Patent ID: 6498645
Filing Date: 2002-12-24
Classification: G01N

Abstract:
A method for the substantially complete detection of all particles, within a predetermined size range, contained in an injectable solution, in a transparent container therefor, said method comprising the steps of:a) pre-positioning particles in the container whereby rotation of the container causes substantially all of the particles in the injectable solution in the container to rotate in a shell volume adjacent the inner walls of the container, with said shell volume having a predetermined thickness; b) illuminating all the particles rotating within the shell volume with lighting means; and c) detecting at least one of light scatter, light reflection and light extinction caused by said particles, with detector means having a depth of focus of detection in opposite volumes of the shell along a cross sectional diameter of the container; wherein detector means is positioned, relative to the container whereby a focal point of detection coincides with the center of the cross sectional diameter, whereby the size of detected particles in the opposite volumes is accurately mathematically compensatible to an actual size; and wherein said lighting means provides at least two directed lights, spaced 120Â° from each other, with said container being masked relative to each of said lights whereby each light illuminates different opposite volumes of the shell, with each of the opposite volumes being bounded by two opposing 90Â° arc segments of the container, symmetrically disposed around the principal optical plane, which optical plane is normal to the respective sensing faces of the photo detectors and perpendicular to the surface of each detector means, and wherein the said inspected volumes are further bounded by two container quadrant chords which connect the ends of the two opposing 90Â° arc segments of the container.