Test element analysis system

• US 20030157724A1
• Filed: 03/11/2003
• Published: 08/21/2003
• Est. Priority Date: 12/24/1999
• Status: Active Grant

• Current Assignee: Roche Diagnostics GmbH (Roche Holding AG)
• Original Assignee: Roche Diagnostics GmbH (Roche Holding AG)
• Inventors: Kocherscheidt, Gerrit, Asfour, Jean-Michel, Petrich, Wolfgang, Schmid, Wilfried
• Granted Patent: US 7,262,061 B2
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• 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

Abstract

Test element analysis system for the analytical investigation of a sample, in particular of a body liquid of human beings or animals, comprising test elements (2) with a carrier film (5) and a test field (7) fixed to the flat side (6) of the carrier film (5), the test field (7) containing a reagent system the reaction of which with the sample (21) leads to an optically measurable change in the detection zone (24) which is characteristic for the analysis, and an evaluation instrument with a measuring device for measuring the optically measurable change. In order to obtain a very high measuring accuracy and an easy handling at the same time, the carrier film (5) of the test element (2) comprises a light guide layer (26), the detection zone (24) of the test field (7) is in optical contact to the light guide layer (26) in a coupling out zone (33), enabling the coupling out of light from the light guide layer (26) to the detection zone (24), the primary light (29) of the light emitter (16) is coupled into the entry surface (31) in the light guide layer (26) in such a manner that a light guide section (32) of the light path of the primary light (29) runs between the entry surface and the detection zone (24) inside the carrier film (5), and the secondary light is reflected from the detection zone (24) into the light guide layer (26) in such a manner that a light guide section (34) of the light path of the secondary light runs between the detection zone (24) and the detector (17) inside the light guide layer (26).

Claims

1. Test element analysis system for the analytical investigation of a liquid sample, in particular of a body liquid of human beings or of animals, comprising

test elements (2) with a carrier film (5) of plastic material and a test field (7) secured to a flat side (6) of the carrier film (5) which test field is contacted, in order to perform an analysis, with the sample (21) in such a manner that liquid sample components penetrate into the test field (7), wherein the test field (7) contains a reagent system the reaction of which with components of the sample (21) causes an optically measureable change in a detection zone (24) located on the side of the test field (7) directed towards the carrier film (5), said change being characteristic for the analysis and

an evaluation instrument (3) with a test element holder (12) for positioning a test element (2) in a measuring position, and with a measuring device (18) for measuring the optically measurable change in the detection zone (24), wherein the measuring device (18) comprises a light emitter (16) for irradiating primary light (29) onto the detection zone (24) and a detector (17) for detecting secondary light (35) diffusely reflected from the detection zone (24),

characterized in that

the carrier film (5) of the test element (2) comprises a light guide layer (26),

the carrier film (5) comprises a coupling out zone (33) which is a part of the flat side of the carrier film (5) to which the test field (7) is fixed and within which the detection zone (24) of the test field (7) is in optical contact to the carrier film (5) in such a manner that light is coupled out from the light guide layer (26) into the detection zone (24),

the primary light (29) of the light emitter (16) is coupled into the light guide layer (26) via an entry surface (31), in such a manner that a light guide section (32) of the light path of the primary light (29) between the entry surface (31) and the detection zone (24) runs inside the interior of the light guide layer (26) and

the secondary light which is diffusely reflected from the detection zone (24) is reflected into the light guide layer (26) and a light guide section (34) of the light path of the secondary light between the detection zone (24) and the detector (17) runs inside the carrier film (5).

2. Test element analysis system according to claim 1, characterized in that the test element (2) is positioned in the measuring position in such a manner that a first partial section (22) of the test element is located inside the housing (11) of the evaluation instrument (3) and a second partial section (23) protrudes from the housing (11) of the evaluation instrument (3) to be easily accessible, wherein the entry surface (31) is located in the first partial section (22) and the test field (7) is located in the second partial section (23).

13. Method for the analytical investigation of a sample, in particular of a body liquid of human beings or animals, using a test element analysis system according to claim 1, characterized in that

the primary light (29) emitted from the light emitter (16) is coupled into the light guide layer (36) through the entry surface (31),

the coupled in primary light (29) is guided inside the light guide layer (26) to the coupling out zone (33) where it is coupled out in such a manner that it illuminates at least a part of the detection zone (24),

secondary light generated by diffuse reflection in the detection zone (24) is transported inside the light guide layer (26) towards the detector (17) and

the secondary light is coupled out from the light guide layer (26) towards the detector (17).

3. Test element for the analytical investigation of a liquid sample, in particular of a body liquid of human beings or animals,

with a carrier film (5) of plastic material and a test field (7) secured to a flat side (6) of the carrier film (5) which test field is contacted, in order to perform an analysis, with the sample (21) in such a manner that liquid sample components penetrate into the test field (7),

wherein the test field (7) contains a reagent system the reaction of which with components of the sample (21) causes an optically measurable change in a detection zone (24) which is a part of the test field (7), the change being characteristic for the analysis, and wherein primary light irradiated onto the detection zone 10 is diffusely reflected therefrom

characterized in that

the carrier film (5) of the test element (2) comprises a light guide layer (26),

the carrier film (5) comprises a coupling out zone (33) which is a part of the flat side of the carrier film (5) to which the test field (7) is fixed and within which the detection zone (24) of the test field (7) is in optical contact to the carrier film (5) in such a manner that light is coupled out from the light guide layer (26) into the detection zone (24),

the light guide layer (26) comprises an entry surface (31) for coupling in primary light in such a manner that a light guide section (32) of the light path of the primary light coupled into the light guide layer (26) runs inside the light guide layer (26) between the entry surface (31) and the detection zone (24),

the secondary light which is diffusely reflected from the detection zone (24) is reflected into the light guide layer (26), and a light guide section (34) of the light path of the secondary light runs between the detection zone (24) and the detector (17) inside the carrier film (5).

4. Test element according to claim 3, characterized in that the side of the light guide layer (26) opposed to the coupling out zone (33) is adapted, at least in sections thereof, to cause a change of the light propagation direction of the primary light (29) towards the detection zone (24).

5. Test element according to any one of claims 3 or 4, characterized in that the side of the light guide layer (26) which is opposed to the detection zone (24) is adapted, at least in sections thereof, to cause a change of the propagation direction of the secondary light (35) diffusely reflected from the detection zone, to coincide with the direction of the light guide layer (26) leading towards the detector (17).

6. Test element according to any one of claims 3 to 5, characterized in that the test field (7) is sufficiently absorbent to transport liquid sample components in the coupling out zone to the flat side (6) of the carrier film (5) to which the test field (7) is secured in such a manner that the liquid sample components wet the light guide layer (26) in the coupling out zone (33).

7. Test element according to any one of claims 3 to 6, characterized in that the light guide layer (26) in the coupling out zone (33) is roughened in order to improve the coupling out of the primary light.

8. Test element according to any one of claims 3 to 7, characterized in that the test field (7) contains components causing strong optical diffusion.

9. Test element according to any one of claims 3 to 8, characterized in that the carrier film (5) comprises two light guide layers, the primary light is coupled into a first light guide layer serving as primary light guide (27), and the secondary light-from the detection zone (24) is coupled into a second light guide layer serving as secondary light guide (28).

10. Test element according to claim 9, characterized in that the test field (7) is fixed to the flat side (6) of the primary light guide (27) which is opposed to the secondary light guide (28).

11. Test element according to any one of claims 9 or 10, characterized in that the light guide layers (27, 28) are separated, at least on a part of their length, by an optical barrier (39).

12. Test element according to claim 11, characterized in that the optical barrier comprises three partial layers, a first partial layer (43) being adjacent to the primary light guide (27) and having a refraction index which is lower than the refraction index of the primary light guide (27), a second partial layer (44) being adjacent to the secondary light guide (27) and having a refraction index which is lower than the refraction index of the secondary light guide, and a third partial layer (45) running between the first partial layer (43) and the second partial layer (44) and being metallically reflecting.

14. Method according to claim 13, using a test element according to any one of claims 3 to 11, characterized in that the primary light is transported in the primary light guide (27) from the coupling in surface (31) to the coupling out surface (33), and inside the secondary light guide (28) towards the detector (17).