![]() |
Barbrina Dunmire Senior Engineer 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. |
More Info |
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. |
![]() |
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 |
![]() |
Fragmentation of stones by burst wave lithotripsy in the first 19 humans Harper, J.D., J.E. Lingeman, R.M. Sweet, I.S. Metzler, P. Sunaryo, J.C. Williams, A.D. Maxwell, J. Thiel, B.M. Cunitz, B. Dunmire, M.R. Bailey, and M.D. Sorensen, "Fragmentation of stones by burst wave lithotripsy in the first 19 humans," J. Urol., 207, doi:10.1097/JU.0000000000002446, 2022. |
More Info |
1 May 2022 ![]() |
![]() |
|||||
We report stone comminution in the first 19 human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses. This was a prospective multi-institutional feasibility study recruiting subjects undergoing clinical ureteroscopy (URS) for at least 1 stone ≤12 mm as measured on computerized tomography. During the planned URS, either before or after ureteroscope insertion, BWL was administered with a handheld transducer, and any stone fragmentation and tissue injury were observed. Up to 3 stones per subject were targeted, each for a maximum of 10 minutes. The primary effectiveness outcome was the volume percent comminution of the stone into fragments ≤2 mm. The primary safety outcome was the independent, blinded visual scoring of tissue injury from the URS video. Overall, median stone comminution was 90% (IQR 20, 100) of stone volume with 21 of 23 (91%) stones fragmented. Complete fragmentation (all fragments ≤2 mm) within 10 minutes of BWL occurred in 9 of 23 stones (39%). Of the 6 least comminuted stones, likely causative factors for decreased effectiveness included stones that were larger than the BWL beamwidth, smaller than the BWL wavelength or the introduction of air bubbles from the ureteroscope. Mild reddening of the papilla and hematuria emanating from the papilla were observed ureteroscopically. The first study of BWL in human subjects resulted in a median of 90% comminution of the total stone volume into fragments ≤2 mm within 10 minutes of BWL exposure with only mild tissue injury. |
![]() |
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., 22, 345-359, doi:10.1002/acm2.13074, 2021. |
More Info |
1 Sep 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. |
![]() |
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. |
More Info |
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). |
![]() |
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. |
More Info |
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. |
![]() |
Evidence of microbubbles on kidney stones in humans Simon, J.C., J.R. Holm, J. Thiel, B. Dunmire, B.W. Cunitz, and M.R. Bailey, "Evidence of microbubbles on kidney stones in humans," Ultrasound Med. Biol., 46, 1802-1807, doi:10.1016/j.ultrasmedbio.2020.02.010, 2020. |
More Info |
1 Jul 2020 ![]() |
![]() |
|||||
The color Doppler ultrasound twinkling artifact has been found to improve detection of kidney stones with ultrasound; however, it appears on only ~60% of stones. Evidence from ex vivo kidney stones suggests twinkling arises from microbubbles stabilized in crevices on the stone surface. Yet it is unknown whether these bubbles are present on stones in humans. Here, we used a research ultrasound system to quantify twinkling in humans with kidney stones in a hyperbaric chamber. Eight human patients with non-obstructive kidney stones previously observed to twinkle were exposed to a maximum pressure of 4 atmospheres absolute (ATA) while breathing air, except during the 10-min pause at 1.6 ATA and while the pressure decreased to 1 ATA, during which patients breathed oxygen to minimize the risk of decompression sickness. A paired one-way t-test was used to compare the mean twinkle power at each pressure pause with baseline twinkling, with p < 0.05 considered to indicate significance. Results revealed that exposure to 3 and 4 ATA of pressure significantly reduced twinkle power by averages of 35% and 39%, respectively, in 7 patients (p = 0.04); data from the eighth patient were excluded because of corruption. This study supports the theory that microbubbles are present on kidney stones in humans. |
![]() |
In-office ultrasound facilitates timely clinical care at a multidisciplinary kidney stone center Sorensen, M.D., J. Thiel, J. Dai, M. Bailey, B. Dunmire, P.C. Samson, H. Chang, M.K. Hall, B. Butierrez, R.M. Sweet, and J.D. Harper, "In-office ultrasound facilitates timely clinical care at a multidisciplinary kidney stone center," Urol. Pract., 7, 167-172, doi:10.1097/UPJ.0000000000000082, 2020. |
More Info |
1 May 2020 ![]() |
![]() |
|||||
A considerable publication record exists comparing sensitivity and specificity of radiological ultrasound (including point of care ultrasound) to computerized tomography for stone disease. However, the practical application of in-office ultrasound to support the growing number of kidney stone centers around the world represents a nuanced topic that is ripe for study and discussion. We provide a descriptive analysis of how in-office ultrasound is being used as an adjunct to clinical care based on our experience during 50 days in clinic at an institutionally affiliated, multidisciplinary kidney stone center. Clinic subjects gave consent and underwent ultrasound as part of research studies. Ultrasonograms were shared with and verified by the treating physician before the patient was discharged from care. We counted the number of times research imaging altered the care plan. Of the 60 patients enrolled the clinician used the information obtained from the studies in 20 (33%) to determine the course of clinical care that resulted in a change in treatment or process. Ultrasound has the potential to be a cost-effective and valuable tool that can provide more efficient workflow within a kidney stone center or urology clinic. |
![]() |
Quantitative assessment of effectiveness of ultrasonic propulsion of kidney stones Dai, J.C., M.D. Sorensen, H.C. Chang, P.C. Samson, B. Dunmire, B.W. Cunitz, J. Thiel, Z. Liu, M.R. Bailey, and J.D. Harper, "Quantitative assessment of effectiveness of ultrasonic propulsion of kidney stones," J. Endourol., 33, doi:10.1089/end.2019.0340, 2019. |
More Info |
15 Oct 2019 ![]() |
![]() |
|||||
Ultrasonic propulsion is an investigative modality to noninvasively image and reposition urinary stones. Our goals were to test safety and effectiveness of new acoustic exposure conditions from a new transducer, and to use simultaneous ureteroscopic and ultrasonic observation to quantify stone repositioning. |
![]() |
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. |
More Info |
26 Dec 2018 ![]() |
![]() |
|||||
Proceedings, 176th Meeting of the Acoustical Society of America, 5-9 November 2018, Victoria, BC, Canada. |
![]() |
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. |
More Info |
21 Dec 2018 ![]() |
![]() |
|||||
176th Meeting of the Acoustical Society of America 5-9 November 2018, Victoria, BC, Canada. |
![]() |
Measurement of posterior acoustic stone shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing Dai, J.C., B. Dunmire, Z. Liu, K.M. Sternberg, M.R. Bailey, J.D. Harper, and M.D. Sorensen, "Measurement of posterior acoustic stone shadow on ultrasound is a learnable skill for inexperienced users to improve accuracy of stone sizing," J. Endourol., 32, doi:10.1089/end.2018.0577, 2018. |
More Info |
8 Nov 2018 ![]() |
![]() |
|||||
Introduction: Studies suggest that the width of the acoustic shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for training in the adoption of the acoustic shadow sizing technique by clinical providers. |
![]() |
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. |
More Info |
1 May 2018 ![]() |
![]() |
|||||
Purpose |
![]() |
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. |
More Info |
1 Apr 2018 ![]() |
![]() |
|||||
Purpose |
![]() |
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. |
More Info |
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. |
![]() |
Effect of stone size and composition on ultrasonic propulsion ex vivo Janssen, K.M., T.C. Brand, M.R. Bailey, B.W. Cunitz, J.D. Harper, M.D. Sorensen, and B. Dunmire, "Effect of stone size and composition on ultrasonic propulsion ex vivo," Urology, 111, 225-229, doi:10.1016/j.urology.2017.09.013, 2018. |
More Info |
1 Jan 2018 ![]() |
![]() |
|||||
Objective |
![]() |
Characterizing the acoustic output of an ultrasonic propulsion device for urinary stones Cunitz, B.W., B. Dunmire, and M.R. Bailey, "Characterizing the acoustic output of an ultrasonic propulsion device for urinary stones," IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 64, 1818-1827, doi:10.1109/TUFFC.2017.2758647, 2017. |
More Info |
1 Dec 2017 ![]() |
![]() |
|||||
A noninvasive ultrasound (US) system to facilitate the passage of small kidney stones has been developed. The device incorporates a software-based US platform programmed with brightness mode and Doppler for visualizing stones, plus long duration focused pulses for repositioning stones using the same transducer. This paper characterizes the acoustic outputs of the ultrasonic propulsion device. Though the application and outputs are unique, measurements were performed based on the regulatory standards for both diagnostic US and extracorporeal lithotripters. The extended length of the pulse, time varying pressure output over the pulse, the use of focused targeting, and the need to regulate the output at shallow depths, however, required modifications to the traditional acoustic measurement methods. Output parameters included spatial-peak intensities, mechanical index (MI), thermal index, pulse energy, focal geometry, and target accuracy. The imaging and Doppler operating modes of the system meet the Food and Drug Administration acoustic power and intensity limits for diagnostic US device. Push mode operates at a maximum MI of 2.2, which is above the limit of 1.9 for diagnostic US, but well below any lithotripsy device and an ISPTA of 548 mW/cm2, which is below the 720-mW/cm2 limit for diagnostic US. |
![]() |
Design and characterization of a research phantom for shock-wave enhanced irradiations in high intensity focused ultrasound therapy Kreider, W., B. Dunmire, J. Kucewicz, C. Hunter, T. Khokhlova, G. Schade, A. Maxwell, O. Sapozhnikov, L. Crum, and V. Khokhlova, "Design and characterization of a research phantom for shock-wave enhanced irradiations in high intensity focused ultrasound therapy," Proc., IEEE International Ultrasonics Symposium, 6-9 September, Washington, D.C., doi:10.1109/ULTSYM.2017.8092866 (IEEE, 2017). |
More Info |
2 Nov 2017 ![]() |
![]() |
|||||
The use of shock waves for enhancing thermal effects and mechanically ablating tissue is gaining increased attention in high intensity focused ultrasound (HIFU) applications such as tumor treatment, drug delivery, noninvasive biopsy, and immunotherapy. For abdominal targets, the presence of ribs and inhomogeneous adipose tissue can affect shock formation through aberration, absorption, and diffraction. The goal of this study was to design and validate a phantom for investigating the impact of different tissue structures on shock formation in situ. A transducer with driving electronics was developed to operate at 1.2 MHz with the ability to deliver either short pulses at high powers (up to 5 kW electric power) or continuous output at moderate powers (up to 700 W). Fat and muscle layers were represented by phantoms made from polyvinyl alcohol. Ribs were 3D-printed from a photopolymer material based on 3D CT scan images. Representative targeted tissue was comprised of optically transparent alginate or polyacrylamide gels. The system was characterized by hydrophone measurements free-field in water and in the presence of a body wall or rib phantoms. Shocked waveforms with peak positive/negative pressures of +100 / 20 MPa were measured at the focus in a free field at 1 kW electric source power. When ribs were present, shocks formed at about 50% amplitude at the same power, and higher pressures were measured with ribs positioned closer to the transducer. A uniform body wall structure attenuated shock amplitudes by a smaller amount than non-uniform, and the measurements were insensitive to the axial position of the phantom. Signal magnitude loss at the focus for both the rib phantoms and abdominal wall tissue were consistent with results from real tissues. In addition, boiling histotripsy lesions were generated and visualized in the target gels. The results demonstrate that the presence of ribs and absorptive tissue-mimicking layers do not prevent shock formation at the focus. With real-time lesion visualization, the phantom is suitable for adaptation as a training tool. |
![]() |
Imaging in situ human kidney stones with the color Doppler ultrasound twinkling artifact Simon, J., B. Dunmire, B. Cunitz, O. Sapozhnikov, J. Thiel, J. Holm, and M. Bailey, "Imaging in situ human kidney stones with the color Doppler ultrasound twinkling artifact," Proc., IEEE International Ultrasonics Symposium, 6-9 September, Washington, D.C., doi:10.1109/ULTSYM.2017.8092599 (IEEE, 2017). |
More Info |
2 Nov 2017 ![]() |
![]() |
|||||
Hyperbaric pressures of 3100 atmospheres absolute (ATA) have been shown to reduce the color Doppler ultrasound twinkling artifact on ex vivo human kidney stones, leading to the hypothesis that surface crevice microbubbles cause twinkling. Similarly supportive for the crevice bubble hypothesis is the suppression of kidney stone twinkling in animals breathing elevated levels of carbon dioxide. However, it is unclear whether stable microbubbles can exist on the surface of kidney stones in the human body. For the first time, we investigate the effect of hyperbaric pressure on in situ human kidney stones to determine whether stable microbubbles exist as measured by the color Doppler ultrasound twinkling artifact. |
![]() |
Preclinical safety and effectiveness of a longer beam and burst duration for ultrasonic repositioning of urinary stones Dunmire, B., K.M. Janssen, T.C. Brand, B.W. Cunitz, Y.-N. Wang, J.C. Simon, F. Starr, H. Denny Liggitt, J. Thiel, J.D. Harper, M.D. Sorensen, and M.R. Bailey, "Preclinical safety and effectiveness of a longer beam and burst duration for ultrasonic repositioning of urinary stones," Proc., IEEE International Ultrasonics Symposium, 6-9 September 2017, Washington, D.C., doi:10.1109/ULTSYM.2017.8092038 (IEEE, 2017). |
More Info |
2 Nov 2017 ![]() |
![]() |
|||||
In the first-in-human trial of ultrasonic propulsion, subjects passed collections of residual stone fragments after repositioning with a C5-2 probe. Here, effectiveness and safety in moving multiple fragments is compared between the C5-2 and a custom SC-50 probe that produces a longer beam and burst duration. |
![]() |
Quantification of renal stone contrast with ultrasound in human subjects Cunitz, B.W., J.D. Harper, M.D. Sorensen, Y.A. Haider, J. Thiel, P.C. May, Z. Liu, M.R. Bailey, B. Dunmire, and M. Bruce, "Quantification of renal stone contrast with ultrasound in human subjects," J. Endourol., 31, 1123-1130, doi:10.1089/end.2017.0404, 2017. |
More Info |
1 Nov 2017 ![]() |
![]() |
|||||
Purpose: Greater visual contrast between calculi and tissue would improve ultrasound (US) imaging of urolithiasis and potentially expand clinical use. The color Doppler twinkling artifact has been suggested to provide enhanced contrast of stones compared with brightness mode (B-mode) imaging, but results are variable. This work provides the first quantitative measure of stone contrast in humans for B-mode and color Doppler mode, forming the basis to improve US for the detection of stones. |
![]() |
Ultrasound-induced bubble clusters in tissue-mimicking agar phantoms Movahed, P., W. Kreider, A.D. Maxwell, B. Dunmire, and J.B. Freund, "Ultrasound-induced bubble clusters in tissue-mimicking agar phantoms," Ultrasound Med. Biol., 43, 2318-2328, doi:10.1016/j.ultrasmedbio.2017.06.013, 2017. |
More Info |
1 Oct 2017 ![]() |
![]() |
|||||
Therapeutic ultrasound can drive bubble activity that damages soft tissues. To study the potential mechanisms of such injury, transparent agar tissue-mimicking phantoms were subjected to multiple pressure wave bursts of the kind being considered specifically for burst wave lithotripsy. A high-speed camera recorded bubble activity during each pulse. Various agar concentrations were used to alter the phantom's mechanical properties, especially its stiffness, which was varied by a factor of 3.5. However, the maximum observed bubble radius was insensitive to stiffness. During 1000 wave bursts of a candidate burst wave lithotripsy treatment, bubbles appeared continuously in a region that expanded slowly, primarily toward the transducer. Denser bubble clouds are formed at higher pulse repetition frequency. The specific observations are used to inform the incorporation of damage mechanisms into cavitation models for soft materials. |
![]() |
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. |
More Info |
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. |
![]() |
Developing complete ultrasonic management of kidney stones for spaceflight Simon, J.C., B. Dunmire, M.D. Sorensen, and M.R. Bailey, "Developing complete ultrasonic management of kidney stones for spaceflight," J. Space Safety Eng., 3, 50-57, 2016. |
More Info |
1 Sep 2016 ![]() |
![]() |
|||||
Bone demineralization, dehydration, and stasis put astronauts at an increased risk of forming kidney stones in space. The incidence of kidney stones and the potential for a mission-critical event are expected to rise as expeditions become longer and immediate transport to Earth becomes more problematic. At the University of Washington, we are developing an ultrasound-based stone management system to detect stones with S-modeTM ultrasound imaging, break stones with burst wave lithotripsy (BWLTM), and reposition stones with ultrasonic propulsion (UPTM) on Earth and in space. This review discusses the development and current state of these technologies, as well as integration on the flexible ultrasound system sponsored by NASA and the National Space Biomedical Research Institute. |
![]() |
First-in-human clinical trial of ultrasonic propulsion of kidney stones Harper, J.D., B.W. Cunitz, B. Dunmire, F.C. Lee, M.D. Sorensen, R.S. Hsi, J. Thiel, H. Wessells, J.E. Lingeman, and M.R. Bailey, "First-in-human clinical trial of ultrasonic propulsion of kidney stones," J. Urol., 195, 956-964, doi:10.1016/j.juro.2015.10.131, 2016. |
More Info |
1 Apr 2016 ![]() |
![]() |
|||||
Ultrasonic propulsion is a new technology using focused ultrasound energy applied transcutaneously to reposition kidney stones. We report the findings from the first human investigational trial of ultrasonic propulsion toward the applications of expelling small stones and dislodging large obstructing stones. |
![]() |
Use of the acoustic shadow width to determine kidney stone size with ultrasound Dunmire, B., J.D. Harper, B.W. Cunitz, F.C. Lee, R. Hsi, Z. Liu, M.R. Bailey, and M.D. Sorensen, "Use of the acoustic shadow width to determine kidney stone size with ultrasound," J. Urol., 195, 171-176, doi:10.1016/j.juro.2015.05.111, 2016. |
More Info |
1 Jan 2016 ![]() |
![]() |
|||||
Ultrasound is known to overestimate kidney stone size. We explored measuring the acoustic shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy. A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the acoustic shadow were measured by 4 operators blinded to the true size of the stone. |
![]() |
Renal vasoconstriction occurs early during shockwave lithotripsy in humans Lee, F.C., R.S. Hsi, M.D. Sorensen, M. Paun, B. Dunmire, Z. Liu, M. Bailey, and J.D. Harper, "Renal vasoconstriction occurs early during shockwave lithotripsy in humans," J. Endourol., 29, 1392-1395, doi:10.1089/end.2015.0315, 2015. |
More Info |
1 Dec 2015 ![]() |
![]() |
|||||
In animal models, pretreatment with low-energy shock waves and a pause decreased renal injury from shockwave lithotripsy (SWL). This is associated with an increase in perioperative renal resistive index (RI). A perioperative rise is not seen without the protective protocol, which suggests that renal vasoconstriction during SWL plays a role in protecting the kidney from injury. The purpose of our study was to investigate whether there is an increase in renal RI during SWL in humans. |
![]() |
Non-invasive measurement of the temperature rise in tissue surrounding a kidney stone subjected to ultrasonic propulsion Oweis, G.F., B.L. Dunmire, B.W. Cunitz, and M.R. Bailey, "Non-invasive measurement of the temperature rise in tissue surrounding a kidney stone subjected to ultrasonic propulsion," Proc., 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 25-29 August, Milan, Italy, 2576-2579, doi:10.1109/EMBC.2015.7318918 (IEEE, 2015). |
More Info |
25 Aug 2015 ![]() |
![]() |
|||||
Transcutaneous focused ultrasound (US) is used to propel kidney stones using acoustic radiation force. It is important to estimate the level of heating generated at the stone/tissue interface for safety assessment. An in-vitro experiment is conducted to measure the temperature rise in a tissue-mimicking phantom with an embedded artificial stone and subjected to a focused beam from an imaging US array. A novel optical-imaging-based thermometry method is described using an optically clear tissue phantom. Measurements are compared to the output from a fine wire thermocouple placed on the stone surface. The optical method has good sensitivity, and it does not suffer from artificial viscous heating typically observed with invasive probes and thermocouples. |
![]() |
Tools to improve the accuracy of kidney stone sizing with ultrasound Dunmire, B., F.C. Lee, R.S. Hsi, B.W. Cunitz, M. Paun, M.R. Bailey, M.D. Sorensen, and J.D. Harper, "Tools to improve the accuracy of kidney stone sizing with ultrasound," J. Endourol. 29, 147-152, doi:, 2015. |
More Info |
30 Jan 2015 ![]() |
![]() |
|||||
Ultrasound (US) overestimates stone size when compared with CT. The purpose of this work was to evaluate the overestimation of stone size with US in an in vitro water bath model and investigate methods to reduce overestimation. |
![]() |
Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones Harper, J.D., B. Dunmire, Y.-N. Wang, J.C. Simon, D. Liggitt, M. Paun, B.W. Cunitz, F. Starr, M.R. Bailey, K.L. Penniston, F.C. Lee, R.S. Hsi, and M.D. Sorensen, "Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones," Urology, 84, 484-489, doi:10.1016/j.urology.2014.04.041, 2014. |
More Info |
1 Aug 2014 ![]() |
![]() |
|||||
Objective |
![]() |
Focused ultrasound to displace renal calculi: Threshold for tissue injury Wang, Y.-N., J.C. Simon, B.W. Cunitz, F.L. Starr, M. Paun, D.H. Liggitt, A.P. Evan, J.A. McAteer, Z. Liu, B. Dunmire, and M.R. Bailey, "Focused ultrasound to displace renal calculi: Threshold for tissue injury," J. Therapeut. Ultrasound, 2, doi:10.1186/2050-5736-2-5, 2014. |
More Info |
31 Mar 2014 ![]() |
![]() |
|||||
The global prevalence and incidence of renal calculi is reported to be increasing. Of the patients that undergo surgical intervention, nearly half experience symptomatic complications associated with stone fragments that are not passed and require follow-up surgical intervention. In a clinical simulation using a clinical prototype, ultrasonic propulsion was proven effective at repositioning kidney stones in pigs. The use of ultrasound to reposition smaller stones or stone fragments to a location that facilitates spontaneous clearance could therefore improve stone-free rates. The goal of this study was to determine an injury threshold under which stones could be safely repositioned. |
![]() |
Content and face validation of a curriculum for ultrasonic propulsion of calculi in a human renal model Hsi, R.S., B. Dunmire, B.W. Cunitz, X. He, M.D. Sorensen, J.D. Harper, M.R. Bailey, and T.S. Lendvay, "Content and face validation of a curriculum for ultrasonic propulsion of calculi in a human renal model," J. Endourol., 28, 459-463, doi:10.1089/end.2013.0589, 2014. |
More Info |
20 Mar 2014 ![]() |
![]() |
|||||
Purpose: Ultrasonic propulsion to reposition urinary tract calculi requires knowledge about ultrasound image capture, device manipulation, and interpretation. The purpose of this study was to validate a cognitive and technical skills curriculum to teach urologists ultrasonic propulsion to reposition kidney stones in tissue phantoms. |
![]() |
A reflectance model for non-contact mapping of venous oxygen saturation using a CCD camera Li, J., B. Dunmire, K.W. Beach, and D.F. Leotta, "A reflectance model for non-contact mapping of venous oxygen saturation using a CCD camera," Opt. Commun., 308, 78-84, doi:10.1016/j.optcom.2013.06.041, 2013. |
More Info |
1 Nov 2013 ![]() |
![]() |
|||||
A method of non-contact mapping of venous oxygen saturation (SvO2) is presented. A CCD camera is used to image skin tissue illuminated alternately by a red (660 nm) and an infrared (800 nm) LED light source. Low cuff pressures of 3040 mmHg are applied to induce a venous blood volume change with negligible change in the arterial blood volume. A hybrid model combining the BeerLambert law and the light diffusion model is developed and used to convert the change in the light intensity to the change in skin tissue absorption coefficient. A simulation study incorporating the full light diffusion model is used to verify the hybrid model and to correct a calculation bias. SvO2 in the fingers, palm, and forearm for five volunteers are presented and compared with results in the published literature. Two-dimensional maps of venous oxygen saturation are given for the three anatomical regions. |
![]() |
An ultrasound system to identify and characterize kidney stones Cunitz, B.W., B.L. Dunmire, M.D. Sorensen, R. Hsi, F. Lee, O.A. Sapozhnikov, J.D. Harper, and M. Bailey, "An ultrasound system to identify and characterize kidney stones," J. Acoust. Soc. Am., 134, 3976, doi:10.1121/1.4830485, 2013. |
More Info |
1 Nov 2013 ![]() |
![]() |
|||||
Ultrasound imaging has tissue and blood imaging modes. This report describes development of a kidney stone imaging mode. Two plane pulses generate a B-mode image. Overlaid in color are regions of high decorrelation between the pulses. Our previous data [UMB, 39, 1026-1038 (2013)] indicate the pulses excite bubbles on the stone surface, which causes the decorrelation. As such this mode automatically identifies stones in the image while scanning at a high frame rate. Further in a control box placed on the stone, highly focused beams are scanned across the stone and a harmonic B-mode image is produced to sharpen the lateral resolution. This mode is used to refine the size and shape of the stone. The first mode is used to aid visualization of stones. Our team is also using it to target and track stones that move with respiration during shock wave lithotripsy (SWL) and as an indicator of stone susceptibility to SWL since surface bubbles contribute to comminution. Improved stone sizing by the second mode aids treatment planning, and resolution of surface roughness is another indicator of stone fragility. |
![]() |
Holography and numerical projection methods for characterizing the three-dimensional acoustic fields of arrays in continuous-wave and transient regimes Kreider, W., A.D. Maxwell, P.V. Yuldashev, B.W. Cunitz, B. Dunmire, O.A. Sapozhnikov, and V.A. Khokhlova, "Holography and numerical projection methods for characterizing the three-dimensional acoustic fields of arrays in continuous-wave and transient regimes," J. Acoust. Soc. Am., 134, 4153, doi:10.1121/1.4831222, 2013. |
More Info |
1 Nov 2013 ![]() |
![]() |
|||||
The use of projection methods is increasingly accepted as a standard way of characterizing the 3D fields generated by medical ultrasound sources. When combined with hydrophone measurements of pressure amplitude and phase over a surface transverse to the wave propagation, numerical projection can be used to reconstruct 3D fields that account for operational details and imperfections of the source. Here, we use holography measurements to characterize the fields generated by two array transducers with different geometries and modes of operation. First, a seven-element, high-power therapy transducer is characterized in the continuous-wave regime using holography measurements and nonlinear forward-projection calculations. Second, a C5-2 imaging probe (Philips Healthcare) with 128 elements is characterized in the transient regime using holography measurements and linear projection calculations. Results from the numerical projections for both sources are compared with independent hydrophone measurements of select waveforms, including shocked focal waveforms for the therapy transducer. Accurate 3D field representations have been confirmed, though a notable sensitivity to hydrophone calibrations is revealed. Uncertainties associated with this approach are discussed toward the development of holography measurements combined with numerical projections as a standard metrological tool. |
![]() |
Focused ultrasound to expel calculi from the kidney: Safety and efficacy of a clinical prototype device Harper, J.D., M.D. Sorensen, B.W. Cunitz, Y.-N. Wang, J.C. Simon, F. Starr, M. Paun, B. Dunmire, H.D. Liggitt, A.P. Evan, J.A. McAteer, R.S. Hsi, and M.R. Bailey, "Focused ultrasound to expel calculi from the kidney: Safety and efficacy of a clinical prototype device," J. Urol., 190, 1090-1095, doi:10.1016/j.juro.2013.03.120, 2013. |
More Info |
9 Apr 2013 ![]() |
![]() |
|||||
Purpose |
![]() |
Characterizing an agar/gelatin phantom for image guided dosing and feeback control of high-intensity focused ultrasound Dunmire, B., J.C. Kucewicz, S.B. Mitchell, L.A. Crum, and K.M Sekins, "Characterizing an agar/gelatin phantom for image guided dosing and feeback control of high-intensity focused ultrasound," Ultrasound Med. Biol., 39, 300-311, 2013. |
More Info |
1 Feb 2013 ![]() |
![]() |
|||||
The temperature dependence of an agar/gelatin phantom was evaluated. The purpose was to predict the material property response to high-intensity focused ultrasound (HIFU) for developing ultrasound guided dosing and targeting feedback. Changes in attenuation, sound speed, shear modulus and thermal properties with temperature were examined from 20°C to 70°C for 3 weeks post-manufacture. The attenuation decreased with temperature by a power factor of 0.15. Thermal conductivity, diffusivity and specific heat all increased linearly with temperature for a total change of approximately 16%, 10% and 6%, respectively. Sound speed had a parabolic dependence on temperature similar to that of water. Initially, the shear modulus irreversibly declined with even a slight increase in temperature. Over time, the gel maintained its room temperature shear modulus with moderate heating. A stable phantom was achieved within 2 weeks post-manufacture that possessed quasi-reversible material properties up to nearly 55°C. |
![]() |
Autoregressive ultrasound imaging method to enhance kidney stone twinkling and suppress blood flow Kucewicz, J.C., B.W. Cunitz, B. Dunmire, M.R. Bailey, and L.A. Crum, "Autoregressive ultrasound imaging method to enhance kidney stone twinkling and suppress blood flow," J. Acoust. Soc. Am., 129, 2376, doi:10.1121/1.3587699, 2011. |
More Info |
1 Apr 2011 ![]() |
![]() |
|||||
"Twinkling" is a widely reported ultrasound artifact whereby kidney stones and other similar calcified, strongly reflective objects appear as turbulent, flowing blood in color and power Doppler. The twinkling artifact has been shown to improve kidney stone detection over B-mode imaging alone, but its use has several limitations. Principally, twinkling can be confused with blood flow, potentially leading to an incorrect diagnosis. Here a new method is reported for explicitly suppressing the display of color from blood flow to enhance and/or isolate the twinkle signal. The method applies an autoregressive model to standard Doppler pulses in order to differentiate tissue, blood flow, and twinkling. The algorithm was implemented on a software-based, open architecture ultrasound system and tested by a sonographer on phantoms and on stones implanted in a live porcine kidney. Stones of 3-10 mm were detected reproducibly while suppressing blood flow in the image. In conclusion, a new algorithm designed to specifically detect stones has been tested and has potential clinical utility especially as efforts are made to reduce radiation exposure on diagnosis and monitoring. |
![]() |
Understanding changes in tissue phantom material properties with temperature Dunmire, B.L., J.C. Kucewicz, S.B. Mitchell, L.A. Crum, and K.M. Sekins, "Understanding changes in tissue phantom material properties with temperature," J. Acoust. Soc. Am., 129, 2405, doi:10.1121/1.3587832, 2011. |
More Info |
1 Apr 2011 ![]() |
![]() |
|||||
Phantoms used for high intensity focused ultrasound (HIFU) applications require rigorous evaluation of material properties since, locally, the material experiences extreme changes in temperature and stresses with the HIFU treatment. Here we present the testing of an agar-gelatin phantom intended for both acoustic radiation force imaging (ARFI) and HIFU applications. The phantom shear modulus, speed of sound, attenuation, and thermal properties were all evaluated over the range of room temperature to 80C. With the exception of the thermal properties, all measurements were taken during both heating and cool down. Cavitation threshold and melting point were also tested. The change in material sound speed and thermal properties with temperature were quasireversible and similar to that of water. Material attenuation showed a slight decrease with temperature, but appeared to also be reversible. Shear modulus decreased significantly with temperature, going to near zero. The response was not reversible, returning to only approximately one-third of the starting value. These results demonstrate the complex material response that can occur with HIFU treatment. The results also raise the question of how well the test procedures, and thus results, properly reflect the true HIFU conditions. |
![]() |
Tissue pulsatility imaging of cerebral vasoreactivity during hyperventilation Kucewicz, J.C., B. Dunmire, N.D. Giardino, D.F. Leotta, M. Paun, S.R. Dager, and K.W. Beach, "Tissue pulsatility imaging of cerebral vasoreactivity during hyperventilation," Ultrasound Med. Biol., 34, 1200-1208, doi:10.1016/j.ultrasmedbio.2008.01.001, 2008. |
More Info |
1 Aug 2008 ![]() |
![]() |
|||||
Tissue Pulsatility Imaging (TPI) is an ultrasonic technique that is being developed at the University of Washington to measure tissue displacement or strain due to blood flow over the cardiac and respiratory cycles. This technique is based in principle on plethysmography, an older non-ultrasound technology for measuring expansion of a whole limb or body part due to perfusion. TPI adapts tissue Doppler signal processing methods to measure the "plethysmographic" signal from hundreds or thousands of sample volumes in an ultrasound image plane. This paper presents a feasibility study to determine if TPI can be used to assess cerebral vasoreactivity. Ultrasound data were collected transcranially through the temporal acoustic window from four subjects before, during, and after voluntary hyperventilation. In each subject, decreases in tissue pulsatility during hyperventilation were observed that were statistically correlated with the subject's end-tidal CO2 measurements. |
![]() |
Functional tissue pulsatility imaging of the brain during visual stimulation Kucewicz, J.C., B. Dunmire, D.F. Leotta, H. Panagiotides, M. Paun, and K.W. Beach, "Functional tissue pulsatility imaging of the brain during visual stimulation," Ultrasound Med. Biol., 33, 681-690, 2007. |
More Info |
1 May 2007 ![]() |
![]() |
|||||
Functional tissue pulsatility imaging is a new ultrasonic technique being developed to map brain function by measuring changes in tissue pulsatility as a result of changes in blood flow with neuronal activation. The technique is based in principle on plethysmography, an older, nonultrasound technology for measuring expansion of a whole limb or body part as a result of perfusion. Perfused tissue expands by a fraction of a percent early in each cardiac cycle when arterial inflow exceeds venous outflow, and it relaxes later in the cardiac cycle when venous drainage dominates. Tissue pulsatility imaging (TPI) uses tissue Doppler signal processing methods to measure this pulsatile "plethysmographic" signal from hundreds or thousands of sample volumes in an ultrasound image plane. A feasibility study was conducted to determine if TPI could be used to detect regional brain activation during a visual contrast-reversing checkerboard block paradigm study. During a study, ultrasound data were collected transcranially from the occipital lobe as a subject viewed alternating blocks of a reversing checkerboard (stimulus condition) and a static, gray screen (control condition). Multivariate analysis of variance was used to identify sample volumes with significantly different pulsatility waveforms during the control and stimulus blocks. In 7 of 14 studies, consistent regions of activation were detected from tissue around the major vessels perfusing the visual cortex. |
![]() |
In vivo ultrasonic measurement of tissue vibration at a stenosis: A case study Plett, M.I., K.W. Beach, B. Dunmire, K.G. Brown, J.F. Primozich, and E. Strandness Jr., "In vivo ultrasonic measurement of tissue vibration at a stenosis: A case study," Ultrasound Med. Biol., 27, 1049-1058, 2001. |
More Info |
1 Aug 2001 ![]() |
![]() |
|||||
It is known that bruits often can be heard downstream from stenoses. They are thought to be produced by disturbed blood flow and vessel wall vibrations. Our understanding of bruits has been limited, though, to analysis of sounds heard at the level of the skin. For direct measurements from the stenosis site, we developed an ultrasonic pulse-echo multigate system using quadrature phase demodulation. The system simultaneously measures tissue displacements and blood velocities at multiple depths. This paper presents a case study of a severe stenosis in a human infrainguinal vein bypass graft. During systole, nearly sinusoidal vessel wall vibrations were detected. Solid tissue vibration amplitudes measured up to 2 microm, with temporal durations of 100 ms and frequencies of roughly 145 Hz and its harmonics. Cross-axial oscillations were also found in the lumen that correlate with the wall vibrations, suggesting coupling between wall vibration and blood velocity oscillation. |
In The News
![]() |
Expelling stones with ultrasonic propulsion Nature Reviews Urology, Rebecca Kelsey Ultrasonic propulsion can be used to reposition kidney stones and facilitate the passage of stone fragments, according to a new study. |
17 Nov 2015
|
![]() |
![]() |
2014 Awards of Excellence recognize campus, community contributions UW News and Information The University of Washington honored the contributions and achievements of faculty, staff, distinguished alumni and top scholars during the 44th annual Awards of Excellence ceremony Thursday, June 12. |
12 Jun 2014
|
![]() |
![]() |
Doctors using new technology to treat kidney stones KING 5 News (Seattle) Kidney stones: one in five of us will get them at some point, and high protein diets might add to your risk. But doctors are now using 21st century technology to control this ancient condition. |
10 Jan 2014
|
![]() |
Inventions
![]() |
Transvaginal or Transrectal Probe for Ureter Stone Lithotripsy Record of Invention Number: 49263 |
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 |
More Info |
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. |
![]() |
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
|
![]() |
![]() |
Audio Feedback for Improving the Accuracy of BWL Targeting Record of Invention Number: 48254 Mike Bailey, Bryan Cunitz, Barbrina Dunmire, Christopher Hunter, Wayne Kreider, Adam Maxwell, Yak-Nam Wang |
Disclosure
|
25 Jan 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 |
More Info |
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. |
![]() |
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
|
![]() |
![]() |
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 |
More Info |
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. |
![]() |
Novel Probe and Workflow for Ultrasonic Propulsion Record of Invention Number: 47322 Mike Bailey, Bryan Cunitz, Brian Dickinson, Barbrina Dunmire, Brian MacConaghy, Adam Maxwell |
Disclosure
|
1 May 2015
|
![]() |
![]() |
Applications of Ultrasonic Propulsion Record of Invention Number: 47073 |
Disclosure
|
3 Oct 2014
|
![]() |
![]() |
Assortment of Push Profiles for Pushing a Variety of Kidney Stones Record of Invention Number: 47072 Mike Bailey, Bryan Cunitz, Barbrina Dunmire, Oleg Sapozhnikov |
Disclosure
|
3 Oct 2014
|
![]() |
![]() |
Single Element Broadly Focused Ultrasonic Propulsion Device Record of Invention Number: 47074 |
Disclosure
|
3 Oct 2014
|
![]() |
![]() |
Ultrasound to rotate an obstructing kidney stone Record of Invention Number: 47066 |
Disclosure
|
29 Sep 2014
|
![]() |
![]() |
Non-Contact Reflectance Imaging of Oxygen Saturation in Venous Blood Record of Invention Number: 46171 |
Disclosure
|
1 Aug 2012
|
![]() |
![]() |
An Ultrasound Phantom for Detecting and Repositioning Kidney Stones Record of Invention Number: 45981 |
Disclosure
|
1 Mar 2012
|
![]() |
![]() |
Computational Flow Modeling for Dialysis Access Surgical Planning Record of Invention Number: 8701D Barbrina Dunmire, Dan Leotta, Alberto Aliseda, James J. Riley, Kirk W. Beach, Edward Stutzman, R. Eugene Zierler |
Disclosure
|
20 May 2010
|
![]() |