Abstract

An optical analyzer has been developed to monitor biochemical reactions that are used in diagnostic tests, which are typically conducted in clinical hemostasis–thrombosis laboratories. The module measures changes in the optical transmission of up to 15 samples simultaneously at 35 wavelength bands from 395 to 710 nm. The full spectrum transmission data for all samples are collected five times per second. This is accomplished with the use of a 50 W tungsten halogen lamp and holographic diffraction gratings that produce a first order transmission spectrum across a 40 element linear array of Si detectors. A rotating shutter device makes it possible to use only five detector arrays for monitoring all 15 samples. The arrays are scanned synchronously with the rotating shutter. Signals from the diodes are integrated over time through a charge coupled amplifier. The gratings are used under the Bragg condition with an angular dispersion of 0.07°/nm in the first order and with peak efficiencies exceeding 50% at 475 nm. A digital to analog converter is used with the amplifiers to provide a variable gain for each detector element. This feature is used to normalize and optimize the detectors’ output signals.

© 1992 Optical Society of America