Rapid method for determining the erythrocyte sedimentation rate in a sample of anticoagulated whole blood

A method for determining the magnitude of intercellular erythrocyte repulsion in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording successive positions of an erythrocyte/plasma interface in said capillary tube at successive known time intervals during said centrifuging step so as to establish a time-related red cell layer compaction curve for the erythrocytes in said blood sample, said compaction curve having an essentially linear portion and a non-linear portion;
• d) the step of selecting a segment of said compaction curve which lies in said non-linear portion of said compaction curve;
• and
• e) the step of determining a mathematical function for said selected segment of said compaction curve in relation to a known elapsed time period, where said function of said selected segment is representative of the magnitude of intercellular erythrocyte repulsion in said blood sample.

A method for determining the magnitude of intercellular erythrocyte repulsion in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording positions of an erythrocyte/plasma interface in said capillary tube at known time intervals during said centrifuging step so as to define a non-linear time-related red cell layer compaction curve for the erythrocytes in said blood sample;
• and
• d) the steps of essentially linearizing a plurality of the erythrocyte/plasma interface positions occurring in said curve during a known time span, and calculating a slope for said linearized positions so as to determine the magnitude of intercellular erythrocyte repulsion in said blood sample.

A method for determining the magnitude of intercellular erythrocyte repulsion in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording positions of an erythrocyte/plasma interface in said capillary tube at known time intervals during said centrifuging step so as to establish a time-related red cell layer compaction curve for the erythrocytes in said blood sample which curve has an initial linear portion and a subsequent non-linear portion;
• and
• d) the step of calculating a slope (sl) of mathematically essentially linearized erythrocyte/plasma interface positions occurring in said non-linear portion of said curve during a known time span so as to determine the magnitude of intercellular erythrocyte repulsion in said blood sample.

A method for determining an erythrocyte sedimentation rate (Vc) in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording positions of an erythrocyte/plasma interface in said capillary tube at known time intervals during said centrifuging step so as to establish a time related red cell layer compaction curve for the erythrocytes in said blood sample which curve has an initial linear portion and a subsequent non-linear portion;
• d) the step of calculating a slope (sl) of an essentially linearized mathematical transformation of a plurality of the erythrocyte/plasma interface positions which occur in said non-linear portion of said curve during a known time span;
• e) the step of determining a Y intercept for said slope thereby determining a length (ip) for a packed erythrocyte layer which would occur if the blood sample were centrifuged forever;
• and
• f) the step of deriving a Vc for the blood sample by solving the equation:
• Vc=ip/sl.

A method for determining a Westergren equivalent of an erythrocyte sedimentation rate (Vc) in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording positions of an erythrocyte/plasma interface in said capillary tube at known time intervals during said centrifuging step so as to establish a time-related red cell layer compaction curve for the erythrocytes in said blood sample which curve has an initial linear portion and a subsequent non-linear portion;
• d) the step of calculating a slope (sl) of an essentially linearized mathematical transformation of a plurality of the erythrocyte/plasma interface positions which occur in said non-linear portion of said curve during a known time span;
• e) the step of determining a Y intercept for said slope thereby determining a length (ip) for a packed erythrocyte layer which would occur if the blood sample were centrifuged forever;
• f) the step of deriving a Vc for the blood sample by solving the equation:
• Vc=ip/sl;
• and
• g) the step of converting the derived Vc to Westergren equivalent sedimentation rate units by solving the equation:
• VW=k1+(k2·Vc);
• wherein VW is the erythrocyte sedimentation rate expressed in Westergren units of mm/hr;
• k1 is a calculated intercept constant;
• and k2 is a calculated slope constant.

A method for determining the magnitude of intercellular erythrocyte repulsion in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording positions of an erythrocyte/plasma interface in said capillary tube at known time intervals during said centrifuging step so as to establish a time-related red cell layer compaction curve for the erythrocytes in said blood sample, said compaction curve having an initial approximately linear portion and a subsequent non-linear portion;
• d) the step of determining a point in time in said compaction curve wherein the position of said compacting erythrocyte,/plasma interface changes from said approximately linear portion to said non-linear portion;
• and
• e) the step of mathematically manipulating said non-linear portion of said compaction curve so as to derive indices which relate to the magnitude of intercellular erythrocyte repulsion in said blood sample.

A method for determining the magnitude of intercellular erythrocyte repulsion in a sample of anticoagulated whole blood, said method comprising:

• a) the step of placing the anticoagulated sample of whole blood in a transparent capillary tube;
• b) the step of centrifuging said blood sample in said capillary tube for a period of time;
• c) the step of recording positions of an erythrocyte/plasma interface in said capillary tube at known time intervals during said centrifuging step so as to establish a time-related red cell layer compaction curve for the erythrocytes in said blood sample, said compaction curve having an initial approximately linear portion and a subsequent non-linear portion;
• d) the step of determining a point in time in said compaction curve wherein successive positions of said compacting erythrocyte/plasma interface is non-linear;
• and
• e) the step of determining a slope of mathematically derived indices of a linearization of a plurality of erythrocyte/plasma interface positions which occur in said non-linear portion of said curve after said point in time, said slope being determinative of the magnitude of intercellular erythrocyte repulsion in said blood sample.