Dr. Nirmala Ramanujam Profile

Dr. Nirmala Ramanujam

Associate Professor at Duke Univ

SPIE Involvement:

Author | Editor

Publications (50)

SPIE Journal Paper | 17 July 2024 Open Access

In vivo spectroscopy to concurrently characterize five metabolic and vascular endpoints relevant to aggressive breast cancer

Victoria D’Agostino, Riley Deutsch, Michelle Kwan, Enakshi Sunassee, Megan Madonna, Gregory Palmer, Brian Crouch, Nirmala Ramanujam

BIOS, Vol. 1, Issue 02, 025002, (July 2024) https://doi.org/10.1117/12.10.1117/1.BIOS.1.2.025002

KEYWORDS: Tumors, Fluorophores, Tissues, In vivo imaging, Monte Carlo methods, Spectroscopy, Fluorescence, Crosstalk, Biomedical optics, Glucose

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Proceedings Article | 13 March 2024 Presentation + Paper

Development of a multi-scale imaging tool to quantify in vivo metabolic heterogeneity

Enakshi Sunassee, Riley Deutsch, Megan Madonna, Brian Crouch, Nirmala Ramanujam

Proceedings Volume 12827, 1282705 (2024) https://doi.org/10.1117/12.3001764

KEYWORDS: Tumors, In vivo imaging, Image segmentation, Tunable filters, Mode conditioning cables, Light emitting diodes, Optical filters, Mitochondria, Microscopes, Light sources and illumination

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Proceedings Article | 6 March 2023 Presentation

Accelerating the impact of technology and innovation for global cervical cancer prevention

Nirmala Ramanujam

Proceedings Volume PC12369, PC1236905 (2023) https://doi.org/10.1117/12.2661105

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Proceedings Article | 6 March 2023 Presentation + Paper

Multi-modal mobile colposcope for real-time cervical precancer detection: a pilot study in Mozambique

Jackson Coole, Ruchika Mitbander, David Brenes, Alex Kortum, Yajur Maker, Eliane Monteiro, Arlete Mariano, Ricardina Rangeiro, Guilhermina Tivir, Hira Atif, Celda Mavume, Nafissa Osman, Carla Carrilho, Rosita Mugolo, Andrea Neves, Shababa Matin, Richard Schwarz, Jennifer Carns, Mila Salcedo, Nirmala Ramanujam, Ellen Baker, Cesaltina Lorenzoni, Kathleen Schmeler, Rebecca Richards-Kortum

Proceedings Volume 12369, 1236908 (2023) https://doi.org/10.1117/12.2650551

KEYWORDS: Biopsy, Cervical cancer, Imaging systems, Diagnostics, Point-of-care devices, Multimodal imaging, Cervix, Histopathology, Pathology, Education and training

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Proceedings Article | 7 March 2022 Presentation

Development of a fluorescence illumination optimization algorithm for mobile imaging applications in resource limited settings

Riley Deutsch, Roujia Wang, Brian Crouch, Nimmi Ramanujam

Proceedings Volume PC11950, PC1195006 (2022) https://doi.org/10.1117/12.2609801

KEYWORDS: Algorithm development, Genetic algorithms, Optimization (mathematics), Luminescence, Systems modeling, Statistical modeling, Pathology, Light, In vivo imaging, Tissues

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Proceedings Article | 7 March 2022 Presentation

A deep learning approach for Cervical Automated Risk Assessment (CARE) using images from a low-cost, portable Pocket colposcope

Erica Skerrett, Zichen Miao, Mercy Asiedu, Qiang Qiu, Mercy Nyamewaa Asiedu, Guillermo Sapiro, Nimmi Ramanujam

Proceedings Volume PC11950, PC119500D (2022) https://doi.org/10.1117/12.2608935

KEYWORDS: Cervix, Cervical cancer, Cancer, Visualization, Optical inspection, Receivers, Oncology, Iodine, Diagnostics, Convolutional neural networks

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Proceedings Article | 7 March 2022 Presentation

Smart algorithms for Colposcopic Automated Risk Assessment (CARE)

Nirmala Ramanujam

Proceedings Volume PC11950, PC1195001 (2022) https://doi.org/10.1117/12.2617142

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Proceedings Article | 20 March 2020 Presentation

The Pocket Colposope: Concept to Scale (Conference Presentation)

Nimmi Ramanujam

Proceedings Volume 11229, 112290Z (2020) https://doi.org/10.1117/12.2563844

KEYWORDS: Clinical trials

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SPIE Journal Paper | 15 May 2018 Open Access

Assessing effects of pressure on tumor and normal tissue physiology using an automated self-calibrated, pressure-sensing probe for diffuse reflectance spectroscopy

Gregory Palmer, Hengtao Zhang, Chen-Ting Lee, Husam Mikati, Joseph Herbert, Marlee Krieger, Jesko von Windheim, Dave Koester, Daniel Stevenson, Daniel Rocke, Ramon Esclamado, Alaatin Erkanli, Nirmala Ramanujam, Mark Dewhirst, Walter Lee

JBO, Vol. 23, Issue 05, 057004, (May 2018) https://doi.org/10.1117/12.10.1117/1.JBO.23.5.057004

KEYWORDS: Calibration, Tumors, Tissue optics, Tissues, Diffuse reflectance spectroscopy, Scattering, Lamps, Sensors, Data modeling, Statistical modeling

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Proceedings Article | 1 March 2018 Presentation + Paper

Optimizing fluorescently tethered Hsp90 inhibitor dose for maximal specific uptake by breast tumors

Brian Crouch, Joy Duer, Roujia Wang, Jennifer Gallagher, Allison Hall, Mary Scott Soo, Philip Hughes, Timothy A. J. Haystead, Nirmala Ramanujam

Proceedings Volume 10478, 1047804 (2018) https://doi.org/10.1117/12.2285210

KEYWORDS: Tumors, Biopsy, Luminescence, Breast cancer, Breast, Tissues, Cancer, Biological research, Proteins, Surgery

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Proceedings Article | 13 February 2018 Presentation + Paper

Image processing and machine learning techniques to automate diagnosis of Lugol's iodine cervigrams for a low-cost point-of-care digital colposcope

Mercy Nyamewaa Asiedu, Anish Simhal, Christopher Lam, Jenna Mueller, Usamah Chaudhary, John Schmitt, Guillermo Sapiro, Nimmi Ramanujam

Proceedings Volume 10485, 1048508 (2018) https://doi.org/10.1117/12.2282792

KEYWORDS: Specular reflections, Cervix, Pathology, Iodine, RGB color model, Algorithm development, Cervical cancer, Feature extraction, Diagnostics, Machine learning

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SPIE Journal Paper | 22 February 2017 Open Access

Miniature spectral imaging device for wide-field quantitative functional imaging of the morphological landscape of breast tumor margins

Brandon Nichols, Antonio Llopis, Gregory Palmer, Samuel McCachren, Ozlem Senlik, David Miller, Martin Brooke, Nan Jokerst, Joseph Geradts, Rachel Greenup, Nimmi Ramanujam

JBO, Vol. 22, Issue 02, 026007, (February 2017) https://doi.org/10.1117/12.10.1117/1.JBO.22.2.026007

KEYWORDS: Tissues, Tissue optics, Optical properties, Breast, Photodiodes, Personal digital assistants, Imaging spectroscopy, Tumors, Imaging devices, Functional imaging

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SPIE Journal Paper | 21 June 2016 Open Access

Correlation of breast tissue histology and optical signatures to improve margin assessment techniques

Stephanie Kennedy, Matthew Caldwell, Torre Bydlon, Christine Mulvey, Jenna Mueller, Lee Wilke, William Barry, Nimmi Ramanujam, Joseph Geradts

JBO, Vol. 21, Issue 06, 066014, (June 2016) https://doi.org/10.1117/12.10.1117/1.JBO.21.6.066014

KEYWORDS: Collagen, Scattering, Tissues, Tissue optics, Breast, Brain-machine interfaces, Biomedical optics, Model-based design, Mie scattering, Pathology

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Proceedings Article | 26 April 2016 Presentation

Label-free vascular imaging in a spontaneous hamster cheek pouch carcinogen model for pre-cancer detection (Conference Presentation)

Fangyao Hu, Robert Morhard, Heather Liu, Helen Murphy, Sina Farsiu, Nimmi Ramanujam

Proceedings Volume 9703, 970313 (2016) https://doi.org/10.1117/12.2213782

KEYWORDS: Cancer, Vascular imaging, Tumors, Image resolution, Spectral resolution, Oncology, In vivo imaging, Microscopes, Minerals, Image segmentation

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SPIE Journal Paper | 9 June 2015 Open Access

Special Section Guest Editorial: Light for Life: International Year of Light 2015

Rainer Leitgeb, Peter Andersen, Jürgen Popp, Nirmala Ramanujam, Katarina Svanberg

JBO, Vol. 20, Issue 06, 061101, (June 2015) https://doi.org/10.1117/12.10.1117/1.JBO.20.6.061101

KEYWORDS: Photonics, Biomedical optics, Tissue optics, Biomedical engineering, Medicine, Microscopy, Tissues, Optical imaging, Diagnostics, Image enhancement

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Proceedings Article | 4 March 2014 Paper

Optical monitoring of glucose demand and vascular delivery in a preclinical murine model

Amy Frees, Narasimhan Rajaram, Sam McCachren, Alex Vaz, Mark Dewhirst, Nimmi Ramanujam

Proceedings Volume 8947, 894705 (2014) https://doi.org/10.1117/12.2040950

KEYWORDS: Tumors, Glucose, Tissues, Luminescence, Blood, Cancer, In vivo imaging, Mode conditioning cables, Breast cancer, Blood circulation

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Proceedings Article | 25 March 2013 Paper

Monitoring of cycling hypoxia and angiogenesis in FaDu head and neck tumors using a side-firing sensor

Bing Yu, Amy Shah, Bingqing Wang, Narasimhan Rajaram, Quanli Wang, Nirmala Ramanujam, Gregory Palmer, Mark Dewhirst

Proceedings Volume 8578, 85781E (2013) https://doi.org/10.1117/12.2002837

KEYWORDS: Tumors, Hypoxia, Tissues, Oxygen, Sensors, Head, Neck, Blood vessels, Absorption, Data modeling

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Proceedings Article | 22 February 2013 Paper

Quantitative segmentation of fluorescence microscopy images of heterogeneous tissue: Approach for tuning algorithm parameters

Jenna Mueller, Zachary Harmany, Jeffrey Mito, Stephanie Kennedy, Yongbaek Kim, Leslie Dodd, Joseph Geradts, David Kirsch, Rebecca Willett, J. Quincy Brown, Nimmi Ramanujam

Proceedings Volume 8587, 85871F (2013) https://doi.org/10.1117/12.2006429

KEYWORDS: Tissues, Image segmentation, Tumors, Microscopy, Luminescence, Medicine, Pathology, Image resolution, Biomedical engineering, Computer engineering

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SPIE Journal Paper | 31 July 2012 Open Access

Publisher's Note: Experimental validation of an inverse fluorescence Monte Carlo model to extract concentrations of metabolically relevant fluorophores from turbid phantoms and a murine tumor model

Chengbo Liu, Narasimhan Rajaram, Karthik Vishwanath, Tony Jiang, Nirmala Ramanujam, Gregory Palmer

JBO, Vol. 17, Issue 7, 079805, (July 2012) https://doi.org/10.1117/12.10.1117/1.JBO.17.7.079805

KEYWORDS: Luminescence, Monte Carlo methods, Tumors, Instrument modeling, Biomedical optics, Biomedical engineering, Biological research, Life sciences, Roads, Radiation oncology

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SPIE Journal Paper | 24 July 2012 Open Access

Experimental validation of an inverse fluorescence Monte Carlo model to extract concentrations of metabolically relevant fluorophores from turbid phantoms and a murine tumor model

Chengbo Liu, Narasimhan Rajaram, Karthik Vishwanath, Tony Jiang, Nirmala Ramanujam, Gregory Palmer

JBO, Vol. 17, Issue 7, 077012, (July 2012) https://doi.org/10.1117/12.10.1117/1.JBO.17.7.077012

KEYWORDS: Luminescence, Monte Carlo methods, Absorption, Calibration, Reflectivity, Tissues, Rhodamine, Scattering, Optical properties, Tissue optics

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Proceedings Article | 22 February 2012 Paper

Diffuse reflectance spectral imaging for breast tumor margin assessment

Justin Lo, Sulochana Dhar, Bing Yu, Martin Brooke, Thomas Kuech, Nan Jokerst, Nimmi Ramanujam

Proceedings Volume 8214, 821407 (2012) https://doi.org/10.1117/12.909259

KEYWORDS: Tumors, Breast, Imaging systems, Imaging spectroscopy, Signal to noise ratio, Diffuse reflectance spectroscopy, Tissue optics, Tissues, Photodiodes, Scattering

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Proceedings Article | 27 September 2011 Paper

Tissue quantification in photon-limited microendoscopy

Zachary Harmany, Jenna Mueller, Qunicy Brown, Nimmi Ramanujam, Rebecca Willett

Proceedings Volume 8138, 81380F (2011) https://doi.org/10.1117/12.892856

KEYWORDS: Tumors, Tissue optics, Photonic microstructures, Tissues, Reconstruction algorithms, Computer simulations, Cancer, Breast cancer, Endoscopy, Fiber optics

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Proceedings Article | 23 February 2011 Paper

Using wide-field quantitative diffuse reflectance spectroscopy in combination with high-resolution imaging for margin assessment

Stephanie Kennedy, Jenna Mueller, Torre Bydlon, J. Quincy Brown, Nimmi Ramanujam

Proceedings Volume 7890, 78900C (2011) https://doi.org/10.1117/12.875735

KEYWORDS: Tissues, Tumors, Image resolution, Luminescence, Diffuse reflectance spectroscopy, Breast, Imaging spectroscopy, Breast cancer, Tissue optics, Scattering

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Proceedings Article | 22 February 2011 Paper

Calibration schemes of a field-compatible optical spectroscopic system to quantify neovascular changes in the dysplastic cervix

Vivide Tuan-Chyan Chang, Delson Merisier, Bing Yu, David Walmer, Nirmala Ramanujam

Proceedings Volume 7891, 78910A (2011) https://doi.org/10.1117/12.875855

KEYWORDS: Calibration, Diffuse reflectance spectroscopy, Scattering, Tissue optics, Cervical cancer, Spectrometers, Absorption, Spectroscopy, Cervix, Light emitting diodes

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Proceedings Article | 22 February 2011 Paper

A compact, cost-effective diffuse reflectance spectroscopic imaging system for quantitative tissue absorption and scattering

Justin Lo, Bing Yu, Thomas Kuech, Nirmala Ramanujam

Proceedings Volume 7890, 78900B (2011) https://doi.org/10.1117/12.873617

KEYWORDS: Imaging spectroscopy, Imaging systems, Tissue optics, Absorption, Scattering, Photodiodes, Breast, Diffuse reflectance spectroscopy, Spectroscopy, Spectroscopes

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SPIE Journal Paper | 1 January 2011 Open Access

Instrument independent diffuse reflectance spectroscopy

Bing Yu, Henry Fu, Nirmala Ramanujam

JBO, Vol. 16, Issue 1, 011010, (January 2011) https://doi.org/10.1117/12.10.1117/1.3524303

KEYWORDS: Calibration, Lamps, Diffuse reflectance spectroscopy, Tissue optics, Reflectivity, Spectral calibration, Scattering, Tissues, Data analysis, Fiber optics

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SPIE Journal Paper | 1 September 2010 Open Access

Visible light optical spectroscopy is sensitive to neovascularization in the dysplastic cervix

Vivide Chang, Sarah Bean, Peter Cartwright, Nirmala Ramanujam

JBO, Vol. 15, Issue 05, 057006, (September 2010) https://doi.org/10.1117/12.10.1117/1.3495730

KEYWORDS: Tissues, Optical spectroscopy, Cervix, Biopsy, Cervical cancer, Visible radiation, In vivo imaging, Absorption, Tissue optics, Monte Carlo methods

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Proceedings Article | 26 February 2010 Paper

Assessment of breast tumor margins via quantitative diffuse reflectance imaging

J. Quincy Brown, Torre Bydlon, Stephanie Kennedy, Joseph Geradts, Lee Wilke, William Barry, Lisa Richards, Marlee Junker, Jennifer Gallagher, Nimmi Ramanujam

Proceedings Volume 7573, 75730O (2010) https://doi.org/10.1117/12.841949

KEYWORDS: Breast, Scattering, Tumors, Tissues, Pathology, Surgery, Cancer, Performance modeling, Diffuse reflectance spectroscopy, Tissue optics

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SPIE Journal Paper | 1 January 2010 Open Access

Preferential accumulation of 5-aminolevulinic acid-induced protoporphyrin IX in breast cancer: a comprehensive study on six breast cell lines with varying phenotypes

Stacy Millon, Julie Ostrander, Siavash Yazdanfar, J. Quincy Brown, Janelle Bender, Anita Rajeha, Nirmala Ramanujam

JBO, Vol. 15, Issue 01, 018002, (January 2010) https://doi.org/10.1117/12.10.1117/1.3302811

KEYWORDS: Luminescence, Breast cancer, Confocal microscopy, Breast, Tissues, Cancer, Tumors, Imaging spectroscopy, Fluorescence spectroscopy, Tissue optics

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SPIE Journal Paper | 1 September 2009 Open Access

Quantitative optical spectroscopy can identify long-term local tumor control in irradiated murine head and neck xenografts

Karthik Vishwanath, Daniel Klein, Kevin Chang, Thies Schroeder, Mark Dewhirst, Nirmala Ramanujam

JBO, Vol. 14, Issue 05, 054051, (September 2009) https://doi.org/10.1117/12.10.1117/1.3251013

KEYWORDS: Tumors, Diffuse reflectance spectroscopy, Cancer, Chromium, Head, Neck, Optical spectroscopy, Oncology, Animal model studies, Tumor growth modeling

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SPIE Journal Paper | 1 March 2009 Open Access

Quantitative diffuse reflectance and fluorescence spectroscopy: tool to monitor tumor physiology in vivo

Gregory Palmer, Ronald Viola, Thies Schroeder, Pavel Yarmolenko, Mark Dewhirst, Nirmala Ramanujam

JBO, Vol. 14, Issue 02, 024010, (March 2009) https://doi.org/10.1117/12.10.1117/1.3103586

KEYWORDS: Tumors, Luminescence, Diffuse reflectance spectroscopy, Sensors, Absorption, Physiology, Tissue optics, Optical spectroscopy, Oxygen, Tissues

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SPIE Journal Paper | 1 November 2008 Open Access

Cost-effective diffuse reflectance spectroscopy device for quantifying tissue absorption and scattering in vivo

Bing Yu, Justin Lo, Thomas Kuech, Gregory Palmer, Janelle Bender, Nirmala Ramanujam

JBO, Vol. 13, Issue 06, 060505, (November 2008) https://doi.org/10.1117/12.10.1117/1.3041500

KEYWORDS: Tissue optics, Scattering, Absorption, Photodiodes, Optical properties, Tissues, Imaging spectroscopy, In vivo imaging, Imaging systems, Diffuse reflectance spectroscopy

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SPIE Journal Paper | 1 May 2008 Open Access

Diagnosis of breast cancer using fluorescence and diffuse reflectance spectroscopy: a Monte-Carlo-model-based approach

Changfang Zhu, Gregory Palmer, Tara Breslin, Josephine Harter, Nirmala Ramanujam

JBO, Vol. 13, Issue 03, 034015, (May 2008) https://doi.org/10.1117/12.10.1117/1.2931078

KEYWORDS: Tissues, Luminescence, Breast, Scattering, Absorption, Diffuse reflectance spectroscopy, Breast cancer, Collagen, Tumor growth modeling, Monte Carlo methods

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We explore the use of Monte-Carlo-model-based approaches for the analysis of fluorescence and diffuse reflectance spectra measured ex vivo from breast tissues. These models are used to extract the absorption, scattering, and fluorescence properties of malignant and nonmalignant tissues and to diagnose breast cancer based on these intrinsic tissue properties. Absorption and scattering properties, including -carotene concentration, total hemoglobin concentration, hemoglobin saturation, and the mean reduced scattering coefficient are derived from diffuse reflectance spectra using a previously developed Monte Carlo model of diffuse reflectance. A Monte Carlo model of fluorescence described in an earlier manuscript was employed to retrieve the intrinsic fluorescence spectra. The intrinsic fluorescence spectra were decomposed into several contributing components, which we attribute to endogenous fluorophores that may present in breast tissues including collagen, NADH, and retinol/vitamin A. The model-based approaches removes any dependency on the instrument and probe geometry. The relative fluorescence contributions of individual fluorescing components, as well as -carotene concentration, hemoglobin saturation, and the mean reduced scattering coefficient display statistically significant differences between malignant and adipose breast tissues. The hemoglobin saturation and the reduced scattering coefficient display statistically significant differences between malignant and fibrous/benign breast tissues. A linear support vector machine classification using (1) fluorescence properties alone, (2) absorption and scattering properties alone, and (3) the combination of all tissue properties achieves comparable classification accuracies of 81 to 84% in sensitivity and 75 to 89% in specificity for discriminating malignant from nonmalignant breast tissues, suggesting each set of tissue properties are diagnostically useful for the discrimination of breast malignancy.

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SPIE Journal Paper | 1 March 2008 Open Access

Monte-Carlo-based model for the extraction of intrinsic fluorescence from turbid media

Gregory Palmer, Nirmala Ramanujam

JBO, Vol. 13, Issue 02, 024017, (March 2008) https://doi.org/10.1117/12.10.1117/1.2907161

KEYWORDS: Luminescence, Optical properties, Absorption, Scattering, Monte Carlo methods, Tissues, Optical spheres, Tissue optics, Diffuse reflectance spectroscopy, Refractive index

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SPIE Journal Paper | 1 March 2007 Open Access

In vivo multiphoton fluorescence lifetime imaging of protein-bound and free nicotinamide adenine dinucleotide in normal and precancerous epithelia

Melissa Skala, Kristin Riching, Damian Bird, Annette Gendron-Fitzpatrick, Jens Eickhoff, Kevin Eliceiri, Patricia Keely, Nirmala Ramanujam

JBO, Vol. 12, Issue 02, 024014, (March 2007) https://doi.org/10.1117/12.10.1117/1.2717503

KEYWORDS: In vivo imaging, Fluorescence lifetime imaging, Luminescence, Tissues, Multiphoton fluorescence microscopy, Mode conditioning cables, Tumor growth modeling, Biopsy, Statistical analysis, Multiphoton microscopy

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Proceedings Article | 6 February 2007 Paper

A scaling Monte Carlo method for diffuse reflectance computation from multi-layered media

Quan Liu, Nirmala Ramanujam

Proceedings Volume 6435, 643509 (2007) https://doi.org/10.1117/12.708574

KEYWORDS: Monte Carlo methods, Reflectivity, Tissues, Diffuse reflectance spectroscopy, Optical properties, Refractive index, Computer simulations, Anisotropy, Tissue optics, Photon transport

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SPIE Journal Paper | 1 March 2005 Open Access

Use of a multiseparation fiber optic probe for the optical diagnosis of breast cancer

Changfang Zhu, Gregory Palmer, Tara Breslin, Fushen Xu, Nirmala Ramanujam

JBO, Vol. 10, Issue 02, 024032, (March 2005) https://doi.org/10.1117/12.10.1117/1.1897398

KEYWORDS: Tissues, Luminescence, Diffuse reflectance spectroscopy, Breast, Fiber optics, Principal component analysis, Absorption, Statistical analysis, Breast cancer, Optical spectroscopy

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Proceedings Article | 29 July 2003 Paper

Noninvasive cerebral hemoglobin oxygenation quantification of fetal sheep under hypoxic stress in utero using frequency-domain diffuse optical two-layer model

Regine Choe, Turgut Durduran, Guoqiang Yu, Mark Nijland, Peter Nathanielsz, Britton Chance, Arjun Yodh, Nirmala Ramanujam

Proceedings Volume 4955, (2003) https://doi.org/10.1117/12.478175

KEYWORDS: Blood, Near infrared spectroscopy, Hypoxia, Tissues, Head, Data modeling, Sensors, Arteries, Signal detection, Fetus

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SPIE Journal Paper | 1 April 2003 Open Access

Experimental validation of Monte Carlo modeling of fluorescence in tissues in the UV-visible spectrum

Quan Liu, Changfang Zhu, Nirmala Ramanujam

JBO, Vol. 8, Issue 02, (April 2003) https://doi.org/10.1117/12.10.1117/1.1559057

KEYWORDS: Monte Carlo methods, Tissues, Luminescence, Absorption, Fiber optics, Scattering, Diffuse reflectance spectroscopy, Optical properties, Fiber optics tests, Atrial fibrillation

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SPIE Journal Paper | 1 April 2003 Open Access

Effect of fiber optic probe geometry on depth-resolved fluorescence measurements from epithelial tissues: a Monte Carlo simulation

Changfang Zhu, Quan Liu, Nirmala Ramanujam

JBO, Vol. 8, Issue 02, (April 2003) https://doi.org/10.1117/12.10.1117/1.1559058

KEYWORDS: Luminescence, Tissues, Fluorescence spectroscopy, Optical properties, Monte Carlo methods, Photons, Fiber optics, Fiber optics tests, Charge-coupled devices, Optical fibers

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Proceedings Article | 25 September 2001 Paper

On-line monitoring of oxy- and deoxy-hemoglobin using near-infrared spectroscopic techniques

Gargi Vishnoi, Re-Gine Choe, N. Ramanujam, Martha Rode, Britton Chance

Proceedings Volume 4417, (2001) https://doi.org/10.1117/12.441341

KEYWORDS: Blood, Absorption, Near infrared, Modulation, Tissue optics, Diffusion, Scattering, Photons, Phase measurement, Near infrared spectroscopy

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SPIE Journal Paper | 1 October 2000 Open Access

Trans-abdominal monitoring of fetal arterial blood oxygenation using pulse oximetry

Anna Zourabian, Andrew Siegel, Britton Chance, Nirmala Ramanujam, Martha Rode, David Boas

JBO, Vol. 5, Issue 04, (October 2000) https://doi.org/10.1117/12.10.1117/1.1289359

KEYWORDS: Signal detection, Blood, Oxygen, Absorption, Oximetry, Tissue optics, Scattering, Tissues, Heart, Fetus

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SPIE Journal Paper | 1 July 2000 Open Access

Modeling photon transport in transabdominal fetal oximetry

Steven Jacques, Nirmala Ramanujam, Gargi Vishnoi, Re-Gine Choe, Britton Chance

JBO, Vol. 5, Issue 03, (July 2000) https://doi.org/10.1117/12.10.1117/1.429996

KEYWORDS: Brain, Sensors, Natural surfaces, Tissues, Optical spheres, Tissue optics, Absorption, Oximetry, Optical properties, Fetus

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SPIE Journal Paper | 1 April 2000 Open Access

Photon migration through fetal head in utero using continuous wave, near infrared spectroscopy: clinical and experimental model studies

Nirmala Ramanujam, Gargi Vishnoi, Andreas Hielscher, Martha Rode, Iraj Forouzan, Britton Chance

JBO, Vol. 5, Issue 02, (April 2000) https://doi.org/10.1117/12.10.1117/1.429984

KEYWORDS: Head, Near infrared, Absorption, Abdomen, Tissues, Tissue optics, Blood, Sensors, Spectroscopy, Fetus

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SPIE Journal Paper | 1 April 2000 Open Access

Photon migration through fetal head in utero using continuous wave, near infrared spectroscopy: development and evaluation of experimental and numerical models

Gargi Vishnoi, Andreas Hielscher, Nirmala Ramanujam, Britton Chance

JBO, Vol. 5, Issue 02, (April 2000) https://doi.org/10.1117/12.10.1117/1.429983

KEYWORDS: Head, Tissue optics, Tissues, Signal detection, Absorption, Near infrared, Diffusion, Sensors, Optical properties, Fetus

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Proceedings Article | 15 July 1999 Paper

Noninvasive transabdominal monitoring of fetal cerebral oxygenation using pulse oximetry

Anna Zourabian, Andrew Siegel, Nirmala Ramanujam, Britton Chance, David Boas, Gargi Vishnoi, Re-Gine Choe

Proceedings Volume 3597, (1999) https://doi.org/10.1117/12.356783

KEYWORDS: Signal detection, Oximetry, Heart, Sensors, Oxygen, Blood, Tissues, Tissue optics, Arteries, Fetus

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Proceedings Article | 15 July 1999 Paper

Tissue phantom studies on photon migration through fetal brain in utero using near-infrared spectroscopy

Gargi Vishnoi, Andreas Hielscher, Nirmala Ramanujam, Shoko Nioka, Britton Chance

Proceedings Volume 3597, (1999) https://doi.org/10.1117/12.356788

KEYWORDS: Head, Tissue optics, Tissues, Sensors, Scattering, Absorbance, Diffusion, Spectroscopy, Absorption, Fetus

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Proceedings Article | 15 July 1999 Paper

Feasibility of frequency domain NIR spectrometer to measure fetal cerebral blood oxygenation in utero

Re-Gine Choe, Gargi Vishnoi, Nirmala Ramanujam, Vasilis Ntziachristos, Shoko Nioka, Britton Chance, Arjun Yodh, Martha Rode, Iraj Forouzan, Mark Morgan

Proceedings Volume 3597, (1999) https://doi.org/10.1117/12.356782

KEYWORDS: Blood, Spectroscopy, Tissue optics, Signal detection, Near infrared, Optical properties, Diffusion, Absorption, Tissues, Fetus

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Proceedings Article | 6 December 1996 Paper

Detection of cervical precancer using optical spectroscopy (Extended Abstract)

Nirmala Ramanujam, Michele Follen-Mitchell, Anita Mahadevan-Jansen, Constantinos Pitris, Anant Agrawal, Sharon Thomsen, Gregg Staerkel, Thomas Wright, Rebecca Richards-Kortum

Proceedings Volume 2926, (1996) https://doi.org/10.1117/12.260814

KEYWORDS: Algorithm development, Raman spectroscopy, Tissues, Luminescence, Optical spectroscopy, Diagnostics, Fluorescence spectroscopy, Cervix, Target detection, In vivo imaging

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Proceedings Article | 8 May 1995 Paper

Optical techniques for diagnosis of cervical precancers: a comparison of Raman and fluorescence spectroscopies

Anita Mahadevan-Jansen, Nirmala Ramanujam, Michele Follen-Mitchell, Anais Malpica, Sharon Thomsen, Rebecca Richards-Kortum

Proceedings Volume 2388, (1995) https://doi.org/10.1117/12.208469

KEYWORDS: Tissues, Raman spectroscopy, Luminescence, Algorithm development, Calibration, Inflammation, Diagnostics, In vivo imaging, Rhodamine, Fluorescence spectroscopy

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