System and method for analyzing a body fluid

• US 9,128,066 B2
• Filed: 07/15/2011
• Issued: 09/08/2015
• Est. Priority Date: 01/16/2009
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Zimmer, Volker, Petrich, Wolfgang
• Primary Examiner(s): HIXSON, CHRISTOPHER
• Application Number:
  US13/183,976
• Publication Number:
  US 20120006105A1
• Time in Patent Office: 1,516 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0295 Strip shaped analyte sensors for apparatus classified in A61B5/145 or A61B5/157
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• 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 5/150511 Details of construction of shaft
• CPC Class Codes: A61B 5/15146 Devices loaded with multiple lancets simultaneously, e.g. for serial firing without reloading, for example by use of stocking means. multiple simultaneous cutting or piercing A61B5/150977
• CPC Class Codes: G01N 33/487 of liquid biological material
• CPC Class Codes: G01N 35/00009 provided with a sample supporting tape, e.g. with absorbent zones

Abstract

The invention concerns a system for analyzing a body fluid comprising a collecting element which receives the body fluid in a reservoir, a test element designed to detect an analyte in the body fluid, a transfer device for making a fluidic connection between the collecting element and the test element, and a detection unit which detects an analyte-specific measurement signal on the test element during a measurement interval. According to the invention it is proposed that the transfer device always brings the test element into contact with the body fluid located in the reservoir during the measurement interval and that the transfer device is configured to physically separate the test element and the collecting element from one another after the measurement interval.

Claims

1. A system for analyzing a body fluid comprising

a collecting element which receives the body fluid in a reservoir,

a test element designed to detect an analyte in the body fluid,

a transfer device for making a fluidic connection between the collecting element and the test element, and

a detection unit which detects an analyte-specific measurement signal on the test element during a measurement interval, wherein

the transfer device permanently brings the test element into contact with the body fluid located in the reservoir during the measurement interval so that a liquid column is maintained on a detection area of the test element,

the liquid volume of the reservoir is defined such that the liquid column over the detection area does not fall below a minimum height for the duration of the measurement interval;

and

the transfer device is configured to physically separate the test element and the collecting element from one another after the measurement interval.

2. The system according to claim 1, wherein the minimum height of the liquid column is more than 10 μ

m, preferably more than 50 μ

m.

3. The system according to claim 1, wherein the test element is designed to distribute the body fluid two-dimensionally over a spreading area during the measurement interval, and that the size of the spreading area and the volume of the reservoir are matched in such a manner that a liquid column is maintained over the detection area during the measurement interval.

4. The system according to claim 1, wherein the reservoir has a depth between 50 and 150 μ

m, a width between 50 and 150 μ

m and a length of more than 1 mm.

5. The system according to claim 4, wherein the length is about 2 mm.

6. The system according to claim 1, wherein the detection area has a size in the range of 0.1 mm² to 1 mm².

7. The system according to claim 1, wherein the analyte-specific measurement signal is detected within a period of 0 to 15 s after making the fluidic connection between the collecting element and test element.

8. The system according to claim 1, wherein the end of the measurement interval is determined as being when the change in the measurement signal per unit of time has reached a predefined value.

9. The system according to claim 1, wherein the collecting element and test element are spaced apart as separate components in an initial state and that the fluidic connection can be made while actively moving the collecting element and/or the test element.

10. The system according to claim 1, wherein the fluid is taken up by a lancing process and that the fluidic connection of the collecting element to the test element is not made until after the lancing process.

11. The system according to claim 1, wherein the reservoir is formed by a capillary structure, in particular a linear capillary channel or capillary gap which is preferably open on one side.

12. The system according to claim 1, wherein the detection area is formed by a dry chemistry layer in particular based on enzymes for a photometric detection.

13. The system according to claim 1, wherein the collecting element is provided with a hydrophilic coating at least in the area of the reservoir.

14. The system according to claim 1, wherein the collecting element and the test element can be separated again from one another after the measurement interval preferably by means of the transfer device.