Device for measuring blood coagulation and method thereof

• US 20040072357A1
• Filed: 10/14/2003
• Published: 04/15/2004
• Est. Priority Date: 12/19/2000
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: LifeScan Scotland Limited (Johnson & Johnson)
• Inventors: McAleer, Jerome, Alvarez-Icaza, Manuel, Stiene, Matthias, Allen, John, Plotkin, Elliot, Richter, Tanja
• Granted Patent: US 7,005,857 B2
• Time in Patent Office: Days
• US Class Current: 436/69
• CPC Class Codes: A61B 10/0045 Devices for taking samples of body liquids devices for taking blood samples A61B5/15
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150213 Venting means
• CPC Class Codes: A61B 5/150358 Strips for collecting blood, e.g. absorbent optical reagent test strips G01N21/8483; chemical reagent test strips G01N33/4875, G01N33/52
• CPC Class Codes: A61B 5/150419 comprising means for capillary action
• CPC Class Codes: A61B 5/15045 comprising means for capillary action
• CPC Class Codes: A61B 5/150755 Blood sample preparation for further analysis, e.g. by separating blood components or by mixing
• CPC Class Codes: A61B 5/15142 Devices intended for single use, i.e. disposable

Abstract

A device and method for measuring the clotting times in a fluid, typically blood, within a microchannel whereby the onset of clotting is determined by measurement of the rate of change or value of capacitance or impedance between two electrodes situated on either side of the microchannel. There is provided a disposable test-strip (100) comprising an upper and lower support (101) and (103). A microchannel (102) is formed into the upper surface of the lower support member (103). A second substrate layer (101) is laminated on top of the support member (103), thereby closing the open microchannel (102). Electrodes (104) are formed on the respective outer surfaces of the substrate layers and coplanar to the channel.

Claims

1. A device for the measurement of clotting times of a fluid comprising an inlet port for the collection of the fluid sample and in fluid connection with at least a microchannel, whereby at least two electrodes are situated along the length of the microchannel.

2. A device according to claim 1 where the electrodes are of differing lengths and size dimensions.

3. A device according to claim 1 where the electrodes are situated on the inner surface of the microchannel.

4. A device according to claim 1 whereby the electrodes are situated on the outer surface of the microchannel.

5. A device according to claim 1 whereby the inlet port is a penetration device suitable for penetration into the skin of a user for collection of a fluid sample.

6. A device according to claim 1 whereby an agent for the promotion of clotting of the fluid is situated on an inner surface of the device.

7. A device according to claim 1 comprising a reservoir in fluid connection with the channel for collection of the fluid sample.

8. A device according to claim 1 comprising a plurality of microchannels.

9. A device according to claim 1 whereby the area of cross-section of the microchannel varies along its length.

10. A device according to claim 8 whereby the microchannels are of different diameters.

11. A method of fabricating a device according to the previous claims comprising providing a first laminate, microfabricating said laminate to produce a microchannel, a fluid inlet port and optionally a fluid collection reservoir, providing an electrode along the length of the microchannel, providing a second laminate with an electrode provided on it surface and laminating said first and second laminates.

12. A method according to claim 11 where additionally flow controlling and fill detection means are provided on or within the device.

13. A method of measuring the clotting times of a fluid comprising introducing the fluid sample into a microchannel, whereby the total distance of flow of the fluid within a microchannel is determined by a measurement of the ratio of capacitance or impedance of the filled to the unfilled portion of the channel.

14. A method of measuring the clotting times of a fluid comprising introducing the fluid sample into a microchannel whereby the speed of flow of fluid within the microchannel is determined by measuring the rate of change of capacitance or impedance.

15. A method of measuring the clotting times of a fluid comprising introducing the fluid sample into a microchannel whereby the coagulative state of the fluid within the microchannel is determined by measuring the rate of change of capacitance or impedance of the fluid.