Method and a system for determination of components of a substance

• US 5,981,951 A
• Filed: 11/04/1997
• Issued: 11/09/1999
• Est. Priority Date: 03/13/1995
• Status: Expired due to Fees

• Current Assignee: Diamyd Medical AB
• Original Assignee: Diamyd Medical AB
• Inventors: Essen-Moller, Anders
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Israel, Andrew
• Application Number:
  US08/913,135
• Time in Patent Office: 735 Days
• Field of Search: 250/341.1, 250/343, 250/339.12, 250/339.11
• US Class Current: 250/341.1
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence

Abstract

A method and system for determining the presence of one or more components in a liquid substance including illumination of the substance utilizing a light with at least one definite wave length preferably within the almost infrared area and detecting transmitted and/or reflected light and analyzing the detected light wherein the detection is performed extremely fast so as to detect a step response corresponding to an approaching or fading light pulse transmitted or reflected through the substance.

Claims

1. A method to determine the presence of at least one component in a liquid substance by means of spectroscopy comprising the steps of illuminating the substance by means of light with at least one definite wave length within the almost infrared wave length area and detecting transmitted and/or reflected light and analyzing the detected light characteristics, said detecting being performed during an extremely short time period such that a step response corresponding to an approaching or fading light pulse passing through the liquid substance is detected.

2. A method according to claim 1

wherein the step of illuminating includes directing a plane-polarized light through the substance and detecting the plane-polarized light angle distortion.

3. A method according to claim 2, wherein the substance is blood, the blood-glucose-contents then being determined.

4. A method according to claim 2, wherein the determination relates to a substance in the human body and is non-invasive.

5. A method according to claim 4, including passing various wave lengths through the substance.

6. The method of claim 2 including applying an electrical and/or magnetic field over the substance during said detection.

7. A method according to claim 6 wherein said period of time is such that the at least one component of the substance is effectively substantially stationary.

8. A method according to claim 1 wherein said period of time is such that the at least one component of the substance is effectively substantially stationary.

9. A method according to claim 1, wherein the light has at least two wave lengths and said detection is by means of differential spectroscopy.

10. A method according to claim 1, wherein the substance is blood, the blood-glucose-contents then being determined.

11. A method according to claim 1, the determination relates to a substance in the human body and is non-invasive.

12. A method according to claim 1, including passing various wave lengths through the substance.

14. A system according to claim 10 including means for applying an electrical and/or magnetic field over the substance during said detecting.

15. A system according to claim 14, wherein said means for detecting are non-invasive.

16. A system according to claim 15, wherein said substance is blood, the presence of glucose being determined.

13. A system to determine the presence of at least one component in a liquid substance by means of spectroscopy including means for illuminating the substance with light with at least one wave length within the almost infrared wave length area, and means for detecting transmitted and/or reflected light and means for analyzing detected light characteristics, the improvement comprising said means for detecting including means for detecting a step response corresponding to an approaching or fading light pulse passing through the liquid substance during a short period of time.

17. A system according to claim 13, wherein said means for detecting detect at least two different wave lengths by means of differential spectroscopy.

18. A system according to claim 13 wherein said means for illuminating includes means for generating plane-polarized light through the substance.