Method for measuring blood coagulation time

Claim 1

An improved method for measuring the coagulation time of a blood sample in which a blood sample-reagent mixture is formed by introducing a sample and at least one reagent into a cuvette, which improved method comprises moving the sample-reagent mixture in the cuvette so that the mixture flows back and forth around a sharp edge formed by the intersection, by an acute angle, of opposite faces of a partition of the cuvette, said edge projecting into the cuvette, whereby a clot forms on this edge.

Claim 6

A method for measuring the clotting time of a blood sample with an apparatus including a cuvette for receiving a blood sample and at least one reagent which thereby form a sample-reagent mixture, said cuvette having an upper portion divided into two chambers by a partition therein and having a bottom, the partition having opposing faces and a sharp wedge-shaped edge portion formed by the intersection, at an acute angle, of such opposing faces of the partition and situated within the cuvette at a predetermined distance from the bottom of the cuvette to permit unobstructed communication of said blood sample-reagent mixture between the two chambers and to permit flow of the blood sample-reagent mixture from one chamber to the other around the edge portion when variable air pressure is applied to the cuvette thereby causing a clot to form on said edge portion; one of the chambers being connected via an opening with means for producing variable air pressure to effect movement of the blood sample-reagent mixture from one chamber to the other around the edge portion, the method comprising: (a) introducing the blood sample into the cuvette; (b) introducing the reagent into the cuvette, the resulting blood sample-reagent mixture having a height above the edge of the partition in relation to the bottom of the cuvette; (c) detecting the point of time at which the blood sample-reagent mixture is formed by means of a first light beam which passes through the cuvette, above the edge portion approximately adjacent the partition; (d) introducing varying air pressure into the chamber of the upper portion of the cuvette which is connected to the variable air pressure means, thereby causing the blood sample-reagent mixture to flow back and forth around said edge portion and form a clot on said edge portion; and (e) detecting the point of time at which the clot is formed by means of a second light beam which passes through the cuvette, close to and below the edge portion.

Claim 7

A method for measuring the clotting time of a blood sample with an apparatus including a cuvette for receiving a blood sample and at least one reagent which thereby form a sample-reagent mixture, said cuvette having an upper portion divided into two chambers by a partition therein and having a bottom, the partition having opposing faces and a sharp wedge-shaped edge portion formed by the intersection, at an acute angle, of such opposing faces of the partition and situated within the cuvette at a predetermined distance from the bottom of the cuvette to permit unobstructed communication of said blood sample-reagent mixture between the two chambers and to permit flow of the blood sample-reagent mixture from one chamber to the other around the edge portion when variable air pressure is applied to the cuvette thereby causing a clot to form on said edge portion; one of the chambers being connected via an opening with means for producing variable air pressure to effect movement of the blood sample-reagent mixture from one chamber to the other around the edge portion, the method comprising: (a) introducing the blood sample into the cuvette; (b) introducing the reagent into the cuvette, the resulting blood sample-reagent mixture having a height above the edge of the partition in relation to the bottom of the cuvette; (c) detecting the point of time at which the blood sample-reagent mixture is formed by means of a first light beam which passes through the cuvette, above the edge portion approximately adjacent the partition; (d) introducing varying air pressure into the chamber of the upper portion of the cuvette which is connected to the variable air pressure means, thereby causing the blood sample-reagent mixture to flow back and forth around said edge portion and form a clot on said edge portion; and (e) detecting the point of time at which the clot is formed by means of a second light beam which passes through the cuvette, close to and below the edge portion.