Test instrument

• US 5,397,537 A
• Filed: 12/08/1993
• Issued: 03/14/1995
• Est. Priority Date: 09/08/1989
• Status: Expired due to Term

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Koike, Masufumi, Kanda, Zensho, Hayakawa, Tsuyoshi, Miyaguchi, Katsuhiko, Morikawa, Naoki
• Primary Examiner(s): Jones, W. Gary
• Assistant Examiner(s): EDWARDS, LAURA ESTELLE
• Application Number:
  US08/162,976
• Time in Patent Office: 461 Days
• Field of Search: 422/56, 422/57, 422/58, 436/168, 436/169, 435/16
• US Class Current: 422/403
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements

Abstract

A test instrument for uniformly spreading a collected specimen on a reagent layer has a first opening for collecting the specimen, a specimen spreading layer having an upper surface a portion of which is exposed to the first opening, the reagent layer provided so that an upper surface thereof is in contact with the lower surface of the specimen spreading layer, and a support layer provided on a lower surface of the reagent layer. Even if the specimen does not attached itself in a uniform distribution over the large area of the first opening, it will be evenly distributed at the second opening, the opening area of which is smaller than that of the first opening at which measurement is performed. When an absorbing layer provided in the proximity of the edge portion of the first opening is supplied with an excess amount of the specimen, a direct path to the absorbing layer is blocked by the inner peripheral region of the first opening so that the absorbing layer is soaked via the spreading layer. Consequently, the specimen is distributed on the reagent layer uniformly and at a fixed concentration irrespective of the amount thereof.

Claims

1. A test instrument on which a specimen is spread for being measured by a measuring device, comprising:

a base member having a first opening for passing a specimen,

a second opening in said base member,

a flat specimen spreading layer obtained from flat material and having a first portion of a first surface thereof which is exposed to said first opening and a second portion of said first surface which is not exposed to said first opening,

a flat reagent layer obtained from flat material and being in contact with a second surface of said specimen spreading layer,

a flat light-transmissive layer obtained from flat material in contact with said reagent layer,

said second opening provided on an opposite side of said base member than said first opening, at which second opening measurement is performed by a measuring device,

said second opening is smaller than said first opening,

a flat absorbing layer provided in direct contact with the second portion of the first surface of said flat specimen spreading layer in order to absorb excess specimen which has been collected on said flat specimen spreading layer while allowing said first portion to remain exposed to said first opening, thus allowing said flat specimen spreading layer to be exposed to atmosphere for quickly drying said reagent layer, and wherein an edge portion of said second opening is chamfered with a predetermined angle to allow a wider optical path transmitted from the measuring device.

2. The test instrument according to claim 1, wherein the diameter of said first opening is set to be about twice the diameter of said second opening.

3. The test instrument according to claim 2, wherein the reagent layer comprises a reagent for reacting with said specimen so that blood-sugar value can be measured by coloration of the reagent layer.

4. The test instrument according to claim 2, wherein the reagent layer comprises a reagent for reacting with said specimen so that uric acid can be measured by coloration of the reagent layer.

5. The test instrument according to claim 2, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Oxaloacetic Transaminase can be measured by coloration of the reagent layer.

6. The test instrument according to claim 2, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Pyruvic Transaminase can be measured by coloration of the reagent layer.

7. The test instrument according to claim 1, which further comprises a covering portion which includes said first opening, wherein the first opening in the covering portion is gradually decreasing towards said specimen spreading layer and has said absorbing layer therein.

8. The test instrument according to claim 7, wherein said inner peripheral region of said first opening is formed into a circular cone-shaped configuration having an opening area which gradually diminishes toward said specimen spreading layer.

9. The test instrument according to claim 8, wherein the reagent layer comprises a reagent for reacting with said specimen so that blood-sugar value can be measured by coloration of the reagent layer.

10. The test instrument according to claim 8, wherein the reagent layer comprises a reagent for reacting with said specimen so that uric acid can be measured by coloration of the reagent layer.

11. The test instrument according to claim 8, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Oxaloacetic Transaminase can be measured by coloration of the reagent layer.

12. The test instrument according to claim 8, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Pyruvic Transaminase can be measured by coloration of the reagent layer.

13. The test instrument according to 7, wherein an inner peripheral region of said first opening is formed into a circular cone-shaped configuration having an outwardly bulging curved surface and an opening area which gradually diminishes toward said specimen spreading layer.

14. The test instrument according to claim 13, wherein the reagent layer comprises a reagent for reacting with said specimen so that blood-sugar value can be measured by coloration of the reagent layer.

15. The test instrument according to claim 13, wherein the reagent layer comprises a reagent for reacting with said specimen so that uric acid can be measured by coloration of the reagent layer.

16. The test instrument according to claim 13, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Oxaloacetic Transaminase can be measured by coloration of the reagent layer.

17. The test instrument according to claim 13, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Pyruvic Transaminase can be measured by coloration of the reagent layer.

18. The test instrument according to claim 7, wherein the reagent layer comprises a reagent for reacting with said specimen so that blood-sugar value can be measured by coloration of the reagent layer.

19. The test instrument according to claim 7, wherein the reagent layer comprises a reagent for reacting with said specimen so that uric acid can be measured by coloration of the reagent layer.

20. The test instrument according to claim 7, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Oxaloacetic Transaminase can be measured by coloration of the reagent layer.

21. The test instrument according to claim 7, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Pyruvic Transaminase can be measured by coloration of the reagent layer.

22. The test instrument according to claim 1, wherein the reagent layer comprises a reagent for reacting with said specimen so that blood-sugar value can be measured by coloration of the reagent layer.

23. The test instrument according to claim 1, wherein the reagent layer comprises a reagent for reacting with said specimen so that uric acid can be measured by coloration of the reagent layer.

24. The test instrument according to claim 1, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Oxaloacetic Transaminase can be measured by coloration of the reagent layer.

25. The test instrument according to claim 1, wherein the reagent layer comprises a reagent for reacting with said specimen so that Glutamic Pyruvic Transaminase can be measured by coloration of the reagent layer.

26. The test instrument according to claim 1, further comprising backward insertion preventing means on the base member for preventing the test instrument from being inserted backwardly into the measuring device.

27. The test instrument according to claim 26, wherein said backward insertion preventing means is formed near said first opening.

28. The test instrument according to claim 26, further comprising a second backward insertion preventing means mounted on the measuring device for coacting with the backward insertion preventing means on said base member.

29. The test instrument according to claim 28, wherein said second backward insertion preventing means is formed as a cut-out and said backward insertion preventing means on said base member is formed as a projection to mate with said cutout.

30. A test instrument on which a specimen is spread for being measured by a measuring device, comprising:

a base member having a first opening for passing a specimen;

a second opening in said base member;

a specimen spreading layer having a first portion of a first surface thereof which is exposed to said first opening and a second portion of said first surface which is not exposed to said first opening;

a reagent layer in contact with a second surface of said specimen spreading layer;

a support member in contact with said reagent layer;

said second opening provided on an opposite side of said base member than said first opening, at which second opening measurement is performed by a measuring device;

an absorbing layer provided in direct contact with the second portion of the first surface of said specimen spreading layer in order to absorb excess specimen which has been collected on said specimen spreading layer while allowing said first portion to remain exposed to said first opening;

wherein the diameter of said first opening is about twice the diameter of said second opening; and

a covering portion of said base member which includes said first opening and which gradually extends towards said specimen spreading layer and said absorbing layer is mounted between said covering portion and the second portion of the first surface of the specimen spreading layer; and

wherein an edge portion of said second opening is chamfered with a predetermined angle to allow a wider optical path transmitted from the measuring device.

31. The test instrument according to claim 30, wherein an inner peripheral region of said first opening is formed into a circular cone-shaped configuration having an opening area which gradually extends toward said specimen spreading layer.

32. The test instrument according to claim 30, wherein said absorbing layer is annular and said covering portion extends into a center part of said annular absorbing layer.

33. A test instrument on which a specimen is spread for being measured by a measuring device comprising:

a base member having a first opening for passing said specimen;

a second opening in said base member;

a specimen spreading layer having a first portion of a first surface thereof which is exposed to said first opening and a second portion of said first surface which is not exposed to said first opening;

a reagent layer in contact with a second surface of said specimen spreading layer;

a support member in contact with said reagent layer;

said second opening provided on an opposite side of said base member than said first opening, at which second opening measurement is performed by a measuring device;

said second opening is smaller than said first opening;

an absorbing layer provided in direct contact with the second portion of the first surface of said specimen spreading layer in order to absorb excess specimen which has been collected on said specimen spreading layer while allowing said first portion to remain exposed to said first opening; and

wherein an edge portion of said second opening is chamfered with a predetermined angle to allow a wider optical path transmitted from said measuring device.

34. The test instrument according to claim 33, wherein the diameter of said first opening is about twice the diameter of said second opening.

35. The test instrument according to claim 33, further comprising a covering portion of said base member which includes said first opening, wherein the first opening in the covering portion gradually extends towards said specimen spreading layer and said absorbing layer is mounted between the covering portion and the second portion of the first surface of the specimen spreading layer.