Abstract: Preparing and analyzing a fluid for a multi-spectral analysis is disclosed. The multi-spectral analysis includes providing two or more separate and independent types of spectroscopies including at least a first spectrometer and a second spectrometer of a spectrometer system to examine the fluid after that fluid has passed through one or more sample preparation processes to increase a purity of a target biological entity in the fluid and thereby enhance signal to noise ratios in measurements and related data analysis operations.

Abstract: Radiation from a collimated linear source (7, 8) is directed partly into a light guide structure (6) and partly glancing over the surface of the light guide structure (6). The radiation (15, 20) travelling inside the light guide is coupled out by micro-optical structures to illuminate the underlying reflective or superlying transmissive LCD. Radiation (17A, 17B) travelling across the surface outside the light guide (6) is directed towards an array of light sensitive detectors. Interruption of this radiation by a pen (21) or a finger (21) is detected and the position of the interruption is deduced.