Method and device for measuring blood coagulation or lysis by viscosity changes

• US 6,338,821 B1
• Filed: 04/04/2000
• Issued: 01/15/2002
• Est. Priority Date: 06/27/1997
• Status: Expired due to Term

• Current Assignee: Alere San Diego Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Hemosense Incorporated (Abbott Laboratories Incorporated)
• Inventors: Jina, Arvind N.
• Primary Examiner(s): WALLENHORST, MAUREEN
• Application Number:
  US09/542,886
• Time in Patent Office: 651 Days
• Field of Search: 436/69, 422/56, 422/58, 422/82.01, 422/82.02, 422/73, 73/540.1, 73/540.2, 600/369
• US Class Current: 422/73
• CPC Class Codes: G01N 33/4905 Determining clotting time of blood by chemical methods G01N33/86, C12Q1/54
• CPC Class Codes: G01N 33/86 involving blood coagulating time or factors, or their receptors

Abstract

The present invention provides a single-use electronic device and test card for use therein which performs a coagulation or lysis assay of a blood sample. The device includes a housing having an exterior surface and defining an interior area and means for receiving the sample through the housing into the interior space. A non-porous substrate is positioned within the interior space for receiving the sample thereon. A reagent accelerates the coagulation of the sample and is positioned on the substrate and in contact with the sample. Optionally, an electroactive species may also be reacted with the sample. The device also includes means for measuring the viscosity of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay. Processing means positioned within the interior space is connected to the measuring means for receiving and converting the electrical signal into a digital output corresponding to the coagulation/lysis assay using assay calibration information stored therein. Display means visually displays the digital output external to the housing and is connected to the processing means. A method of determining the coagulation or lysis of a sample provides for accelerating the coagulation of the sample by chemically reacting the sample with at least one reagent on the substrate to produce a detectable change in the viscosity of the sample which correlates with the state of coagulation or lysis of the sample and measuring the viscosity of the sample and generating an electrical signal which correlates to a curve of the coagulation/lysis assay.

Claims

1. An electronic device for performing a coagulation or lysis assay of a blood sample, the device comprising:

a housing having an exterior surface and defining an interior area;

means for receiving the blood sample through the housing into the interior area;

a non-porous substrate positioned within the interior area for receiving the blood sample thereon and retaining the blood sample in a particular position on the substrate;

a reagent for accelerating the coagulation of the blood sample positioned on the substrate and in contact with the blood sample;

means for measuring the viscosity of the blood sample in the particular position and generating an electrical signal which correlates to a curve of the coagulation or lysis assay; and

processing means being positioned within the interior area and connected to the measuring means for receiving and converting the electrical signal into a digital output corresponding to the coagulation or lysis assay using assay calibration information stored in the device.

2. The device of claim 1 wherein the measuring means includes:

means for generating a signal of predetermined frequency, the generating means being positioned within the interior area;

a plurality of electrodes being positioned on the substrate and contacting the blood sample in the particular position, the electrodes connecting to the generating means for passing the signal into the blood sample, the electrodes generating an electrical signal corresponding to the conductivity/resistivity of the blood sample.

3. The device of claim 1 wherein the device further includes a heater being positioned within the interior area and in thermal contact with the substrate so that the substrate can be warmed to a pre-determined temperature upon receiving the blood sample.

4. The device of claim 1 wherein the processing means further calibrates the electrical signal to a reference standard using the stored assay calibration information.

5. The device of claim 1 wherein the processing means further receives the ambient temperature of the assay device from a sensor within the housing and adjusts assay results using the stored assay calibration information.

6. The device of claim 1 wherein the assay calibration information stored in the device determines results for at least one of assays selected from the group consisting of a Prothrombin Time, an Activated Clotting Time, an Activated Partial Thromboplastin Time, platelet aggregation, and fibrinogen.

7. A single-use electronic device for performing a coagulation or lysis assay of a blood sample, the device comprising:

a housing having an exterior surface and defining an interior area;

means for receiving the blood sample through the housing into the interior area;

a non-porous substrate positioned within the interior area for receiving the blood sample thereon;

a reagent for accelerating the coagulation of the blood sample in contact with the blood sample and positioned in the housing;

means for measuring the viscosity of the blood sample and generating an electrical signal which correlates to a curve of the coagulation or lysis assay, the substrate retaining the sample in continuous, direct contact with the measuring means; and

processing means being positioned within the interior area and connected to the measuring means for receiving and converting the electrical signal into a digital output corresponding to the coagulation or lysis assay using assay calibration information stored in the device.

8. The device of claim 7 wherein the measuring means includes:

means for generating a signal of predetermined frequency, the generating means being positioned within the interior area;

a plurality of electrodes being positioned on the substrate and contacting the blood sample, the electrodes connecting to the generating means for passing the signal into the blood sample, the electrodes generating an electrical signal corresponding to the conductivity/resistivity of the blood sample.

9. The device of claim 7 wherein the device further includes a heater being positioned within the interior area and in thermal contact with the substrate so that the substrate can be warmed to a pre-determined temperature upon receiving the blood sample.

10. The device of claim 7 wherein the processing means further calibrates the electrical signal to a reference standard using the stored assay calibration information.

11. The device of claim 7 wherein the processing means further receives the ambient temperature of the assay device from a sensor within the housing and adjusts assay results using the stored assay calibration information.

12. The device of claim 7 wherein the assay calibration information stored in the device determines results for at least one of assays selected from the group consisting of a Prothrombin Time, an Activated Clotting Time, an Activated Partial Thromboplastin Time, platelet aggregation, and fibrinogen.

13. A single-use electronic device for performing a coagulation or lysis assay of a blood sample, the device comprising:

a housing having an exterior surface and defining an interior area;

means for receiving the blood sample through the housing into the interior area;

a non-porous substrate positioned within the interior area for receiving the blood sample thereon;

a reagent for accelerating the coagulation of the blood sample in contact with the blood sample and positioned in the housing;

means for measuring the viscosity of the blood sample by electrolytic conductance which correlates to a curve of the coagulation or lysis assay; and

processing means being positioned within the interior area area connected to the measuring means for generating a digital output corresponding to the coagulation or lysis assay using assay calibration information stored in the device.

14. The device of claim 13 wherein the measuring means includes:

means for generating a signal of predetermined frequency, the generating means being positioned within the interior area;

a plurality of electrodes being positioned on the substrate and contacting the blood sample, the electrodes connecting to the generating means for passing the signal into the blood sample, the electrodes generating an electrical signal corresponding to the electrical conductance of the blood sample, the processing means receiving and converting the electrical signal into the digital output.

15. The device of claim 14 wherein the processing means further calibrates the electrical signal to a reference standard using the stored assay calibration information.

16. The device of claim 13 wherein the device further includes a heater being positioned within the interior area and in thermal contact with the substrate so that the substrate can be warmed to a pre-determined temperature upon receiving the blood sample.

17. The device of claim 13 wherein the processing means further receives the ambient temperature of the assay device from a sensor within the housing and adjusts assay results using the stored assay calibration information.

18. The device of claim 13 wherein the assay calibration information stored in the device determines results for at least one of assays selected from the group consisting of a Prothrombin Time, an Activated Clotting Time, an Activated Partial Thromboplastin Time, platelet aggregation, and fibrinogen.