Prof. Kartikeya Murari Profile

Prof. Kartikeya Murari

Associate Professor at Univ of Calgary

SPIE Involvement:

Author

Publications (9)

SPIE Journal Paper | 24 May 2024 Open Access

Distinguishing motion artifacts during optical fiber-based in-vivo hemodynamics recordings from brain regions of freely moving rodents

Anupam Bisht, Kathryn Simone, Jaideep S. Bains, Kartikeya Murari

NPh, Vol. 11, Issue S1, S11511, (May 2024) https://doi.org/10.1117/12.10.1117/1.NPh.11.S1.S11511

KEYWORDS: Simulations, Hemodynamics, Optical fibers, Brain, Motion measurement, Backscatter, Tissues, Animals, Motion models, Algorithm development

Read Abstract +

SignificanceMotion artifacts in the signals recorded during optical fiber-based measurements can lead to misinterpretation of data. In this work, we address this problem during in-vivo rodent experiments and develop a motion artifacts correction (MAC) algorithm for single-fiber system (SFS) hemodynamics measurements from the brains of rodents.Aim(i) To distinguish the effect of motion artifacts in the SFS signals. (ii) Develop a MAC algorithm by combining information from the experiments and simulations and validate it.ApproachMonte-Carlo (MC) simulations were performed across 450 to 790 nm to identify wavelengths where the reflectance is least sensitive to blood absorption-based changes. This wavelength region is then used to develop a quantitative metric to measure motion artifacts, termed the dissimilarity metric (DM). We used MC simulations to mimic artifacts seen during experiments. Further, we developed a mathematical model describing light intensity at various optical interfaces. Finally, an MAC algorithm was formulated and validated using simulation and experimental data.ResultsWe found that the 670 to 680 nm wavelength region is relatively less sensitive to blood absorption. The standard deviation of DM (σDM) can measure the relative magnitude of motion artifacts in the SFS signals. The artifacts cause rapid shifts in the reflectance data that can be modeled as transmission changes in the optical lightpath. The changes observed during the experiment were found to be in agreement to those obtained from MC simulations. The mathematical model developed to model transmission changes to represent motion artifacts was extended to an MAC algorithm. The MAC algorithm was validated using simulations and experimental data.ConclusionsWe distinguished motion artifacts from SFS signals during in vivo hemodynamic monitoring experiments. From simulation and experimental data, we showed that motion artifacts can be modeled as transmission changes. The developed MAC algorithm was shown to minimize artifactual variations in both simulation and experimental data.

DOWNLOAD PAPER

Proceedings Article | 13 March 2024 Presentation + Paper

System for simultaneous measurement of fluorescence and hemodynamics (SSMFH) from deep brain regions of freely moving rodents

Anupam Bisht, Govind Peringod, Grant Gordon, Jaideep Bains, Kartikeya Murari

Proceedings Volume 12828, 128280A (2024) https://doi.org/10.1117/12.3002776

KEYWORDS: Fluorescence, Hemodynamics, Brain, Light emitting diodes, Blood, Animals, Oxygen, Photometry, Design

Read Abstract +

Proceedings Article | 4 March 2022 Presentation + Paper

Investigating presence of motion artifacts in the oxygen saturation signal during in-vivo fiber photometry

Anupam Bisht, Kathryn Simone, Govind Peringod, Grant Gordon, Jaideep Bains, Kartikeya Murari

Proceedings Volume 11946, 1194603 (2022) https://doi.org/10.1117/12.2609877

KEYWORDS: Reflectivity, Brain, Tissue optics, Mathematical modeling, Hemodynamics, Blood, Tissues, Oxygen, In vivo imaging, Photometry

Read Abstract +

Proceedings Article | 1 March 2019 Paper

A miniaturized intrinsic optical sensing system (MiniIOS) for hemodynamic monitoring in freely-behaving rodents

Linhui Yu, Kartikeya Murari

Proceedings Volume 10865, 1086512 (2019) https://doi.org/10.1117/12.2507110

KEYWORDS: Absorption, Sensors, Reflectivity, Hemodynamics, Microcontrollers, Photodiodes, Optical sensing, Sensing systems, Brain

Read Abstract +

SPIE Journal Paper | 12 April 2018 Open Access

Open-source, cost-effective system for low-light in vivo fiber photometry

Kathryn Simone, Tamás Füzesi, David Rosenegger, Jaideep Bains, Kartikeya Murari

NPh, Vol. 5, Issue 02, 025006, (April 2018) https://doi.org/10.1117/12.10.1117/1.NPh.5.2.025006

KEYWORDS: Luminescence, In vivo imaging, Photometry, Optical fibers, Tissue optics, Signal to noise ratio, Signal detection, Calcium, Modulation, Neurons

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 12 February 2018 Paper

Hemodynamic monitoring in different cortical layers with a single fiber optical system

Linhui Yu, M. Sohail Noor, Zelma H. Kiss, Kartikeya Murari

Proceedings Volume 10481, 104811H (2018) https://doi.org/10.1117/12.2289138

KEYWORDS: Brain, Hemodynamics, Spectroscopy, Fiber optics, Neuroimaging, Animal model studies, Biomedical optics and medical imaging, Functional imaging

Read Abstract +

SPIE Journal Paper | 27 February 2012 Open Access

Increased illumination uniformity and reduced photodamage offered by the Lissajous scanning in fiber-optic two-photon endomicroscopy

Wenxuan Liang, Kartikeya Murari, Yuying Zhang, Yongping Chen, Xingde Li, Ming-Jun Li

JBO, Vol. 17, Issue 02, 021108, (February 2012) https://doi.org/10.1117/12.10.1117/1.JBO.17.2.021108

KEYWORDS: Luminescence, Fiber optics, Endomicroscopy, Ferroelectric materials, Numerical simulations, Electrodes, In vitro testing, Imaging systems, Data acquisition, Signal detection

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 1 May 2011 Open Access

Multiexposure laser speckle contrast imaging of the angiogenic microenvironment

Abhishek Rege, Kartikeya Murari, Alan Seifert, Nitish Thakor, Arvind Pathak

JBO, Vol. 16, Issue 05, 056006, (May 2011) https://doi.org/10.1117/12.10.1117/1.3582334

KEYWORDS: Laser speckle contrast imaging, Brain, Speckle, Image processing, Blood circulation, In vivo imaging, Neuroimaging, Ear, Wound healing, Spatial resolution

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 29 August 2008 Paper

Simultaneous wireless electrophysiological and neurochemical monitoring

Kartikeya Murari, Mohsen Mollazadeh, Nitish Thakor, Gert Cauwenberghs

Proceedings Volume 7035, 70350Q (2008) https://doi.org/10.1117/12.801235

KEYWORDS: Amplifiers, Clocks, Neurotransmitters, Neurons, Brain, Electroencephalography, Very large scale integration, Electrodes, Interfaces, Capacitors

Read Abstract +

Showing 5 of 9 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years