Differentiating cancer types using a urine test for volatile organic compounds.

Background: In the human body, volatile organic compounds (VOCs) are produced by different tissues then secreted in different body fluids and subsequently excreted. Here we explore a non-invasive method for the detection of liver, prostate and bladder cancers.

Methods: We recruited 140 cases.

Personal ammonia sensor for industrial environments.

The realisation of an opto-chemical ammonia sensor suitable for personal monitoring tasks is described, comprising a cyanine dye immobilised in a microporous glass thin film. The fabrication of sensor platforms incorporating embossed grating couplers provides a compact optical design with effective waveguiding characteristics, resulting in reversible ammonia sensitivity in the 5-100 ppm range in under 2 min. Cross-sensitivity of sensor response with water and other potential interferents is considered.

Correlation and image recognition with surface-scattered light.

Image recognition by use of coherent optical processors and light diffusely scattered from the surface of an optically rough object is reported. A theoretical description is presented and shows that the image speckles are carriers for the Fourier spectra of the object at the matched spatial-filter plane. Experimental results of optical autocorrelation and cross correlation are given.

Contrast enhancement of underwater images with coherent optical image processors.

The use of coherent optical processors for improving the quality of degraded underwater images is discussed, and a holographic filter suitable for the enhancement of contrast in underwater images is described. The filter is a modified matched spatial filter, and it performs a nonlinear local contrast enhancement. The theory of the operation of the coherent optical image processor with this new filter is presented and experimentally verified.

Fiducial markers for increasing the versatility of optical correlation in the measurement of faults on integrated-circuit wafers.

A microscope-coherent optical processor is used for the measurement of the registration errors on integrated-circuit wafers. The measurements are obtained from the optical correlation of wafers with reference wafer patterns by use of matched spatial filters. Previously, the intricate pattern of the active circuit area of wafers has been used in the correlation process, and a new matched spatial filter had to be created for each different integrated circuit.