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Bryan Cunitz

Engineer IV






B.A. Physics, Colby College, 1999

B.S. Engineering, Dartmouth College, 2000

M.S. Electrical Engineering, University of Washington, 2005


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

Ultrasonic Detection and Propulsion of Kidney Stones

An ultrasound-based system assembled from commercial components and customized software control locates kidney stones, applies an acoustic radiative force, and repositions the stones so they are more likely to pass naturally. Watch urologist test the system.

2 May 2013

SonoMotion: A Budding Start-up Company

A research team has developed new technologies to treat kidney stone disease with an ultrasound-based system. Embraced by clinicians, their advances are now being taken to the next step: transition the prototype to an approved device that will roll into hospitals and clinics around the world.

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11 Feb 2013

At the Center for Industrial and Medical Ultrasound a team of scientists, engineers, and students has developed an ultrasound-based system that may provide an office procedure to speed the natural passage of kidney stones. The system uses commercial ultrasound components to locate stones in kidneys. It creates clear pictures of them and then applies an acoustic radiative force, repositioning stones in the kidney so they are more likely to pass naturally.

As a research team, considerable technical advancements have been made and valuable feedback and cooperation has been garnered from the user community – the clinicians. The scientists, engineers, urologists, and commercialization experts are now collaborating to take the next steps.

SonoMotion has partnered with a hardware manufacturing company and licensed the ultrasonic propulsion of kidney stones technology with the University of Washington. The next big step will be to transition the prototype system into one that will pass the rigors of FDA review and be ready to roll into hospitals and clinics around the world.

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2000-present and while at APL-UW

Impact of stone type on caviation in burst wave lithotripsy

Hunter, C., A.D. Maxwell, B. Cunitz, B. Dunmire, M.D. Sorensen, J.C. Williams Jr., A. Randad, M. Bailey, and W. Kreider, "Impact of stone type on caviation in burst wave lithotripsy," Proc. Mtgs. Acoust., 35, 020005, doi:10.1121/2.0000950, 2018.

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26 Dec 2018

Proceedings, 176th Meeting of the Acoustical Society of America, 5-9 November 2018, Victoria, BC, Canada.

Non-invasive kidney stone treatments such as shock wave lithotripsy (SWL) and burst wave lithotripsy (BWL) rely on the delivery of pressure waves through tissue to the stone. In both SWL and BWL, the potential to hinder comminution by exciting cavitation proximal to the stone has been reported. To elucidate how different stones alter prefocal cavitation in BWL, different natural and synthetic stones were treated in vitro using a therapy transducer operating at 350 kHz (peak negative pressure 7 MPa, pulse length 20 cycles, pulse repetition frequency 10 Hz). Stones were held in a confined volume of water designed to mimic the geometry of a kidney calyx, with the water filtered and degassed to maintain conditions for which the cavitation threshold (in the absence of a stone) matches that from in vivo observations. Stone targeting and cavitation monitoring were performed via ultrasound imaging using a diagnostic probe aligned coaxially with the therapy transducer. Quantitative differences in the extent and location of cavitation activity were observed for different stone types — e.g., stones (natural and synthetic) that are known to be porous produced larger prefocal cavitation clouds. Ongoing work will focus on correlation of such cavitation metrics with stone fragmentation.

Update on clinical trials of kidney stone repositioning and preclinical results of stone breaking with one system

Bailey, M.R., Y.-N. Wang, W. Kreider, J.C. Dai, B.W. Cunitz, J.D. Harper, H. Chang, M.D. Sorensen, Z. Liu, O. Levy, B. Dunmire, and A.D. Maxwell, "Update on clinical trials of kidney stone repositioning and preclinical results of stone breaking with one system," Proc. Mtgs. Acoust, 35, 020004, doi:10.1121/2.0000949, 2018.

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21 Dec 2018

176th Meeting of the Acoustical Society of America 5-9 November 2018, Victoria, BC, Canada.

Our goal is an office-based, handheld ultrasound system to target, detach, break, and/or expel stones and stone fragments from the urinary collecting system to facilitate natural clearance. Repositioning of stones in humans (maximum 2.5 MPa, and 3-second bursts) and breaking of stones in a porcine model (maximum 50 cycles, 20 Hz repetition, 30 minutes, and 7 MPa peak negative pressure) have been demonstrated using the same 350-kHz probe. Repositioning in humans was conducted during surgery with a ureteroscope in the kidney to film stone movement. Independent video review confirmed stone movements (≥ 3 mm) in 15 of 16 kidneys (94%). No serious or unanticipated adverse events were reported. Experiments of burst wave lithotripsy (BWL) effectiveness on breaking human stones implanted in the porcine bladder and kidney demonstrated fragmentation of 7 of 7 stones on post mortem dissection. A 1-week survival study with the BWL exposures and 10 specific pathogen-free pigs, showed all findings were within normal limits on clinical pathology, hematology, and urinalysis. These results demonstrate that repositioning of stones with ultrasonic propulsion and breaking of stones with BWL are safe and effective.

An in vivo demonstration of efficacy and acute safety of burst wave lithotripsy using a porcine model

Wang, Y.-N., W. Kreider, C. Hunter, B.W. Cunitz, J. Thiel, F. Starr, J.C. Dai, Y. Nazari, D. Lee, J.C. Williams, M.R. Bailey, and A.D. Maxwell, "An in vivo demonstration of efficacy and acute safety of burst wave lithotripsy using a porcine model," Proc. Mtgs. Acoust., 35, 02009, doi:10.1121/2.0000975, 2018.

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5 Nov 2018

Proceedings, 176th Meeting of the Acoustical Society of America, 5-9 November 2018, Victoria, BC, Canada.

Burst wave lithotripsy (BWL) is a new non-invasive method for stone comminution using bursts of sub-megahertz ultrasound. A porcine model of urolithiasis and techniques to implement BWL treatment has been developed to evaluate its effectiveness and acute safety. Six human calcium oxalate monohydrate stones (6–7 mm) were hydrated, weighed, and surgically implanted into the kidneys of three pigs. Transcutaneous stone treatments were performed with a BWL transducer coupled to the skin via an external water bath. Stone targeting and treatment monitoring were performed with a co-aligned ultrasound imaging probe. Treatment exposures were applied in three 10-minute intervals for each stone. If sustained cavitation in the parenchyma was observed by ultrasound imaging feedback, treatment was paused and the pressure amplitude was decreased for the remaining time. Peak negative focal pressures between 6.5 and 7 MPa were applied for all treatments. After treatment, stone fragments were removed from the kidneys. At least 50% of each stone was reduced to <2 mm fragments. 100% of four stones were reduced to <4 mm fragments. Magnetic resonance imaging showed minimal injury to the functional renal volume. This study demonstrated that BWL could be used to effectively fragment kidney stones with minimal injury.

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Determining a Presence of an Object

Patent Number: 10,136,835

Mike Bailey, Wei Lu, Oleg Sapozhnikov, Bryan Cunitz

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27 Nov 2018

Methods, computing devices, and computer-readable medium are described herein related to producing detection signals configured to induce an excited state of an object. A computing device may receive reflection signals, where the reflection signals correspond to at least one detection signals reflected from the object. Based on the received reflection signals, a presence of the object in the excited state may be determined. Further, an output device may provide an indication of the presence of the object in the excited state.

Ultrasound Based Method and Apparatus for Stone Detection and to Facilitate Clearance Thereof

Patent Number: 10,039,562

Mike Bailey, Bryan Cunitz, Barbrina Dunmire

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7 Aug 2018

Described herein are methods and apparatus for detecting stones by ultrasound, in which the ultrasound reflections from a stone are preferentially selected and accentuated relative to the ultrasound reflections from blood or tissue. Also described herein are methods and apparatus for applying pushing ultrasound to in vivo stones or other objects, to facilitate the removal of such in vivo objects.

Targeting Methods and Devices for Non-invasive Therapy Delivery

Record of Invention Number: 48305

Bryan Cunitz, Mike Bailey, Barbrina Dunmire, Michael Kennedy Hall, Adam Maxwell, Matthew Sorenson


11 Apr 2018

More Inventions

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center