Process for affinity viscosimetry and viscosimetric affinity sensor

• US 20010035047A1
• Filed: 07/02/2001
• Published: 11/01/2001
• Est. Priority Date: 04/07/1997
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Andreas Thomas, Karl Ernst Ehwald, Rudolf Ehwald, Uwe Beyer
• Inventors: Ehwald, Rudolf, Ehwald, Karl Ernst, Thomas, Andreas, Beyer, Uwe
• Granted Patent: US 6,477,891 B2
• Time in Patent Office: Days
• US Class Current: 73/54.01
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: G01N 11/08 by measuring pressure required to produce a known flow
• CPC Class Codes: G01N 2001/4016 being a selective membrane, e.g. dialysis or osmosis

Abstract

The invention concerns a process for affinity viscosimetry and a viscosimetric affinity sensor on the basis of sensitive liquids with analyte-dependent viscosity which are localized within a perfusable dialysis chamber and contain colloidal constituents which are cross-linked by affinity bonds. The viscosimetric affinity sensor according to this invention is characterized by the spatial or temporal separation of analyte diffusion from the measurement of the flow resistance. An important advantage of the invention consists in small volume-displacement and negligible structural change within the matrix to be investigated.

Claims

1. A process for measuring analyte concentrations by affinity viscosimetry consisting in pumping of the sensitive liquid through a conductor for streaming liquids with integrated dialysis chamber and measuring device for viscosity, whereby the maximum shear rate of the sensitive liquid, which occurs at the measuring process, is at least twice the maximum shear rate of the sensitive liquid occuring, in the dialysis chamber during the dialysis process.

2. A viscosimetric affinity sensor for carrying out a process according to

claim 1

, characterized by a liquid-conductor perfusable by the sensitive liquid and containing a dialysis chamber, a measuring chamber for the flow resistance and a connected pumping device, whereby the flow resistance of the measuring chamber is layed out such that the maximum shear rate in the sensitive liquid during the measuring process is more than twice the maximum shear rate occuring in the sensitive liquid during the dialysis process.

3. A viscosimetric affinity sensor according to

claim 2

, characterized by the following peculiarity:

the dialysis chamber is part of a needle-like body.

4. A viscosimetric affinity sensor according to claims 2 or 3, characterized by the following peculiarity:

the liquid-conductor contains a pressure sensor.

5. A viscosimetric affinity sensor according to one of the

claims 2

to

4

, characterized by the following peculiarity:

the measuring chamber is situated within a needle-like body, the dialysis chamber is situated at its surface.

6. A viscosimetric affinity sensor according to one of the

claims 2

to

5

, characterized by the following peculiarity:

the sensitive liquid fills the dialysis chamber and the measuring chamber, and borders within the measuring chamber or within an additional chamber to a fluid of low viscosity which is not miscible with water.

7. A viscosimetric affinity sensor according to

claim 6

, characterized by the following peculiarity:

the additional chamber contains one ore more electrodes, by the help of which the position of the meniscus between fluid and sensitive liquid can be followed.

8. A viscosimetric affinity sensor according to one of the

claims 2

to

7

, characterized by the following peculiarity:

the sensor contains a valve or a valve-like device for interruption of the cohesion within the sensitive liquid by introduction of a gas or another fluid with low viscosity, whereby this valve or valve-like device is placed between the dialysis chamber and the measuring chamber or between the dialysis chamber and the pump.

9. A viscosimetric affinity sensor according to one of the claims 2-8, characterized by the following peculiarity:

the lumen of the dialysis chamber consists of a space between a solid body and the dialysis membrane.