Measuring system and measuring method, in particular for determining blood glucose

• US 8,373,851 B2
• Filed: 07/02/2012
• Issued: 02/12/2013
• Est. Priority Date: 01/28/2010
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Hoenes, Joachim, Wehowski, Frederic, Mischler, Reinhold, Harttig, Herbert
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US13/540,001
• Publication Number:
  US 20130003043A1
• Time in Patent Office: 225 Days
• Field of Search: 356 39- 42
• US Class Current: 356/39
• CPC Class Codes: G01N 2021/3155 Measuring in two spectral ranges, e.g. UV and visible
• CPC Class Codes: G01N 21/3151 using two sources of radiation of different wavelengths G01N21/33 - G01N21/39 take precedence
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04
• CPC Class Codes: G01N 2201/06193 Secundary in-situ sources, e.g. fluorescent particles
• CPC Class Codes: G01N 2201/0696 Pulsed

Abstract

A measuring system for determining blood glucose includes a photometric measuring unit with a light source and a detector, and an analytical test element, to which a body fluid sample can be applied, and which can be placed in a beam path between the light source and the detector for optical detection of an analyte. For an improved multi-wavelength measurement, it is proposed that the light source includes a first emitter that can be actuated in a first wavelength range to emit pulsating alternating light and a second emitter that can be excited in a second wavelength range to emit fluorescent light.

Claims

1. A measuring system, comprising:

a photometric measuring unit comprising a light source and a detector; and

an analytical test element to which a sample of body fluid can be applied and which can be placed in a beam path between the light source and the detector for optical detection of an analyte, wherein the light source includes a first emitter that is actuated in a first wavelength range for emitting pulsed alternating light and a second emitter including a fluorescent substance that is excited by the pulsed first emitter to emit fluorescent light in a second wavelength range, wherein both emitters are jointly oriented towards a measuring surface of the test element.

2. The measuring system according to claim 1, wherein the alternating light has a pulse duration and the fluorescent light decays with a fluorescent life cycle, and the fluorescent life cycle is multiple times greater than the pulse duration.

3. The measuring system according to claim 1, wherein the first emitter is in the form of a light emitting diode emitting light.

4. The measuring system according to claim 3, wherein the light emitting diode is configured to emit light in the UV range.

5. The measuring system according to claim 1, wherein the second emitter is configured to be optically excited to emit visible fluorescent light.

6. The measuring system according to claim 1, wherein the second emitter is applied as a fluorescent layer to an emission surface of the first emitter.

7. The measuring system according to claim 1, wherein the detector includes a photoreceptor configured for the collective detection of the alternating and the fluorescent light.

8. The measuring system according to claim 1, wherein the detector includes two amplifying channels configured for wavelength-selective determination of measurement values.

9. The measuring system according to claim 1, wherein the detector includes a lock-in amplifier that is configured to be modulated with a pulse frequency of the alternating light for detecting an alternating light signal component generated by the alternating light.

10. The measuring system according to claim 1, wherein the detector comprises an amplifier that functions as an integrator configured to detect a composite signal generated by the alternating light and the fluorescent light.

11. The measuring system according to claim 10, wherein the detector includes a signal processor configured to determine signal components of at least one of the alternating light and the fluorescent light.

12. The measuring system according to claim 11, wherein the signal processor is configured to subtract the alternating light signal component from the composite signal to determine the signal components.

13. The measuring system according to claim 1, wherein the measuring unit is integrated in a hand-held device and the test element is configured as a disposable for single use in the hand-held device.

14. The measuring system according to claim 1, wherein the test element is coupled to the light source by an optical unit and the optical coupling can be monitored by a separate signal evaluation in one of the first and second wavelength ranges.

15. The measuring system according to claim 14, wherein the optical unit is one of a lens and an optical fiber.

16. A measuring method for determining blood glucose in a body fluid sample applied to a disposable test element, comprising:

optically scanning the test element by a photometric measuring unit comprising a light source and a detector, wherein a first emitter of the light source is actuated in a first wavelength range to emit pulsed alternating light, and a second emitter formed by a fluorescent substance is excited in a second wavelength range by the pulsed first emitter to emit fluorescent light that is superimposed on the alternating light, wherein both emitters are jointly oriented towards a measuring surface of the test element.

17. The measuring method according to claim 16, wherein a signal component related to the alternating light is detected by a time-resolved signal detection.

18. The measuring method according to claim 16, wherein a signal component related to the alternating light is detected by a lock-in amplifier.

19. The measuring method according to claim 16, wherein in one wavelength range, a measurement value for an analyte in the sample is detected, and in the other wavelength range, a control value is detected for optical coupling of the test element to the measuring unit.