Method and apparatus for determining the hematocrit of a blood sample utilizing the intrinsic pigmentation of hemoglobin contained within the red blood cells

An apparatus for determining the hematocrit of a blood sample, comprising:

• 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;
• an imaging unit that is operable to image at least a portion of the sample quiescently residing within the chamber, which portion contains one or more red blood cells contacting the interior surfaces and one or more red blood cell void areas contacting the interior surfaces, and produce image signals representative of such imaged sample portion;
• and
• a programmable analyzer operable to determine, using the image signals, optical density values of the imaged portion of the sample on a per image unit basis, and to average the optical density values of image units optically aligned with the red blood cells contacting the interior surfaces, and assign an upper boundary value to the average optical density value of those image units, and to average the optical density values of image units optically aligned with the one or more red blood cell void areas and assigning a lower boundary value to the optical density values of those image units, and to determine the hematocrit of the sample by assigning relative values to the optical density value of image units of the imaged sample portion as a function of the upper and lower boundary values, and averaging the relative values.

An apparatus for determining the hematocrit of a blood sample quiescently residing within an analysis chamber, which chamber has a height extending between an interior surface of a first panel and an interior surface of a second panel, the apparatus comprising:

• an imaging unit that is operable to image at least a portion of the sample quiescently residing within the chamber that contains red blood cells contacting the interior surfaces and one or more red blood cell void areas contacting the interior surfaces, and produce image signals representative of such imaged sample portion;
• and
• a programmable analyzer operable to determine, using the image signals, optical density values of the imaged portion of the sample on a per image unit basis, and to average the optical density values of the image units optically aligned with the red blood cells contacting the interior surfaces, and assign an upper boundary value to the average optical density value of those pixels, and to average the optical density values of the image units optically aligned with the one or more red blood cell void areas and to assign a lower boundary value to the optical density values of those pixels, and to determine the hematocrit of the sample by assigning relative values to the optical density value of image units of the imaged sample portion as a function of the upper and lower boundary values, and averaging the relative values.