We report a label-free Surface Enhanced Raman Spectroscopy (SERS) for pleural fluid analysis to distinguish Lung cancer from controls patients. Herein, we have used a novel silver coated silicon Nanopillar (SCSNP) as SERS substrate to acquire multiple SERS spectra for each pleural fluid sample and advanced chemometrics methods. We report a classification accuracy of 85% along with sensitivity and specificity of 87% and 83% respectively for the detection of Lung cancer over control pleural fluid samples with a receiver operating characteristics (ROC) area under curve value of 0.92 using PLS-DA binary classifier to distinguish between lung cancer over control subjects.
Inflammatory skin disorder, eczema, is usually assessed by subjective disease scoring systems such as SCORAD and EASI. These scoring systems are based on clinical observations and questionnaires and hence it is subjected to inter and intra-assessor variability. Here, for the first time, we used optoacoustic imaging to image the structural and morphological changes of the skin in a non-invasive manner. Through a clinical study, we computed specific metrics such as epidermis thickness, total blood volume, vessel diameter in the dermis, ratio of low and high frequency signals. We trained a linear kernel-based support vector machine model for eczema classification using these metrics. We could achieve an accuracy of 86.6% and high sensitivity and specificity of 96.2% and 82.1% respectively. We also formulated a novel Eczema Vascular and Structural Index (EVSI) to objectively assess the severity of eczema.
A speckle pattern is a direct fingerprint of surface height variation on the sample. In this paper, angular speckle correlation technique is applied to estimate surface roughness Ra of an additive manufactured sample with different surface roughness Ra values varying from 5μm to 20μm. Feasibility study is conducted to evaluate the correct incidence and the change in incidence angle for angular speckle correlation. Speckle correlation is computed from two speckle images that are recorded at two different incidence angles on the rough surface and surface roughness information is gleaned. Test results in terms of surface roughness measurement from standard calibration plate and additive layer manufactured samples are presented.
Wire grid polarizers (WGP), are sub-wavelength gratings with applications in display projection
system due to their compact size, wide field of view and long-term stability. Measurement and testing
of these structures are important to optimize their use. This is done by first measuring the Mueller
Matrix of the WGP using a Mueller Matrix Polarimeter. Next the Finite Difference Time Domain
(FDTD) method is used to simulate a similar Mueller matrix thus providing the period and step height
of the WGP. This approach may lead to more generic determination of sub-wavelength structures
including diffractive optical structures.
A simple, full-field method to characterize phase modulation property of translucent twisted nematic spatial light
modulator (TN-LCSLM) is presented using Digital Holography (DH). Generally, amplitude and phase modulation is
coupled due to simultaneous distortion in twist alignment and tilt order with applied field. The change in birefringence of
liquid crystal material with respect to input grey scale produces phase modulation of wavefront transmitted through TNLCSLM.
Most existing techniques for phase modulation characterization of LCSLM are complex requiring lengthy
calculations and measure a very small region of total active region of SLM. In this paper, a transmission Digital
Holographic system is used to extract phase information from the digitally recorded and numerically reconstructed
wavefront. The advantage of phase modulation characterization using DH is that the phase value from larger area inside
the active region of TN-LCSLM can be visualized and quantified in real time.
Liquid crystal cells have always been an important part of commercially available displays, modulators and projectors. In
this paper, Jones matrix representation including four independent parameters for twisted nematic liquid crystal (TN-LC)
cell has been demonstrated. The physical parameters of the TN-LC cell such as twist angle, birefringence and director
orientation at the input face of cell has been calculated using intensity transmittance of an experimental set-up that
includes circularly polarized light and TN-LC cell sandwiched between two polarizers. The physical parameters have
been calculated without any ambiguity using three different wavelengths.
The knowledge from above measurement gives the general information about the birefringence and hence liquid crystal
cell gap thickness. To acquire full-field liquid crystal cell gap thickness measurement phase shift polariscope has been
adopted. The four phase shifted images through the rotating analyzer gives the full-field cell gap thickness measurement.
The experimental results have been compared with the commercial point wise measurement and are in good agreement.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.