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Dan Leotta

Senior Engineer

Email

leotta@uw.edu

Phone

206-616-6787

Education

B.S. Bioengineering, Syracuse University, 1982

M.S. Electrical Engineering, Massachusetts Institute of Technology, 1985

Ph.D. Bioengineering, University of Washington, 1998

Publications

2000-present and while at APL-UW

Tissue properties and respiratory kinematics of the tongue base and soft palate in the obese OSA minipig

Leotta, D.F., D. Ly, G. Galil, J. Thiel, E. Willis, N. Balu, and Z.-J. Liu, "Tissue properties and respiratory kinematics of the tongue base and soft palate in the obese OSA minipig," Plos One, 18, doi:10.1371/journal.pone.0293907, 2023.

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7 Dec 2023

Obesity is a common finding and a major pathogenetic factor in obstructive sleep apnea (OSA) in adults. To understand the mechanisms behind this, the present study investigated the tissue properties and respiratory kinematics of the tongue base and soft palate in the obese OSA minipig model. In 4 verified obese/OSA and 3 non-obese/non-OSA control minipigs, MRI fat-weighted images, ultrasound elastography (USE), and sleep video-fluoroscopy (SVF) were performed to quantify the fat composition, tissue stiffness, and respiratory kinematics of the tongue base and soft palate during sedated sleep. The results indicated that the fat composition gradually increased from the rostral to caudal tongue base, particularly in the posterior 1/3 of the tongue base, regardless of the presence of obesity and OSA. However, this trend was not seen in the soft palate and pharyngeal wall. The pharyngeal wall presented the highest fat composition as compared with the tongue base and soft palate. Overall, obese OSA minipigs showed stiffer tongue tissue than the controls, particularly in the rostral region of the tongue in obese Yucatan minipigs. The respiratory moving ranges of the soft palate were greater in both dorsal-ventral and rostral-caudal directions and during both respiratory and expiratory phases in OSA obese than control minipigs, and the largest moving ranges were seen in OSA obese Panepinto minipigs. The moving range of the tongue base was significantly smaller. These results suggest more fat infiltration in the caudal region of the tongue base regardless of the presence of obesity and/or OSA. The greater tissue stiffness of the tongue in obese OSA minipigs may result from altered neuromuscular drive.

Automated brain segmentation for guidance of ultrasonic transcranial tissue pulsatility image analysis

Leotta, D.F., J.C. Kucewicz, N. LaPiana, and P.D. Mourad, "Automated brain segmentation for guidance of ultrasonic transcranial tissue pulsatility image analysis," Neurosci. Inf., 3 doi:10.1016/j.neuri.2023.100146, 2023.

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1 Dec 2023

Tissue pulsatility imaging is an ultrasonic technique that can be used to map regional changes in blood flow in the brain. Classification of regional differences in pulsatility signals can be optimized by restricting the analysis to brain tissue. For 2D transcranial ultrasound imaging, we have implemented an automated image analysis procedure to specify a region of interest in the field of view that corresponds to brain.

Our segmentation method applies an initial K-means clustering algorithm that incorporates both echo strength and tissue displacement to identify skull in ultrasound brain scans. The clustering step is followed by processing steps that use knowledge of the scan format and anatomy to create an image mask that designates brain tissue. Brain regions were extracted from the ultrasound data using different numbers of K-means clusters and multiple combinations of ultrasound data. Masks generated from ultrasound data were compared with reference masks derived from Computed Tomography (CT) data.

A segmentation algorithm based on ultrasound intensity with two K-means clusters achieves an accuracy better than 80% match with the CT data. Some improvement in the match is found with an algorithm that uses ultrasound intensity and displacement data, three K-means clusters, and addition of an algorithm to identify shallow sources of ultrasound shadowing.

Several segmentation algorithms achieve a match of over 80% between the ultrasound and Computed Tomography brain masks. A final tradeoff can be made between processing complexity and the best match of the two data sets.

Comparative study of histotripsy pulse parameters used to inactivate Escherichia coli in suspension

Ambedkar, P.A., Y.-N. Wang, T. Khokhlova, M. Bruce, D.F. Leotta, S. Totten, A.D. Maxwell, K.T. Chan, W.C. Liles, E.P. Dellinger, W. Monsky, A.A. Adedipe, and T.J. Matula, "Comparative study of histotripsy pulse parameters used to inactivate Escherichia coli in suspension," Ultrasound Med. Biol., 49, 2451-2458, doi:10.1016/j.ultrasmedbio.2023.08.004, 2023.

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1 Dec 2023

Bacterial loads can be effectively reduced using cavitation-mediated focused ultrasound, or histotripsy. In this study, gram-negative bacteria (Escherichia coli) in suspension were used as model bacteria to evaluate the effectiveness of two regimens of histotripsy treatments: cavitation histotripsy (CH) and boiling histotripsy (BH).

The results of this study suggest that both CH and BH can be used to inactivate E. coli in suspension, with the optimal regimen depending on the attainable peak negative focal pressure at the target.

More Publications

Inventions

Fenestration template for endovascular repair of aortic aneurysms

Patent Number: 9,811,613

Dan Leotta, Benjamin Starnes

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Patent

7 Nov 2017

To provide simple yet accurate stent graft fenestration, a patient-specific fenestration template is used as a guide for graft fenestration. To generate the fenestration template, a patient's medical imaging data such as CT scan data may be used to generate a 3-D digital model of an aorta lumen of the patient. The aorta lumen may encompass one or more branch vessels, which may be indicated on the 3-D digital model. Based on the 3-D digital model or a segment thereof, the fenestration template may be generated, for example, using 3-D printing technology. The fenestration template may include one or more holes or openings that correspond to the one or more branch vessels. To fenestrate a stent graft, the fenestration template is coupled to the stent graft so that the holes or openings on the fenestration template indicate the fenestration locations.

Fenestration template for endovascular repair of aortic aneurysms

Patent Number: 9,305,123

Dan Leotta, Benjamin Starnes

More Info

Patent

5 Apr 2016

To provide simple yet accurate stent graft fenestration, a patient-specific fenestration template is used as a guide for graft fenestration. To generate the fenestration template, a patient's medical imaging data such as CT scan data may be used to generate a 3-D digital model of an aorta lumen of the patient. The aorta lumen may encompass one or more branch vessels, which may be indicated on the 3-D digital model. Based on the 3-D digital model or a segment thereof, the fenestration template may be generated, for example, using 3-D printing technology. The fenestration template may include one or more holes or openings that correspond to the one or more branch vessels. To fenestrate a stent graft, the fenestration template is coupled to the stent graft so that the holes or openings on the fenestration template indicate the fenestration locations.

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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