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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

Characterization and ex vivo evaluation of an extracorporeal high-intensity focused ultrasound (HIFU) system

Zhou, Y.F., B.W. Cunitz, B. Dunmire, Y.-N. Wang, S.G. Karl, C. Warren, S. Mitchell, and J.H. Hwang, "Characterization and ex vivo evaluation of an extracorporeal high-intensity focused ultrasound (HIFU) system," J. Appl. Clin. Med. Phys., EOR, doi:10.1002/acm2.13074, 2021.

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4 Aug 2021

High-intensity focused ultrasound (HIFU) has been in clinical use for a variety of solid tumors and cancers. Accurate and reliable calibration is in a great need for clinical applications. An extracorporeal clinical HIFU system applied for the investigational device exemption (IDE) to the Food and Drug Administration (FDA) so that evaluation of its characteristics, performance, and safety was required.

The acoustic pressure and power output was characterized by a fiber optic probe and a radiation force balance, respectively, with the electrical power up to 2000 W. An in situ acoustic energy was established as the clinical protocol at the electrical power up to 500 W. Temperature elevation inside the tissue sample was measured by a thermocouple array. Generated lesion volume at different in situ acoustic energies and pathological examination of the lesions was evaluated ex vivo.

Acoustic pressure mapping showed the insignificant presence of side/grating lobes and pre- or post-focal peaks (≤–12 dB). Although distorted acoustic pressure waveform was found in the free field, the nonlinearity was reduced significantly after the beam propagating through tissue samples (i.e., the second harmonic of –11.8 dB at 500 W). Temperature elevation was <10°C at a distance of 10 mm away from a 20-mm target, which suggests the well-controlled HIFU energy deposition and no damage to the surrounding tissue. An acoustic energy in the range of 750–1250 J resulted in discrete lesions with an interval space of 5 mm between the treatment spots. Histology confirmed that the lesions represented a region of permanently damaged cells by heat fixation, without causing cell lysis by either cavitation or boiling.

Our characterization and ex vivo evaluation protocol met the IDE requirement. The in-situ acoustic energy model will be used in clinical trials to deliver almost consistent energy to the various targets.

First in-human burst wave lithotripsy for kidney stone comminution: Initial two case studies

Harper, J.D., I. Metzler, M.K. Hall, T.T. Chen, A.D. Maxwell, B.W. Cunitz, B. Dunmire, J. Thiel, J.C. Williams, M.R. Bailey, and M.D. Sorensen, "First in-human burst wave lithotripsy for kidney stone comminution: Initial two case studies," J. Endourol., 35, 506-511, doi:10.1089/end.2020.0725, 2021.

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1 Apr 2021

Purpose: To test the effectiveness (Participant A) and tolerability (Participant B) of urinary stone comminution in the first in-human trial of a new technology, burst wave lithotripsy (BWL).

Materials and Methods: An investigational BWL and ultrasonic propulsion system was used to target a 7-mm kidney stone in the operating room before ureteroscopy (Participant A). The same system was used to target a 7.5 mm ureterovesical junction stone in clinic without anesthesia (Participant B).

Results: For Participant A, a ureteroscope inserted after 9 minutes of BWL observed fragmentation of the stone to < 2 mm fragments. Participant B tolerated the procedure without pain from BWL, required no anesthesia, and passed the stone on day 15.

Conclusions: The first in-human tests of BWL pulses were successful in that a renal stone was comminuted in < 10 minutes, and BWL was also tolerated by an awake subject for a distal ureteral stone.

In vitro evaluation of urinary stone comminution with a clinical burst wave lithotripsy system

Ramesh, S., T.T. Chen, A.D. Maxwell, B.W. Cunitz, B. Dunmire, J. Thiel, J.C. Williams, A. Gardner, Z. Liu, I. Metzler, J.D. Harper, M.D. Sorensen, and M.R. Bailey, "In vitro evaluation of urinary stone comminution with a clinical burst wave lithotripsy system," J. Endourol., 34, 1167-1173, doi:10.1089/end.2019.0873, 2020.

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1 Nov 2020

Objective: Our goals were to validate stone comminution with an investigational burst wave lithotripsy (BWL) system in patient-relevant conditions and to evaluate the use of ultrasonic propulsion to move a stone or fragments to aid in observing the treatment endpoint.

Materials and Methods: The Propulse-1 system, used in clinical trials of ultrasonic propulsion and upgraded for BWL trials, was used to fragment 46 human stones (5–7 mm) in either a 15-mm or 4-mm diameter calix phantom in water at either 50% or 75% dissolved oxygen level. Stones were paired by size and composition, and exposed to 20-cycle, 390-kHz bursts at 6-MPa peak negative pressure (PNP) and 13-Hz pulse repetition frequency (PRF) or 7-MPa PNP and 6.5-Hz PRF. Stones were exposed in 5-minute increments and sieved, with fragments >2 mm weighed and returned for additional treatment. Effectiveness for pairs of conditions was compared statistically within a framework of survival data analysis for interval censored data. Three reviewers blinded to the experimental conditions scored ultrasound imaging videos for degree of fragmentation based on stone response to ultrasonic propulsion.

Results: Overall, 89% (41/46) and 70% (32/46) of human stones were fully comminuted within 30 and 10 minutes, respectively. Fragments remained after 30 minutes in 4% (1/28) of calcium oxalate monohydrate stones and 40% (4/10) of brushite stones. There were no statistically significant differences in comminution time between the two output settings (p = 0.44), the two dissolved oxygen levels (p = 0.65), or the two calyx diameters (p = 0.58). Inter-rater correlation on endpoint detection was substantial (Fleiss' kappa = 0.638, p < 0.0001), with individual reviewer sensitivities of 95%, 86%, and 100%.

Conclusions: Eighty-nine percent of human stones were comminuted with a clinical BWL system within 30 minutes under conditions intended to reflect conditions in vivo. The results demonstrate the advantage of using ultrasonic propulsion to disperse fragments when making a visual determination of breakage endpoint from the real-time ultrasound image.

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Inventions

Transvaginal or Transrectal Probe for Ureter Stone Lithotripsy

Record of Invention Number: 49263

Mike Bailey, Barbrina Dunmire, Jeff Thiel

Disclosure

12 May 2021

Broadly Focused Ultrasonic Propulsion Probes, Systems, and Methods

Disclosed herein are ultrasonic probes and systems incorporating the probes. The probes are configured to produce an ultrasonic therapy exposure that, when applied to a kidney stone, will exert an acoustic radiation force sufficient to produce ultrasonic propulsion. Unlike previous probes configured to produce ultrasonic propulsion, however, the disclosed probes are engineered to produce a relatively large (both wide and long) therapy region effective to produce ultrasonic propulsion. This large therapy region allows the probe to move a plurality of kidney stones (or fragments from lithotripsy) in parallel, thereby providing the user the ability to clear several stones from an area simultaneously. This "broadly focused" probe is, in certain embodiments, combined in a single handheld unit with a typical ultrasound imaging probe to produce real-time imaging. Methods of using the probes and systems to move kidney stones are also provided.

Patent Number: 10,667,831

Mike Bailey, Bryan Cunitz, Barbrina Dunmire, Adam Maxwell, Oren Levy

Patent

2 Jun 2020

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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Patent

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.

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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