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Adam Maxwell Research Assistant Professor, Urology maxwell@apl.washington.edu Phone 206-221-6530 |
Videos
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PIXUL: PIXelated ULtrasound Speeds Disease Biomarker Search |
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26 Apr 2018
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Accurate assessment of chromatin modifications can be used to improve detection and treatment of various diseases. Further, accurate assessment of chromatin modifications can have an important role in designing new drug therapies. This novel technology applies miniature ultrasound transducers to shear chromatin in standard 96-well microplates. PIXUL saves researchers hours of sample preparation time and reduces sample degradation. |
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Mechanical Tissue Ablation with Focused Ultrasound An experimental noninvasive surgery method uses nonlinear ultrasound pulses to liquefy tissue at remote target sites within a small focal region without damaging intervening tissues. |
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23 Mar 2017
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Boiling histotripsy utilizes sequences of millisecond-duration HIFU pulses with high-amplitude shocks that form at the focus by nonlinear propagation effects. Due to strong attenuation of the ultrasound energy at the shocks, these nonlinear waves rapidly heat tissue and generate millimeter-sized boiling bubbles at the focus within each pulse. Then the further interaction of subsequent shocks with the vapor cavity causes tissue disintegration into subcellular debris through the acoustic atomization mechanism. |
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Burst Wave Lithotripsy: An Experimental Method to Fragment Kidney Stones CIMU researchers are investigating a noninvasive method to fragment kidney stones using ultrasound pulses rather than shock waves. Consecutive acoustic cycles accumulate and concentrate energy within the stone. The technique can be 'tuned' to create small fragments, potentially improving the success rate of lithotripsy procedures. |
20 Nov 2014
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Publications |
2000-present and while at APL-UW |
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Evaluation of renal stone comminution and injury by burst wave lithotripsy in a pig model Maxwell, A.D., Y.-N. Wang, W. Kreider, B.W. Cunitz, F. Starr, D. Lee, Y. Nazari, J.C. Williams Jr., M.R. Bailey, and M.D. Sorensen, "Evaluation of renal stone comminution and injury by burst wave lithotripsy in a pig model," J. Endourol., 33, doi:10.1089/end.2018.0886, 2019. |
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15 Oct 2019 ![]() |
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Burst wave lithotripsy is an experimental technology to noninvasively fragment kidney stones with focused bursts of ultrasound (US). This study evaluated the safety and effectiveness of specific lithotripsy parameters in a porcine model of nephrolithiasis. |
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Quantification of acoustic radiation forces on solid objects in fluid Ghanem, M.A., A.D. Maxwell, O.A. Sapozhnikov, V.A. Khokhlova, and M.R. Bailey, "Quantification of acoustic radiation forces on solid objects in fluid," Phys. Rev. Appl., 12, doi:10.1103/PhysRevApplied.12.044076, 2019. |
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1 Oct 2019 ![]() |
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Theoretical models allow design of acoustic traps to manipulate objects with radiation force. A model of the acoustic radiation force by an arbitrary beam on a solid object is validated against measurement. The lateral force in water of different acoustic beams is measured and calculated for spheres of different diameters (26 wavelengths λ in water) and compositions. This is the first effort to validate a general model, to quantify the lateral force on a range of objects, and to electronically steer large or dense objects with a single-sided transducer. Vortex beams and two other beam shapes having a ring-shaped pressure field in the focal plane are synthesized in water by a 1.5-MHz, 256-element focused array. Spherical targets (glass, brass, ceramic, 26 mm dia.) are placed on an acoustically transparent plastic plate that is normal to the acoustic beam axis and rigidly attached to the array. Each sphere is trapped in the beam as the array with the attached plate is rotated until the sphere falls from the acoustic trap because of gravity. Calculated and measured maximum obtained angles agree on average to within 22%. The maximum lateral force occurs when the target diameter equals the beam width; however, objects up to 40% larger than the beam width are trapped. The lateral force is comparable to the gravitation force on spheres up to 90 mg (0.0009 N) at beam powers on the order of 10 W. As a step toward manipulating objects, the beams are used to trap and electronically steer the spheres along a two-dimensional path. |
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The impact of dust and confinement on fragmentation of kidney stones by shockwave lithotripsy in tissue phantoms Randad, A., J. Ahn, W. Kreider, M.R. Bailey, J.D. Harper, M.D. Sorensen, and A.D. Maxwell, "The impact of dust and confinement on fragmentation of kidney stones by shockwave lithotripsy in tissue phantoms," J. Endourol., 33, doi:10.1089/end.2018.0516, 2019. |
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1 May 2019 ![]() |
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Objective: The goal was to test whether stone composition and kidney phantom configuration affected comminution in extracorporeal shockwave lithotripsy (SWL) laboratory tests. Confinement may enhance the accumulation of dust and associated cavitation bubbles in the fluid surrounding the stone. It is known that high shockwave delivery rates in SWL are less effective because bubbles generated by one shockwave do not have sufficient time to dissolve, thereby shielding the next shockwave. |
In The News
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Move it along: Ultrasound to rid kidney stones sans surgery UW Health Sciences NewsBeat, Samantha Sauer Every year, more than a half-million people in the United States go to the emergency room for kidney stones. The common condition leads to hundreds of thousands of surgeries each year. |
12 Jan 2016
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Inventions
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Focused Ultrasound Apparatus and Methods of Use Patent Number: 10,350,439 |
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Patent
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16 Jul 2019
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Methods for diagnosing a pathologic tissue membrane, as well as a focused ultrasound apparatus and methods of treatment are disclosed to perform ureterocele puncture noninvasively using focused ultrasound-generated cavitation or boiling bubbles to controllably erode a hole through the tissue. An example ultrasound apparatus may include (a) a therapy transducer having a treatment surface, wherein the therapy transducer comprises a plurality of electrically isolated sections, (b) at least one concave acoustic lens defining a therapy aperture in the treatment surface of the therapy transducer, (c) an imaging aperture defined by either the treatment surface of the therapy transducer or by the at least one concave acoustic lens and (d) an ultrasound imaging probe axially aligned with a central axis of the therapy aperture. |
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Device and Method to Break Urinary Stones in Pets Record of Invention Number: 48640 Mike Bailey, Dan Leotta, Elizabeth Lynch, Brian MacConaghy, Adam Maxwell |
Disclosure
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28 May 2019
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Method to Create Patterns for Tissue Growth in Tissue Engineering Record of Invention Number: 48638 |
Disclosure
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28 May 2019
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