Dr. Timothy J. Muldoon Profile

Dr. Timothy J. Muldoon

Associate Professor at Univ of Arkansas

SPIE Involvement:

Conference Program Committee | Author | Student Chapter Advisor

Area of Expertise:

Biomedical optics , Endoscopy , Modeling , Targeted contrast agents , In vivo imaging , Diagnostic imaging

Websites:

Personal Website

Publications (25)

Proceedings Article | 5 March 2021 Presentation + Paper

Optical and molecular longitudinal tracking of primary colorectal murine tumors shows differences in the angiogenic response to maximum-tolerated and metronomic approaches

Ariel Mundo, Abdussaboor Muhammad, Timothy Muldoon

Proceedings Volume 11655, 116551C (2021) https://doi.org/10.1117/12.2576906

KEYWORDS: Tumors, Diffuse reflectance spectroscopy, Toxicity, Oxygen, Optical tracking, Endoscopy, Colorectal cancer, Colon

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SPIE Journal Paper | 22 April 2020 Open Access

Diffuse reflectance spectroscopy to monitor murine colorectal tumor progression and therapeutic response (Erratum)

Ariel Mundo, Gage Greening, Michael Fahr, Lawrence Hale, Elizabeth Bullard, Narasimhan Rajaram, Timothy Muldoon

JBO, Vol. 25, Issue 04, 049803, (April 2020) https://doi.org/10.1117/12.10.1117/1.JBO.25.4.049803

KEYWORDS: Tumors, Diffuse reflectance spectroscopy, Reflectance spectroscopy, Biomedical engineering, Computer science, Chemistry, Biochemistry, Optical properties

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Proceedings Article | 9 March 2020 Presentation

Optical spectroscopic and imaging biomarkers of ulcerative colitis disease progression and remission (Conference Presentation)

Ariel Mundo, Elizabeth Bullard, Kyle Quinn, Timothy Muldoon

Proceedings Volume 11216, 1121605 (2020) https://doi.org/10.1117/12.2543369

KEYWORDS: Ocean optics, Spectroscopy, Imaging spectroscopy, Optical spectroscopy imaging, Optical spectroscopy, Optical imaging, Endoscopy, Luminescence, Colon, Oxygen

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SPIE Journal Paper | 6 March 2020 Open Access

Diffuse reflectance spectroscopy to monitor murine colorectal tumor progression and therapeutic response

Ariel Mundo, Gage Greening, Michael Fahr, Lawrence Hale, Elizabeth Bullard, Narasimhan Rajaram, Timothy Muldoon

JBO, Vol. 25, Issue 03, 035002, (March 2020) https://doi.org/10.1117/12.10.1117/1.JBO.25.3.035002

KEYWORDS: Tumors, Data modeling, Diffuse reflectance spectroscopy, Reflectivity, Error control coding, In vivo imaging, Tissues, Magnesium, Endoscopy, Data acquisition

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Proceedings Article | 13 March 2019 Presentation

Monitoring therapeutic response of murine tumor allografts of colon carcinoma in response to combined immunotherapy and chemotherapy (Conference Presentation)

Gage Greening, Shelby Bess, Haley James, Ariel Mundo, Timothy Muldoon

Proceedings Volume 10885, 1088502 (2019) https://doi.org/10.1117/12.2510194

KEYWORDS: Tumors, Colon, Colorectal cancer, Tumor growth modeling, Cancer, Animal model studies, Control systems, Diffuse reflectance spectroscopy, Polarization, Indium oxide

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Proceedings Article | 4 March 2019 Presentation + Paper

Characterization of a multimodal endoscopically deployable veterinary spectroscopy and imaging probe to determine therapeutic response in a murine orthotopic tumor model

Ariel Mundo, Gage Greening, Timothy Muldoon

Proceedings Volume 10890, 108901L (2019) https://doi.org/10.1117/12.2507485

KEYWORDS: Tumors, Imaging spectroscopy, Spectroscopy, Scattering, Colon, Calibration, Optical properties, In vivo imaging

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SPIE Journal Paper | 27 August 2018 Open Access

Sampling depth of a diffuse reflectance spectroscopy probe for in-vivo physiological quantification of murine subcutaneous tumor allografts

Gage Greening, Ariel Mundo, Narasimhan Rajaram, Timothy Muldoon

JBO, Vol. 23, Issue 08, 085006, (August 2018) https://doi.org/10.1117/12.10.1117/1.JBO.23.8.085006

KEYWORDS: Tumors, Tissues, Optical properties, Diffuse reflectance spectroscopy, Tissue optics, Calibration, In vivo imaging, Skin, Scattering, Optical fibers

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SPIE Journal Paper | 27 July 2018 Open Access

Two-layer inverse model for improved longitudinal preclinical tumor imaging in the spatial frequency domain

Syeda Tabassum, Vivian Pera, Gage Greening, Timothy J. Muldoon, Darren Roblyer

JBO, Vol. 23, Issue 07, 076011, (July 2018) https://doi.org/10.1117/12.10.1117/1.JBO.23.7.076011

KEYWORDS: Tumors, Optical properties, Skin, Monte Carlo methods, Tissues, Tissue optics, Spatial frequencies, Tumor growth modeling, Animal model studies, Computer simulations

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Proceedings Article | 14 March 2018 Presentation

Long-term longitudinal monitoring of chemotherapy response using Spatial Frequency Domain Imaging using an improved two-layer Monte Carlo based inverse model (Conference Presentation)

Syeda Tabassum, Vivian Pera, Gage Greening, Timothy Muldoon, Darren Roblyer

Proceedings Volume 10472, 1047208 (2018) https://doi.org/10.1117/12.2289293

KEYWORDS: Tumors, Monte Carlo methods, Prostate, Diffuse optical imaging, Physiology, Skin, Functional imaging, Tissues, Absorption, Scattering

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Proceedings Article | 24 April 2017 Presentation

Optical metabolic imaging of colorectal adenocarcinoma derived organoids: assessing cellular-level resistance to therapy (Conference Presentation)

Haley James, Sandra Prieto, Gage Greening, Timothy Muldoon

Proceedings Volume 10068, 100680K (2017) https://doi.org/10.1117/12.2252578

KEYWORDS: Resistance, Tumors, Optical imaging, In vitro testing, Cancer, Cell death, Rectum, CRTs, Luminescence, Vehicle control

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SPIE Journal Paper | 2 March 2017 Open Access

Considerations for point-of-care diagnostics: evaluation of acridine orange staining and postprocessing methods for a three-part leukocyte differential test

Amy Powless, Roxanna Conley, Karan Freeman, Timothy Muldoon

JBO, Vol. 22, Issue 03, 035001, (March 2017) https://doi.org/10.1117/12.10.1117/1.JBO.22.3.035001

KEYWORDS: Adaptive optics, Roentgenium, Blood, Point-of-care devices, Luminescence, Hematology, Diagnostics, Imaging systems, Magnesium, Statistical analysis

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SPIE Journal Paper | 3 June 2016 Open Access

Quantitative analysis of ex vivo colorectal epithelium using an automated feature extraction algorithm for microendoscopy image data

Sandra Prieto, Keith Lai, Jonathan Laryea, Jason Mizell, Timothy Muldoon

JMI, Vol. 3, Issue 02, 024502, (June 2016) https://doi.org/10.1117/12.10.1117/1.JMI.3.2.024502

KEYWORDS: Image segmentation, Image quality, Tissues, Image enhancement, Image processing algorithms and systems, Quantitative analysis, Image analysis, Feature extraction, Image contrast enhancement, Binary data

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Proceedings Article | 18 March 2016 Paper

Spatially resolved diffuse reflectance spectroscopy of two-layer turbid media by densely packed multi-pixel photodiode reflectance probe

Ozlem Senlik, Gage Greening, Timothy Muldoon, Nan Jokerst

Proceedings Volume 9700, 97000O (2016) https://doi.org/10.1117/12.2213124

KEYWORDS: Diffuse reflectance spectroscopy, Photodiodes, Tissue optics, Optical properties, Skin, Tissues, Reflectance spectroscopy, Spectroscopy, Sensors, Silicon, Monte Carlo methods, Reflectivity, Palladium, Photon transport

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Proceedings Article | 14 March 2016 Presentation + Paper

Quantitative structural markers of colorectal dysplasia in a cross sectional study of ex vivo murine tissue using label-free multiphoton microscopy

Sandra Prieto, Gage Greening, Keith Lai, Timothy Muldoon

Proceedings Volume 9712, 97121P (2016) https://doi.org/10.1117/12.2213069

KEYWORDS: Multiphoton microscopy, Collagen, Tissues, Second-harmonic generation, Harmonic generation, Mouse models, Image analysis, Colon, Neodymium, 3D acquisition, Optical filters

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Proceedings Article | 7 March 2016 Presentation + Paper

A light sheet confocal microscope for image cytometry with a variable linear slit detector

Joshua Hutcheson, Foysal Khan, Amy Powless, Devin Benson, Courtney Hunter, Ingrid Fritsch, Timothy Muldoon

Proceedings Volume 9720, 97200U (2016) https://doi.org/10.1117/12.2211164

KEYWORDS: Confocal microscopy, Sensors, Microfluidics, Image sensors, Microscopy, Microscopes, Diagnostics, Microfluidic imaging, Magnetism, Objectives, Electrodes, Mirrors

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Proceedings Article | 4 March 2016 Presentation + Paper

Low-cost computing and network communication for a point-of-care device to perform a 3-part leukocyte differential

Amy Powless, Lauren Feekin, Joshua Hutcheson, Daisy Alapat, Timothy Muldoon

Proceedings Volume 9715, 97150A (2016) https://doi.org/10.1117/12.2213267

KEYWORDS: Point-of-care devices, Diagnostics, Blood, Hematology, Lab on a chip, Imaging systems, Computer networks, Imaging devices, Flow cytometry, Cameras, Adaptive optics, Computing systems, MATLAB

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Proceedings Article | 4 March 2016 Presentation + Paper

In vivo measurement of non-keratinized squamous epithelium using a spectroscopic microendoscope with multiple source-detector separations

Gage Greening, Narasimhan Rajaram, Timothy Muldoon

Proceedings Volume 9715, 97150Z (2016) https://doi.org/10.1117/12.2211866

KEYWORDS: Absorption, Scattering, Tissue optics, Spectroscopy, Reflectivity, Data acquisition, In vivo imaging, Diffuse reflectance spectroscopy, Calibration, Tissues, Reflectance spectroscopy, Oxygen, Optical properties

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Proceedings Article | 9 April 2015 Paper

Qualitative and quantitative comparison of colonic microendoscopy image features to histopathology

Sandra Prieto, Amy Powless, Keith Lai, Jonathan Laryea, Jason Mizell, Timothy Muldoon

Proceedings Volume 9328, 93280B (2015) https://doi.org/10.1117/12.2079816

KEYWORDS: Tissues, Tumors, Colorectal cancer, Medical imaging, Surgery, Imaging systems, Pathology, Cancer, Colon, Ions

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Colorectal cancer is the second leading cause of cancer deaths in the United States, affecting more than 130,000 Americans every year1. Determining tumor margins prior to surgical resection is essential to providing optimal treatment and reducing recurrence rates. Colorectal cancer recurrence can occur in up to 20% of cases, commonly within three years after curative treatment. Typically, when colorectal cancers are resected, a margin of normal tissue on both sides of the tumor is required. The minimum margin required for colon cancer is 5 cm and for the lower rectum 2 cm. However, usually more normal tissue is taken on both sides of the tumor because the blood supply to the entire segment is removed with the surgery and therefore the entire segment must be removed. Anastomotic recurrences may result from inadequate margins. Pathologists look at the margins to ensure that there is no residual tumor and this is usually documented in the pathology report. We have developed a portable, point-of-care fiber bundle microendoscopy imaging system for detection of abnormalities in colonic epithelial microstructure. The system comprises a laptop, a modified fiber bundle image guide with a 1mm active area diameter and custom LabVIEW interface, and is approved for imaging surgically resected colon tissue at the University of Arkansas for Medical Sciences. The microendoscopy probe provides high-resolution images of superficial epithelial histology in real-time to assist surgical guidance and to localize occult regions of dysplasia which may not be visible. Microendoscopy images of freshly resected human colonic epithelium were acquired using the microendoscopy device and subsequently mosaicked using custom post-processing software. Architectural changes in the glands were mapped to histopathology H&E slides taken from the precise location of the microendoscopy images. Qualitatively, glandular distortion and placement of image guide was used to map normal and dysplastic areas of the colonic tumor and surrounding region from microendoscopy images to H&E slides. Quantitative metrics for correlating images were also explored and were obtained by analyzing glandular diameter and spatial distribution as well as image texture.

Proceedings Article | 12 March 2015 Paper

Molecule-specific darkfield and multiphoton imaging using gold nanocages

Amy Powless, Samir Jenkins, Mary Lee McKay, Jingyi Chen, Timothy Muldoon

Proceedings Volume 9339, 93390B (2015) https://doi.org/10.1117/12.2080152

KEYWORDS: Gold, Live cell imaging, Receptors, Multiphoton microscopy, Nanoparticles, Nanostructures, Biomedical optics, Molecules, Breast, Tissue optics

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Proceedings Article | 9 March 2015 Paper

Design and validation of a diffuse reflectance and spectroscopic microendoscope with poly(dimethylsiloxane)-based phantoms

Gage Greening, Amy Powless, Joshua Hutcheson, Sandra Prieto, Aneeka Majid, Timothy Muldoon

Proceedings Volume 9332, 93320R (2015) https://doi.org/10.1117/12.2076300

KEYWORDS: Diffuse reflectance spectroscopy, Reflectance spectroscopy, Fiber optics, Tissues, Scattering, Luminescence, Tissue optics, Multimode fibers, Spectroscopy, Titanium dioxide

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Proceedings Article | 5 March 2015 Paper

High-throughput microfluidic line scan imaging for cytological characterization

Joshua Hutcheson, Amy Powless, Aneeka Majid, Adair Claycomb, Ingrid Fritsch, Kartik Balachandran, Timothy Muldoon

Proceedings Volume 9320, 93200Y (2015) https://doi.org/10.1117/12.2079946

KEYWORDS: Microfluidics, Cameras, Blood, Line scan cameras, Flow cytometry, Cancer, Point-of-care devices, Data acquisition, Image sensors, Sensors

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SPIE Journal Paper | 11 November 2014 Open Access

Characterization of thin poly(dimethylsiloxane)-based tissue-simulating phantoms with tunable reduced scattering and absorption coefficients at visible and near-infrared wavelengths

Gage Greening, Raeef Istfan, Laura Higgins, Kartik Balachandran, Darren Roblyer, Mark Pierce, Timothy Muldoon

JBO, Vol. 19, Issue 11, 115002, (November 2014) https://doi.org/10.1117/12.10.1117/1.JBO.19.11.115002

KEYWORDS: Scattering, Tissue optics, Absorption, Optical properties, Multilayers, Optical coherence tomography, Tissues, Optical phantoms, Coating, Titanium dioxide

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Proceedings Article | 2 March 2010 Paper

Wide-field and high-resolution optical imaging for early detection of oral neoplasia

Mark Pierce, Richard Schwarz, Kelsey Rosbach, Darren Roblyer, Tim Muldoon, Michelle Williams, Adel El-Naggar, Ann Gillenwater, Rebecca Richards-Kortum

Proceedings Volume 7548, 75481U (2010) https://doi.org/10.1117/12.848347

KEYWORDS: Imaging systems, Cancer, Optical imaging, Tissue optics, Luminescence, Diagnostics, Visualization, In vivo imaging, Reflectivity, Microscopes

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SPIE Journal Paper | 1 March 2010 Open Access

Evaluation of quantitative image analysis criteria for the high-resolution microendoscopic detection of neoplasia in Barrett's esophagus

Timothy Muldoon, Nadhi Thekkek, Darren Roblyer, Dipen Maru, Noam Harpaz, Jonathan Potack, Sharmila Anandasabapathy, Rebecca Richards-Kortum

JBO, Vol. 15, Issue 02, 026027, (March 2010) https://doi.org/10.1117/12.10.1117/1.3406386

KEYWORDS: Image analysis, Diagnostics, Esophagus, Endoscopy, Image classification, Tissues, Algorithm development, Biopsy, Cancer, Digital imaging

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Proceedings Article | 24 February 2010 Paper

Low-cost, portable imaging systems for cancer detection

Mark Pierce, Richard Schwarz, Dong-Suk Shin, Darren Roblyer, Tim Muldoon, Mohammed Rahman, Ann Gillenwater, Sharmila Anandasabapathy, Rebecca Richards-Kortum

Proceedings Volume 7556, 755606 (2010) https://doi.org/10.1117/12.848553

KEYWORDS: Cancer, Imaging systems, Cervical cancer, Prototyping, In vivo imaging, Optical diagnostics, Optical imaging, Luminescence, Visualization, Confocal microscopy

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