Capillary flow device and method for measuring activated partial thromboplastin time
First Claim
1. In a method for determining activated partial thromboplastin time in a fluid medium employing a device comprising, in a housing, a continuous capillary track comprising an inlet port, at least one capillary unit acting as the motive force for moving the fluid medium in the device, and a venting port, wherein said capillary track further contains a reagent capable of initiating blood clotting, and in which a blood sample is introduced into said entry port, said sample is allowed to transit said capillary track by capillary action, and said activated partial thromboplastin time is determined from the time required for blood coagulation and flow stoppage in said capillary track, the improvement that comprises:
- utilizing as said reagent a mixture of (1) an activating agent for activated partial thromboplastin time measurements wherein said activating agent is a sulfatide or sulfoglycosylsphingolipid and (2) a phospholipid component, said activating agent and said phospholipid component being provided in amounts sufficient to initiate clotting, and to provide a time of flow stoppage that is essentially independent of blood hematocrit.
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Accused Products
Abstract
Methods and devices are provided for carrying out activated partial thromboplastin time (APTT) analysis on a whole blood sample to which no anticoagulant has been added by applying the sample to a capillary track contained in a housing, wherein the capillary track comprises sample entry and venting ports, at least one capillary track connecting the entry and venting ports, and reagents capable of initiating an APTT analysis, wherein clotting time is measured by the cessation of blood flow in the capillary track.
255 Citations
28 Claims
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1. In a method for determining activated partial thromboplastin time in a fluid medium employing a device comprising, in a housing, a continuous capillary track comprising an inlet port, at least one capillary unit acting as the motive force for moving the fluid medium in the device, and a venting port, wherein said capillary track further contains a reagent capable of initiating blood clotting, and in which a blood sample is introduced into said entry port, said sample is allowed to transit said capillary track by capillary action, and said activated partial thromboplastin time is determined from the time required for blood coagulation and flow stoppage in said capillary track, the improvement that comprises:
utilizing as said reagent a mixture of (1) an activating agent for activated partial thromboplastin time measurements wherein said activating agent is a sulfatide or sulfoglycosylsphingolipid and (2) a phospholipid component, said activating agent and said phospholipid component being provided in amounts sufficient to initiate clotting, and to provide a time of flow stoppage that is essentially independent of blood hematocrit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. In a device for determining activated partial thromboplastin time comprising, in a housing, a continuous capillary track comprising an inlet port, at least one capillary unit acting as the motive force for moving the fluid medium in the device, and a venting port, wherein said capillary track further contains a reagent capable of initiating blood clotting, and in which a blood sample is introduced into said entry port, said sample is allowed to transit said capillary track by capillary action, and said activated partial thromboplastin time is determined from the time required for blood coagulation and flow stoppage in said capillary track, the improvement that comprises:
provided as said reagent a mixture of (1) an activating agent for activated prothrombin time measurements wherein said activating agent is a sulfatide or sulfoglycosylsphingolipid and (2) a phospholipid component, said activating agent and said phospholipid component being provided in amounts sufficient to initiate blood clotting, and to provide a time of flow stoppage that is essentially independent of blood hematocrit. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
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22. A capillary flow device capable of being used in an analysis for activated partial thromboplastin time, comprising:
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a housing containing; a continuous capillary pathway comprising an entry port, a first capillary unit, a reagent chamber, a second capillary unit, and a venting port; and a reagent in said reagent chamber, wherein; (1) said first capillary unit comprises a capillary channel from 5 to 15 mm in length and having a width in the range of from 0.75 to 2 mm, and a height in the range of from 0.05 to 0.125 mm; (2) said reagent chamber comprises a capillary chamber having a length in the range of from 5 to 15 mm, a width in the range of from 3 to 8 mm, and a height in the range of from 0.05 to 0.125 mm; (3) said second capillary unit comprises a capillary channel having an initial radius in the range of from 0.05 to 0.175 mm and a final radius that provides capillary flow for a blood sample, said channel having one flat side, the remaining sides of said channel being formed by flat surfaces or curved surfaces joined without forming angles, all curved surfaces being convex relative to said flat side, wherein at least a portion of said second capillary increases in effective diameter with increasing distance from said reagent chamber; (4) said reagent comprises an activator for activated partial thromboplastin time wherein said activator is a sulfatide or sulfoglycosylsphingolipid and a phospholipid component said activator and said phospholipid component being provided in amounts sufficient to initiate blood clotting and to provide a time of flow stoppage that is essentially independent of blood hematocrit clotting; and (5) said capillary track having a total volume in the range of from 20 to 100 μ
l. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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Specification