Method for determining the fibrinogen level of a blood sample

United States Patent [19]

Grossman et al.

[11] Patent Number: [45] Date of Patent:

5,156,974 Oct. 20, 1992

[54] METHOD FOR DETERMINING THE FIBRINOGEN LEVEL OF A BLOOD SAMPLE

[75] Inventors: Hyman Grossman, Lambertville, N.J.; Michael Rauscb, Warrington, Pa.

[73] Assignee: Biodata Corporation, Hatboro, Pa.

[21] Appl. No.: 199,551

[22] Filed: May 27, 1988

[51] Int. CI.' G01N 33/86

[52] U.S. CI 436/69; 436/171;

436/805; 435/4; 435/13; 73/64.43; 364/413.09;

356/39

[58] Field of Search 436/63, 69, 86, 164,

436/171, 805; 435/4, 13; 73/64.1; 364/413.09;

356/39

[56] References Cited

U.S. PATENT DOCUMENTS

3,307,392 3/1967 Owen et al 73/64.1

3,458,287 7/1969 Gross et al 73/64.1

4,047,890 7/1977 Eichelberger et al 23/230 B

4,289,498 7/1981 Baughman et al 23/230 B

Primary Examiner—James C. Housel

Assistant Examiner—David Redding

Attorney, Agent, or Firm—Seidel, Gonda, Lavorgna &

Monaco

[57] ABSTRACT

A method for determining the fibrinogen level of a patient blood plasma in an optical density based prothrombin time test. The method and apparatus utilize a novel parameter DELTA which factors out statistical inaccuracies associated with prior art test methods. The patient fibrinogen level is determined using DELTA points calculated from blood samples having known fibrinogen levels in the low, normal and high ranges. A piece wise function is then constructed around the DELTA points and the fibrinogen level of a patient blood sample is calculated using four equations prestored in a non-volatile memory.

3 Claims, 13 Drawing Sheets

PCOV-ACOV PCOV