A series of hyperspectral transmission images of hematoxylin and eosin stained tissue sections from cervical biopsies
were acquired at 10 nm intervals and assembled into a hyperspectral image cube. Custom software providing extraction
of spectra at each pixel allows selection of images with maximum contrast for determination of selected features and
differentiation of tissue features. Illumination profiles were created using a spectrally and temporally programmable
light engine based on a spatial light modulator that can dynamically create any narrow or broadband spectral profile was
used to select illumination wavelengths. Images were acquired with a monochrome CCD camera. Several methods of
combining images from individual or composite spectral bands to recreate color images for pathologist review are
shown. Unlike current "mechanical" illumination systems employing optical filters, filter wheels, motors, shutters and
multiple control interfaces, the light engine integrates the lamp, wavelength control, intensity control and exposure
control in a simple MEMS based system, where the only moving part is the lamp cooling fan. Illumination can now be
programmed dynamically with digital control of all illumination parameters allowing wavelengths and intensities to be
changed much faster than with filter wheels, and providing exposure control orders of magnitude more precise than
mechanical shutters. This system can be integrated with digital imaging systems. Digitally controlled illumination is bit
additive with image data providing high dynamic range imaging with monochrome or with color imaging devices.
Performance of image analysis software for nuclear morphometric and tissue architecture analysis are compared for
different wavelength regions.
We report a spectrally and temporally programmable light engine based on a spatial light modulator that can dynamically create any narrow or broadband spectral profile for hyperspectral, fluorescence, or principal component imaging. Most hyperspectral or multispectral imaging systems use wavelength selection devices such as acousto-optic tunable filters (AOTFs), tunable grating or prism-based monochromators, or filter wheels. While these devices can select wavelengths they cannot create arbitrary spectral profiles. This simple and economical system can be controlled at high speed (up to 5000 illumination profiles per second). Digitally controlled illumination is bit additive with image data providing high dynamic range imaging with monochrome or color imaging devices. This is especially advantageous for endoscopes employing small well CCD or CMOS sensors since the dynamic range now can extend beyond the limits of the sensor itself. In this report we show multispectral images of in vivo tissue and in vitro tissue samples using endoscopes, surgical microscopes and conventional microscopes.