Microsensor for determination of glucose and other analysis in liquids based on affinity viscosimetry

• US 6,210,326 B1
• Filed: 07/07/1997
• Issued: 04/03/2001
• Est. Priority Date: 01/06/1995
• Status: Expired due to Fees

• Current Assignee: Ehwald, Rudolf
• Original Assignee: Ehwald, Rudolf
• Inventors: Ehwald, Rudolf
• Primary Examiner(s): Lacyk, John P.
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US08/888,734
• Time in Patent Office: 1,366 Days
• Field of Search: 600/300, 600/301, 600/322, 600/366, 600/317, 600/353, 422/68.1, 422/52, 205/777.5, 205/781.5, 205/403, 73/304, 73/130.4, 73/19.03, 73/28.03, 73/723, 384/550, 384/571, 436/50, 435/14
• US Class Current: 600/365
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

A microsensor for the determination of glucose and other analytes in liquids, based on affinity viscosimetry. The sensor based on affinity viscosimetry with stable working properties can be sufficiently minaturized for implantation in the organism. The sensor has a completely closed liquid conducting system having a dialysis chamber of a dialysis hollow fiber filled with the aqueous polymer system, and a measuring system for electrical signal transduction working in such a way that the sensitive polymer solution and eventually other liquids which are not miscible but hydraulically coupled with the polymer solution, are able to move on a closed path. The measuring system contains a micromotor to induce the liquid movement and a signal transducer sensitive to either pressure, volume or streaming to form signals related unequivocally to viscosity.

Claims

1. A microsensor for the determination of concentration of glucose or other analytes in liquids, based on microsystem technology and viscosity measurement of an analyte-sensitive polymer solution enclosed in a dialysis hollow fiber suitable for implantation in the human body, comprising a hollow conductor;

a closed circuit of at least One liquid in said hollow conductor said dialysis hollow fiber containing said analyte-sensitive polymer solution;

an analyte concentration measuring system, said hollow conductor combining said dialysis hollow chamber and said analyte-concentration measuring system, said analyte-concentration measuring system including a micromotor for moving said analyte-sensitive polymer solution, said at least one liquid transducing forces between said micromotor and said analyte-sensitive polymer solution within said dialysis hollow fiber, and a Signal transducer operatively connected to said micromotor to generate Signals unequivocally related to viscosity of said analyte-sensitive polymer solutions said signal transducer being selected from the group consisting of a pressure-sensitive signal transducer, a volume-sensitive signal transducer, and a flow-sensitive signal transducer.

2. A microsensor for the determination of concentration of glucose or other analytes in liquids, based on microsystem technology and viscosity measurement of an analyte-sensitive polymer solution enclosed in a dialysis hollow fiber, comprising a hollow conductor;

a closed circuit of at least one liquid in said hollow conductor said dialysis hollow fiber containing said analyte-sensitive polymer solution;

an analyte concentration measuring system, said hollow conductor combining said dialysis hollow chamber and said analyte-concentration measuring system, said analyte-concentration measuring system including a micromotor for moving said analyte-sensitive polymer solution, said at least one liquid transducing forces between said micromotor and said analyte-sensitive polymer solution within said dialysis hollow fiber, and a signal transducer operatively connected to said micromotor to generate signals unequivocally related to viscosity of said analyte-sensitive polymer solution said signal transducer being selected from the group consisting of a pressure-sensitive signal transducer, a volume-sensitive signal transducer, and a flow-sensitive signal transducer.

3. The micro sensor according to claim 2, wherein said micrometer is identical with said signal transducer by transducing a back-effect of the viscosity—

dependent convective resistance of said analyte sensitive polymer solution within said hollow conductor to the movement or energy demand of the micromotor into an electrical signal.

4. The microsensor according to claim 2, wherein said signal transducer includes at least one photosensor which registrates changes in a light intensity around one or more light absorbing or reflecting bodies or interphases between liquids contained in said hollow conductor.

5. The microsensor according to claim 2, wherein said dialysis hollow fiber with the analyte-sensitive polymer solution and said measuring system are co-integrated with a wireless transducing unit for energy and signals forming said signal transducer into a unit which is separated galvanically from an energy source and a display.

6. The microsensor according to claim 2, wherein said hollow conductor contains a liquid which is not miscible with water besides the analyte-sensitive polymer solution, said analyte-sensitive polymer solution and said at least one liquid being not miscible but hydraulically coupled to each other and being mobile withinin said hollow conductor.

7. The microsensor according to claim 6, wherein movement of interfaces between an aqueous phase and a nonaqueous phase is restricted to partial volumes of the hollow conductor according to shape-and material-dependent surface forces between liquids and walls of said hollow conductor.

8. The microsensor according to claim 7, wherein said hollow conductor has one or more parts, where two liquids which are not miscible with each other and differ in dielectrical constant and electrical conductivity touch each other between electrodes of a condensator which is one of said micromotor and said signal transducer.

9. The microsensor according to claim 3, wherein said micromotor and said signal transducer are formed by an active membrane which is hydraulically coupled with said analyte-sensitive polymer solution, for transducing a time-dependent deflection from a rest position between the active membrane and a solid counter electrode into an electrical signal.

10. The microsensor according to claim 9, wherein said counter electrode and a first side of said active membrane limit a variable first hollow space which is connected with one end of said dialysis hollow fiber containing with said analyte sensitive polymer solution, whereas the second side of the active membrane is at the border of a second variable hollow space which is connected with the other end of said dialysis hollow fiber, said first hollow space at the first side of the active membrane and said second hollow space at the second side of the active membrane are separated from surroundings of said hollow conductor and each other by rigid vacuum-tight walls, respectively.

11. The microsensor according to claim 10, wherein a volume of said first hollow space and a volume of said second hollow space are filed with an inert dielectric liquid which is not miscible with said analyte sensitive solution but hydraulically direct coupled to said analyte sensitive solution within said hollow conductor.

12. The microsensor according to claim 2, wherein said dialysis hollow fiber is a dialysis chamber.