Patent ID: 7307721

Claim:
An imaging system for imaging particles in a fluid, the particles characterized by an average diameter or size, the imaging system comprising: a sample cell for containing samples of fluid flowing therethrough; an imaging means for sequentially capturing images of particles within the sample cell with a pre-determined exposure time per image of at least 1 msec and an image capture rate of at least 0.1 image per second to obtain a plurality of images, wherein each of the images is characterized by a field of view in the direction of the fluid flow of at least 0.1 mm; a flow control means for slowing down the fluid flow within the sample cell during capturing of the images so that an average displacement of the particles within the field of view in the sample cell in the direction of the fluid flow during each of the image captures is less than 10% of the average particle diameter or size, and accelerating the fluid flow through the sample cell between capturing the images, so that the fluid within the field of view is substantially replaced between capturing of consecutive two of the plurality of images.