Tissue analyzer

Abstract

A system is disclosed for counting particles/cells within a counting box of precisely known volume that is completely inside a transparent section or sample. The box has a chosen height with defined upper and lower limits and appropriately selected width and depth dimensions. It resides completely within the sample and has no surface in common with an exterior surface of the sample. The system includes a compound light microscope that has a depth of focus which is small in relation to the thickness dimension of the counting box. The microscope includes adjustment means for moving the focal plane through a range which is greater than the height of the counting box. Display means are provided which show the portion of the sample that is within the depth of focus and user-operated means is provided to enable the user to mark the cells so displayed. Indicator means are further provided to either audibly or visually indicate to the user when the adjustment means cause the focal plane to pass beyond either the upper or lower height limits of the counting box. The indicator means further includes means for accumulating a count of cells within the counting volume as the user operates the marker means. Means are also provided to compensate for optical foreshortening.