Test strip with flared sample receiving chamber

• US 20050019212A1
• Filed: 06/18/2004
• Published: 01/27/2005
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Operations Limited (Roche Holding AG)
• Inventors: Bhullar, Raghbir S., Walling, Paul Douglas, Funke, Tom, Surridge, Nigel, Riggles, Randall K.
• Granted Patent: US 8,071,030 B2
• Time in Patent Office: Days
• US Class Current: 422/56
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing

Abstract

A test strip with a sample receiving chamber having a novel flared portion that terminates in a sample receiving opening. The flared portion provides a reservoir from which sample fluid can be drawn into the capillary or sample receiving chamber. The wider opening provided by the present invention is easier to “target” with a sample fluid. In preferred embodiments, the hydrophilic reagent layer extends to the dosing end or side of the test strip and further promotes wicking of the sample into the sample receiving chamber and thus reduces dose hesitation. In other preferred embodiments, a tapered dosing end is provided on the test strip in combination with the flared portion, and this combination create a test strip that will draw sample fluid into the sample receiving chamber regardless of where along the dosing edge of the test strip the fluid sample makes contact.

Claims

1. A test strip for analyzing a fluid, comprising:

a test strip body defining a sample receiving chamber having a flared portion terminating in a fluid receiving opening and an elongated portion extending inwardly from the flared portion;

the test strip body defining a vent in communication with the sample receiving chamber, whereby air can escape from the vent as fluid is drawn into the sample receiving chamber; and

a testing area positioned in the sample receiving chamber for analyzing the fluid.

2. The test strip of claim 1, wherein the flared portion is defined by a pair of opening walls that narrow in a direction toward the elongated portion.

3. The test strip of claim 1, wherein the flared portion is defined by a pair of curved opening walls.

4. The test strip of claim 1, wherein:

the elongated portion is defined by a pair of substantially parallel opposing sidewalls and an end wall connecting the sidewalls; and

the flared portion is defined by a pair of walls that narrow in a direction toward the elongated portion.

5. The test strip of claim 1, the test strip body further comprising:

a base substrate;

a covering layer overlying the base substrate; and

a spacing layer sandwiched between the base substrate and the covering layer, the spacing layer defining a void that defines the perimeter of the sample receiving chamber between the base substrate and the covering layer.

6. The test strip of claim 5, wherein the vent is formed in the covering layer.

7. The test strip of claim 6, wherein the covering layer comprises two pieces separated by a gap which overlies the sample receiving chamber and defines the vent.

8. The test strip of claim 5, wherein the covering layer, the spacing layer and the base substrate are all substantially flat.

9. The test strip of claim 5, wherein the covering layer and the base substrate include substantially aligned edges that comprise a fluid receiving end of the test strip at which the fluid receiving opening is disposed.

10. The test strip of claim 9, wherein the aligned edges are substantially straight.

11. The test strip of claim 9, wherein the aligned edges comprise a convex profile.

12. The test strip of claim 9, wherein the aligned edges are curved.

13. The test strip of claim 9, wherein the aligned edges comprise a notch which further defines the opening.

14. The test strip of claim 1, wherein the sample receiving chamber has a volume less than or equal to 1.0 μ

l.

15. The test strip of claim 1, wherein the sample receiving chamber has a volume of less than or equal to 0.5 μ

l.

16. The test strip of claim 1, wherein the sample receiving chamber includes at least one electrode and a reagent layer covering the at least one electrode.

17. The test strip of claim 16, wherein the reagent layer extends to the sample receiving opening.

18. The test strip of claim 1, wherein the fluid receiving opening is disposed at a tapered fluid receiving end of the test strip.

19. The test strip of claim 18, wherein the fluid receiving end comprises two sides that angle toward one another and terminate in a dosing edge that is narrower than a width of the test strip.

20. The test strip of claim 19, wherein the dosing edge is substantially straight.

21. A test strip, comprising:

a base substrate;

a covering layer overlying the base substrate and comprising a vent;

a spacing layer disposed between the covering layer and the base substrate, the spacing layer having a void that defines a sample receiving chamber disposed between the base substrate and the covering layer; and

the sample receiving chamber defining a flared portion that terminates in a fluid receiving opening.

22. The test strip of claim 21, wherein the covering layer, the base substrate and the spacing layer are substantially flat, and further wherein the sample receiving chamber comprises a substantially constant height and a width that varies at the flared portion.

23. The test strip of claim 22, wherein the sample receiving chamber includes an elongated portion having a substantially constant width extending from the flared portion.

24. The test strip of claim 21, wherein the sample receiving chamber includes an elongated portion having a substantially constant width extending from the flared portion.

25. The test strip of claim 21, wherein the vent is positioned proximate a terminal end of the sample receiving chamber.

26. The test strip of claim 21, wherein the covering layer and the base substrate include substantially aligned edges that comprise a fluid receiving end or side of the test strip at which the fluid receiving opening is located.

27. The test strip of claim 26, wherein the aligned edges are substantially straight.

28. The test strip of claim 26, wherein the aligned edges comprise a convex profile.

29. The test strip of claim 26, wherein the aligned edges are curved.

30. The test strip of claim 26, wherein the aligned edges comprise the fluid receiving end.

31. The test strip of claim 26, wherein the aligned edges comprise a notch which further defines the opening.

32. The test strip of claim 31, wherein the notch is smaller than the flared portion.

33. The test strip of claim 31, wherein the notch and flared portion have substantially matching shapes.

34. The test strip of claim 31, wherein the notch is disposed centrally with respect to the flared portion.

35. The test strip of claim 21, further comprising at least one electrode and a reagent layer disposed in the sample receiving chamber, the reagent layer covering the at least one electrode.

36. The test strip of claim 35, wherein the reagent layer extends to the sample receiving opening.

37. The test strip of claim 21, wherein the fluid receiving opening is disposed at a tapered fluid receiving end of the test strip.

38. The test strip of claim 37, wherein the fluid receiving end comprises two sides that angle toward one another and terminate in a dosing edge that is narrower than a width of the test strip.

39. The test strip of claim 38, wherein the dosing edge is substantially straight.

40. A test strip, comprising:

a base substrate having a reagent layer disposed thereon;

a covering layer overlying the base substrate and comprising a chamber cover and a body cover having a slot therebetween;

a sample receiving chamber disposed between the base substrate and the covering layer, the slot being in communication with the sample receiving chamber and defining a vent opening in the covering layer that allows air to escape as fluid enters the sample receiving chamber; and

wherein the sample receiving chamber comprises a flared portion defining a sample receiving opening.

41. The test strip of claim 40, wherein the slot comprises a gap which spaces the body cover from the chamber cover.

42. The test strip of claim 40, wherein the sample receiving chamber comprises an elongated portion extending inwardly from the flared portion.

43. The test strip of claim 42, wherein the flared portion is defined by a pair of opening walls that narrow in a direction toward the elongated portion.

44. The test strip of claim 42, wherein the flared portion is defined by a pair of curved opening walls.

45. The test strip of claim 42, wherein:

the elongated portion is defined by a pair of substantially parallel opposing sidewalls and an end wall connecting the sidewalls; and

the flared portion is defined by a pair of walls that narrow in a direction toward the elongated portion.

46. The test strip of claim 40, wherein the covering layer and the base substrate include substantially aligned edges that comprise a fluid receiving end or side of the test strip at which the sample receiving opening is disposed.

47. The test strip of claim 46, wherein the aligned edges are substantially straight.

48. The test strip of claim 46, wherein the aligned edges comprise a convex profile.

49. The test strip of claim 46, wherein the aligned edges are curved.

50. The test strip of claim 46, wherein the aligned edges comprise a notch which further defines the sample receiving opening.

51. The test strip of claim 46, wherein the aligned edges comprise the fluid receiving end of the test strip.

52. The test strip of claim 40, further comprising an electrode disposed in the sample receiving chamber, the electrode being covered by the reagent layer.

53. The test strip of claim 40, wherein the chamber cover overlies the sample-receiving chamber.

54. The test strip of claim 40, further comprising a spacing layer disposed between the covering layer and the base substrate, the spacing layer defining a void portion that further defines the height and perimeter of the sample receiving chamber between the base substrate and the covering layer.

55. The test strip of claim 54, wherein the void portion defines the flared portion and further defines an elongated portion extending inwardly from the flared portion.

56. The test strip of claim 54, wherein the void terminates at a position substantially aligned with the slot.

57. The test strip of claim 40, wherein the sample receiving opening is disposed at a tapered fluid receiving end of the test strip.

58. The test strip of claim 57, wherein the fluid receiving end comprises two sides that angle toward one another and terminate in a dosing edge that is narrower than a width of the test strip.

59. The test strip of claim 58, wherein the dosing edge is substantially straight.

60. A test strip, comprising:

a base substrate having a reagent layer disposed thereon;

a covering layer overlying the base substrate;

a sample receiving chamber disposed between the base substrate and the covering layer, the sample receiving chamber comprising a flared portion terminating in a sample receiving opening located at an edge of the test strip; and

wherein the reagent layer is disposed in the flared portion and extends to the opening located at the edge of the test strip.

61. The test strip of claim 60, further comprising a slot in communication with the sample receiving chamber, the slot defining a vent opening in the covering layer that allows air to escape as fluid enters the sample receiving chamber.

62. The test strip of claim 60, wherein the sample receiving chamber comprises an elongated portion extending inwardly from the flared portion.

63. The test strip of claim 62, wherein the flared portion is defined by a pair of opening walls that narrow in a direction toward the elongated portion.

64. The test strip of claim 62, wherein the flared portion is defined by a pair of curved opening walls.

65. The test strip of claim 62, wherein:

the elongated portion is defined by a pair of substantially parallel opposing sidewalls and an end wall connecting the sidewalls; and

the flared portion is defined by a pair of walls that narrow in a direction toward the elongated portion.

66. The test strip of claim 60, wherein the covering layer and the base substrate include substantially aligned edges that comprise a fluid receiving end or side of the test strip at which the fluid receiving opening is disposed.

67. The test strip of claim 66, wherein the aligned edges are substantially straight.

68. The test strip of claim 66, wherein the aligned edges comprise a convex profile.

69. The test strip of claim 66, wherein the aligned edges are curved.

70. The test strip of claim 66, wherein the aligned edges comprise a notch which further defines the sample receiving opening.

71. The test strip of claim 66, wherein the substantially aligned edges comprise the fluid receiving end of the test strip.

72. The test strip of claim 60, further comprising an electrode disposed in the sample receiving chamber, the electrode being covered by the reagent layer.

73. The test strip of claim 60, further comprising a spacing layer disposed between the covering layer and the base substrate, the spacing layer defining a void portion that further defines the height and perimeter of the sample receiving chamber between the base substrate and the covering layer.

74. The test strip of claim 73, wherein the height is substantially constant throughout the sample receiving chamber.

75. The test strip of claim 60, wherein the sample receiving opening is disposed at a tapered fluid receiving end of the test strip.

76. The test strip of claim 75, wherein:

the fluid receiving end comprises two sides that angle toward one another and terminate in the edge at which the sample receiving opening is located; and

the edge is narrower than a width of the test strip.

77. The test strip of claim 76, wherein the edge is substantially straight.

78. A method of making a test strip, comprising:

(a) providing a base substrate, a spacing layer and a covering layer;

(b) forming a void in the spacing layer, the void having an elongated portion and a bulbous portion;

(c) laminating the spacing layer to the base substrate and laminating the covering layer to the spacing layer, thereby forming a test strip precursor; and

(d) cutting through the precursor to make the test strip, the cut crossing the bulbous portion of the void and forming a sample receiving edge of the test strip, wherein the void defines a sample receiving chamber having a flared portion terminating in a sample receiving opening at the sample receiving edge of the test strip.

79. The method of claim 78, wherein the sample receiving edge comprises an end of the test strip.

80. The method of claim 78, wherein the sample receiving edge comprises a side of the test strip.

81. The method of claim 78, wherein the void formed in step (b) has a continuous periphery.

82. The method of claim 78, wherein the void formed in step (b) has a discontinuous periphery.

83. The method of claim 78, wherein the flared portion is Y-shaped.

84. The method of claim 78, further comprising an elongated portion of the sample receiving chamber extending inwardly from the flared portion.

85. The method of claim 78, wherein the void extends through the spacing layer, wherein the sample receiving chamber is bounded by the covering layer and the base substrate.

86. The method of claim 78, wherein:

the base substrate comprises a web of base substrate material, the spacing layer comprises a web of spacing layer material and the covering layer comprises a web of covering layer material;

the void formed in step (b) comprises a plurality of voids spaced apart; and

the method further comprises cutting the precursor into a plurality of test strips.

87. The method of claim 78, further comprising printing a graphic onto the test strip precursor.

88. The method of claim 87, further comprising performing the printing the graphic onto the test strip precursor after performing step (d).

89. The method of claim 78, wherein the sample receiving edge is positioned at a dosing end of the test strip and the dosing end is tapered.

90. The method of claim 89, wherein the dosing end comprises two sides that angle toward one another and terminate in a dosing edge that is narrower than a width of the test strip.

91. The method of claim 90, wherein the dosing edge is substantially straight.

92. A test strip, comprising:

a base substrate having a reagent layer disposed thereon;

a covering layer overlying the base substrate;

a sample receiving chamber disposed between the base substrate and the covering layer, the sample receiving chamber comprising a flared portion terminating in a sample receiving opening at a dosing end of the test strip; and

wherein the dosing end is tapered.

93. The test strip of claim 92, wherein the reagent layer is disposed in the flared portion and extends to a dosing edge of the dosing end.

94. The test strip of claim 92, wherein the covering layer comprises a chamber cover overlying the sample receiving chamber.

95. The test strip of claim 94, wherein the chamber cover further comprises a hydrophilic coating disposed thereon, the hydrophilic coating defining a ceiling of the sample receiving chamber.

96. The test strip of claim 94, wherein a portion of the chamber cover facing the sample receiving chamber is hydrophilic.

97. The test strip of claim 96, wherein the reagent layer extends to a dosing edge of the dosing end.

98. The test strip of claim 94, wherein the chamber cover is hydrophilic.

99. The test strip of claim 98, wherein the reagent layer extends to a dosing edge of the dosing end.

100. The test strip of claim 94, wherein the chamber cover comprises a substantially transparent material.

101. The test strip of claim 92, wherein the dosing end comprises two sides that angle toward one another and terminate in a dosing edge that is narrower than a width of the test strip.

102. The test strip of claim 101, wherein the dosing edge is substantially straight.

103. The test strip of claim 92, wherein the dosing end comprises a curved shape.

104. The test strip of claim 92, further comprising a spacing layer disposed between the base substrate and the covering layer, the spacing layer defining a void that defines a sample receiving chamber between the base substrate and the covering layer.

105. The test strip of claim 104, wherein the spacing layer comprises a first color and the reagent layer comprises a second color that contrasts with the first color.

106. The test strip of claim 105, wherein the covering layer is substantially transparent over the sample receiving chamber, whereby the contrasting colors of the reagent layer and the spacing layer are visible through the covering layer.

107. The test strip of claim 106, wherein the first color and the second color contrast with blood.

108. The test strip of claim 105, wherein the covering layer comprises a chamber cover, the chamber cover is substantially transparent and the contrasting colors of the reagent layer and the spacing layer are visible through the chamber cover.

109. The test strip of claim 108, wherein the first color and the second color contrast with blood.

110. The test strip of claim 104, further comprising a graphic disposed on the spacing layer.

111. The test strip of claim 110, wherein the graphic comprises a chevron.

112. A test strip, comprising:

a base substrate having a reagent layer disposed thereon, the reagent layer comprising a first color;

a covering layer overlying the base substrate;

a spacing layer disposed between the base substrate and the covering layer, the spacing layer defining a void that defines a sample receiving chamber between the base substrate and the covering layer, the spacing layer comprising a second color that contrasts with the first color; and

the sample receiving chamber comprising a flared portion terminating in a sample receiving opening at a dosing end of the test strip.

113. The test strip of claim 112, wherein the covering layer comprises a chamber cover overlying the sample receiving chamber.

114. The test strip of claim 113, wherein the chamber cover comprises a transparent or translucent material, whereby the contrasting colors of the reagent layer and spacing layer are visible through the chamber cover.

115. The test strip of claim 114, wherein the contrasting colors of the reagent layer and the spacing layer contrast with blood.

116. The test strip of claim 113, wherein the chamber cover comprises a hydrophilic underside.

117. The test strip of claim 112, further comprising a graphic disposed on the spacing layer.

118. The test strip of claim 117, wherein the graphic comprises a chevron.

119. The test strip of claim 112, wherein the dosing end is tapered.

120. The test strip of claim 119, wherein the dosing end comprises two sides that angle toward one another and terminate in a dosing edge that is narrower than the width of the test strip.

121. The test strip of claim 120, wherein the dosing edge is substantially straight.

122. The test strip of claim 112, wherein the reagent layer extends to a dosing edge of the test strip.