System, for monitoring the concentration of analytes in body fluids

• US 20040249311A1
• Filed: 07/14/2004
• Published: 12/09/2004
• Est. Priority Date: 02/06/2001
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: List, Hans, Haar, Hans-Peter
• Granted Patent: US 7,276,027 B2
• Time in Patent Office: Days
• US Class Current: 600/584
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: G01N 33/48764 Test tape taken off a spool

Abstract

The invention concerns a system for monitoring the concentration of analytes in body fluids, in particular in interstitial fluid and comprises a catheter having an implantable region and an outlet opening for withdrawing fluid in particular body fluid. A first and a second analytical zone are contacted sequentially with fluid from the catheter and undergo a detectable change when an analyte is present. The analytical zones can be contacted manually with fluid and also preferably in an automated fashion by means of a device. A system according to the invention additionally has an analytical device for analysing the analytical zones in order to determine the concentration of the analyte on the basis of changes caused by the analyte. A further subject matter of the present invention are catheters for use in systems according to the invention as well as magazines containing test zones.

Claims

1. System for monitoring the concentration of analytes in body fluids, in particular in interstitial fluid, comprising

a) a catheter having an implantable region and an outlet opening for the withdrawal of fluid, in particular body fluid,

b) a first and a second analytical zone which, after contact with the withdrawn fluid, undergo a detectable change when an analyte is present in the fluid,

c) a device for contacting the first analytical zone with fluid from the catheter and for subsequently contacting the second analytical zone with fluid from the catheter,

d) an analytical device to analyse the changes on the analytical zones caused by the analyte-containing fluid in order to determine the concentration of an analyte to be monitored.

2. System as claimed in claim 1, in which the contacting is carried out by bringing together the outlet opening and the first and second analytical zone.

3. System as claimed in claim 1, in which the test zones are contacted by moving portions of fluid out of the catheter onto the first and second test zone by means of an ejector unit.

4. System as claimed in claim 1, in which the first and second analytical zone are areas of a continuous test element, preferably of a tape.

5. System as claimed in claim 1, in which the first and second analytical zone are separate objects that are attached to a common support.

6. System as claimed in claim 1, in which the first and second analytical zone are located on separate supports.

7. System as claimed in claim 1, in which an underpressure is applied to the outlet opening in order to convey liquid.

8. System as claimed in claim 1 or 7, in which the catheter is designed such that no liquid emerges from the outlet opening until an underpressure is applied to the outlet opening.

9. System as claimed in claim 1, 7 or 8 in which the bringing together of the analytical zone and outlet opening is synchronised with the application of an underpressure such that liquid emerging from the outlet opening is taken up by the analytical zone.

10. System as claimed in claim 1, in which the said analytical device or an additional application detection device detects the presence of fluid or the presence of an adequate amount of fluid in or on an analytical zone and interrupts further contact of the analytical zone with fluid.

11. System as claimed in claim 7, in which the said analytical device or an additional application detection device detects the presence of fluid or the presence of an adequate amount of fluid in or on an analytical zone and interrupts the application of the underpressure to the outlet opening.

12. System as claimed in claim 1 comprising a control device which synchronises the bringing together of the first and second analytical zone with the outlet opening.

13. System as claimed in claim 1, 10 or 11 in which the amount of fluid taken up by an analytical zone is essentially equal to or more than the active inner volume of the catheter.

14. System as claimed in claim 1, in which the catheter remains implanted between contact with the first and second analytical zone.

15. System as claimed in claim 1, in which the analytical zones are designed to be used once.

16. System as claimed in claim 1, in which the system comprises a carrying unit for carrying the system on the body and a magazine in which the analytical zones are disposed which is designed to be inserted into the carrying unit.

17. System as claimed in claim 1, in which the amount of fluid taken up by an analytical zone is less than 100 nl and is preferably in the range between 10 and 50 nl.

18. System as claimed in claim 1, in which the analytical device is designed for an optical analysis of analytical zones.

19. Method for monitoring the concentration of analytes in body fluids, in particular in interstitial fluid, comprising the steps

bringing together a first analytical zone with an outlet opening of an implanted catheter in order to contact the first analytical zone with fluid,

analysing the change caused by analyte-containing fluid on the analytical zone in order to determine the concentration of an analyte to be monitored.

20. Method as claimed in claim 19, in which after the first analytical zone has been contacted with liquid, a second analytical zone is brought together with the outlet opening and contacted with liquid and a change on the second analytical zone caused by analyte-containing liquid is analysed in order to determine the concentration of an analyte to be monitored.

21. Method as claimed in claim 19 or 20 in which the analytical zone is moved manually towards the outlet opening.

22. Method as claimed in claim 19 or 20 in which the analytical zone and outlet opening are brought together by a device.

23. Kit for monitoring the concentration of analytes in body fluids, in particular in interstitial fluid comprising,

a carrying unit with a catheter comprising an implantable region and an outlet opening for withdrawing fluid, in particular a body fluid,

two or more analytical zones for contact with fluid which undergo a detectable change when an analyte is present in the fluid,

an analytical device located in the carrying unit or present separately for analysing changes caused by the analyte-containing fluid on the two or more analytical zones in order to determine the concentration of an analyte to be monitored.

24. Kit as claimed in claim 23 having a device for bringing together a first analytical zone with the outlet opening in order to contact the first analytical zone with fluid and for subsequently bringing together the second analytical zone with the outlet opening in order to contact the second analytical zone with fluid.

25. Catheter for providing fluid for their analysis comprising

a hollow implantable region (10, 110′

, 310) which has at least one inlet opening for fluid or a membrane for taking up the analyte from the outer space,

a hollow region (11) connected to the implantable region which has a larger inner diameter than the implantable region and

which has a withdrawal opening (13) in the hollow region that has a larger inner diameter which is located near to the site connecting the said regions.

26. Catheter as claimed in claim 25, in which the withdrawal opening (13) is connected to a withdrawal tube with a hydrophobic inner wall.

27. Catheter as claimed in claim 25, in which the inner wall of the catheter is hydrophilic.

28. Catheter as claimed in claim 25, in which the length of the implantable region (10, 110′

, 310) is between 3 and 10 mm.

29. Catheter as claimed in claim 25, which has a holding plate (15, 315) to attach the catheter to a body.

30. Catheter as claimed in claim 25, which has a holding device (302) for test elements which is arranged such that fluid emerging from the catheter is contacted with a test zone of the test element when a test element is present in the holding device.

31. Magazine for analytical zones which

has an outlet opening for fluid,

at least one first and a second analytical zone, and

a device for bringing the first and second analytical zone near to the inlet opening such that fluid entering the magazine contacts the respective analytical zone.

32. Magazine as claimed in claim 31, which is closed such that an underpressure can be generated in the magazine by sucking air out of the magazine.

33. Magazine as claimed in claim 31 or 32, which has an optical window.

34. Magazine as claimed in claim 31, in which the first and second analytical zone are provided by a tape-like test element.

35. Magazine as claimed in claim 31, which has a fluid link to a catheter for removing fluid from a body.