MOTILITY SCANNER AND METHOD

An improved motility scanner is disclosed for characterizing the motion of sperm, bacteria, particles suspended in flowing fluids and the like. The motility scanner includes an improved optical system, a source of illumination for the system and radiation sensing means including electronic image reversal means coupled to the system. A disposable specimen holder allows external loading thereof and its positioning on a heated specimen support. The illumination source functions as a collimator in directing all of the emanating illumination onto the specimen. Both directly transmitted light and light scattered by the specimen are received by an imaging lens and are both focussed thereby onto pixels of a light sensitive device. A movable plate provided with a retarding member is designed to be located at the plane conjugate to the plane of the small source aperature. The directly transmitted light is transmitted through the retarding member and/or the attenuating member. The light scattered by the specimen, however, travels for the most part through the plate in areas not covered by the retarding and/or attenuating members.