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Mike Bailey

Senior Principal Engineer

Associate Professor, Mechanical Engineering and Adjunct Assistant Professor, Urology

Email

bailey@apl.washington.edu

Phone

206-685-8618

Research Interests

Medical Ultrasound, Acoustic Cavitation

Biosketch

Dr. Bailey's current research focuses on the role of cavitation in lithotripsy (kidney stone treatment) and ultrasound surgery. He is the lead APL-UW researcher on two collaborative programs among the Laboratory, Indiana University, Moscow State University, and the California Institute of Technology to optimize acoustic waves to exploit bioeffects due to cavitation. Previously, he was one of the designers of a shock wave lithotripter developed at APL-UW to concentrate cavitation and damage on the kidney stone and not on the kidney tissue. Dr. Bailey joined APL-UW in 1996.

Education

B.S. Mechanical Engineering, Yale University, 1991

M.S. Mechanical Engineering, The University of Texas at Austin, 1994

Ph.D. Mechanical Engineering, The University of Texas at Austin, 1997

Videos

Ultrasonic Propulsion of Residual Kidney Stone Framents

Ultrasonic propulsion, an investigational kidney stone treatment for awake un-anesthetized patients, sweeps stone fragments toward the ureter to facilitate their natural passage through the urine.

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9 Sep 2024

Ultrasonic propulsion, an investigational kidney stone treatment for awake un-anesthetized patients, sweeps stone fragments toward the ureter to facilitate their natural passage through the urine.

Nearly half of patients with small residual fragments following kidney stone surgery, relapse within five years.

Repositioning the fragments results in a 70% lower incidence of relapse -- urgent medical visit or a subsequent surgery. Time to relapse was also longer by nearly 1.5 year in the treatment group.

This study, led by University of Washington and Puget Sound VA investigators, was funded by the NIH.

Sorensen, M.D., et al., "Randomized controlled trial of ultrasonic propulsion-facilitated clearance of residual kidney stone fragments versus observation," J. Urol., doi:10.1097/JU.0000000000004186, 2024.
https://www.auajournals.org/doi/10.10...

Ultrasonic Kidney Stone Treatment for Pet Cats and Marine Mammals

A research kidney stone treatment system that is now undergoing clinical trials in humans was modified to noninvasively fragment stones in pet cats. The design accounted for differences in anatomic scale, acoustic window, skin-to-stone depth, and stone size. Veterinarian collaborators at the University of Minnesota have treated ureteral stones successfully in three cats.

The human system has also been used to treat a dolphin with a ureteral stone blockage and a harbor seal to reduce the stone burden in his kidneys.

20 Dec 2023

Ultrasonic tweezers: Technology to lift and steer solid objects in a living body

In a recent paper, a CIMU team describes successful experiments to manipulate a solid object within a living body with ultrasound beams transmitted through the skin.

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15 Jul 2020

A collaborative, international research teams developed and tuned an ultrasound transducer to create vortex shaped beams that can trap, grab, levitate, and move in three dimensions mm-scale objects. The team is working to apply this technology to their all-in-one kidney stone treatment system that, in clinical trials, uses ultrasound to non-invasively break, erode, and move stones and stone fragments out of the kidney so that they may pass naturally from the body.

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Publications

2000-present and while at APL-UW

No injury observed in kidneys treated with burst wave lithotripsy in therapeutically anticoagulated pigs

Shelton, T.M., B.A. Connors, M.E. Rivera, J.E. Lingeman, M.R. Bailey, and J.C. Williams Jr., "No injury observed in kidneys treated with burst wave lithotripsy in therapeutically anticoagulated pigs," J. Endourol., EOR, doi:10.1089/end.2024.0466, 2025.

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16 Jan 2025

Introduction: Current American Urological Association guidelines recommend that patients with acute obstructive kidney stone requiring continuous anticoagulation/antiplatelet therapy should not be treated by shockwave lithotripsy or percutaneous nephrolithotomy because of the risk of catastrophic renal hemorrhage possible with those techniques. Currently, ureteroscopy is the only recommended surgical treatment. We evaluated if burst wave lithotripsy (BWL) could be used in these cases by treating pigs with BWL while undergoing anticoagulation therapy.

Materials and Methods: Six pigs (31–37 kg) were given 200 units/kg porcine heparin, and then the right kidney of each animal was treated with a dose of BWL (18,000 ultrasound pulses at 10 Hz, 20 cycles/pulse, peak positive pressure of 12 MPa) known to fracture kidney stones. The contralateral kidney served as a control. Therapeutic anticoagulation was confirmed by evaluating activated partial thromboplastin time (aPTT). Microhematuria was checked by urine test strips. Kidneys were subsequently evaluated for hemorrhagic injury via MRI.

Results: aPTT was significantly elevated (>100 seconds) throughout the entire treatment period (p = <0.001) indicating therapeutic anticoagulation. Gross hematuria was not observed in any of the pigs. After BWL, microhematuria averaged 145.8 red blood cells (RBC)/μL in the BWL-treated kidney and 48 RBC/μL in the control kidneys, and there was no statistically significant difference noted in microhematuria rates between the two groups (p = 0.16). Hemorrhagic injury measured only 0.10 ± 0.02% of the tissue in the BWL-treated kidneys and 0.12 ± 0.04% in the control side, with a paired difference of –0.03 ± 0.05%, showing no significant difference (p = 0.58).

Conclusions: A typical clinical dose of BWL causes no hemorrhagic injury to the kidney even during therapeutic anticoagulation therapy. This result suggests that BWL should be safe to use in patients with stone undergoing anticoagulation/antiplatelet therapy.

Randomized controlled trial of ultrasonic propulsion-facilitated clearance of residual kidney stone fragments vs. observation

Sorensen, M.D., and 16 others including B. Dunmire, J. Thiel, B.W. Cunitz, J.C. Kucewicz, and M.R. Bailey, "Randomized controlled trial of ultrasonic propulsion-facilitated clearance of residual kidney stone fragments vs. observation," J. Urol., 6, 811-820, doi:10.1097/JU.0000000000004186, 2024.

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1 Dec 2024

Ultrasonic propulsion is an investigational procedure for awake patients. Our purpose was to evaluate whether ultrasonic propulsion to facilitate residual kidney stone fragment clearance reduced relapse.

This multicenter, prospective, open-label, randomized, controlled trial used single block randomization (1:1) without masking. Adults with residual fragments (individually 5 mm or smaller) were enrolled. Primary outcome was relapse as measured by stone growth, a stone-related urgent medical visit, or surgery by 5 years or study end. Secondary outcomes were fragment passage within 3 weeks and adverse events within 90 days. Cumulative incidence of relapse was estimated using the Kaplan-Meier method. Log-rank test was used to compare the treatment (ultrasonic propulsion) and control (observation) groups.

The trial was conducted from May 9, 2015, through April 6, 2024. Median follow-up (interquartile range) was 3.0 (1.8–3.2) years. The treatment group (n = 40) had longer time to relapse than the control group (n = 42; P < .003). The restricted mean time-to-relapse was 52% longer in the treatment group than in the control group (1530 ± 92 days vs 1009 ± 118 days), and the risk of relapse was lower (hazard ratio 0.30, 95% CI 0.13–0.68) with 8 of 40 and 21 of 42 participants, respectively, experiencing relapse. Omitting 3 participants not asked about passage, 24 treatment (63%) and 2 control (5%) participants passed fragments within 3 weeks of treatment. Adverse events were mild, transient, and self-resolving, and were reported in 25 treated participants (63%) and 17 controls (40%).

Application of a novel burst wave lithotripsy and ultrasonic propulsion technology for the treatment of ureteral calculi in a bottlenose dolphin (Tursiops truncatus) and renal calculi in a harbor seal (Phoca vitulina)

Holmes, A.E., and 17 others including J. Thiel and M.R. Bailey, "Application of a novel burst wave lithotripsy and ultrasonic propulsion technology for the treatment of ureteral calculi in a bottlenose dolphin (Tursiops truncatus) and renal calculi in a harbor seal (Phoca vitulina)," Urolithiasis, 52, doi:10.1007/s00240-023-01515-6, 2024.

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8 Jan 2024

Marine mammals may develop kidney stones, which can be challenging to treat. We describe burst wave lithotripsy (BWL) and ultrasonic propulsion to treat ureteral calculi in a 48-year-old female bottlenose dolphin (Tursiops truncatus) and to reduce renal stone burden in a 23-year-old male harbor seal (Phoca vitulina). BWL and ultrasonic propulsion were delivered transcutaneously in sinusoidal ultrasound bursts to fragment and reposition stones. Targeting and monitoring were performed with real-time imaging integrated within the BWL system. Four dolphin stones were obtained and fragmented ex vivo. The dolphin case received a 10-min and a 20-min BWL treatment conducted approximately 24 h apart to treat two 8–10 mm partially obstructing right mid-ureteral stones, using oral sedation alone. For the harbor seal, while under general anesthesia, retrograde ureteroscopy attempts were unsuccessful because of ureteral tortuosity, and a 30-min BWL treatment was targeted on one 10-mm right kidney stone cluster. All 4 stones fragmented completely to < 2-mm fragments in < 20 min ex vivo. In the dolphin case, the ureteral stones appeared to fragment, spread apart, and move with ultrasonic propulsion. On post-treatment day 1, the ureteral calculi fragments shifted caudally reaching the ureteral orifice on day 9. On day 10, the calculi fragments passed, and the hydroureter resolved. In the harbor seal, the stone cluster was observed to fragment and was not visible on the post-operative computed tomography scan. The seal had gross hematuria and a day of behavior indicating stone passage but overall, an uneventful recovery. BWL and ultrasonic propulsion successfully relieved ureteral stone obstruction in a geriatric dolphin and reduced renal stone burden in a geriatric harbor seal.

More Publications

In The News

Pushing kidney stone fragments reduces stones' recurrence

UW Medicine News

Using ultrasound to reposition the smaller grains significantly lowers patients’ returns to the operating room, a study finds.

12 Sep 2024

Office procedure found to get stone fragments rolling

Medscape, Howard Wolinsky

An experimental handheld ultrasonic device used in an office setting was shown to guide residual kidney stone fragments out of the body and markedly reduce the risk for relapse.

4 May 2024

Kidney stone breakthrough procedure at UW called 'game changer' for patients (video)

KOMO News, Preston Phillips

A groundbreaking medical procedure for those with kidney stones will soon be offered at the University of Washington after more than two decades of research. It will also give astronauts the go ahead they need from NASA to travel to Mars.

10 May 2023

More News Items

Inventions

Noninvasive fragmentation of urinary tract stones with focused ultrasound

Patent Number: 12,167,864

Bryan Cunitz, Wayne Kreider, Oleg Sapozhnikov, Mike Bailey

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Patent

17 Dec 2024

A method for attempting to fragment or comminute an object in a body using ultrasound includes producing a burst wave lithotripsy (BWL) waveform by a therapy transducer. The BWL waveform is configured to fragment or comminute the object. The BWL waveform includes a first burst of continuous ultrasound cycles and a second burst of continuous ultrasound cycles. A burst frequency corresponds to a frequency of repeating the bursts of the BWL waveform. The method also includes determining a cycle frequency f of the continuous ultrasound cycles within the first burst and the second burst based on a target fragment size D, where the cycle frequency is: f(MHz)=0.47/D(mm).

Boiling histotripsy methods and systems for uniform volumetric ablation of an object by high-intensity focused ultrasound waves with shocks

Patent #12,157,018

Patent Number: 12,157,018

Vera Khokhlova, Mike Bailey, Wayne Kreider, Oleg Sapozhnikov, Yak-Nam Wang

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Patent

3 Dec 2024

An example method includes generating an acoustic ultrasound wave that is focused at a focal point. The method further includes sequentially directing the focal point upon distinct portions of an object to form respective shock waves at the distinct portions of the object. The method further includes, via the respective shock waves, causing the distinct portions of the object to boil and form respective vapor cavities. The method further includes causing substantially uniform ablation of a region of the object that comprises the distinct portions. The substantially uniform ablation is caused via interaction of the respective shock waves with the respective vapor cavities. An example ablation system and an example non-transitory computer-readable medium, both related to the example method, are also disclosed.

High Intensity Focused Ultrasound Systems for Treating Tissue

Inventors: Y.-N. Wang, M.R. Bailey, T.D. Khokhlova (Seattle), W. Kreider, A.D. Maxwell, G.R. Schade (Seattle), and V.A. Khokhlova

Patent Number: 11,857,813

Yak-Nam Wang, Mike Bailey, Wayne Kreider, Adam Maxwell, Vera Khokhlova

Patent

2 Jan 2024

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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