APL-UW Home

Jobs
About
Campus Map
Contact
Privacy
Intranet

Dan Leotta

Senior Engineer

Email

dfleotta@apl.washington.edu

Phone

206-616-6787

Education

Bachelor of Science Bioengineering, Syracuse University, 1982

Master of Science Electrical Engineering, Massachusetts Institute of Technology, 1985

Doctor of Philosophy Bioengineering, University of Washington, 1998

Publications

2000-present and while at APL-UW

Analysis of factors influencing accuracy of volume flow measurement in dialysis access fistulas based on duplex ultrasound simulation

Ziegler, R.E., D.F. Leotta, K. Samson, A. Aliseda, M.D. Anderson, and F.H. Sheehan, "Analysis of factors influencing accuracy of volume flow measurement in dialysis access fistulas based on duplex ultrasound simulation," Vasc. Endovasc. Surg., 53, 529-535, doi:10.1177/1538574419858811, 2019.

More Info

1 Oct 2019

We developed a duplex ultrasound simulator and used it to assess accuracy of volume flow measurements in dialysis access fistula (DAF) models. The simulator consists of a mannequin, computer, and mock transducer. Each case is built from a patient's B-mode images that are used to create a 3-dimensional surface model of the DAF. Computational fluid dynamics is used to determine blood flow velocities based on model vessel geometry. The simulator displays real-time B-mode and color-flow images, and Doppler spectral waveforms are generated according to user-defined settings. Accuracy was assessed by scanning each case and measuring volume flow in the inflow artery and outflow vein for comparison with true volume flow values. Four examiners made 96 volume flow measurements on four DAF models. Measured volume flow deviated from the true value by 35 ± 36%. Mean absolute deviation from true volume flow was lower for arteries than veins (22 ± 19%, N = 48 vs. 58 ± 33%, N = 48, p < 0.0001). This finding is attributed to eccentricity of outflow veins which resulted in underestimating true cross-sectional area. Regression analysis indicated that error in measuring cross-sectional area was a predictor of error in volume flow measurement (β = 0.948, p < 0.001). Volume flow error was reduced from 35 ± 36% to 9 ± 8% (p < 0.000001) by calculating vessel area as an ellipse. Duplex volume flow measurements are based on a circular vessel shape. DAF inflow arteries are circular, but outflow veins can be elliptical. Simulation-based analysis showed that error in measuring volume flow is mainly due to assumption of a circular vessel.

Evaluation of examiner performance using a duplex ultrasound simulator. Flow velocity measurements in dialysis access fistula models

Leotta, D.F., R.E. Ziegler, K. Sansom, A. Aliseda, M.D. Anderson, and F.H. Sheehan, "Evaluation of examiner performance using a duplex ultrasound simulator. Flow velocity measurements in dialysis access fistula models," Ultrasound Med. Biol., 44, 1712-1720, doi:10.1016/j.ultrasmedbio.2018.04.012, 2018.

More Info

1 Aug 2018

We developed a duplex ultrasound simulator for training and assessment of scanning skills. We used the simulator to test examiner performance in the measurement of flow velocities in dialysis access fistulas. Test cases were created from 3-D ultrasound scans of two dialysis access fistulas by reconstructing 3-D blood vessel models and simulating blood flow velocity fields within the lumens. The simulator displays a 2-D B-mode or color Doppler image corresponding to transducer position on a mannequin; a spectral waveform is generated according to Doppler sample volume location and system settings. Examiner performance was assessed by comparing the measured peak systolic velocity (PSV) with the true PSV provided by the computational flow model. The PSV measured by four expert examiners deviated from the true value by 7.8 ± 6.1%. The results indicate the ability of the simulator to objectively assess an examiner's measurement accuracy in complex vascular targets.

An upgraded camera-based imaging system for mapping venous blood oxygenation in human skin tissue

Li, J., X. Zhang, L. Qiu, and D.F. Leotta, "An upgraded camera-based imaging system for mapping venous blood oxygenation in human skin tissue," Opt. Commun., 370, 276-282, doi:10.1016/j.optcom.2016.03.030, 2016.

More Info

1 Jul 2016

Highlights

A camera-based mapping of venous oxygenation saturation SvO2 was further developed.

Monte Carlo method was used for modeling the imaging system.

Curvature and motion correction algorithms were included in the image process.

The spatial resolution for SvO2 map achieved was 1.25 mm×1.25 mm.

The measured SvO2 was validated by a NIRS system and in line with published data.

More Publications

Inventions

Device and Method to Break Urinary Stones in Pets

Record of Invention Number: 48640

Mike Bailey, Dan Leotta, Elizabeth Lynch, Brian MacConaghy, Adam Maxwell

Disclosure

28 May 2019

Easy 3D Ultrasound Imaging and Volume Quantification

Record of Invention Number: 48367

Mike Bailey, Bryan Cunitz, Dan Leotta

Disclosure

28 May 2019

Transcranial Doppler Simulator for Training and Assessment

Record of Invention Number: 48515

Florence Sheehan, Alberto Aliseda, Mark Anderson, Dan Leotta, Kurt Sansom, Deepak Sharma

Disclosure

7 Jan 2019

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
Close

 

Close