Patent ID: 7951599

Claim:
A method for determining the hematocrit of a blood sample, comprising the steps of: depositing the sample into an analysis chamber operable to quiescently hold the sample for analysis, the chamber defined by an interior surface of a first panel, and an interior surface of a second panel, wherein both panels are transparent, and the chamber has a height extending between the interior surfaces of the panels, which height is such that at least some red blood cells within the sample contact both of the interior surfaces of the panels and one or more areas void of red blood cells within the quiescent sample extend between the interior surfaces; imaging at least a portion of the quiescent sample, which sample portion contains the red blood cells and the one or more red blood cell void areas contacting the interior surfaces, to determine an optical density value of the imaged portion of the sample on a per image unit basis; selecting and averaging the optical density values of the image units optically aligned with the red blood cells contacting the interior surfaces, and assigning an upper boundary value of 100% to the average optical density value of those image units; selecting and averaging the optical density values of the image units optically aligned with the one or more red blood cell void areas, and assigning a lower boundary value of 0% to the optical density values of those image units; and determining the hematocrit of the sample by assigning relative values to the optical density value of each image unit of the imaged sample portion as a function of the upper and lower boundary values, and averaging the relative values.