Device and Method for Drawing a Sample and Analyzing Body

• US 20070213638A1
• Filed: 06/25/2004
• Published: 09/13/2007
• Est. Priority Date: 06/27/2003
• Status: Abandoned Application

• Current Assignee: Ehrfeld Mikrotechnik AG
• Original Assignee: Ehrfeld Mikrotechnik AG
• Inventors: Ehrfeld, Wolfgang, Herbrechtsmeier, Peter, Azzawi, Alexander, Schwank, Thomas, Kammermeier, Stefan, Nagy, Karoly, Linnebach, Egbert
• Application Number:
  US11/578,758
• Publication Number:
  US 20070213638A1
• Time in Patent Office: Days
• US Class Current: 600/583
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150099 by negative pressure, other than vacuum extraction into a syringe by pulling on the piston rod or into pre-evacuated tubes
• CPC Class Codes: A61B 5/150167 Adjustable piercing speed of skin piercing element, e.g. blade, needle, lancet or canula, for example with varying spring force or pneumatic drive
• CPC Class Codes: A61B 5/150175 Adjustment of penetration depth
• CPC Class Codes: A61B 5/150213 Venting means
• CPC Class Codes: A61B 5/150236 Pistons, i.e. cylindrical bodies that sit inside the syringe barrel, typically with an air tight seal, and slide in the barrel to create a vacuum or to expel blood
• CPC Class Codes: A61B 5/150244 Rods for actuating or driving the piston, i.e. the cylindrical body that sits inside the syringe barrel, typically with an air tight seal, and slides in the barrel to create a vacuum or to expel blood
• CPC Class Codes: A61B 5/150259 Improved gripping, e.g. with high friction pattern or projections on the housing surface or an ergonometric shape
• CPC Class Codes: A61B 5/150435 Specific design of proximal end
• CPC Class Codes: A61B 5/15113 Manually triggered, i.e. the triggering requires a deliberate action by the user such as pressing a drive button
• CPC Class Codes: A61B 5/15125 comprising a vacuum or compressed fluids
• CPC Class Codes: A61B 5/15186 Devices loaded with a single lancet, i.e. a single lancet with or without a casing is loaded into a reusable drive device and then discarded after use; drive devices reloadable for multiple use
• CPC Class Codes: A61B 5/1519 comprising driving means, e.g. a spring, for propelling the piercing unit
• CPC Class Codes: A61B 5/15194 fully automatically retracted, i.e. the retraction does not require a deliberate action by the user, e.g. by terminating the contact with the patient's skin
• CPC Class Codes: A61B 5/157 Devices characterised by integrated means for measuring characteristics of blood

Abstract

The invention relates to a device for drawing a sample and analyzing body fluids, and to a corresponding method. The device comprises a handle (1), which accommodates a pneumatic drive device, and a sensor unit (2) that contains a microneedle (3) on an elastic membrane (4) and at least one sensor system (5). The handle (1) and the sensor unit are detachably connected to one another, and the pneumatic drive device interacts with the sensor unit (2) in such a manner that the drive device exerts pressure onto the elastic membrane (4) so that the microneedle (3) pierces the surface of the skin in order to draw body fluid. During the ensuing decreasing pressure, the elastic membrane (4) returns to its original shape, and body fluid is suctioned, due to the resulting underpressure, from the location of piercing and into the interior of the sensor unit (2) to the at least one sensor system (5). Particularly advantageous is the integration of a measuring unit (10), which determines concentration values resulting from the physical or chemical property changes arising on the sensor system (5). A display (12) can serve to display the measured values.

Claims

1. An apparatus for drawing a sample and analyzing bodily fluids, comprising

a handle holding a pneumatic actuator, and

a sensor unit that comprises a microneedle attached to an elastic membrane and at least one sensor system, the handle and the sensor unit being detachably connected to each other and the pneumatic actuator exerting pressure on the elastic membrane so that the microneedle pierces the skin and subsequently, as the pressure is reduced, the elastic membrane returns to its original shape and thus produces reduced pressure in the interior of the sensor unit, as a result of which bodily fluid is directed to at least one sensor system and causes a physical or chemical property change of the sensor system.

2. The apparatus according to claim 1, characterized in that the handle comprises a measuring unit for determining the physical or chemical property changes caused in the sensor system.

3. The apparatus according to claim 2, characterized in that the measuring unit uses the physical or chemical property changes to determine at least one concentration value.

4. The apparatus according to claim 3, characterized in that a display provided on the apparatus shows the concentration value determined by the measuring unit.

5. The apparatus according to claim 2, characterized in that at least one sensor system and the measuring unit are designed for an optical measuring method.

6. The apparatus according to claim 5, characterized in that at least one sensor system and the measuring unit are designed for a fluorescence spectroscopic measuring method.

7. The apparatus according to claim 6, characterized in that at least one sensor system and the measuring unit are designed for a fluorescence spectroscopic measuring method on the basis of fluorescence resonance energy transfer.

8. The apparatus according to claim 1, characterized in that the sensor unit comprises several sensor systems.

9. The apparatus according to claim 8, characterized in that the sensor unit has a rotatably latching feed passage for the bodily fluid, so that the bodily fluid is only directed to one sensor system and upon completed measurement of a test sample the feed passage is rotated further by one notch to open the access for bodily fluid to the next sensor system.

10. The apparatus according to claim 1, characterized in that a detachable connection between the handle and the sensor unit is configured as a plug, clamping, snap-fit, screw or adhesive connection.

11. The apparatus according to claim 1, characterized in that the sensor unit comprises a control unit for detecting the correct, particularly sufficient, filling level with bodily fluid.

12. The apparatus according to claim 11, characterized in that the control unit comprises an electric resistivity measuring unit.

13. The apparatus according to claim 11, characterized in that the control unit defines a filling volume of less than 0.5 microliters as the target value for a sufficient filling level.

14. The apparatus according to claim 1, characterized in that the electric energy required for the components of the apparatus is produced by coupling piezoelectric or electromagnetic elements to the pneumatic actuator.

15. The apparatus according to claim 1, characterized in that the sensor unit comprises a sealing ring on the bottom.

16. The apparatus according to claim 15, characterized in that the sealing ring has an adhesive layer on the bottom.

17. The apparatus according to claim 1, characterized in that the sensor unit is closed on the bottom in a sterile fashion by a removable or a pretensioned tearable cover film.

18. The apparatus according to claim 1, characterized in that the handle has a first adjustment member for variably defining the piercing depth of the microneedle.

19. The apparatus according to claim 18, characterized in that the handle has a second adjustment member for variably defining the piercing speed of the microneedle.

20. The apparatus according to claim 19, characterized in that the handle has a third adjustment member for variably defining the suction speed of bodily fluid in the sensor unit.

21. The apparatus according to claim 1, characterized in that a filter arrangement is provided upstream of at least one sensor system.

22. The apparatus according to claim 1, characterized in that one or more reservoirs with reagents and/or rinsing solutions are provided upstream of at least one sensor system.

23. A method for drawing a sample and analyzing bodily fluids, comprising the following steps:

a pneumatic actuator accommodated in a handle exerts pressure on an elastic membrane in a sensor unit so that a microneedle attached to the elastic membrane pierces the skin,

after reducing the pressure, the elastic membrane returns to its original shape and thus produces reduced pressure in the interior of the sensor unit, as a result of which bodily fluid is directed to at least one sensor system and causes a physical or chemical property change there of the sensor system.

24. The method according to claim 23, characterized in that in a further step the physical or chemical property changes caused in at least one sensor system are used by a measuring unit provided in the handle to determine a concentration value.

25. The method according to claim 24, characterized in that in a further step the concentration values determined by the measuring unit are displayed on a display.

26. The method according to claim 24, characterized in that in a further step the concentration values determined by the measuring unit are transmitted to an external apparatus by means of a transponder or transmitter.

27. The method according to claim 26, characterized in that the external apparatus is an automatic syringe or a pump for administering appropriate therapeutic agents.

28. The method according to claim 26, characterized in that the external apparatus is a display unit, a mobile telephone, a watch, a computer or a PDA.

29. The method according to claim 23, characterized in that the apparatus according to claim 4 is used.