Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Department of Sensor and Biomedical Technology

Biosensors play a vital role in all areas to measure various parameters like temperature, strain, pressure and displacement etc. Measurement of the physical, chemical, and biological parameters in natural environments for ecosystems protection is very important. Fiber optic biosensors have usually been used in medical and biological diagnostics. Fiber optic sensors offer a number of advantages over electric counterparts due to their small size, high sensitivity, and possibility of distributed measurements. Now a day, the technology is heading towards the real time monitoring of parameters and automation in control of process. For that the sensor should be very sensitive and accurate. In the present investigation, a Fiber Bragg Grating (FBG) based, pressure and strain sensor simulation has been carried out using PTOLEMY II software for biological applications. The main advantage is that its sensing principle is based on its reflecting property and it is easy to transmit the measured parameter. Simulation of this sensor will help to understand and predict the value of temperature and strain, based on the shifted wavelength. In the present investigation, a new simulation tool has been developed for Fiber Bragg Grating based temperature and strain sensor, to determine the shift in wavelength. Measurements were made over a temperature range of -20 °C to 140 °C and strain range of 200 to 2000 με. Temperature vs. shift in wavelength and strain vs. shift in wavelength graphs were plotted. The temperature and strain sensitivity were found to be 5.89 pm/ °C and 0.67 pm/μe. The results are showing very good accuracy and hence the sensor can be effectively used for biological applications with high sensitivity.

World University root node

School of Electronics Engineering

Vellore Campus

Optoelectronics and Advanced Materials, Rapid Communications

Fiber Bragg Grating based temperature and strain sensor simulation for biomedical applications

Microwave imaging systems offer much promise for biomedical applications such as cancer detection because of their good penetration, non invasive and non ionizing nature and low cost. The resolution is one of the major problems faced in such systems, which can be improved by applying signal processing techniques. The key element for the microwave imaging system is the antenna. In this paper we have discussed about the characteristics of an antenna suitable for this purpose. © 2008 SBM/SBMag.

Journal of Microwaves and Optoelectronics

A modified bow-tie antenna for microwave imaging applications

Diabetic retinopathy is one of the common complications of diabetes. Unfortunately, in many cases the patient is not aware of any symptoms until it is too late for effective treatment. Analysis of the evoked potential response of the retina, optical nerve and optical brain centre will pave a way for the early diagnosis of diabetic retinopathy and prognosis during the treatment process. In this paper, diabetic retinopathy classification using transient visual evoked potential phase spectral periodicity is presented. The phase spectral periodicity of the different diabetic retinopathy patients and the corresponding latency values are computed. The results are statistically analysed and presented. © 2008 Inderscience Enterprises Ltd.

International Journal of Medical Engineering and Informatics

Staging of diabetic retinopathy using TVEP phase spectral periodicity analysis

The laser beam parameters of a lamp pumped Q-switched Nd: YAG laser have been characterized for ultra hard wide band gap photonic material.

Journal of Optoelectronics and Advanced Materials

Characterization of laser beam parameters for optical microfabrication of ultrahard and wide band gap photonic materials for MOEMS applications

The characterization of physicochemical properties of the internal environment of sol-gel thin films is required for understanding and designing applications in optical biosensors. We have investigated the dip coated tetraethyl-orthosilicate (TEOS) derived sol-gel thin films deposited on microscopic glass cover slips using molar ratio (water or ethanol / TEOS) R=32 using fluorescence spectroscopic measurements (emission, lifetime and anisotropy) on entrapped fluorescent probes. The effect of water and/or ethanol was studied as a function of storage (60 days) using fluorescent probes Hoechst 33258 (H258) and Pyranine (PY). Distribution of fluorescent probes in thin film was studied using confocal microscope. Emission maxima of H258 entrapped thin films from sol prepared using water as solvent showed emission maximum at 503 nm indicating the presence of water like environment which did not change during storage. On the contrary, PY entrapped thin films depicted emission bands at 434 nm and 513 nm, characteristics of ethanol and water respectively, up to the first few weeks and then the band at 434 nm prevailed (60 days), suggesting heterogeneous internal environment. Thin films from sol prepared using ethanol as solvent showed presence of ethanol through out storage. Fluorescence lifetime data of these probes in both sol-gel and thin films also suggested presence of heterogeneous internal environment. Thin films prepared from sol-gel using water as solvent suggested release of ethanol in the pores during hydrolysis and condensation reaction, which were clearly indicated by PY. The effect of sodium phosphate buffer was also studied in sol-gel and thin films. The results of these measurements showed that both the probes H258 and PY could be used effectively in monitoring the physicochemical properties of internal environment of thin films and sol-gel as a function of storage. © Springer Science + Business Media, LLC 2006.

Journal of Sol-Gel Science and Technology

Fluorescence spectroscopic study of dip coated sol-gel thin film internal environment using fluorescent probes Hoechst33258 and Pyranine

Diabetic retinopathy is one of the common complications of diabetes. Unfortunately, in many cases the patient is not aware of any symptoms until it is too late for effective treatment. Thorough analysis of evoked potential response of the retina, optical nerve and optical brain center will pave a way for early diagnosis of diabetic retinopathy and enable prognosis during the treatment process. This paper presents a non-invasive Transient Visual Evoked Potential phase spectral components periodicity measure based method to classify diabetic retinopathy subjects. © 2006 IEEE.

IEEE International Conference on Engineering of Intelligent Systems, ICEIS 2006

Sol-gel-immobilized-urease conductometric biosensor on a thick film interdigitated electrode was developed. The biosensor can be used for heavy metal ions determination in liquid samples. The biosensor exhibited good response to changes in urea concentration within the range of 1mM to 15 mM. After standardizing the sensor for Urea, the biosensor has been used to determine the heavy metal ions of different concentrations. The concentration range of Urea that can be detected by using this sensor is 1mM to 15mM.The heavy metals range is from 0.1mM to 10mM. Among the three metals used, the amount of inhibition is found to be more in Cadmium, then Copper and then Lead. The sensitivity is 1 mM in spectrophotometric technique and 5 mM in electrical method. The described sensor is tested for synthetic effluents in laboratory conditions. By further refinement, it can be used to test real industrial samples. © 2006 Taylor and Francis Group, LLC.

VIT Unitversity

Biotechnology & Biotechnological Equipment

Enzyme based Biosensor for Heavy Metal Ions Determination

Transient visual evoked potential (TVEP) has been used as one of the valuable diagnostic tool in clinical environment. Various types of analyze have been performed on TVEP recordings for identifying diagnostically significant information. Conventional methods of detection of visual anomalies, based on TVEP require long periods of testing and averaging. Hence the problem of patient fatigue affects the accuracy of the results. This paper presents an approach to analysis TVEP latency using spectral components. This new approach was successfully tested on 300 normal and 450 abnormal subjects with certain disorders to identify the change in latency. © 2006 JD.

Iranian Journal of Electrical and Computer Engineering

Identification of transient visual evoked potential latency using spectral components

Friction Stir Spot Welding (FSSW) is a solid state joining technology that has the potential to find applications in the automotive and aerospace industries. One of the FSSW approaches currently used is the refill method. Having numerical models capable to represent the physics of this process with reasonable accuracy can be useful to optimize process parameters and explore new tool designs. In this paper, a three-dimensional isothermal finite element model of the plunge phase of a refill FSSW process is presented. ABAQUS/Explicit is employed to obtain the deformations, stresses and strains induced in the plates being spot welded. Virtual tracers are also incorporated in the simulation in an attempt to visualize the material flow near the tool. A comparison of results provided by the simulation with previously reported experimental data shows that it gives an acceptable approximation but additional refinement of the model is needed.

SAE Technical Papers

Visualization of material flow in the refill friction stir spot welding process

The complex dielectric constants at room temperature of various goat tissues (liver, muscle, kidney, heart and brain) were measured in the frequency range 1 to 10 GHz with the help of a HP Network Analyser HP 8510A. Open ended coaxial cable method was employed for the measurement. The system imperfections are completely avoided by calibrating the system with four known materials and their reflection coefficients were used in the calculation along with the reflection coefficient of the sample. The relaxation frequency in the δ region, spread of relaxation, volume fraction of protein present in tissues are calculated from the measured dielectric data. © 2005 IEEE.