Measuring and testing – Liquid analysis or analysis of the suspension of solids in a... – Gelling or coagulation
Patent
1994-08-03
1996-10-22
Williams, Hezron E.
Measuring and testing
Liquid analysis or analysis of the suspension of solids in a...
Gelling or coagulation
73 6443, 73 6165, 73 6169, 422 73, 422 8205, 436 70, 356 39, 128637, 128DIG22, G01N 2100, G01N 3349, G01N 3386
Patent
active
055678696
DESCRIPTION:
BRIEF SUMMARY
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of PCT/DK92/00382 filed Dec. 18, 1992, the contents of which are incorporated herein by reference.
The provision of a blood sample for quantitation of various blood parameters is a routine procedure for many medical investigations. Commonly, a sample of some ml is taken and sent to a laboratory where the relevant parameters such as coagulation time, hematocit, sedimentation rate, hemoglobin percentage, etc are quantified.
To obtain a sample of some ml it is necessary to pass a cannula into a vein to make the necessary amount of blood flow into a vessel. The vessel must then be carefully labelled and sent to the laboratory wherefrom the determined data will issue later.
By this procedure the blood sample when taken has added to it an anticoagulant to prevent the blood from coagulating on its way to the laboratory. In the laboratory the effect of the anticoagulant is neutralized to make the sample equate a sample of fresh blood.
It is wanted to provide a method and an apparatus making it possible to decide the relevant parameters on the basis of fresh blood, the measuring beginning practically at the very moment the blood sample leaves the patient's body and being ended about 30 minutes later. The apparatus should be handy and portable to an extent making it possible to allocate the apparatus to the patient so that the blood sample may be passed into the apparatus, which may then be placed at the bedside until the result is ready. Further, the method should make it possible to perform the measurement on a blood sample which may be provided by simply pricking a finger or an earlobe to obtain a sample not larger than 25 .mu.l, i.e. a sample which could be provided without help from a professional to puncture a vein.
A method of measuring the coagulation time for a blood sample is known, which method comprises the steps of entering the sample into a capillary element and measuring the coagulation time as the time elapsing from the moment when the blood sample enters the photometer measuring the translucence, which moment is indicated by a sudden fall of the translucence, until the moment when the translucence reaches a maximum after this sudden fall.
However, it has appeared that the development of the properties of light passing through or being scattered or reflected by a blood sample beyond the time of the occurrence of the first translucence maximum reveals interesting information of other relevant blood parameters.
According to the invention, a method for quantitation of relevant blood parameters comprises the following steps: mm, sample as a function of time, and/or other well-defined points of the obtained light signal/time curve.
A light signal/time curve may have a course with a first sharp extreme value corresponding to the moment when the sample is introduced in the measuring part of the cuvette. If for example the light signal is the translucence of the sample, this extreme value is a minimum. From this minimum the translucence will rise to a maximum being the second extreme value from which it descends again to a relatively flat minimum representing a third extreme value, whereupon it rises again to a fourth extreme value, a high maximum from which it finally descends almost linearly.
The recording of the curve may be made by frequent storing, e.g. once a second, of connected values for measured light signal and time elapsed from a starting moment, mainly defined by the first sudden change in the light signal corresponding to the entering of the sample. These recordings make it possible to define the extreme values and to calculate slopes in different positions on the curve. However, when only the time elapsed between two incidents is needed, the recording of the intermediate light signal values may be omitted.
The time elapsing from the starting moment until a well-defined point in relation to the second extreme value is taken as an expression of the coagulation time.
The slope of the curve when passing from the first extr
REFERENCES:
patent: 3307392 (1967-03-01), Owen et al.
patent: 3458287 (1969-07-01), Gross et al.
patent: 3814585 (1974-06-01), Bailly
patent: 3923397 (1975-12-01), Shuck
patent: 4011142 (1977-03-01), Jacobi
patent: 4252536 (1981-02-01), Kishimoto et al.
patent: 4303336 (1981-12-01), Cullis
patent: 4848900 (1989-07-01), Kuo et al.
patent: 5188940 (1993-02-01), Krause et al.
patent: 5298224 (1994-03-01), Plum
patent: 5350676 (1994-09-01), Oberhardt et al.
Patent Abstracts of Japan, vol. 9, No. 239, P-391 (1985).
Patent Abstracts of Japan, vol. 13, No. 138, P-852 (1988).
Hauch Ole
Knudsen Jens B.
Plum Thomas M.
Harrington, Esq. James
Larkin Daniel S.
Novo Nordisk A S
Williams Hezron E.
Zelson Esq. Steve T.
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