A new type of endoscope is being developed which utilizes an optical raster scanning system for imaging through
an endoscope. The optical raster scanner utilizes a high speed, multifaceted, rotating polygon mirror system for horizontal
deflection, and a slower speed galvanometer driven mirror as the vertical deflection system. When used in combination,
the optical raster scanner traces out a raster similar to an electron beam raster used in television systems. This flying spot
of light can then be detected by various types of photosensitive detectors to generate a video image of the surface or scene
being illuminated by the scanning beam.
The optical raster scanner has been coupled to an endoscope. The raster is projected down the endoscope, thereby
illuminating the object to be imaged at the distal end of the endoscope. Elemental photodetectors are placed at the distal
or proximal end of the endoscope to detect the reflected illumination from the flying spot of light. This time sequenced
signal is captured by an image processor for display and processing. This technique offers the possibility for very small
diameter endoscopes since illumination channel requirements are eliminated. Using various lasers, very specific spectral
selectivity can be achieved to optimum contrast of specific lesions of interest. Using several laser lines, or a white light
source, with detectors of specific spectral response, multiple spectrally selected images can be acquired simultaneously. The
potential for co-linear therapy delivery while imaging is also possible.