Dr. Chetan A. Patil Profile

Dr. Chetan A. Patil

at Temple Univ

SPIE Involvement:

Conference Program Committee | Author

Publications (21)

Proceedings Article | 13 March 2024 Presentation

Pulsatile 3D-printed multilayer optical phantoms with microchannels for testing pulse oximeters

Derek Bashe, Michael Butler, Anmol Jarang, Quinlan McGrath, Mohammed Shahriar Arefin, Chetan Patil, Christine O'Brien, Leonid Shmuylovich

Proceedings Volume PC12833, PC128330B (2024) https://doi.org/10.1117/12.3002150

KEYWORDS: Oximeters, Optical phantoms, Infrared radiation, Skin, Signal attenuation, Scattering, Oximetry, Reflectivity, Optical properties, Infrared photography

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Proceedings Article | 13 March 2024 Presentation + Paper

Modification of oximeter ratio to reduce pigmentation bias in pulse oximetry

Mohammed Shahriar Arefin, Leonid Shmuylovich, Chetan Patil

Proceedings Volume 12833, 1283303 (2024) https://doi.org/10.1117/12.3003274

KEYWORDS: Oximeters, Monte Carlo methods, Calibration, Oximetry, Skin, Oxygen, Mathematical optimization, Computer simulations, Blood oxygen saturation, Tissue optics, Photoplethysmography

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Proceedings Article | 12 March 2024 Presentation + Paper

Modeling transcutaneous Vis-NIR spectroscopy of metacarpal bone

Mohammed Shahriar Arefin, William Querido, Amanda Spurri, Nancy Pleshko, Chetan Patil

Proceedings Volume 12839, 1283907 (2024) https://doi.org/10.1117/12.3003263

KEYWORDS: Monte Carlo methods, Osteoporosis, Near infrared spectroscopy, Bone, Skin, Simulations, Absorbance, Optical properties, Tissues, Spectroscopy, Fiber optics, Modeling, Absorption

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SPIE Journal Paper | 10 September 2022 Open Access

Model-based characterization platform of fiber optic extended-wavelength diffuse reflectance spectroscopy for identification of neurovascular bundles

Yu Sun, Alexander Dumont, Mohammed Shahriar Arefin, Chetan Patil

JBO, Vol. 27, Issue 09, 095002, (September 2022) https://doi.org/10.1117/12.10.1117/1.JBO.27.9.095002

KEYWORDS: Tissues, Nerve, Model-based design, Short wave infrared radiation, Optical phantoms, Monte Carlo methods, Fiber optics, Systems modeling, Spectroscopy, Optical properties

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Significance: Fiber-optic extended-wavelength diffuse reflectance spectroscopy (EWDRS) using both visible/near-infrared and shortwave-infrared detectors enables improved detection of spectral absorbances arising from lipids, water, and collagen and has demonstrated promise in a variety of applications, including detection of nerves and neurovascular bundles (NVB). Development of future applications of EWDRS for nerve detection could benefit from the use of model-based analyses including Monte Carlo (MC) simulations and evaluation of agreement between model systems and empirical measurements.Aim: The aim of this work is to characterize agreement between EWDRS measurements and simulations and inform future applications of model-based studies of nerve-detecting applications.Approach: A model-based platform consisting of an ex vivo microsurgical nerve dissection model, unique two-layer optical phantoms, and MC model simulations of fiber-optic EWDRS spectroscopic measurements were used to characterize EWDRS and compare agreement across models. In addition, MC simulations of an EWDRS measurement scenario are performed to provide a representative example of future analyses.Results: EWDRS studies performed in the common chicken thigh femoral nerve microsurgical dissection model indicate similar spectral features for classification of NVB versus adjacent tissues as reported in porcine models and human subjects. A comparison of measurements from unique EWDRS issue mimicking optical phantoms and MC simulations indicates high agreement between the two in homogeneous and two-layer optical phantoms, as well as in dissected tissues. Finally, MC simulations of measurement over a simulated NVB indicate the potential of future applications for measurement of nerve plexus.Conclusions: Characterization of agreement between fiber-optic EWDRS measurements and MC simulations demonstrates strong agreement across a variety of tissues and optical phantoms, offering promise for further use to guide the continued development of EWDRS for translational applications.

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Proceedings Article | 2 March 2022 Paper

Reducing racial bias in transcutaneous measurements with mobile phone camera based spatially resolved diffuse reflectance

Brandon Harrison-Smith, Mohammed Arefin, Alexander Dumont, Chetan Patil

Proceedings Volume 11958, 1195804 (2022) https://doi.org/10.1117/12.2610519

KEYWORDS: Sensors, Calibration, Monte Carlo methods, Cell phones, RGB color model, Skin, Instrument modeling, Statistical modeling, Diffuse reflectance spectroscopy, Data modeling

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Proceedings Article | 2 March 2022 Presentation + Paper

Characterization of extended-wavelength diffuse reflectance spectroscopy for identification of neurovascular bundles using Monte Carlo models, optical phantoms, and ex vivo animal tissues

Yu Sun, Chetan Patil

Proceedings Volume 11951, 1195105 (2022) https://doi.org/10.1117/12.2609778

KEYWORDS: Tissues, Monte Carlo methods, Animal model studies, Statistical modeling, Optical properties, Optical phantoms, Diffuse reflectance spectroscopy, Near infrared

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Proceedings Article | 2 March 2022 Presentation + Paper

Monte Carlo based simulations of racial bias in pulse oximetry

Mohammed Shahriar Arefin, Alexander Dumont, Chetan Patil

Proceedings Volume 11951, 1195103 (2022) https://doi.org/10.1117/12.2610483

KEYWORDS: Calibration, Monte Carlo methods, Oximeters, Oximetry, Oxygen, Statistical modeling, Hypoxia, Stochastic processes, Optical properties, Blood oxygen saturation

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Pulse oximetry is a common tool to perform a non-invasive optical estimate (SpO2) of arterial blood oxygen saturation level (SaO2). Although the principle of pulse oximetry has been established for a long time Recent clinical studies reported oximeter over-estimation bias in black patients. Measurement accuracy is an important factor, as over-estimation could impact clinical decision-making. Prior Monte-Carlo (MC) simulation-based studies showed increased melanin could reduce the oximeter signal intensity. These studies didn’t show the impact of pigmentation on calibration equation development in a population cohort. Extending MC simulations to study the influence of bias in calibration model enrollment, along with the corresponding optical estimation errors would offer insight into the basis of important clinical observations. Here, an MC simulation platform was developed to assess how pigmentation distribution in the racial demographics could impact calibration model development. MC simulations of oximeter measurements from <1200 simulated patient finger models were generated using a stochastic sampling-based technique, where patient optical properties (including pigmentation) were statistically assigned to generate a variation of measurements across different population cohorts. MC simulations of oximeter calibration studies representative of prior FDA 510(k) guidelines e.g.- minimum 20% darkly pigmented population) in comparison with alternative enrollment distributions. Performance of oximeter calibration equations was evaluated with unique population distributions of test subjects. Results showed that even if the calibration equations were developed from a representative population cohort, the predicted SpO2 show overestimation in high pigmentation cohorts. This over-estimation minimizes when the calibration is generated from distributions with an increased pigmented subject enrollment. The sensitivity to detect hypoxia in the highly pigmented cohort (sensitivity=0.95) is lower than the low pigmented cohort(sensitivity=0.98) when the representative population distribution was used to develop the calibration equation.

Proceedings Article | 19 March 2018 Presentation

Mobile phone based transcutaneous billirubinometry (Conference Presentation)

Brandon Harrison, Alexander Dumont, Hendrik Weitkamp, Chetan Patil

Proceedings Volume 10485, 1048505 (2018) https://doi.org/10.1117/12.2293845

KEYWORDS: Cell phones, Cameras, Diagnostics, Genetics, Visualization, Diffuse reflectance spectroscopy, Monte Carlo methods, Optical fabrication

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Proceedings Article | 13 February 2018 Paper

Development of accelerated Raman and fluorescent Monte Carlo method

Alexander Dumont, Chetan Patil

Proceedings Volume 10490, 104900P (2018) https://doi.org/10.1117/12.2293831

KEYWORDS: Raman spectroscopy, Luminescence, Raman scattering, Monte Carlo methods, Tissues, Tissue optics, Optical properties, Inspection, Tumors, Scattering

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Proceedings Article | 19 April 2017 Presentation

SWIR dispersive Raman spectroscopy for discrimination of normal and malignant kidney tissue (Conference Presentation)

Miki Haifler, Isaac Pence, Amnon Zisman, Robert Uzzo, Richard Greenberg, Alexander Kutikov, Marc Smaldone, David Chen, Rosalia Viterbo, Benjamin Ristau, Anita Mahadevan-Jansen, Alexander Dumont, Chetan Patil

Proceedings Volume 10038, 100380O (2017) https://doi.org/10.1117/12.2256617

KEYWORDS: Kidney, Remote sensing, Tissues, Tissue optics, Raman spectroscopy, Cancer, Computed tomography, Surgery, Tomography, Short wave infrared radiation

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Proceedings Article | 3 March 2017 Paper

Development of mobile phone based transcutaneous billirubinometry

Alexander Dumont, Brandon Harrison, Zachary McCormick, Nishant Ganesh Kumar, Chetan Patil

Proceedings Volume 10055, 100550T (2017) https://doi.org/10.1117/12.2257428

KEYWORDS: Cell phones, Monte Carlo methods, Diffuse reflectance spectroscopy, Cameras, Visualization, Skin, Optical fabrication, Tissue optics, Image analysis, Sensors, Absorption, Bismuth, Anisotropy, Reflectivity, Blood

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Proceedings Article | 4 March 2014 Paper

Longitudinal study of arteriogenesis with swept source optical coherence tomography and hyperspectral imaging

Kristin Poole, Chetan Patil, Christopher Nelson, Devin McCormack, Megan Madonna, Craig Duvall, Melissa Skala

Proceedings Volume 8934, 89341Z (2014) https://doi.org/10.1117/12.2042037

KEYWORDS: Optical coherence tomography, Hyperspectral imaging, Ischemia, Speckle, Therapeutics, Blood, Data modeling, Temperature metrology, Oxygen, Visualization

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SPIE Journal Paper | 24 May 2013 Open Access

Polarization control of Raman spectroscopy optimizes the assessment of bone tissue

Alexander Makowski, Chetan Patil, Anita Mahadevan-Jansen, Jeffry Nyman

JBO, Vol. 18, Issue 05, 055005, (May 2013) https://doi.org/10.1117/12.10.1117/1.JBO.18.5.055005

KEYWORDS: Polarization, Bone, Remote sensing, Raman spectroscopy, Collagen, Minerals, Tissues, Carbonates, Data modeling, Microscopes

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Proceedings Article | 20 March 2013 Paper

In vivo imaging of gold nanorod contrast agents using photothermal optical coherence tomography

Jason Tucker-Schwartz, Travis Meyer, Chetan Patil, Craig Duvall, Melissa Skala

Proceedings Volume 8571, 85712C (2013) https://doi.org/10.1117/12.2007202

KEYWORDS: Optical coherence tomography, In vivo imaging, Capillaries, Ear, Reflectivity, Gold, Molecular imaging, Scattering, Solids, Nanorods

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SPIE Journal Paper | 1 January 2011 Open Access

Integrated system for combined Raman spectroscopy-spectral domain optical coherence tomography

Chetan Patil, Jeroen Kalkman, Dirk Faber, Jeffry Nyman, Ton van Leeuwen, Anita Mahadevan-Jansen

JBO, Vol. 16, Issue 1, 011007, (January 2011) https://doi.org/10.1117/12.10.1117/1.3520132

KEYWORDS: Optical coherence tomography, Raman spectroscopy, Remote sensing, Tissues, Skin, Sensors, Imaging systems, Spectrographs, Retina, System integration

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Proceedings Article | 3 March 2010 Paper

Structural and biochemical characterization of the rat retina with combined Raman spectroscopy-spectral domain optical coherence tomography (RS-SDOCT)

Chetan Patil, Jeroen Kalkman, Dirk Faber, John Penn, Ton van Leeuwen, Anita Mahadevan-Jansen

Proceedings Volume 7550, 75501B (2010) https://doi.org/10.1117/12.843106

KEYWORDS: Optical coherence tomography, Raman spectroscopy, Retina, Remote sensing, Tissues, Spectrographs, Instrument modeling, Eye, Sensors, Oxygen

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Proceedings Article | 3 March 2010 Paper

Characterization of bone quality in prostate cancer bone metastases using Raman spectroscopy

Xiaohong Bi, Chetan Patil, Colm Morrissey, Martine Roudier, Anita Mahadevan-Jansen, Jeffry Nyman

Proceedings Volume 7548, 75484L (2010) https://doi.org/10.1117/12.853551

KEYWORDS: Bone, Raman spectroscopy, Prostate cancer, Crystals, Minerals, Tumors, Collagen, Carbonates, Tissues, Principal component analysis

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Proceedings Article | 2 March 2010 Paper

A clinical probe for combined Raman spectroscopy-optical coherence tomography (RS-OCT) of the skin cancers

Chetan Patil, Harish Krishnamoorthi, Darrel Ellis, Ton van Leeuwen, Anita Mahadevan-Jansen

Proceedings Volume 7548, 75480L (2010) https://doi.org/10.1117/12.843708

KEYWORDS: Raman spectroscopy, Optical coherence tomography, Skin, Skin cancer, Remote sensing, Signal detection, Optical filters, Cancer, Confocal microscopy, Imaging spectroscopy

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Proceedings Article | 24 February 2009 Paper

Raman spectroscopy for assessment of bone quality in MMP-2 knockout mice

Xiaohong Bi, Jeffry Nyman, Chetan Patil, Philip Masui, Conor Lynch, Anita Mahadevan-Jansen

Proceedings Volume 7166, 71660B (2009) https://doi.org/10.1117/12.813928

KEYWORDS: Bone, Minerals, Raman spectroscopy, Crystals, Carbonates, Collagen, Remote sensing, Tissues, Crystallography, Genetics

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Proceedings Article | 23 February 2009 Paper

A MEMS based handheld confocal microscope with Raman spectroscopy for in-vivo skin cancer diagnosis

Christopher Arrasmith, Chetan Patil, David Dickensheets, Anita Mahadevan-Jansen

Proceedings Volume 7169, 71690N (2009) https://doi.org/10.1117/12.812071

KEYWORDS: Confocal microscopy, Raman spectroscopy, Microscopes, In vivo imaging, Skin, Objectives, Mirrors, Microelectromechanical systems, Skin cancer, Reflectivity

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Proceedings Article | 14 June 2002 Paper

Real-time optical coherence tomography of the anterior segment using hand-held and slit-lamp adapted systems

Sunita Radhakrishnan, Chetan Patil, Andrew Rollins, Diana Reeves, Jonathan Lass, David Bardenstein, Volker Westphal, Jonathan Roth, Joseph Izatt

Proceedings Volume 4619, (2002) https://doi.org/10.1117/12.470488

KEYWORDS: Optical coherence tomography, Image segmentation, Iris, Eye, Real time imaging, Tumors, Visualization, Ultrasonography, Image acquisition, Confocal microscopy

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