility with reality. Stone’s material is an important factor, affecting the fragmentation
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Affiliation(s)
- Mahdi Moghimnezhad
- MSc, Department of Mechanical Engineering, K. N . Toosi University of Technology, Tehran, Iran
| | - Azadeh Shahidian
- PhD, Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Mohammad Andayesh
- BSc, Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran
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Xiang G, Ma X, Liang C, Yu H, Liao D, Sankin G, Cao S, Wang K, Zhong P. Variations of stress field and stone fracture produced at different lateral locations in a shockwave lithotripter field. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2021; 150:1013. [PMID: 34470261 PMCID: PMC8357445 DOI: 10.1121/10.0005823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
During clinical procedures, the lithotripter shock wave (LSW) that is incident on the stone and resultant stress field is often asymmetric due to the respiratory motion of the patient. The variations of the LSW-stone interaction and associated fracture pattern were investigated by photoelastic imaging, phantom experiments, and three-dimensional fluid-solid interaction modeling at different lateral locations in a lithotripter field. In contrast to a T-shaped fracture pattern often observed in the posterior region of the disk-shaped stone under symmetric loading, the fracture pattern gradually transitioned to a tilted L-shape under asymmetric loading conditions. Moreover, the model simulations revealed the generation of surface acoustic waves (SAWs), i.e., a leaky Rayleigh wave on the anterior boundary and Scholte wave on the posterior boundary of the stone. The propagation of SAWs on the stone boundary is accompanied by a progressive transition of the LSW reflection pattern from regular to von Neumann and to weak von Neumann reflection near the glancing incidence and, concomitantly, the development and growth of a Mach stem, swirling around the stone boundary. The maximum tensile stress and stress integral were produced by SAWs on the stone boundary under asymmetric loading conditions, which drove the initiation and extension of surface cracks into the bulk of the stone that is confirmed by micro-computed tomography analysis.
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Affiliation(s)
- Gaoming Xiang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Xiaojian Ma
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Cosima Liang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Hongyang Yu
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Defei Liao
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Georgy Sankin
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Shunxiang Cao
- Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Kevin Wang
- Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
| | - Pei Zhong
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
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Raymond SJ, Maragh J, Masic A, Williams JR. Towards an understanding of the chemo-mechanical influences on kidney stone failure via the material point method. PLoS One 2020; 15:e0240133. [PMID: 33306670 PMCID: PMC7732073 DOI: 10.1371/journal.pone.0240133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/20/2020] [Indexed: 11/18/2022] Open
Abstract
This paper explores the use of the meshfree computational mechanics method, the Material Point Method (MPM), to model the composition and damage of typical renal calculi, or kidney stones. Kidney stones are difficult entities to model due to their complex structure and failure behavior. Better understanding of how these stones behave when they are broken apart is a vital piece of knowledge to medical professionals whose aim is to remove these stone by breaking them within a patient’s body. While the properties of individual stones are varied, the common elements and proportions are used to generate synthetic stones that are then placed in a digital experiment to observe their failure patterns. First a more traditional engineering model of a Brazil test is used to create a tensile fracture within the center of these stones to observe the effect of stone consistency on failure behavior. Next a novel application of MPM is applied which relies on an ultrasonic wave being carried by surrounding fluid to model the ultrasonic treatment of stones commonly used by medical practitioners. This numerical modeling of Extracorporeal Shock Wave Lithotripsy (ESWL) reveals how these different stones failure in a more real-world situation and could be used to guide further research in this field for safer and more effective treatments.
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Affiliation(s)
- Samuel J. Raymond
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Center for Computational Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- * E-mail:
| | - Janille Maragh
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Admir Masic
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - John R. Williams
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Center for Computational Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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Maxwell AD, MacConaghy B, Bailey MR, Sapozhnikov OA. An investigation of elastic waves producing stone fracture in burst wave lithotripsy. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2020; 147:1607. [PMID: 32237849 PMCID: PMC7069764 DOI: 10.1121/10.0000847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Burst wave lithotripsy is a method to noninvasively fragment urinary stones by short pulses of focused ultrasound. In this study, physical mechanisms of stone fracture during burst wave lithotripsy were investigated. Photoelasticity imaging was used to visualize elastic wave propagation in model stones and compare results to numerical calculations. Epoxy and glass stone models were made into rectangular, cylindrical, or irregular geometries and exposed in a degassed water bath to focused ultrasound bursts at different frequencies. A high-speed camera was used to record images of the stone during exposure through a circular polariscope backlit by a monochromatic flash source. Imaging showed the development of periodic stresses in the stone body with a pattern dependent on frequency. These patterns were identified as guided wave modes in cylinders and plates, which formed standing waves upon reflection from the distal surfaces of the stone model, producing specific locations of stress concentration in the models. Measured phase velocities compared favorably to numerically calculated modes dependent on frequency and material. Artificial stones exposed to bursts produced cracks at positions anticipated by this mechanism. These results support guided wave generation and reflection as a mechanism of stone fracture in burst wave lithotripsy.
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Affiliation(s)
- Adam D Maxwell
- Department of Urology, University of Washington School of Medicine, 1959 Northeast Pacific Street, Seattle, Washington 98195, USA
| | - Brian MacConaghy
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA
| | - Michael R Bailey
- Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA
| | - Oleg A Sapozhnikov
- Department of Acoustics, Physics Faculty, Lomonosov Moscow State University, Leninskie Gory, Moscow 119992, Russia
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Cao S, Zhang Y, Liao D, Zhong P, Wang KG. Shock-Induced Damage and Dynamic Fracture in Cylindrical Bodies Submerged in Liquid. INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES 2019; 169:55-71. [PMID: 31423024 PMCID: PMC6697132 DOI: 10.1016/j.ijsolstr.2019.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Understanding the response of solid materials to shock loading is important for mitigating shock-induced damages and failures, as well as advancing the beneficial use of shock waves for material modifications. In this paper, we consider a representative brittle material, BegoStone, in the form of cylindrical bodies and submerged in water. We present a computational study on the causal relationship between the prescribed shock load and the resulting elastic waves and damage in the solid material. A recently developed three-dimensional computational framework, FIVER, is employed, which couples a finite volume compressible fluid solver with a finite element structural dynamics solver through the construction and solution of local, one-dimensional fluid-solid Riemann problems. The material damage and fracture are modeled and simulated using a continuum damage mechanics model and an element erosion method. The computational model is validated in the context of shock wave lithotripsy and the results are compared with experimental data. We first show that after calibrating the growth rate of microscopic damage and the threshold for macroscopic fracture, the computational framework is capable of capturing the location and shape of the shock-induced fracture observed in a laboratory experiment. Next, we introduce a new phenomenological model of shock waveform, and present a numerical parametric study on the effects of a single shock load, in which the shock waveform, magnitude, and the size of the target material are varied. In particular, we vary the waveform gradually from one that features non-monotonic decay with a tensile phase to one that exhibits monotonic decay without a tensile phase. The result suggests that when the length of the shock pulse is comparable to that of the target material, the former waveform may induce much more significant damage than the latter one, even if the two share the same magnitude, duration, and acoustic energy.
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Affiliation(s)
- S. Cao
- Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States
| | - Y. Zhang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 90271, United States
| | - D. Liao
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 90271, United States
| | - P. Zhong
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 90271, United States
| | - K. G. Wang
- Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States
- Corresponding author (K. G. Wang)
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Wollin DA, Tom WR, Jiang R, Simmons WN, Preminger GM, Lipkin ME. An in vitro evaluation of laser settings and location in the efficiency of the popcorn effect. Urolithiasis 2018; 47:377-382. [PMID: 29947996 DOI: 10.1007/s00240-018-1066-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/08/2018] [Indexed: 11/30/2022]
Abstract
To examine different locations and laser settings' effects on the efficiency of the "popcorn" method of laser lithotripsy, which consists of placing the laser in a group of small stones and firing continuously to break them into smaller particles. Pre-fragmented BegoStones were created between 2 and 4 mm to mimic typical popcorning conditions. A 0.5 g collection of fragments was placed into 3D-printed models (a spherical calyx and ellipsoid pelvis model) and a 200-µm laser fiber was positioned above the stones. The laser was fired for 2 min with irrigation, with 5 trials at each setting: 0.2 J/50 Hz, 0.5 J/20 Hz, 0.5 J/40 Hz, 1 J/20 Hz, 0.2 J/80 Hz, 0.5 J/80 Hz. After drying, fragmentation efficiency was determined by calculating the mass of stones reduced to sub-2 mm particles. Statistical analysis was performed with ANOVA and Student's t test. The trials within the calyx model were significantly more efficient compared to the pelvis (0.19 vs 0.15 g, p = 0.01). When comparing laser settings, there was a difference between groups by one-way ANOVA [F(5,54) = 8.503, p = 5.47 × 10-6]. Post hoc tests showed a power setting of 0.5 J/80 Hz was significantly more efficient than low-power settings 0.2 J/50 Hz and 0.5 J/20 Hz (p < 0.05). Additionally, 0.2 J/50 Hz was significantly less efficient than 0.5 J/40 Hz, 1 J/20 Hz, and 0.2 J/80 Hz. Popcorning is most efficient in smaller spaces; we recommend displacement of stones into a calyx before popcorning. No difference was seen between high-power settings, although 0.5 J/40 Hz and 0.5 J/80 Hz performed best, suggesting that moderate energy popcorning methods with at least 0.5 J per pulse are most efficient.
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Affiliation(s)
- Daniel A Wollin
- Division of Urologic Surgery, Duke University Medical Center, Durham, NC, USA.
| | - Westin R Tom
- Duke University School of Medicine, Durham, NC, USA
| | - Ruiyang Jiang
- Division of Urologic Surgery, Duke University Medical Center, Durham, NC, USA
| | - W Neal Simmons
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA
| | - Glenn M Preminger
- Division of Urologic Surgery, Duke University Medical Center, Durham, NC, USA
| | - Michael E Lipkin
- Division of Urologic Surgery, Duke University Medical Center, Durham, NC, USA
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Fovargue D, Mitran S, Sankin G, Zhang Y, Zhong P. An experimentally-calibrated damage mechanics model for stone fracture in shock wave lithotripsy. INTERNATIONAL JOURNAL OF FRACTURE 2018; 211:203-216. [PMID: 30349151 PMCID: PMC6195326 DOI: 10.1007/s10704-018-0283-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 04/05/2018] [Indexed: 05/22/2023]
Abstract
A damage model suggested by the Tuler-Butcher concept of dynamic accumulation of microscopic defects is obtained from experimental data on microcrack formation in synthetic kidney stones. Experimental data on appearance of microcracks is extracted from micro-computed tomography images of BegoStone simulants obtained after subjecting the stone to successive pulses produced by an electromagnetic shock-wave lithotripter source. Image processing of the data is used to infer statistical distributions of crack length and width in representative transversal cross-sections of a cylindrical stone. A high-resolution finite volume computational model, capable of accurately modeling internal reflections due to local changes in material properties produced by material damage is used to simulate the accumulation of damage due to successive shocks. Comparison of statistical distributions of microcrack formation in computation and experiment allows calibration of the damage model. The model is subsequently used to compute fracture of a different aspect-ratio cylindrical stone predicting concurrent formation of two main fracture areas as observed experimentally.
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Affiliation(s)
- Daniel Fovargue
- Department of Mathematics, University of North Carolina, Chapel Hill, North Carolina, 27599-3250
| | - Sorin Mitran
- Department of Mathematics, University of North Carolina, Chapel Hill, North Carolina, 27599-3250
| | - Georgy Sankin
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708
| | - Ying Zhang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708
| | - Pei Zhong
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708
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