Kumar Durairaj | Periyar Maniammai University (original) (raw)
Papers by Kumar Durairaj
Journal of Biosensors & Bioelectronics, 2011
A47. HEALTH EFFECTS OF AIR POLLUTION - ORGANIC DUST/BIOMASS, 2020
Journal of the Optical Society of America A, 2007
Current Medical Imaging Reviews, 2006
describe the system design of the first bioluminescence tomography (BLT) system for parallel acqu... more describe the system design of the first bioluminescence tomography (BLT) system for parallel acquisition of multiple bioluminescent views around a mouse in a number of spectral channels simultaneously. The primary component of this BLT system is a novel mirror module and a unique mouse holder. The mirror module consists of a mounting plate and four mirrors with stages. These mirror stages are right triangular blocks symmetrically arranged and attached to the mounting plate such that the hypotenuse surfaces of the triangular blocks all make 45 ◦ to the plate surface. The cylindrical/polygonal mouse holder has semitransparent rainbow bands on its side surface for the acquisition of spectrally resolved data. Numerical studies and experiments are performed to demonstrate the feasibility of this system. It is shown that bioluminescent signals collected using our system can produce a similar BLT reconstruction quality while reducing the data acquisition time, as compared to the sequential...
Optics …, 2006
Bioluminescence tomography (BLT) is a new molecular imaging mode, which is being actively develop... more Bioluminescence tomography (BLT) is a new molecular imaging mode, which is being actively developed to reveal molecular and cellular signatures as labeled by bioluminescent probes in a living small animal. This technology can help diagnose diseases, evaluate therapies, ...
Indian journal of experimental biology
Indian journal of biochemistry & biophysics
Monte Carlo simulation of photon scattering, with and without abnormal tissue placed at various l... more Monte Carlo simulation of photon scattering, with and without abnormal tissue placed at various locations in the rectangular, semi-circular and semi-elliptical tissue models, has been carried out. The absorption coefficient of the tissue considered as abnormal is high and its scattering coefficient low compared to that of the control tissue. The placement of the abnormality at various locations within the models affects the transmission and surface emission of photons at various locations. The scattered photons originating from deeper layers make the maximum contribution at farther distances from the beam entry point. The contribution of various layers to photon scattering provides valuable data on variability of internal composition. Introduction.
Indian journal of experimental biology
A procedure for non-invasive imaging of the optical attenuation coefficient variation of in vivo ... more A procedure for non-invasive imaging of the optical attenuation coefficient variation of in vivo thick organs/tissues is developed. The laser back-scattered surface profiles at various locations of human forearm, by multi-probe reflectometer, are measured. These profiles are matched by iterative procedure, with that as obtained by Monte Carlo simulation and the corresponding values of attenuation coefficient (equal to the sum of absorption and reduced scattering coefficients) are determined. By interpolation of this data a 100 x 100 grid is constructed and after median filtering of this data a color-coded image of the variability of the optical attenuation coefficient of the forearm is obtained. These images in different subjects show variation due to change in overall tissue composition and blood pooling. This non-invasive imaging procedure may help in identifying the diseased affected regions in healthy tissues and in application of photodynamic therapy.
PURPOSE The performance of bioluminescence tomography depends on knowledge on the distribution of... more PURPOSE The performance of bioluminescence tomography depends on knowledge on the distribution of optical properties of a small animal under study such as a mouse. Here we develop a fiber optic biopsy prototype for in vivo measurement of optical parameters of mouse organs and tissues. METHOD AND MATERIALS A multi-fiber optical biopsy system is under development. The multi fibers are bundled together. The proximal end of the sensing probe has side fire detection fibers and one flat illumination fiber. The distal ends of the side fire fibers face the CCD camera. Using the fiber probe, experiments are conducted on mouse organs and tissues under in vitro and in vivo conditions. In doing so, the biopsy needle is gently pierced into the specimen, and the light of known wavelength and intensity is delivered for illumination. Then, the diffuse signal is collected by the side fire fibers and recorded by the CCD camera. Two readings of fluence with a pre-specified separation distance are meas...
PURPOSE Despite the progress in optical molecular imaging of small animals based on fluorescence ... more PURPOSE Despite the progress in optical molecular imaging of small animals based on fluorescence and bioluminescence, optical molecular imaging of patients has been a challenge due to the limited light penetration depth. Here we report our customized fiber-optic probe to detect bioluminescent sources deep in a patient body. METHOD AND MATERIALS Bioluminescent sources are usually weak and will typically be located deep inside a body once they are FDA-approved. Because of absorption and scattering, the mean-free-path of light is of sub-millimeter order. Hence, such deep sources cannot be effectively detected on the body surface. Our multi-fiber fiber-optic probe is designed and fabricated to detect the optical signal through its insertion into the tissue guided by an ultrasound device. The detection efficiency of the probe is investigated via Monte Carlo simulation and experiments. A 3D tracking and digitizing device is used to record the spatial positions of the sensor tip of the fib...
Continuous Glucose Monitoring Systems are used to track the time course of blood glucose for Diab... more Continuous Glucose Monitoring Systems are used to track the time course of blood glucose for Diabetes people. Prediction of Hypo/Hyper glycemic occurrences are the main task in the management of Diabetes. Our work involved the development of a feed forward back propagation neural network that is trained with the features of incoming continuous glucose monitoring sensor data and prediction of future blood glucose values with the special activation functions. This paper had presented the comparison of Featured neural network with that of Gradient Descent and Levenberg Marquardt back propagation algorithms.
PURPOSE As part of our ongoing work to establish bioluminescence tomography, we seek to determine... more PURPOSE As part of our ongoing work to establish bioluminescence tomography, we seek to determine the optical parameters, including scattering coefficient (ms cm-1), absorption coefficient (ma cm-1) and anisotropy parameter (g), of the mouse in-vivo and in-vitro. METHOD AND MATERIALS A system, consisting of calibrated light source, spectrometer, filter, attenuator and optic fiber, is used for light delivery inside the animal organ/tissue. Desired wavelength and flux of light is selected by the software (OOIIrrad32, Ocean Optics) and guided through the optic fiber. The fiber is positioned inside the trachea of anaesthetized mouse and the mouse is placed in an upright holder. Inside lightproof box liquid nitrogen cooled CCD camera collects the diffuse signal on the surface of the mouse. For the other organs such as spleen, liver etc., the fiber is carefully placed percutaneously at one side of the organ. The CCD collects the light emission from the other side opposite to placement. Th...
PURPOSE To quantify tumor hypoxia that is correlated with poor prognosis and response to therapy,... more PURPOSE To quantify tumor hypoxia that is correlated with poor prognosis and response to therapy, a luminescent spectroscopic method is developed and tested in experiments with tissue phantoms. METHOD AND MATERIALS The phantom background is a nylon material. The absorption, scattering, and anisotropy parameters are 0.2cm-1, 3.0cm-1 and 0.85, respectively. It contains a chamber to hold a specified amount of blood and a hole to host a luminescent source. Normal/coagulated blood samples are used to represent different physiological conditions. The phantom with the blood sample and the light source embedded is placed in the sample holder in front of the CCD camera for the luminescence imaging. The data acquisition is performed in a dark environment four times from horizontal orientations 90 degrees apart. One luminescent view is recorded per acquisition by exposing the camera for 60s for each of four luminescent sources (450nm/550nm/600nm/700nm). In these spectral regions the absorption...
Wireless Personal Communications, 2015
ABSTRACT The beam motion is one of the main causes for major power loss which severely degrades t... more ABSTRACT The beam motion is one of the main causes for major power loss which severely degrades the performance of the Free Space Optical Communication (FSOC) system. Designing a suitable controller to correct the beam motion to increase the beam stability at a point becomes significant. This paper presents an investigation on the performance of two types of controller designed for aiming a laser beam to be at a particular spot under dynamic disturbances generated at the transmitter. The experimental nonlinear input-output data mapping is used as the principal components for the controller design. The first design is based on the Taguchi method while the second is the artificial neural network—cognitive method. These controllers process the beam pointing (beam location) information from an opto-electronic position detector and then generate the necessary outputs to steer the beam with fast steering mirror. Conceptually, the controller design problem is addressed with looking the position error information to decide the level of nonlinear static output map for generating the correction control information. The pipelined-parallel architecture of both controllers are developed in a field programmable gate array (FPGA) and installed at the receiver station. Evidence of the suitability and the effectiveness of the proposed controller in terms of prediction exactness, response to impulse, scintillation, Q-factor and bit error rate are provided through experimental results obtained from the 155 Mbps FSOC data link set-up established for the horizontal range of 0.5 km at an altitude of 15.25 m.
Medical Imaging 2005: Visualization, Image-Guided Procedures, and Display, 2005
Advances in Intelligent Systems and Computing, 2015
Journal of Biosensors & Bioelectronics, 2011
A47. HEALTH EFFECTS OF AIR POLLUTION - ORGANIC DUST/BIOMASS, 2020
Journal of the Optical Society of America A, 2007
Current Medical Imaging Reviews, 2006
describe the system design of the first bioluminescence tomography (BLT) system for parallel acqu... more describe the system design of the first bioluminescence tomography (BLT) system for parallel acquisition of multiple bioluminescent views around a mouse in a number of spectral channels simultaneously. The primary component of this BLT system is a novel mirror module and a unique mouse holder. The mirror module consists of a mounting plate and four mirrors with stages. These mirror stages are right triangular blocks symmetrically arranged and attached to the mounting plate such that the hypotenuse surfaces of the triangular blocks all make 45 ◦ to the plate surface. The cylindrical/polygonal mouse holder has semitransparent rainbow bands on its side surface for the acquisition of spectrally resolved data. Numerical studies and experiments are performed to demonstrate the feasibility of this system. It is shown that bioluminescent signals collected using our system can produce a similar BLT reconstruction quality while reducing the data acquisition time, as compared to the sequential...
Optics …, 2006
Bioluminescence tomography (BLT) is a new molecular imaging mode, which is being actively develop... more Bioluminescence tomography (BLT) is a new molecular imaging mode, which is being actively developed to reveal molecular and cellular signatures as labeled by bioluminescent probes in a living small animal. This technology can help diagnose diseases, evaluate therapies, ...
Indian journal of experimental biology
Indian journal of biochemistry & biophysics
Monte Carlo simulation of photon scattering, with and without abnormal tissue placed at various l... more Monte Carlo simulation of photon scattering, with and without abnormal tissue placed at various locations in the rectangular, semi-circular and semi-elliptical tissue models, has been carried out. The absorption coefficient of the tissue considered as abnormal is high and its scattering coefficient low compared to that of the control tissue. The placement of the abnormality at various locations within the models affects the transmission and surface emission of photons at various locations. The scattered photons originating from deeper layers make the maximum contribution at farther distances from the beam entry point. The contribution of various layers to photon scattering provides valuable data on variability of internal composition. Introduction.
Indian journal of experimental biology
A procedure for non-invasive imaging of the optical attenuation coefficient variation of in vivo ... more A procedure for non-invasive imaging of the optical attenuation coefficient variation of in vivo thick organs/tissues is developed. The laser back-scattered surface profiles at various locations of human forearm, by multi-probe reflectometer, are measured. These profiles are matched by iterative procedure, with that as obtained by Monte Carlo simulation and the corresponding values of attenuation coefficient (equal to the sum of absorption and reduced scattering coefficients) are determined. By interpolation of this data a 100 x 100 grid is constructed and after median filtering of this data a color-coded image of the variability of the optical attenuation coefficient of the forearm is obtained. These images in different subjects show variation due to change in overall tissue composition and blood pooling. This non-invasive imaging procedure may help in identifying the diseased affected regions in healthy tissues and in application of photodynamic therapy.
PURPOSE The performance of bioluminescence tomography depends on knowledge on the distribution of... more PURPOSE The performance of bioluminescence tomography depends on knowledge on the distribution of optical properties of a small animal under study such as a mouse. Here we develop a fiber optic biopsy prototype for in vivo measurement of optical parameters of mouse organs and tissues. METHOD AND MATERIALS A multi-fiber optical biopsy system is under development. The multi fibers are bundled together. The proximal end of the sensing probe has side fire detection fibers and one flat illumination fiber. The distal ends of the side fire fibers face the CCD camera. Using the fiber probe, experiments are conducted on mouse organs and tissues under in vitro and in vivo conditions. In doing so, the biopsy needle is gently pierced into the specimen, and the light of known wavelength and intensity is delivered for illumination. Then, the diffuse signal is collected by the side fire fibers and recorded by the CCD camera. Two readings of fluence with a pre-specified separation distance are meas...
PURPOSE Despite the progress in optical molecular imaging of small animals based on fluorescence ... more PURPOSE Despite the progress in optical molecular imaging of small animals based on fluorescence and bioluminescence, optical molecular imaging of patients has been a challenge due to the limited light penetration depth. Here we report our customized fiber-optic probe to detect bioluminescent sources deep in a patient body. METHOD AND MATERIALS Bioluminescent sources are usually weak and will typically be located deep inside a body once they are FDA-approved. Because of absorption and scattering, the mean-free-path of light is of sub-millimeter order. Hence, such deep sources cannot be effectively detected on the body surface. Our multi-fiber fiber-optic probe is designed and fabricated to detect the optical signal through its insertion into the tissue guided by an ultrasound device. The detection efficiency of the probe is investigated via Monte Carlo simulation and experiments. A 3D tracking and digitizing device is used to record the spatial positions of the sensor tip of the fib...
Continuous Glucose Monitoring Systems are used to track the time course of blood glucose for Diab... more Continuous Glucose Monitoring Systems are used to track the time course of blood glucose for Diabetes people. Prediction of Hypo/Hyper glycemic occurrences are the main task in the management of Diabetes. Our work involved the development of a feed forward back propagation neural network that is trained with the features of incoming continuous glucose monitoring sensor data and prediction of future blood glucose values with the special activation functions. This paper had presented the comparison of Featured neural network with that of Gradient Descent and Levenberg Marquardt back propagation algorithms.
PURPOSE As part of our ongoing work to establish bioluminescence tomography, we seek to determine... more PURPOSE As part of our ongoing work to establish bioluminescence tomography, we seek to determine the optical parameters, including scattering coefficient (ms cm-1), absorption coefficient (ma cm-1) and anisotropy parameter (g), of the mouse in-vivo and in-vitro. METHOD AND MATERIALS A system, consisting of calibrated light source, spectrometer, filter, attenuator and optic fiber, is used for light delivery inside the animal organ/tissue. Desired wavelength and flux of light is selected by the software (OOIIrrad32, Ocean Optics) and guided through the optic fiber. The fiber is positioned inside the trachea of anaesthetized mouse and the mouse is placed in an upright holder. Inside lightproof box liquid nitrogen cooled CCD camera collects the diffuse signal on the surface of the mouse. For the other organs such as spleen, liver etc., the fiber is carefully placed percutaneously at one side of the organ. The CCD collects the light emission from the other side opposite to placement. Th...
PURPOSE To quantify tumor hypoxia that is correlated with poor prognosis and response to therapy,... more PURPOSE To quantify tumor hypoxia that is correlated with poor prognosis and response to therapy, a luminescent spectroscopic method is developed and tested in experiments with tissue phantoms. METHOD AND MATERIALS The phantom background is a nylon material. The absorption, scattering, and anisotropy parameters are 0.2cm-1, 3.0cm-1 and 0.85, respectively. It contains a chamber to hold a specified amount of blood and a hole to host a luminescent source. Normal/coagulated blood samples are used to represent different physiological conditions. The phantom with the blood sample and the light source embedded is placed in the sample holder in front of the CCD camera for the luminescence imaging. The data acquisition is performed in a dark environment four times from horizontal orientations 90 degrees apart. One luminescent view is recorded per acquisition by exposing the camera for 60s for each of four luminescent sources (450nm/550nm/600nm/700nm). In these spectral regions the absorption...
Wireless Personal Communications, 2015
ABSTRACT The beam motion is one of the main causes for major power loss which severely degrades t... more ABSTRACT The beam motion is one of the main causes for major power loss which severely degrades the performance of the Free Space Optical Communication (FSOC) system. Designing a suitable controller to correct the beam motion to increase the beam stability at a point becomes significant. This paper presents an investigation on the performance of two types of controller designed for aiming a laser beam to be at a particular spot under dynamic disturbances generated at the transmitter. The experimental nonlinear input-output data mapping is used as the principal components for the controller design. The first design is based on the Taguchi method while the second is the artificial neural network—cognitive method. These controllers process the beam pointing (beam location) information from an opto-electronic position detector and then generate the necessary outputs to steer the beam with fast steering mirror. Conceptually, the controller design problem is addressed with looking the position error information to decide the level of nonlinear static output map for generating the correction control information. The pipelined-parallel architecture of both controllers are developed in a field programmable gate array (FPGA) and installed at the receiver station. Evidence of the suitability and the effectiveness of the proposed controller in terms of prediction exactness, response to impulse, scintillation, Q-factor and bit error rate are provided through experimental results obtained from the 155 Mbps FSOC data link set-up established for the horizontal range of 0.5 km at an altitude of 15.25 m.
Medical Imaging 2005: Visualization, Image-Guided Procedures, and Display, 2005
Advances in Intelligent Systems and Computing, 2015