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Barbrina Dunmire

Senior Engineer

Email

mrbean@apl.washington.edu

Phone

206-685-6953

Education

B.S. Aeronautics & Astronautics, University of Washington, 1989

M.S. Aeronautics & Astronautics, University of Washington, 1991

M.S. Bioengineering, University of Washington, 1998

Videos

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.

Center for Industrial and Medical Ultrasound - CIMU

CIMU is a group of scientists, engineers, and technicians dedicated to research across the field of bio-medical ultrasonics with the goal of developing technologies that will be used in a clinic to treat patients.

1 Nov 2010

Publications

2000-present and while at APL-UW

Retrospective comparison of measured stone size and posterior acoustic shadow width in clinical ultrasound images

Dai, J.C., B. Dunmire, K.M. Sternberg, Z. Liu, T. Larson, J. Thiel, H.C. Chang, J.D. Harper, M.R. Bailey, M.D. Sorensen, "Retrospective comparison of measured stone size and posterior acoustic shadow width in clinical ultrasound images," World J. Urol., 36, 727-732, doi:10.1007/s00345-017-2156-8, 2018.

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1 May 2018

Purpose

Posterior acoustic shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images.

Methods

Thirty patient image sets where computed tomography (CT) and US images were captured less than 1 day apart were retrospectively reviewed. Five blinded reviewers independently assessed the largest stone in each image set for shadow presence and size. Shadow size was compared to US and CT stone sizes.

Results

Eighty percent of included stones demonstrated an acoustic shadow; 83% of stones without a shadow were ≤5 mm on CT. Average stone size was 6.5 ± 4.0 mm on CT, 10.3 ± 4.1 mm on US, and 7.5 ± 4.2 mm by shadow width. On average, US overestimated stone size by 3.8 ± 2.4 mm based on stone width (p < 0.001) and 1.0 ± 1.4 mm based on shadow width (p < 0.0098). Shadow measurements decreased misclassification of stones by 25% among three clinically relevant size categories (≤ 5, 5.1–10, > 10 mm), and by 50% for stones ≤ 5 mm.

Conclusions

US overestimates stone size compared to CT. Retrospective measurement of the acoustic shadow from the same clinical US images is a more accurate reflection of true stone size than direct stone measurement. Most stones without a posterior shadow are ≤ 5 mm.

Combined burst wave lithotripsy and ultrasonic propulsion fo improved urinary stone fragmentation

Zwaschka, T.A., J.S. Ahn, B.W. Cunitz, M.R. Bailey, B. Dunmire, M.D. Sorensen, J.D. Harper, and A.D. Maxwell, "Combined burst wave lithotripsy and ultrasonic propulsion fo improved urinary stone fragmentation," J. Endourol., 32, 344-349, doi:10.1089/end.2017.0675, 2018.

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1 Apr 2018

Purpose

Burst wave lithotripsy (BWL) is a new technology in development to fragment urinary stones. Ultrasonic propulsion (UP) is a separate technology under investigation for displacing stones. We measure the effect of propulsion pulses on stone fragmentation from BWL.

Materials and Methods

Two artificial stone models (crystalline calcite, BegoStone plaster) and human calcium oxalate monohydrate (COM) stones measuring 5 to 8 mm were subjected to ultrasound exposures in a polyvinyl chloride tissue phantom within a water bath. Stones were exposed to BWL with and without propulsion pulses interleaved for set time intervals depending on stone type. Fragmentation was measured as a fraction of the initial stone mass fragmented to pieces smaller than 2 mm.

Results

BegoStone model comminution improved from 6% to 35% (p < 0.001) between BWL and BWL with interleaved propulsion in a 10-minute exposure. Propulsion alone did not fragment stones, whereas addition of propulsion after BWL slightly improved BegoStone model comminution from 6% to 11% (p < 0.001). BegoStone model fragmentation increased with rate of propulsion pulses. Calcite stone fragmentation improved from 24% to 39% in 5 minutes (p = 0.047) and COM stones improved from 17% to 36% (p = 0.01) with interleaved propulsion.

Conclusions

BWL with UP improved stone fragmentation compared with BWL alone in vitro. The improvement was greatest when propulsion pulses are interleaved with BWL treatment and when propulsion pulses are applied at a higher rate. Thus, UP may be a useful adjunct to enhance fragmentation in lithotripsy in vivo.

PD37-09 kidney stone contrast with color-Doppler twinkling artifact as a function of mechanical index

Cunitz, B., J. Dai, M. Sorenson, R. Sweet, B. Dunmire, J. Thiel, M. Bruce, M. Bailey, Z. Liu, and J. Harper, "PD37-09 kidney stone contrast with color-Doppler twinkling artifact as a function of mechanical index," J. Urol., 199, e734, doi:10.1016/j.juro.2018.02.1744, 2018.

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1 Apr 2018

Kidney stones can exhibit a twinkling artifact under color-flow Doppler ultrasound. There has been much work that suggests the mechanism for this artifact is micron sized bubbles trapped in the cracks of the stone cavitating from the incident Doppler pulses. We hypothesize that the signal-to-clutter ratio (SCR) of stone-to-background in Doppler mode increases with the ultrasound mechanical index (MI), a metric of the likelihood of cavitation, and that a minimum MI is needed for visibility under Doppler.

Our results show the contrast ratio of the twinkling artifact on a kidney stone to background noise increases with the MI. This suggests that adjusting the system settings to increase the MI on the stone, such as lowering the frequency and increasing the amplitude, will improve stone contrast and the ability to detect a kidney stone. Additionally, ultrasound manufacturers can potentially implement a stone-specific imaging preset for Doppler that maximizes the MI of the output while remaining within the regulated safety limits.

More Publications

Inventions

Renal Needle Access Guide for Ultrasound Guided Percutaneous Nephrolithotomy

Record of Invention Number: 48366

Mike Bailey, Helen Chang, Barbrina Dunmire, Jonathan Harper, Katy Kuznetsova

Disclosure

26 Jun 2018

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

Disclosure

11 Apr 2018

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

Patent Number: 9,597,103

Mike Bailey, John Kucewicz, Barbrina Dunmire, Neil Owen, Bryan Cunitz

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Patent

21 Mar 2017

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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