DEVICE FOR HIGH-RESOLUTION DETERMINATION OF THE CONCENTRATION OF SUBSTANCES IN FLUID MEDIA

• US 20130100452A1
• Filed: 10/18/2012
• Published: 04/25/2013
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: BluePoint Medical GmbH & Co. KG.
• Original Assignee: BluePoint Medical GmbH & Co. KG.
• Inventors: Ewald, Hartmut, Damaschke, Nils, DEGNER, Martin
• Granted Patent: US 9,389,171 B2
• Time in Patent Office: Days
• US Class Current: 356/442
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/3577 for analysing liquids, e.g. polluted water
• CPC Class Codes: G01N 2201/062 LED's
• CPC Class Codes: G01N 2201/0624 Compensating variation in output of LED source

Abstract

The present invention relates to a device for determining the concentration of substances in fluid media.

Claims

1. A device for determining the concentration of one or more substances in a fluid medium, said device characterised by the light emission of an MQW LED used for absorption measurement, wherein the emitted light interacts in a measuring system with the substance to be determined, and acts, in a detector unit by means of an optical filter, upon an absorption detector and a reference detector to generate a measurement signal and a reference signal, respectively, whereby the concentration of the substance to be determined is found by comparing these signals.

2. The device according to claim 1, characterised in that at least one edge filter is used as the optical filter.

3. The device according to claim 2, wherein the at least one edge filter is designed as short-wavelength or long-wavelength pass filter.

4. The device according to claim 1, characterised in that at least one bandpass filter with one or a plurality of bandpass characteristics is used as the optical filter.

5. The device according to claim 4, characterised in that the bandpass filter is designed so that the concentration of a plurality of substances can be determined by using a plurality of MQW LEDs.

6. The device according to claim 1, characterised in that the MQW LED is actively cooled.

7. The device according to claim 1, characterised in that the MQW LED is electrically modulated.

8. The device according to claim 1, characterised in that a plurality of MQW LEDs act upon at least one detector unit.

9. The device according to claim 1, characterised in that the optical filter is variable.

10. The device according to claim 9, characterised in that the variable filter is constructed as a Fabry-Pé

rot filter in MEMS technology.

11. The device according to claim 9, characterised in that the variable filter is applied exclusively or additionally before the MQW LED.

12. The device according to claim 11, characterised in that the MQW LED is integrated in the structure of the variable filter.

13. A method for determining the concentration of one or more substances in a fluid medium using the device of claim 1, said method comprising the steps of:

(a) introducing the one or more substances into a detector unit comprised of an optical filter, an absorption detector and a reference detector which generate a measurement signal and a reference signal, respectively; and

(b) measuring the absorption of the one or more substances using the light emission of an MQW LED, wherein the concentration of the one or more substances is determined by comparing the measurement signal with a reference signal.

14. The method according to claim 13, characterised in that substance(s) with broadband absorption characteristics are detected by means of the edge of an absorption band.

15. The method according to claim 13, characterised in that measurement takes place continuously.