Impedance spectroscopy based systems and methods

• US 7,315,767 B2
• Filed: 09/05/2003
• Issued: 01/01/2008
• Est. Priority Date: 03/06/2001
• Status: Expired due to Fees

• Current Assignee: Solianis Holding AG
• Original Assignee: Solianis Holding AG
• Inventors: Hirt, Etienne, Caduff, Andreas, Schrepfer, Thomas W.
• Primary Examiner(s): SINES, BRIAN J
• Application Number:
  US10/656,997
• Publication Number:
  US 20040147819A1
• Time in Patent Office: 1,579 Days
• Field of Search: 422/50, 422/68.1, 422/82.01, 436/43, 436/63, 436/66, 436/86, 436/87, 436/95, 436/149, 700/266, 600/300, 600/347, 600/365, 600/547
• US Class Current: 700/266
• 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
• CPC Class Codes: G01N 22/00 Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more G01N3/00 - G01N17/00, G01N24/00 take precedence
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

One aspect of the invention provides a device that non-invasively determines the concentration of a substance in a target. The device includes a first electrode, a measuring circuit, and a data processor. In one embodiment of the device, the first electrode can be electrically insulated from the target, e.g., a cover layer of insulating material covers the first electrode.

Claims

1. A method for managing a process involving a specimen, the method comprising:

arranging a first electrode at the specimen, wherein the first electrode is electrically insulated from the specimen;

receiving a modulated electrical voltage signal at the first electrode to generate a modulated field in the specimen;

measuring at least one parameter depending on a response of the specimen to the field;

determining a concentration of a substance in the specimen based at least in part on the measured parameter; and

controlling an aspect of the process based at least in part on the determined concentration.

2. The method of claim 1 wherein controlling an aspect of the process comprises controlling a valve based at least in part on the determined concentration.

3. The method of claim 1 wherein the method further comprises arranging a second electrode at the specimen and wherein the modulated electrical voltage generates a modulated field between the first and the second electrode.

4. The method of claim 3 wherein the second electrode is in electric contact with the specimen.

5. The method of claim 3 wherein the method further comprises measuring a temperature of the specimen and using the temperature in the determination of the concentration.

6. The method of claim 1 wherein the modulated electrical voltage signal is a sine wave.

7. The method of claim 6 wherein the modulated electrical voltage signal has a frequency between 10 MHz and 2 GHz.

8. The method of claim 1 wherein the method further comprises arranging an antenna electrode at the specimen in proximity to the first electrode and wherein the response of the specimen is measured by measuring a signal transmitted from the first electrode to the antenna electrode.

9. The method of claim 1 wherein the substance is glucose.

10. The method of claim 1 wherein the specimen is a living body.

11. The method of claim 1 wherein the determining the concentration comprises using calibration data to convert the parameter to the concentration.

12. The method of claim 1 wherein the first electrode forms part of a resonant circuit having a resonance frequency and wherein the resonant circuit is operated substantially at the resonance frequency.

13. The method of claim 12 wherein the resonant circuit is at least part of a tank circuit of an active oscillator and wherein the parameter is one of an amplitude and a frequency of a signal generated by the oscillator.

14. The method of claim 1 wherein receiving a modulated voltage comprises receiving a frequency sweeped modulated voltage wherein the frequency is swept from a frequency below the resonance frequency to a frequency above the resonance frequency.

15. The method of claim 1 wherein the substance is an alcohol.

16. The method of claim 1 wherein the specimen is a salt solution.

17. The method of claim 1 wherein the substance is a salt.