COMBINATION OPTICAL HEMOGLOBIN AND ELECTROCHEMICAL LEAD ASSAY

• US 20160178573A1
• Filed: 12/22/2015
• Published: 06/23/2016
• Est. Priority Date: 12/23/2014
• Status: Active Grant

• Current Assignee: Magellan Diagnostics, Inc. (Meridian Bioscience, Inc.)
• Original Assignee: Magellan Diagnostics, Inc. (Meridian Bioscience, Inc.)
• Inventors: Jensen, Gary Conrad, Sheppard, Norman F. Jr.
• Granted Patent: US 9,759,651 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 21/31 Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01N 21/474 Details of optical heads therefor, e.g. using optical fibres
• CPC Class Codes: G01N 2201/062 LED's
• CPC Class Codes: G01N 2201/0625 Modulated LED
• CPC Class Codes: G01N 2201/0696 Pulsed
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80

Abstract

A sensor and analyzer for measuring an analyte in a liquid sample are disclosed. The sensor includes a substrate with a reservoir disposed therein. The reservoir may include a top surface and a bottom surface, at least one transparent portion forming at least a part of the bottom surface of the reservoir, and a reflector disposed on the upper surface of the reservoir at a location opposite the at least one transparent portion. The analyzer may include a support surface, an aperture extending through the support surface, a light source disposed below the support surface and oriented so that at least a portion of the light emitted from the light source passes through the aperture, and a detector configured to measure an intensity of light received at the detector.

Claims

1. A sensor for measuring an analyte in a liquid sample, the sensor comprising:

a reservoir having a top surface and a bottom surface;

at least one transparent portion forming at least a part of the bottom surface of the reservoir; and

wherein a portion of the top surface comprises a reflector.

2. The sensor of claim 1, further comprising:

a base layer forming the bottom surface of the reservoir, wherein the at least one transparent portion forms at least a portion of the base layer;

a first spacer layer having a first void extending through a thickness of the first spacer layer;

a second spacer layer having a second void extending through a thickness of the second spacer layer, and wherein at least a portion of a bottom surface of the second spacer layer comprises the portion of the top surface of the reservoir comprising the reflector;

a lid having a bottom surface, and wherein at least a portion of the bottom surface of the lid forms at least a portion of the top surface of the reservoir; and

wherein the first spacer layer is disposed on the base layer, the second spacer layer is disposed on the first spacer layer, and the lid is disposed on the second spacer layer.

3. The sensor of claim 2, wherein the second spacer layer also comprises a third void extending through the thickness of the second spacer layer, the second and third voids separated on the second spacer layer by a bridge, a bottom surface of the bridge comprising the portion of the bottom surface of the second spacer layer that comprises the portion of the top surface of the reservoir comprising the reflector.

4. The sensor of claim 2, wherein the reservoir comprises a first depth between the bottom surface of the reservoir and a first portion of the upper surface of the reservoir, and a second depth between the bottom surface of the reservoir and a second portion of the upper surface of the reservoir, wherein the first depth is less than the second depth, and wherein the reflector is disposed on the first portion of the upper surface of the reservoir.

5. The sensor of claim 4, wherein the first depth is equal to the thickness of the first spacer layer, and the second depth is equal to a combined thickness of the thickness of the first spacer layer and the thickness of the second spacer layer.

6. The sensor of claim 2, further comprising at least one electrode disposed on a bottom surface of the reservoir and at least one electrical contact disposed on the base layer, and wherein the at least one electrode is in electrical communication with the at least one electrical contact.

7. The sensor of claim 4, further comprising at least one electrode disposed on a bottom surface of the reservoir at a location where the reservoir comprises the second depth and at least one electrical contact disposed on the base layer, wherein the at least one electrode is in electrical communication with the at least one electrical contact.

8. The sensor of claim 7, wherein a first of the at least one electrodes comprises a colloidal gold deposit.

9. The sensor of claim 8, wherein the sensor is configured to be used to analyze for a hemoglobin concentration of the liquid sample using an optical measurement.

10. An analyzer for measuring an analyte in a liquid sample, the analyzer comprising:

a port for receiving a sensor and having a support surface configured to support the sensor;

an aperture extending through the support surface;

a light source disposed below the support surface and oriented so that at least a portion of the light emitted from the light source passes through the aperture;

a detector configured to measure an intensity of light received at the detector; and

a processor, the processor electrically coupled to the detector to receive an output of the detector.

11. The analyzer of claim 10, further comprising a sapphire window disposed within the aperture.

12. The analyzer of claim 10, wherein the detector is disposed below the support surface of the analyzer.

13. The analyzer of claim 12, wherein the light source comprises first and second light sources configured to alternatingly emit light.

14. The analyzer of claim 13, wherein the first and second light sources are configured so that the light emitted from each passes through the aperture at a 45°

angle relative to a central axis of the aperture.

15. The analyzer of claim 10, wherein the light source and detector are configured to emit and detect light at a wavelength corresponding to an isosbestic point of the liquid sample.

16. The analyzer of claim 10 wherein the light source and detector are configured to emit and detect light with a wavelength of approximately 405 nm.

17. The analyzer of claim 10 further comprising a clock, the clock electrically connected to the light source and the detector, and configured so that the light source can be pulsed at a first frequency and the detector can be demodulated at the first frequency.

18. A method for measuring an analyte in a liquid sample, the method comprising:

inserting a sensor into an analyzer;

introducing the liquid sample into a reservoir in the sensor;

illuminating the liquid sample in the sensor using a light source in the analyzer;

measuring a reflectance of the liquid sample using a detector in the analyzer; and

computing a measurement of the analyte using the measured reflectance.

19. The method of claim 18, wherein the reflectance is measured by measuring light reflected off a reflective surface in the sensor.

20. The method of claim 18, wherein the reflectance is computed by comparing an intensity measured at the detector to a reference intensity.

21. The method of claim 20, wherein the reference intensity is obtained by inserting an empty sensor into the analyzer, illuminating the empty sensor, and measuring an intensity of light received at the detector.

22. The method of claim 21, wherein internally reflected stray light is measured by detecting at the detector the intensity of light reflected off a light absorbing surface as the sensor is inserted into or withdrawn from the analyzer, the method further comprising subtracting the measured internally reflected stray light from the reference intensity and the measured absorbance of the sample to obtain a result which corrects for internally reflected stray light.