Device for the measurement of glucose concentrations

• US 20050203363A1
• Filed: 03/02/2005
• Published: 09/15/2005
• Est. Priority Date: 09/24/2002
• Status: Active Grant

• Current Assignee: Solianis Holding AG
• Original Assignee: Pendragon Medical Ltd.
• Inventors: Caduff, Andreas, Feldman, Yuri
• Granted Patent: US 7,534,208 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement

Abstract

The device of the present invention comprises a ring (1) of a ferrite material and two coils (4, 5) wound around it. A alternating current is fed to one of the coils (4). This current gives rise to an alternating magnetic field within and along the ring, which in turn generates an alternating electric field. A specimen (3) is placed in the alternating electric field. The dielectric properties of the specimen (3) affect the electric field, which in turn induces a magnetic field and generates currents in the coils (4, 5). As the dielectric properties of the specimen (3) depend on its glucose level, the glucose level can therefore be measured by determining a parameter depending on the inductances of the coils.

Claims

1. A device for the measurement of glucose levels characterized by

at least one ring (1),

a coil assembly (4, 5) comprising at least one coil wound around said ring (1), having said ring (1) as a core and generating a magnetic field extending along said ring (1),

a current source (11) generating an AC current in said coil (4, 5) and thereby generating said magnetic field and an alternating electric field,

a detector (12) for measuring a parameter depending on an inductance of said coil assembly (4, 5) and generating a measured signal, and

a converter (13) for converting the measured signal to a glucose level of a specimen located in said alternating electric field.

2. The device of claim 1 wherein said coil assembly (4, 5) comprises a first (4) and a second (5) coil wound around said ring (1) and wherein said inductance is a mutual induction of said first and said second coil.

3. The device of claim 2 wherein said current source generates the AC current in the first coil (4) and said detector (12) measures a voltage or current induced in said second coil (5).

4. The device of claim 1 wherein said inductance is a self induction of said coil.

5. The device of claim 1 wherein said coil (4, 5) is a toroid coil.

6. The device of claim 1 wherein said ring (1) has a magnetic permeability of at least 100.

8. The device of claim 1 wherein said ring (1) comprises a ferrite.

9. The device of claim 1 wherein said converter (13) comprises a memory (14) holding calibration data for converting the measured signal to the glucose level.

10. The device of claim 1 comprising an opening in a center of said ring (1) for receiving the specimen.

11. The device of claim 1 wherein said ring (1) forms a circle.

12. The device of claim 1 wherein said ring (1) comprises a first (1′

) and a second (1″

) part wherein said first and said second parts are at least at one point (7) releasably connected to each other for opening said ring (1).

13. The device of claim 1 wherein said current source (11) is designed for generating a substantially sinusoidal current.

14. The device of claim 1 comprising at least a first and a second ring (1a, 1b), wherein the coil assembly (4, 5) comprises a first coil (4) arranged on the first ring (1a) and a second coil (5) arranged on the second ring (1b).

15. The device of claim 14 wherein said rings (1a, 1b) are coaxial and located at a distance from each other.

7. The device of claim 7 wherein said ring (1) has a magnetic permeability of at least 1000.

16. A method for measuring a glucose level in a specimen comprising the steps of

generating an AC current through a coil of a coil assembly (4, 5), wherein said coil has a ring (1) as a core, and thereby generating an AC magnetic and an alternating electric field,

placing a specimen in said electric field,

measuring a parameter depending on an inductance of said coil assembly (4, 5) and generating a measured signal, and

converting the measured signal to a glucose level of a specimen in said alternating electric field.

17. The method of claim 16 wherein said ring (1) is laid around the specimen.