Method of measuring bleeding volume

• US 7,364,545 B2
• Filed: 04/20/2005
• Issued: 04/29/2008
• Est. Priority Date: 04/20/2005
• Status: Expired due to Fees

• Current Assignee: Jeffrey A. Klein
• Original Assignee: Jeffrey A. Klein
• Inventors: Klein, Jeffrey A.
• Primary Examiner(s): Nasser, Jr.; Robert L.
• Assistant Examiner(s): Mallari; Patricia C
• Application Number:
  US11/110,395
• Publication Number:
  US 20060241504A1
• Time in Patent Office: 1,105 Days
• Field of Search: 600/369, 600/371, 128/DIG.22, 73/644.1
• US Class Current: 600/369
• CPC Class Codes: G01N 33/4905 Determining clotting time of blood by chemical methods G01N33/86, C12Q1/56
• CPC Class Codes: Y10S 128/22 Blood coagulation

Abstract

A method of measuring blood clotting ability of a patient. A known volume of blood is dispensed on a reference disc of blotter paper, such that at least one reference blotch is formed on the reference disc. The surface area of the reference blotch formed on the reference disc, such that a relationship between the volume of blood and the surface area of the reference blotch can be obtained. An incision is made at the patient. A piece of blotter paper to the incision is applied to the incision to collect blood flowing therefrom, such that at least one blotch is formed on the piece of blotter paper. The surface area of the blotch formed on the piece of blotter paper is measured. The volume of the blood absorbed blood by the blotter paper is calculated according to the relationship between the blood volume and the surface area of the blotch.

Claims

1. A method of measuring blood clotting ability of a patient, comprising:

a) dispensing a known volume of blood on a reference disc of blotter paper, such that at least one reference blotch is formed on the reference disc;

b) measuring a surface area of the reference blotch formed on the reference disc;

c) obtaining a relationship between the volume of blood and the surface area of the reference blotch;

d) making an incision on the patient;

e) applying a piece of blotter paper to the incision, such that at least one blotch is formed on the piece of blotter paper;

f) measuring a surface area of the blotch formed on the piece of blotter paper; and

g) calculating the volume of the blood formed on the piece of blotter paper in accordance with the relationship between the blood volume and the surface area of the reference blotch, a sum of the calculated blood volume being indicative of the blood clotting ability of the patient.

2. The method of claim 1, wherein step (a) further comprises using a micropipette to dispense a known volume of blood on the reference disc.

3. The method of claim 1, further comprising repeating steps (e) to (g) until the patient stops bleeding.

4. The method of claim 3, further comprising adding up the blood volume of all blotches on all pieces of blotter paper collected from the incision.

5. The method of claim 3, further comprising counting the bleeding time of the patient.

6. The method of claim 1, wherein step (b) further comprises:

reprinting the reference blotch on a piece of paper to obtain a blotch image;

providing a plurality of paper squares each having a unit surface area;

fitting the blotch image with a first number of paper squares, wherein the first number of paper squares covers an interior surface area of the blotch;

fitting the blotch image with a second number of paper squares, wherein the second number of paper squares covers the interior surface area and a periphery of the blotch only; and

obtaining an average of the first and second numbers; and

multiplying the average with the unit surface area to obtain the surface area of the blotch.

7. The method of claim 6, further comprising:

magnifying the reference blotch by a magnification factor before reprinting; and

dividing the surface area obtained from the step multiplying the average with the unit surface area by the magnification factor.

8. The method of claim 1, wherein step (d) comprising making the incision in the skin of a forearm of the patient.

9. The method of claim 1, wherein step (d) comprises making the incision with a length of about 4 mm and a depth of about 1 mm.

10. The method of claim 1, wherein step (e) comprises applying the piece of blotter paper tangentially to the incision.

11. The method of claim 1, wherein step (b) comprises:

scanning a reference area with a unit surface area to obtain a reference image;

storing the reference image into a memory;

scanning the reference blotch;

comparing the scanned reference blotch with the reference image to derive the surface area of the reference blotch.

12. The method of claim 11, wherein step (f) comprises:

scanning the blotch formed on the piece of blotter paper; and

comparing the scanned blotch with the reference image to derive the surface area of the blotch.

13. A method of measuring blood clotting ability of a patient, comprising:

a) dispensing a known volume of blood around a periphery of a reference disc of blotter paper, such that a plurality of reference blotches in various shapes with the same surface area is formed;

b) repeating step (a) by dispensing different volumes of blood on a set of reference discs of blotter paper;

c) making an incision on a patient;

d) applying a piece of blotter paper to the incision, such that a plurality of blotches is formed on the piece of blotter paper;

e) comparing the blotches formed on the piece of blotter paper with the reference blotches, such that the surface areas and blood volumes of the blotches on the piece of blotter paper can be derived from the reference blotches matching therewith; and

f) adding up the blood volumes represented by all the blotches formed on the piece of blotter paper, a sum of the added up blood volumes being indicative of the blood clotting ability of the patient.

14. The method of claim 13, further comprising repeating step (d) to (f) until the patient stops bleeding from the incision.