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Bryan Cunitz

Engineer IV

Email

bwc@apl.washington.edu

Phone

206-543-6804

Education

B.A. Physics, Colby College, 1999

B.S. Engineering, Dartmouth College, 2000

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

Videos

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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Publications

2000-present and while at APL-UW

Safety and effectiveness of a longer focal beam and burst duration in ultrasonic propulsion for repositioning urinary stones and fragments

Janssen, K.M., T.C. Brand, B.W. Cunitz, Y.-N. Wang, J.C. Simon, F. Starr, H.D. Liggitt, J. Thiel, M.D. Sorensen, J.D. Harper, M.R. Bailey, and B. Dunmire, "Safety and effectiveness of a longer focal beam and burst duration in ultrasonic propulsion for repositioning urinary stones and fragments," J. Endourol., 31, 793-799, doi:10.1089/end.2017.0167, 2017.

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1 Aug 2017

Purpose: In the first-in-human trial of ultrasonic propulsion, subjects passed collections of residual stone fragments repositioned with a C5-2 probe. Here, effectiveness and safety in moving multiple fragments are compared between the C5-2 and a custom (SC-50) probe that produces a longer focal beam and burst duration.

Materials and Methods: Effectiveness was quantified by the number of stones expelled from a calyx phantom consisting of a 30-mm deep, water-filled well in a block of tissue mimicking material. Each probe was positioned below the phantom to move stones against gravity. Single propulsion bursts of 50 ms or 3 s duration were applied to three separate targets: 10 fragments of 2 different sizes (1–2 and 2–3 mm) and a single 4 x 7 mm human stone. Safety studies consisted of porcine kidneys exposed to an extreme dose of 10-minute burst duration, including a 7-day survival study and acute studies with surgically implanted stones.

Results: Although successful in the clinical trial, the shorter focal beam and maximum 50 ms burst duration of the C5-2 probe moved stones, but did not expel any stones from the phantom's 30-mm deep calyx. The results were similar with the SC-50 probe under the same 50 ms burst duration. Longer (3 s) bursts available with the SC-50 probe expelled all stones at both 4.5 and 9.5 cm "skin-to-stone" depths with lower probe heating compared to the C5-2. No abnormal behavior, urine chemistry, serum chemistry, or histological findings were observed within the kidney or surrounding tissues for the 10 min burst duration used in the animal studies.

Conclusions: A longer focal beam and burst duration improved expulsion of a stone and multiple stone fragments from a phantom over a broad range of clinically relevant penetration depths and did not cause kidney injury in animal studies.

Effect of carbon dioxide on the twinkling artifact in ultrasound imaging of kidney stones: A pilot study

Simon, J.C., Y.-N. Wang, B.W. Cunitz, J. Thiel, F. Starr, Z. Liu, and M.R. Bailey, "Effect of carbon dioxide on the twinkling artifact in ultrasound imaging of kidney stones: A pilot study," Ultrasound Med. Bill. 43, 877-883, doi:10.1016/j.ultrasmedbio.2016.12.010, 2017.

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1 May 2017

Bone demineralization, dehydration and stasis put astronauts at increased risk of forming kidney stones in space. The color-Doppler ultrasound "twinkling artifact," which highlights kidney stones with color, can make stones readily detectable with ultrasound; however, our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. On exposure of the pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9–25 min and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling caused by exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles.

Shock formation and nonlinear saturation effects in the ultrasound field of a diagnostic curvilinear probe

Karzova, M.M., P.V. Yuldashev, O.A. Sapozhnikov, V.A. Khokhlova, B.W. Cunitz, W. Kreider, and M.R. Bailey, "Shock formation and nonlinear saturation effects in the ultrasound field of a diagnostic curvilinear probe," J. Acoust. Soc. Am., 141, 2327-2337, doi:10.1121/1.4979261, 2017.

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1 Apr 2017

Newer imaging and therapeutic ultrasound technologies may benefit from in situ pressure levels higher than conventional diagnostic ultrasound. One example is the recently developed use of ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2.3 MHz C5-2 array probe has been used to deliver the acoustic pushing pulses. The probe is a curvilinear array comprising 128 elements equally spaced along a convex cylindrical surface. The effectiveness of the treatment can be increased by using higher transducer output to provide a stronger pushing force; however nonlinear acoustic saturation can be a limiting factor. In this work nonlinear propagation effects were analyzed for the C5-2 transducer using a combined measurement and modeling approach. Simulations were based on the three-dimensional Westervelt equation with the boundary condition set to match low power measurements of the acoustic pressure field. Nonlinear focal waveforms simulated for different numbers of operating elements of the array at several output power levels were compared to fiber-optic hydrophone measurements and were found to be in good agreement. It was shown that saturation effects do limit the acoustic pressure in the focal region of a diagnostic imaging probe.

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Inventions

Supplemental Know How for Pushing, Imaging, and Breaking Kidney Stones

Record of Invention Number: 47878

Mike Bailey, Larry Crum, Bryan Cunitz, Barbrina Dunmire, Vera Khokhlova, Wayne Kreider, John Kucewicz, Dan Leotta

Disclosure

9 Nov 2016

Combination Burst Wave Lithotripsy and Ultrasonic Propulsion for Improved Stone Fragmentation

Record of Invention Number: 47817

Adam Maxwell, Mike Bailey, Bryan Cunitz, Annie Zwaschka

Disclosure

9 Sep 2016

Ultrasound based method and apparatus for stone detection and to facilitate clearance thereof

Patent Number: 9,204,859

Mike Bailey, Bryan Cunitz, Barbrina Dunmire, John Kucewicz, Oleg Sapozhnikov

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Patent

8 Dec 2015

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.

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
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