IV catheter abstract
A safety IV catheter includes a unitary, resilient needle guard
received in a catheter hub. The needle guard includes a proximal
arm or wall that includes an opening through which a needle passes
for axial movement. When the needle is retracted from the catheter
it releases the force that had previously prevented movement of
the needle guard within the catheter hub. This in turn causes the
needle guard to snap into a position in which it is clamped onto
the needle shaft and in which its distal wall blocks access to the
needle tip. In this condition, the spring needle guard and needle
can be removed from the catheter hub. A slot or bulge may be formed
in the needle shaft that engages with the needle guard after the
protected needle and needle guard are removed from the catheter
hub, thereby to prevent removal of the protected needle from the
needle guard.
IV catheter claims
What is claimed is:
1. An IV catheter apparatus comprising a tubular catheter having
a proximal end and a distal end, a needle having a needle shaft
and a tip, said needle being received within said tubular catheter
when in a ready position, a catheter hub attached to the proximal
end of said catheter, said catheter hub having a hollow interior
and an inner wall, said needle being movable between said ready
position in which said tip is outside of said catheter hub and a
retracted position in which said tip is within the interior of said
catheter hub, a unitary needle guard positioned in the interior
of said catheter hub and including a resilient portion engaged by
said needle shaft when said needle is in its said ready position,
a section of said resilient portion of said needle guard being urged
by said needle shaft into contact with an interior wall of said
catheter hub when said needle is in its said ready position, means
formed on said interior wall of said catheter hub for engaging a
segment of said needle guard for retaining said needle guard to
said catheter hub during the movement of said needle between its
said ready position and its said retracted position, said needle
guard including a distal wall extending from said resilient portion
and spaced from said needle tip when said needle is in its said
ready position and movable within the interior of said catheter
hub to a blocking position distal of said needle tip when said needle
is in its said retracted position in which said needle shaft no
longer exerts a force on said resilient portion of said needle guard
such that contact between said section of said needle guard and
said catheter hub is released, and a proximal end wall having a
wall extending distally and upwardly from its lower end and terminating
at a clamping edge for engaging said needle shaft when said needle
is in its said ready position, said needle guard further including
means for clamping said needle guard to said needle upon the movement
of said needle guard to its said blocking position.
2. The catheter apparatus of claim 1 in which said distal wall
of said needle guard is contiguous with said resilient portion,
said distal wall terminating at a curved lip engaging the underside
of said needle shaft when said needle is in its said ready position.
3. The catheter of claim 2 in which said needle guard further
includes a proximal arm and a transverse segment extending between
said distal wall and said proximal arm, said clamping means including
first and second engagement points on said proximal arm and said
transverse segment respectively, which are urged against opposing
locations on said needle shaft when the needle is in the retracted
position, thereby to clamp said needle guard to the needle shaft.
4. The catheter of claim 3 further including a bump formed in
said inner wall of said catheter hub, said bump engaging said needle
guard in said ready position to aid in retaining said needle guard
in said ready position.
5. The catheter of claim 4 in which a slot is formed in said needle
shaft at a location proximal to said needle tip, said slot being
positioned slightly distal of said contact point of said needle
guard proximal arm so that upon additional proximal axial movement
of said needle said contact point on said proximal arm of said needle
guard is received in said needle slot.
6. The catheter of claim 5 further comprising a needle hub affixed
to said proximal end of the needle and further comprising a tether
attached at one end to said needle hub and at its other end to said
needle guard.
7. The catheter of claim 3 further including a groove formed in
said inner wall of said catheter hub, said groove engaging said
needle guard in said ready position to aid in retaining said needle
guard in said ready position.
8. The catheter of claim 7 in which said needle guard further
includes an upper end wall contiguous with said transverse segment
and proximal to said resilient portion and in contact with an opposed
interior wall of the catheter hub in the ready position.
9. The catheter of claim 8 in which said needle guard includes
a proximal end wall extending from said resilient portion and including
an opening allowing said needle to pass therethrough, said needle
further including a large diameter segment on the needle shaft inward
of said needle tip, the diameter of said large diameter segment
being greater than that of said opening in said proximal wall.
10. The catheter of claim 7 in which a slot is formed in said
needle shaft at a location proximal to said needle tip, said slot
being positioned slightly distal of said contact point of said needle
guard proximal arm so that upon additional proximal axial movement
of said needle said contact point on said proximal arm of said needle
guard is received in said needle slot.
11. The catheter of claim 10 further comprising a needle hub affixed
to said proximal end of said needle and further comprising a tether
attached at one end to said needle hub and at its other end to said
needle guard.
12. The catheter of claim 10 in which said needle guard further
includes an upper end proximal to said resilient portion and in
contact with an opposed interior wall of the catheter hub when said
needle is in said ready position.
13. The catheter of claim 3 in which said needle guard further
includes an upper end contiguous with said transverse segment and
proximal to said resilient portion and in contact with an opposed
interior wall of the catheter hub when said needle is in the ready
position.
14. The catheter of claim 2 further including a groove formed
in said inner wall of said catheter hub, said groove engaging said
needle guard in said ready position to aid in retaining said needle
guard in said ready position.
15. The catheter of claim 14 in which said needle guard further
includes an upper end proximal to said resilient portion and in
contact with an opposed interior wall of the catheter hub when said
needle is in said ready position.
16. The catheter of claim 2 further comprising a bump formed in
said inner wall of said catheter hub, said bump engaging said needle
guard in said ready position to aid in retaining said needle guard
in said ready position.
17. The catheter of claim 2 in which said needle guard further
includes an upper end proximal to said resilient portion and in
contact with an opposed interior wall of the catheter hub when said
needle is in its said ready position.
18. The catheter of claim 1 in which said needle guard further
includes a proximal arm and a transverse segment extending between
said distal wall and said proximal arm, said clamping means including
first and second engagement points on said proximal arm and said
transverse segment respectively, which are urged against opposing
locations on said needle shaft when said needle is in the retracted
position, thereby to clamp said needle guard to said needle shaft.
19. The catheter of claim 18 further including a groove formed
in said inner wall of said catheter hub, said groove engaging said
needle guard in said ready position to aid in retaining said needle
guard in said ready position.
20. The catheter of claim 19 in which said needle guard further
includes an upper end wall contiguous with said transverse segment
and proximal to said resilient portion and in contact with an opposed
interior wall of the catheter hub in the ready position.
21. The catheter of claim 18 in which a slot is formed in said
needle shaft at a location proximal to said needle tip, said slot
being positioned slightly distal of said contact point of said needle
guard proximal arm so that upon additional proximal axial movement
of said needle said contact point on said proximal arm of said needle
guard is received in said needle slot.
22. The catheter of claim 18 further comprising a bump formed
in said inner wall of said catheter hub, said bump engaging said
needle guard in said ready position to aid in retaining said needle
guard in said ready position.
23. The catheter of claim 18 in which said needle guard further
includes an upper end wall contiguous with said transverse segment
and proximal to said resilient portion and in contact with an opposed
interior wall of the catheter hub in the ready position.
24. The catheter of claim 1 in which a slot is formed in said
needle shaft at a location proximal to said needle tip, said slot
being positioned slightly distal of said contact point of said needle
guard proximal arm so that upon additional proximal axial movement
of the needle said contact point on said proximal arm of said needle
guard is received in said needle slot.
25. The catheter of claim 24 further comprising a needle hub affixed
to said proximal end of the needle and further comprising a tether
attached at one end to said needle hub and at its other end to said
needle guard.
26. The catheter of claim 24 in which said needle guard further
includes an upper end proximal to said resilient portion and in
contact with an opposed interior wall of the catheter hub when said
needle is in said ready position.
27. The catheter of claim 1 further including a groove formed
in said inner wall of said catheter hub, said groove engaging said
needle guard when said needle is in its said ready position to aid
in retaining said needle guard in said retaining contact with said
inner wall of said catheter hub while said needle moves from its
said ready position to its said retracted position.
28. The catheter of claim 27 in which a slot is formed in said
needle shaft at a location proximal to the needle tip, said slot
being positioned slightly distal of said contact point of said needle
guard proximal arm so that upon additional proximal axial movement
of said needle said contact point on said proximal arm of said needle
guard is received in said needle slot.
29. The catheter of claim 28 further comprising a needle hub affixed
to said proximal end of the needle and further comprising a tether
attached at one end to the needle hub and at its other end to said
needle guard.
30. The catheter of claim 27 in which said needle guard further
includes an upper end proximal to said resilient portion and in
contact with an opposed interior wall of the catheter hub when said
needle is in said ready position.
31. The catheter of claim 1 further comprising a bump formed in
said inner wall of said catheter hub, said bump engaging said needle
guard in said ready position to aid in retaining said needle guard
in said ready position.
32. The catheter of claim 1 in which said needle guard further
includes an upper end proximal to said resilient portion and in
contact with an opposed interior wall of the catheter hub in said
ready position.
33. The catheter of claim 1 in which said needle guard further
comprises a proximal arm having a lower curved segment in contact
with an inner wall of said catheter hub when said needle is in its
said ready position.
34. The catheter of claim 33 in which said proximal arm further
includes an upper end in engagement with an opposed location of
said inner wall of said catheter hub distal to the point of contact
with said lower curved segment when said needle guard is in its
said ready position.
35. The catheter of claim 34 in which a groove is formed in said
lower end of said catheter hub, said distal wall of said needle
guard including a lower curved portion seated in said groove when
said needle is in its said ready position.
36. The catheter of claim 35 in which said needle includes a slot
formed in its periphery at a location proximal to the needle tip,
said needle guard further including a transverse section extending
between said proximal arm and said distal wall and including a flexible
flap received in said needle slot when said needle guard is in its
said blocking position.
37. The catheter of claim 35 in which said needle guard further
comprises a proximal end wall having an opening for receiving said
needle therethrough, said needle further comprising a large diameter
on the needle shaft inward of said needle tip, the diameter of said
large diameter segment being greater than that of said opening in
said proximal end wall.
38. The catheter of claim 1 in which said needle guard includes
first and second distal walls which overlap one another and form
a distal barrier to said needle when said needle guard is in its
said blocking position.
39. The catheter of claim 38 in which said needle guard further
comprises a proximal end wall having an opening for receiving said
needle therethrough and first and second arms extending respectively
between said proximal end wall and said first and second distal
walls.
40. The catheter of claim 39 in which said distal walls each include
a curved protruding segment at the end of said arms, said catheter
hub including an annular groove for receiving said protruding segments
when said needle guard is in its said ready position.
41. The catheter of claim 40 in which each of said arms includes
a wide section hingedly secured to said first and second distal
walls and a narrow section extending from said wide section to said
end wall.
42. The catheter of claim 41 in which said clamping means includes
a clamping edge formed on a proximal end of said wide section.
43. The catheter of claim 42 in which said needle includes a large
diameter segment on the needle shaft inward of said needle tip,
the diameter of said large diameter segment being greater than that
of said opening in said proximal end wall.
44. The catheter of claim 42 in which said needle guard includes
a proximal end wall extending from said resilient portion and including
an opening allowing said needle to pass therethrough, said needle
further including a large diameter segment on the needle shaft inward
of said needle tip, the diameter of said large diameter segment
being greater than that of said opening in said proximal end wall.
45. The catheter of claim 44 in which said needle guard further
comprises a proximal end wall having an opening for receiving said
needle therethrough, said needle further comprising a large diameter
on the needle shaft inward of said needle tip, the diameter of said
large diameter segment being greater than that of said opening in
said proximal end wall.
46. The catheter of claim 1 further comprising a wall extending
distally and upwardly from the lower end of said proximal end wall
and terminating at a clamping edge.
47. The catheter of claim 46 further comprising a resilient finger
formed in said transverse arm, said finger and said clamping edge
engaging opposing surfaces of said needle when said needle is in
its said ready and blocking positions.
48. The catheter of claim 47 in which said needle includes a circumferential
groove forced inwardly of said tip, said finger being adapted to
enter into said groove in the event an axial force is applied to
said needle in the proximal direction when said needle guard is
in its said blocking position.
49. An IV catheter apparatus comprising a tubular catheter having
a proximal end and a distal end, a needle having a needle shaft
and a tip, said needle being received within said tubular catheter
when in a ready position, a catheter hub attached to the proximal
end of said catheter, said catheter hub having a hollow interior
and an inner wall, said needle being movable between said ready
position in which said tip is outside of said catheter hub and a
retracted position in which said tip is within the interior of said
catheter hub, a unitary needle guard positioned in the interior
of said catheter hub and including a resilient portion engaged by
said needle shaft when said needle is in its said ready position,
a section of said resilient portion of said needle guard being urged
by said needle shaft into contact with an interior wall of said
catheter hub when said needle is in its said ready position, and
means formed on said interior wall of said catheter hub for engaging
a segment of said needle guard for retaining said needle guard to
said catheter hub during the movement of said needle between its
said ready position and its said retracted position, said needle
guard including a distal wall extending from said resilient portion
and spaced from said needle tip when said needle is in its said
ready position and movable within the interior of said catheter
hub to a blocking position distal of said needle tip when said needle
is in its said retracted position in which said needle shaft no
longer exerts a force on said resilient portion of said needle guard
such that contact between said section of said needle guard and
said catheter hub is released.
50. The IV catheter apparatus of claim 49 in which said distal
wall of said needle guard is contiguous with said resilient portion,
said distal wall terminating at a curved lip engaging the underside
of said needle shaft when said needle is in its said ready position.
51. The IV catheter apparatus of claim 50 further including a
groove formed in said inner wall of said catheter hub, said groove
engaging said needle guard in said ready position to aid in retaining
said needle guard in said ready position.
52. The IV catheter apparatus of claim 51 in which a slot is formed
in said needle shaft at a location proximal to said needle tip,
said slot being positioned slightly distal of said contact point
of said needle guard proximal arm so that, upon additional proximal
axial movement of said needle, said contact point on said proximal
arm of said needle guard is received in said needle slot.
53. The IV catheter apparatus of claim 52 further comprising a
needle hub affixed to said proximal end of said needle and further
comprising a tether attached at one end to said needle hub and at
its other end to said needle guard.
54. The IV catheter apparatus of claim 52 in which said needle
guard further includes an upper end proximal to said resilient portion
and in contact with an opposed interior wall of the catheter hub
when said needle is in its said ready position.
55. The IV catheter apparatus of claim 51 in which said needle
guard further includes an upper end contiguous with said transverse
segment and proximal to said resilient portion and in contact with
an opposed interior wall of the catheter hub when said needle is
in its said ready position.
56. The IV catheter apparatus of claim 50 further including a
bump formed in said inner wall of said catheter hub, said bump engaging
said needle guard in said ready position to aid in retaining said
needle guard in said ready position.
57. The IV catheter apparatus of claim 56 in which a slot is formed
in said needle shaft at a location proximal to said needle tip,
said slot being positioned slightly distal of said contact point
of said needle guard proximal arm so that, upon additional proximal
axial movement of said needle, said contact point on said proximal
arm of said needle guard is received in said needle slot.
58. The IV catheter apparatus of claim 57 further comprising a
needle hub affixed to said proximal end of the needle and further
comprising a tether attached at one end to said needle hub and at
its other end to said needle guard.
59. The IV catheter apparatus of claim 58 further including a
groove formed in said inner wall of said catheter hub, said groove
engaging said needle guard in said ready position to aid in retaining
said needle guard in said ready position.
60. The IV catheter apparatus of claim 59 in which a slot is formed
in said needle shaft at a location proximal t said needle tip, said
sot being positioned slightly distal of said contact point of said
needle guard proximal arm so that, upon additional proximal axial
movement of said needle, said contact point on said proximal arm
of said needle guard is received in said needle slot.
61. The IV catheter apparatus of claim 59 further comprising a
bump formed in said inner wall of said catheter hub, said bump engaging
said needle guard in said ready position to aid in retaining said
needle guard in said ready position.
62. The IV catheter apparatus of claim 59 in which said needle
guard further includes an upper end contiguous with said transverse
segment and proximal to said resilient portion and in contact with
an opposed interior wall of the catheter hub when said needle is
in its said ready position.
63. The IV catheter apparatus of claim 59 in which said needle
guard further includes an upper end contiguous with said transverse
segment and proximal to said resilient portion and in contact with
an opposed interior wall of the catheter hub when said needle is
in its said ready position.
64. The IV catheter apparatus of claim 56 in which said needle
guard further includes an upper end contiguous with said transverse
segment and proximal to said resilient portion and in contact with
an opposed interior wall of the catheter hub when said needle is
in its said ready position.
65. The IV catheter apparatus of claim 64 in which said needle
guard includes a proximal end wall extending from said resilient
portion and including an opening allowing said needle to pass therethrough,
said needle further including a large diameter segment on the needle
shaft inward of said needle tip, the diameter of said large diameter
segment being greater than that of said opening in said proximal
end wall.
66. The IV catheter apparatus of claim 50 further including a
groove formed in said inner wall of said catheter hub, said groove
engaging said needle guard in said ready position to aid in retaining
said needle guard in said ready position.
67. The IV catheter apparatus of claim 66 in which said needle
guard further includes an upper end proximal to said resilient portion
and in contact with an opposed interior wall of the catheter hub
when said needle is in its said ready position.
68. The IV catheter apparatus of claim 50 further comprising a
bump formed in said inner wall of said catheter hub, said bump engaging
said needle guard in said ready position to aid in retaining said
needle guard in said ready position.
69. The IV catheter apparatus of claim 50 in which said needle
guard further includes an upper end proximal to said resilient portion
and in contact with an opposed interior wall of the catheter hub
when said needle is in its said ready position.
70. The IV catheter apparatus of claim 49 in which a slot is formed
in said needle shaft at a location proximal to said needle tip,
said slot being positioned slightly distal of said contact point
of said needle guard proximal arm so that, upon additional proximal
axial movement of the needle, said contact point on said proximal
arm of said needle guard is received in said needle slot.
71. The IV catheter apparatus of claim 70 further comprising a
needle hub affixed to said proximal end of the needle and further
comprising a tether attached at one end to said needle hub and at
its other end to said needle guard.
72. The IV catheter apparatus of claim 70 in which said needle
guard further includes an upper end proximal to said resilient portion
and in contact with an opposed interior wall of the catheter hub
when said needle is in its said ready position.
73. The IV catheter apparatus of claim 49 further including a
groove formed in said inner wall of said catheter hub, said groove
engaging said needle guard when said needle is in its said ready
position to aid in retaining said needle guard in said retaining
contact with said inner wall of said catheter hub while said needle
moves from its said ready position to its said retracted position.
74. The IV catheter apparatus of claim 73 in which a slot is formed
in said needle shaft at a location proximal to the needle tip, said
slot being positioned slightly distal of said contact point of said
needle guard proximal arm so that, upon additional proximal axial
movement of said needle, said contact point on said proximal arm
of said needle guard is received in said needle slot.
75. The IV catheter apparatus of claim 76 further comprising a
needle hub affixed to said proximal end of the needle and further
comprising a tether attached at one end to the needle hub and at
its other end to said needle guard.
76. The IV catheter apparatus of claim 73 in which said needle
guard further includes an upper end proximal to said resilient portion
and in contact with an opposed interior wall of the catheter hub
when said needle is in its said ready position.
77. The IV catheter apparatus of claim 49 further comprising a
bump formed in said inner wall of said catheter hub, said bump engaging
said needle guard in said ready position to aid in retaining said
needle guard in said ready position.
78. The IV catheter apparatus of claim 49 in which said needle
guard further includes an upper end proximal to said resilient portion
and in contact with an opposed interior wall of the catheter hub
in said ready position.
79. The IV catheter apparatus of claim 49 in which said needle
guard further comprises a proximal arm having a lower curved segment
in contact with an inner wall of said catheter hub when said needle
is in its said ready position.
80. The IV catheter apparatus of claim 79 in which said proximal
arm further includes an upper end in engagement with an opposed
location of said inner wall of said catheter hub distal to the point
of contact with said lower curved segment when said needle is in
its said ready position.
81. The IV catheter apparatus of claim 80 in which a groove is
formed in said lower end of said catheter hub, said distal wall
of said needle guard including a lower curved portion seated in
said groove when said needle is in its said ready position.
82. The IV catheter apparatus of claim 81 in which said needle
includes a slot formed in its periphery at a location proximal to
the needle tip, said needle guard further including a transverse
section extending between said proximal arm and said distal wall
and including a flexible flap received in said needle slot when
said needle guard is in its said blocking position.
83. The IV catheter apparatus of claim 81 in which said needle
guard further comprises a proximal end wall having an opening for
receiving said needle therethrough, said needle further comprising
a large diameter segment on the needle shaft inward of said needle
tip, the diameter of said large diameter segment being greater than
that of said opening in said proximal end wall.
84. The IV catheter apparatus of claim 83 in which said needle
includes a circumferential groove forced inwardly of said tip, said
finger being adapted to enter into said groove in the event an axial
force is applied to said needle in the proximal direction when said
needle guard is in its said blocking position.
85. The IV catheter apparatus of claim 49 in which said needle
guard includes first and second distal walls which overlap one another
and form a distal barrier to said needle when said needle guard
is in its said blocking position.
86. The IV catheter apparatus of claim 85 in which said needle
guard further comprises a proximal end wall having an opening for
receiving said needle therethrough and first and second arms extending
respectively between said proximal end wall and said first and second
distal walls.
87. The IV catheter apparatus of claim 86 in which said distal
walls each include a curved protruding segment at the end of said
arms, said catheter hub including an annular groove for receiving
said protruding segments when said needle guard is in its said ready
position.
88. The IV catheter apparatus of claim 87 in which each of said
arms includes a wide section hingedly secured to said first and
second distal walls and a narrow section extending from said wide
section to said end wall.
89. The IV catheter apparatus of claim 88 in which said needle
guard includes a proximal end wall extending from said resilient
portion and including an opening allowing said needle to pass therethrough,
said needle further including a large diameter segment on the needle
shaft inward of said needle tip, the diameter of said large diameter
segment being greater than that of said opening in said proximal
end wall.
90. The IV catheter apparatus of claim 89 in which said needle
guard further comprises a proximal end wall having an opening for
receiving said needle therethrough, said needle further comprising
a large diameter segment on the needle shaft inward of said needle
tip, the diameter of said large diameter segment being greater than
that of said opening in said proximal end wall.
91. The IV catheter apparatus of claim 88 in which said needle
includes a large diameter segment on the needle shaft inward of
said needle tip, the diameter of said large diameter segment being
greater than that of said opening in said proximal end wall.
92. An IV catheter apparatus comprising a tubular catheter having
a proximal end and a distal end, a needle having a needle shaft
and a tip, said needle being received within said tubular catheter
when in a ready position, a catheter hub attached to the proximal
end of said catheter, said catheter hub having a hollow interior
and an inner wall, said needle being movable between said ready
position in which said tip is outside of said catheter hub and a
retracted position in which said tip is within the interior of said
catheter hub, a unitary needle guard positioned in the interior
of said catheter hub and including a resilient portion engaged by
said needle shaft when said needle is in its said ready position,
a section of said resilient portion of said needle guard being urged
by said needle shaft into contact with an interior wall of said
catheter hub when said needle is in its said ready position, means
formed on said interior wall of said catheter hub for engaging a
segment of said needle guard for retaining said needle guard to
said catheter hub during the movement of said needle between its
said ready position and its said retracted position, said needle
guard including a distal wall extending from said resilient portion
and spaced from said needle tip when said needle is in its said
ready position and movable within the interior of said catheter
hub to a blocking position distal of said needle tip when said needle
is in its said retracted position in which said needle shaft no
longer exerts a force on said resilient portion of said needle guard
such that retaining contact between said section of said needle
guard and said catheter hub is released.
93. The IV catheter apparatus of claim 92 in which said distal
wall of said needle guard is contiguous with said resilient portion,
said resilient portion including a curved lip engaging the underside
of said needle shaft when said needle is in its said ready position.
94. The IV catheter apparatus of claim 93 in which said retaining
means includes a groove formed in said inner wall of said catheter
hub, said groove receiving a portion of said needle guard when said
needle is in its said ready position.
95. The IV catheter apparatus of claim 92 in which said retaining
means includes a groove formed in said inner wall of said catheter
hub, said groove receiving a portion of said needle guard when said
needle is in its said ready position.
96. The IV catheter apparatus of claim 92 in which said needle
guard further includes a transverse arm and a curved upper segment
contiguous with said transverse arm and in contact with an opposed
interior wall of the catheter hub when said needle is in its said
ready position.
97. The IV catheter apparatus of claim 92 in which said needle
guard further comprises a proximal wall having a lower curved segment
in contact with said interior wall of said catheter hub when said
needle is in its said ready position.
98. The IV catheter apparatus of claim 97 in which said proximal
wall further includes an upper end in engagement with an opposed
location of said interior wall of said catheter hub when said needle
guard is in its said ready position.
99. The IV catheter apparatus of claim 98 in which said retaining
means includes a groove formed in said interior wall of said catheter
hub, said distal wall of said needle guard including a lower curved
portion seated in said groove when said needle is in its said ready
position.
100. The IV catheter apparatus of claim 92 in which said needle
guard includes first and second distal walls which overlap one another
and form a distal barrier to said needle when said needle guard
is in its said blocking position.
101. The IV catheter apparatus of claim 100 in which each of said
distal walls includes a curved lip engaging opposing surfaces of
said needle shaft when said needle is in its said ready position.
102. The IV catheter apparatus of claim 101 in which said first
and second distal walls each include a curved protruding segment,
said retaining means including an annular groove formed in said
catheter hub interior wall for receiving said protruding segments
when said needle is in its said ready position.
103. The IV catheter apparatus of claim 102 in which said first
and second distal walls each further include a wide section and
a narrow section extending from said wide section toward said proximal
end wall.
104. The IV catheter apparatus of claim 100 in which said needle
guard further comprises a proximal end wall having an opening for
receiving said needle therethrough and first and second arms extending
respectively between said proximal end wall and said first and second
distal walls.
105. The IV catheter apparatus of claim 104 in which said needle
includes a large diameter segment on the needle shaft inward of
said needle tip, the diameter of said large diameter segment being
greater than that of said opening in said proximal end wall.
106. The IV catheter apparatus of claim 100 in which said first
and second distal walls each include a curved protruding segment,
said retaining means including an annular groove formed in said
catheter hub interior wall for receiving said protruding segments
when said needle is in its said ready position.
107. The IV catheter apparatus of claim 106 in which said first
and second distal walls each further include a wide section and
a narrow section extending from said wide section toward said proximal
end wall.
108. An IV catheter apparatus comprising a tubular catheter having
a proximal end and a distal end, a needle having a needle shaft
and a tip, said needle being received within said tubular catheter
when in a ready position, catheter hub attached to the proximal
end of said catheter, said catheter hub having a hollow interior
and an inner wall, said needle being movable between said ready
position in which said tip is outside of said catheter hub and a
retracted position in which said tip is within the interior of said
catheter hub, and a unitary needle guard substantially positioned
in the interior of said catheter hub and including a resilient portion
engaged by said needle shaft when said needle is in said ready position,
a section of said resilient portion of said needle guard being urged
by said needle shaft into retaining contact with an interior wall
of said catheter hub when said needle is in its said ready position,
said needle guard also including a distal wall extending from said
resilient portion and spaced from said needle tip when said needle
is in its said ready position and movable within the interior of
said catheter hub to a blocking position distal of said needle tip
when said needle is in its said retracted position in which said
needle shaft no longer exerts a force on said resilient portion
of said needle guard such that said retaining contact between said
section of said needle guard and said catheter hub is released upon
the movement of said needle guard to its said blocking position.
109. The IV catheter apparatus of claim 108 in which said needle
guard includes first and second distal walls which overlap one another
and form a distal barrier to said needle when said needle guard
is in its blocking position.
110. The IV catheter apparatus of claim 109 in which said first
and second distal walls include a wide section and a narrow section
extending from said wide section toward said proximal end wall.
111. The IV catheter apparatus of claim 110 in which said needle
guard further comprises a proximal end wall having an opening for
receiving said needle therethrough and first and second arms extending
respectively between said proximal end wall and said first and second
distal walls.
112. The IV catheter apparatus of claim 111 in which said needle
includes a large diameter segment on the needle shaft inward of
said needle tip, the diameter of said large diameter segment being
greater than that of said opening in said proximal end wall.
IV catheter description
BACKGROUND OF THE INVENTION
I.V. catheters are primarily used to administer fluids, sometimes
containing medications, directly into a patient's vascular system.
The catheter is inserted into a patient's vein by a health care
worker by using a handheld placement device that includes a sharp
tip needle. The needle is positioned in the interior hollow portion
of the catheter with its tip extended slightly beyond the edge of
the catheter. The end of the apparatus opposite the needle tip is
made up of the needle connected to a needle hub which is capable
of being held by the health care worker during the insertion procedure.
The insertion procedure contains four basic steps: (1) the health
care worker inserts the needle and catheter together into the patient's
vein; (2) after insertion into the vein with the needle point, the
catheter is forwarded into the vein of the patient by the health
care worker pushing the catheter with his or her finger; (3) the
health care worker withdraws the needle by grasping the hub end
(opposite the point end) while at the same time applying pressure
to the patient's skin at the insertion site with his or her free
hand; and (4) the health care worker then tapes the now inserted
catheter to the patient's skin and connects the exposed end of the
catheter, the catheter hub, to the source of the fluid to be administered
into the patient's vein.
The problem is that immediately after the withdrawal of the needle
from the patient's vein, the health care worker who is, at this
time, involved in at least two urgent procedures must place the
exposed needle tip at a nearby location and address the tasks required
to accomplish the needle withdrawal. It is at this juncture that
the exposed needle tip creates a danger of an accidental needle
stick occurring, which under the circumstances, leaves the health
care worker vulnerable to the transmission of various, dangerous
blood-borne pathogens, including AIDS and hepatitis.
This danger to the health care worker from accidental needle sticks
has caused an impetus for the development of a safer IV catheter
in which the occurrence of such accidental needle sticks is prevented.
Safety catheters that have been developed to achieve this result
are disclosed, for example, in Lemieux Reissue Patent No. Re. 34416
Crawford U.S. Pat. No. 5558651 McLees U.S. Pat. No. 5135504
Gaba U.S. Pat. No. 5697907 and Dombrowski U.S. Pat. No. 4978344.
Kulli U.S. Pat. No. 4929241 and Chamuel U.S. Pat. No. 5053017
disclose a protective needle guard for use with a hypodermic needle.
The prior art safety catheters all exhibit one or more drawbacks
that have thus far limited their usefulness and full acceptance
by health-care workers. For example, in the safety catheter disclosed
in the Lemieux patent, the force required to engage the needle slot
within the guard flange is relatively great and would interfere
with the removal of the needle. Reducing this force to a more acceptable
level would create the possibility of the needle guard remaining
in the catheter hub after the needle is removed from the catheter.
As a result, the safety catheter disclosed in the Lemieux patent
would not consistently function in a reliable manner.
Similarly, the user of the safety catheter disclosed in the Dombrowski
patent would have to exert a considerable force to remove the protective
cap from the catheter hub, when the cap engages a needle. The safety
catheter disclosed in the Dombrowski patent would also be relatively
expensive to fabricate because of its inclusion of a flexible flange
and a tether.
The McLees protective device requires an irksome, extra pulling
action or tug on the needle guard through a retention ring to remove
the protected needle from the catheter hub. The McLees device also
requires the assembly of two separate components and is thus relatively
costly to manufacture. In addition, the needle in the McLees device
includes a larger diameter portion near and at the needle tip. This
feature of the McLees device would require that the remainder of
the needle be of a lesser diameter which would have the adverse
effect of slowing the blood flashback through the needle.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide
a safety IV catheter, which reliably and automatically prevents
accidental, inadvertent contact with the needle tip after use.
It is a further object of the invention to provide a safety catheter
which provides reliable protection to the health care practitioner
against needle sticks without requiring any change in the manner
of use of the safety catheter by the practitioner.
It is another object of the present invention to provide a safety
IV catheter of the type described which is relatively simple and
inexpensive to manufacture.
It is yet a further object of the present invention to provide
a safety catheter of the type described in which removal of the
needle from the needle guard after use is prevented.
To these ends, the safety IV catheter of the invention includes
a resilient spring clip needle guard that includes a distal or front
end and a proximal or rear wall. The spring clip is inserted into
the catheter hub and is urged by the needle shaft into contact with
the inner walls of the catheter hub so that the needle guard is
reliably retained therein. When the needle is withdrawn from the
catheter, the force it had previously exerted on the needle guard
is released causing the needle guard to pivot within the catheter
hub until it clamps onto the needle shaft. At this time, the distal
end wall of the needle guard blocks the distal pointed end tip of
the needle. In addition, the spring clip and protected needle onto
which it is clamped can be readily and safely removed from the catheter
hub. The needle may be provided with a slot or a bulge which cooperates
with the needle guard to prevent the inadvertent removal of the
needle from the needle guard after their removal from the catheter
hub.
In another embodiment of the spring clip safety catheter of the
invention, a retaining groove or bump is formed in the inner wall
of the catheter hub, which, in the ready position, engages a lower
arm of the spring clip to aid in the retention of the spring clip
in the catheter hub.
In yet a further embodiment of the spring clip safety catheter
of the invention, a slot is formed in the needle. After the spring
clip has pivoted to its retracted position and the needle is clamped
by the spring clip, further movement of the needle in the proximal
direction will cause the rear or proximal arm of the spring clip
to seat in the slot, thereby to more securely clamp the needle shaft
to the spring clip.
In a further embodiment of the spring clip catheter guard of the
invention, a tether is connected to the needle hub and the spring
clip guard to prevent the spring clip guard from being pulled off
the protected needle without requiring an excessive clamping force
therebetween.
In yet a further embodiment of the invention the spring clip needle
guard is in the form of resilient intersecting arms, each terminating
at a distal guard wall. When the needle is in the ready position
it passes through the guard and urges the resilient arms away from
each other and against the inner wall of the catheter hub. When
the needle is retracted past the guard walls, the resilient arms
spring to the safety position in which both of the guard walls are
positioned distally from the needle tip, thereby to form a barrier
that prevents inadvertent contact with the needle tip.
To the accomplishment of the above and to such further objects
as may hereinabove appear, the present invention relates to a safety
IV catheter as described with respect to presently preferred embodiments
in the following specification, as considered with the accompanying
drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are views in partial cross-section of a safety
IV catheter in accordance with a first embodiment of the invention
in the ready and retracted positions, respectively;
FIGS. 1C and 1D are views similar to FIGS. 1A and 1B of a possible
variation to the embodiment illustrated therein;
FIGS. 2A and 2B are views in partial cross-section of a safety
IV catheter in accordance with a second embodiment of the invention
in the ready and retracted positions, respectively;
FIGS. 3A and 3B are views in partial cross-section of a safety
IV catheter in accordance with a third embodiment of the invention
in the ready and retracted positions, respectively;
FIGS. 4A and 4B are views in partial cross-section of a safety
IV catheter in accordance with a fourth embodiment of the invention
in the ready and retracted positions, respectively;
FIGS. 5A and 5B are views in partial cross-section of a safety
IV catheter in accordance with a fifth embodiment of the invention
in the ready and retracted positions;
FIGS. 6A and 6B are views in partial cross-section of a safety
IV catheter in accordance with a sixth embodiment of the invention
in the ready and retracted positions, respectively;
FIGS. 7A, 7B and 7C are views in partial cross section of a safety
IV catheter in accordance with a further embodiment of the invention
in the ready, engaged and retracted or protected positions, respectively;
FIGS. 7D and 7E are views similar to FIGS. 7A and 7B of a possible
variation to the embodiment of the invention illustrated therein;
FIG. 8 is a perspective of the spring clip needle guard used in
the embodiment of FIG. 7;
FIG. 9 is a cross-section of the spring clip needle guard of FIG.
8;
FIGS. 10A and 10B are views in partial cross-section of a safety
IV catheter in accordance with still a further embodiment of the
invention shown in the ready and protected positions, respectively;
FIG. 11 is a perspective of the needle guard clip of the embodiment
of FIG. 10;
FIG. 12 is a perspective view of a safety IV catheter in accordance
with another embodiment of the invention; and
FIGS. 13A and 13B are cross-sectional views of the embodiment of
the invention of FIG. 12 in the ready and protected positions, respectively.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The safety IV catheter of the invention, generally designated 10
in the embodiment illustrated in FIGS. A and 1B, includes a needle
hub 12 that includes an axial opening 14 which securely receives
the proximal end of a needle 16 having a sharpened tip 18. The needle
hub 12 as is conventional, is hollow and includes a flash chamber
22. As is also conventional, the needle 16 is received within a
hollow tubular catheter 24 the proximal end of which is concentrically
affixed within the distal end of a catheter hub 26 having a distal
section 28 and a contiguous, larger diameter proximal section 30.
The catheter hub 26 terminates at its proximal end in a luer fitting
32 adapted to receive a tubing set, which in a known manner, administers
intravenous fluid into the patient. The catheter 24 is secured within
an axial passageway 34 in distal hub section 28 by means of a sleeve
20 received within passageway 34 which engages the proximal end
of the catheter. Passageway 34 communicates at its proximal end
with a flash chamber 36 formed in hub section 30.
In the ready position of the catheter shown in FIG. 1A, the distal
end of the needle hub 12 is snugly received in the proximal end
of the interior of chamber 36 such that the needle 16 extends through
the chamber 36 the passageway 34 and distally beyond the catheter
hub 26 and catheter 24 so that its tip extends beyond the tapered
distal end of the catheter.
In use, the distal tip of the needle and the catheter are inserted
into a patient's vein. Thereafter, the health care practitioner
manually places the catheter further into the vein and then withdraws
the needle by grasping and moving by hand the proximal end of the
needle hub 12. The luer of the catheter hub 26 is then fitted with
a source of the fluid that is to be administered into the patient's
vein.
In accordance with the present invention, as the needle 16 is being
withdrawn from the patient, a protective needle guard 40 located
within hub chamber 36 automatically snaps into a retracted position
in which it blocks access to the distal needle tip and prevents
further distal movement of the needle tip, thereby to prevent accidental
contact by the health care practitioner with the needle tip.
As shown in FIGS. 1A and 1B, the needle guard 40 is in the form
of a unitary spring clip that is preferably made of a resilient
metal such as stainless steel. The spring clip includes a resilient
portion which comprises a distal arm 42 terminating at its upper
end in a curved lip 44 and at its lower end in a pointed end 46
which, in the embodiment of FIG. 1 is received within a mating
groove 48 formed in the lower interior wall of catheter hub section
30.
The spring clip needle guard 40 further includes a transverse segment
50 that extends upward and proximally from lower pointed end 46
and terminates at a U-shaped upper end 52. In the ready position
of the spring clip shown in FIG. 1A, upper end 52 abuts against
the upper interior wall of the catheter hub section 30. The spring
clip guard 40 further includes a vertical arm 54 that extends downward
from the U-shaped upper end 52 and terminates above the lower wall
of catheter hub section 30. Transverse segment 50 and proximal vertical
arm 54 respectively include axially aligned openings 56 58 through
which the shaft of needle 16 is free to pass and axially move. The
diameter of opening 58 is slightly greater than that of the needle
shaft, whereas the diameter of the opening 56 is greater than that
of opening 58.
In the ready position of the catheter prior to needle withdrawal,
the shaft of needle 16 engages the curved lip 44 of the spring clip
needle guard 40 thereby to exert an essentially downward force
on the resilient spring clip. That force causes the lower end 46
of the spring clip to seat securely in groove 48 at point a. That
contact, in addition to the abutment of the upper end 52 of the
spring clip with the upper interior wall at the catheter hub at
point b, securely maintains the spring clip needle guard 40 in the
ready position within the catheter hub.
As the needle 16 is retracted to the left, as viewed in FIG. 1A,
to its fully retracted position shown in FIG. 1B, after catheter
insertion into the patient's vein, the distal tip of the needle
moves proximally past the curved lip 44 of the spring clip needle
guard 40 at point c, at which time the downward force previously
exerted by the needle shaft on the spring clip is released.
As a result of the needle 16 moving proximally past point c, the
retention force on spring clip needle guard 40 in the catheter hub
is released causing the spring clip needle guard 40 to pivot or
snap in a clockwise direction to the retracted position shown in
FIG. 1B. As therein shown, distal arm 42 of the needle guard 40
blocks the distal path of the needle 16. Simultaneously with the
blocking and releasing actions, the spring clip guard 40 becomes
securely clamped onto the needle shaft at points d and e, thereby
to securely lock the needle guard 40 onto the needle shaft. At this
time, the needle 16 and needle guard 40 can be removed together
from the catheter hub 26 and the tip of the needle cannot be pushed
past the needle guard because it is blocked by the distal arm 42
and lip 44 of the needle guard.
If desired, a slot 60 may be formed in the needle shaft slightly
proximal to the needle tip. When the needle and needle guard are
in their retracted and clamped positions (FIG. 1B), slot 60 is positioned
slightly distal to the clamping point e of the transverse segment
of the needle guard 40 such that if a subsequent attempt is made
to move the needle further in a rearward or proximal direction,
the transverse segment 50 at point e will seat into slot 60 thereby
to provide an additional force to retain the needle guard 40 on
the needle 16 in the protected position in which access to the needle
tip is prevented.
The safety IV catheter illustrated in FIGS. 1C and 1D is the same
as that illustrated in FIGS. 1A and 1B, except that the slot 60
in the needle shaft in the latter is replaced in the former by a
bulge 61 whose diameter is greater than that of opening 58 in vertical
arm 54. If an attempt is made to move the protected needle illustrated
in FIG. 1C in the rearward or proximal direction, bulge 61 will
engage wall 54 and will thus not be able to pass through opening
58 so as to prevent further proximal movement of the needle and
removal of the needle from the needle guard, as defined.
The embodiment of the invention illustrated in FIG. 2 is similar
to that of FIG. 1 except that instead of the groove formed in the
lower wall of the catheter hub that engages the lower end of the
spring clip, a retaining bump 62 is formed in that wall against
which the lower end 46 of the needle guard 42 seats when the needle
guard 40 is in the ready position in FIG. 2A.
The embodiment of the invention illustrated in FIGS. 3A and 3B
is essentially the same as that of FIG. 2 with the addition of a
tether 64 secured at one end to the needle hub 12 and at its other
end to proximal arm 54 of the spring clip needle guard 40. As shown
in FIG. 3B, the tether 64 is extended to its full length when the
needle hub is retracted to achieve needle removal so as to more
securely retain the needle hub 12 and the spring clip needle guard
40 when the latter is clamped onto the needle when in the retracted
position, in which, as described above, the distal arm 42 of the
spring clip prevents access to the needle tip, and the needle guard
40 and needle are released from the catheter hub.
FIGS. 4A and 4B illustrate a spring clip needle guard embodying
the principles of the invention in an alternative configuration.
As therein shown, the spring clip needle guard 40a includes a resilient
portion comprising a distal arm 65 terminating at its upper end
in a curved lip 66 and at its lower end in a U-shaped portion 67
which, in the ready position illustrated in FIG. 4A, contacts a
bump 68 formed in the lower inner wall of the catheter hub.
A resilient transverse segment 69 having a central opening 70 extends
proximally and upwardly and terminates at an upper U-shaped portion
72. A proximal end wall 74 having an opening 76 depends vertically
from portion 72 and then extends distally in a horizontal lower
segment 78 which has an opening 80 through which the lower halves
of distal arm 65 and transverse segment 69 extend in the ready position
of the needle guard. Segment 78 at its distal end extends upwardly
at a front wall 82 which has a central opening 84 axially aligned
with openings 70 76. At its upper end, distal front wall 82 extends
in the proximal direction in an upper segment 86 which, as shown
in FIG. 4A, contacts the upper inner wall of the catheter hub along
substantially its entire length.
As shown in FIG. 4A, when the catheter is in the ready position,
the needle shaft passes through openings 70 76 and 84 and rests
on curved lip 66 urging arm 65 against bump 68 in the lower wall
of the catheter hub. That engagement along with the resilient engagement
of upper segment 86 with the upper interior wall of the catheter
hub retains the spring clip 40a in its ready position within the
catheter hub.
When the needle hub and needle are retracted to the right, as viewed
in FIG. 4A, by a sufficient amount, the needle tip passes below
lip 66 and then releases its downward force on arm 65. As described
above, with reference to the first-described embodiment, this release
of engagement of the needle shaft and spring clip arm 65 causes
arm 65 to snap upwards to the retracted position illustrated in
FIG. 4B, in which arm 65 and lip 66 extend over the needle tip and
thereby prevent accidental contact with the needle tip as desired.
In this condition, the needle guard is clamped onto the needle shaft
in essentially the same manner described above with respect to the
first-described embodiment, and the needle and needle guard clamped
thereto can be readily removed from the catheter hub, also as described
above, and as shown in FIG. 4B.
The embodiment of the needle guard illustrated in FIGS. 5A and
5B is essentially the same as that shown in FIGS. 4A and 4B with
the addition of a slot 90 near the distal tip end of the needle.
When the needle and needle guard are in their retracted and clamped
position (FIG. 5B), slot 90 is positioned slightly distal to the
clamping point of the transverse segment 69 such that if a subsequent
attempt is made to move the needle further in a rearward or proximal
direction, the transverse segment 69 will seat into slot 90 thereby
to provide an additional force to retain the needle guard in the
needle in the protected position in which access to the needle tip
is prevented.
The embodiment of the invention illustrated in FIGS. 6A and 6B
is the same as that illustrated in FIGS. 4A and 4B except for the
inclusion of a tether 92 secured at one end to the needle hub and
at its other end to the proximal wall of the spring clip needle
guard. As shown in FIG. 6A, in the ready position, the tether is
wound around the distal end of the needle hub. As shown in FIG.
6B, when the needle and needle guard are in their retracted position,
the tether is extended to its full length and adds in the retention
of the needle guard to the needle hub. If desired, the embodiment
of the invention embodiment illustrated in FIGS. 6A and 6B could
also include a needle slot as in the embodiment of the invention
illustrated in FIGS. 5A and 5B.
The embodiment of FIGS. 7A-C, differs from the previously described
embodiments primarily with regard to the construction and operation
of the spring clip needle guard 96. As shown in FIGS. 8 and 9 the
spring clip 96 comprises a resilient portion which includes a central
transverse section 98 which includes a central slot 100. A sloping
section 102 extends from section 98 in the proximal direction and
terminates at a curved end 104 from which a proximal vertical arm
106 extends. Arm 106 terminates at its lower end in a U-shaped section
108. The distal end of transverse section 98 terminates in a curved
section 110 from which a vertical proximal arm 112 extends. Distal
arm 112 terminates at its upper end in a curved arm 114.
A cutout portion in section 98 defines a flexible flap 116 which
terminates at its distal free end in a downwardly sloping locking
tab 118. As in the prior embodiments, proximal arm 106 includes
an opening 58.
As shown in FIG. 7A, spring clip needle guard 96 when in the ready
position illustrated therein, is inserted within catheter hub 26
so as to allow the needle 16 to pass through opening 58 and slot
100. As in the previously described embodiments, the curved end
104 abuts against the inner upper wall of the catheter hub 26 at
point b, and curved section 110 seats within the mating groove 48
at point a formed in the lower, inner wall of the catheter hub.
In addition, the lower curved section 108 contacts at a point f
the lower, inner wall of the catheter hub 26 at a location proximal
to point b.
In operation, the needle is initially withdrawn into the catheter
hub until it reaches the tab engaged position illustrated in FIGS.
7B, in which as therein shown, the locking tab 118 is received within
the needle groove or slot 60. At this point, the spring clip remains
in contact with the inner wall of the catheter hub at points a,
b and f, while the needle tip 18 engages curved end 114 thereby
to urge section 110 into groove 48 at point c. The relative position
of point f with respect to point b prevents the needle and clip
from being prematurely released from the catheter hub by preventing
the distal end of the clip from tipping upwards and the proximal
end from slipping downward with the clip in the tab engaged position
shown in FIG. 7B.
As the needle is withdrawn further away from the patient, as shown
in FIG. 7C, the needle tip passes beyond curved end 114 thereby
releasing the downward force that had been previously exerted on
curved end 114 by the needle.
This sudden release of the downward force on the spring clip end
causes the distal end of the spring clip 96 to pivot upward so that
distal end 112 of spring clip 96 moves rapidly to a position in
which it prevents or blocks motion of the needle in the distal direction.
The spring clip 96 is retained on the needle 16 and will be removed
from the catheter hub 26 when the needle is completely removed.
Movement of the spring clip 96 from its protecting or retracted
position shown in FIG. 7C is further prevented by the insertion
of the locking tab 118 into the needle groove 60 which prevents
the spring clip from rotating around the periphery of the needle.
This, in turn, secures the spring clip on the needle even if the
clip were subjected to a twisting and pulling force.
The safety IV catheter illustrated in FIGS. 7D and 7E is the same
as that illustrated in FIGS. 7A and 7B, except that the slot 60
in the needle shaft in the latter is replaced in the former by a
bulge 61 whose diameter is greater than that of opening 58 in vertical
arm 54. If an attempt is made to move the protected needle illustrated
in FIG. 7D in the rearward or proximal direction, bulge 61 will
engage wall 54 and will not be able to pass through opening 58
so as to prevent any further proximal movement of the needle and
removal of the needle from the needle guard, as desired.
The embodiment of the spring clip needle guard 120 disclosed in
FIGS. 10A, 10B, and 11 comprises a resilient portion which comprises
first and second arms 122 and 124 respectively joined at their proximal
ends in a hinged arrangement at 125 to the ends of a rear wall 126.
The distal ends of arms 122 124 each include a curved protrusion
128 extending to a distal end wall 130 which in turn terminates
in a lip 132. As seen best in FIG. 11 rear wall 126 includes a
central opening 134 and arms 122 and 124 each include a narrow
portion 142 that extends between a distal wide portion 140 and a
proximal wide portion 144. A lateral clamping edge 146 is defined
at the distal wide portion 144.
As shown in FIG. 10A, when the needle guard 120 is in its ready
position, the curved protrusions 128 in each of arms 122 124 are
received in an annular groove or ring 136 formed in the inner wall
of catheter hub 26 which, as in the prior embodiments, is removably
fit into the distal end of a needle hub 12. Also as in the prior
embodiment, a needle 16 having a sharpened tip 18 at its distal
end is received within a tubular catheter 24 which is secured to
the distal end of catheter hub 26. The proximal end of needle 16
passes through opening 134 in rear wall 126. Needle 16 includes
an increased diameter bulge 138 which is sufficiently small to
allow needle 16 to move axially along catheter 24 but greater in
diameter than opening 134 for reasons to be described below.
In the ready position illustrated in FIG. 10A, the needle shaft
passes through the needle guard and applies an outward radial force
on resilient arms 122 124 by means of its engagement with lips
132 so as to urge the curved protrusions 128 of each of the arms
into the annular groove 136 so as to retain needle guard 120 in
a fixed position within the inner wall of catheter hub 26. The shaft
of needle 16 that passes through the needle guard 120 frictionally
engages the inner edges of the narrow portions 142 of arms 122
124 so as to further retain the needle in its ready position.
When the needle is retracted axially, to the right as viewed in
FIG. 10A, within the catheter hub, and moves past the end lip 132
of the needle guard, the radial force previously exerted on arms
122 124 of needle guard 120 is suddenly released. This causes the
distal end walls 130 of the needle guard to be released from their
seat in the annular groove 136 and to pivot inwards into the catheter
hub until, as seen in FIG. 10B, the end walls 130 overlap one another
at a location distally in front of the needle tip, thereby to form
a barrier that prevents inadvertent contact with, and distal movement
of, the needle tip. At the same time, the clamping edges 146 of
the needle guard are urged against the needle tip to restrict further
axial movement of the needle.
As also shown in FIG. 10B, the needle guard 120 and the needle
clamped to the needle guard after needle retraction can be removed
from the catheter hub as a unitary assembly, and safely discarded.
If an attempt is made, intentionally or inadvertently, to pull the
needle further to the right, as viewed in FIG. 10 out of the needle
guard, the bulge 138 on the needle shaft will come into contact
with the end wall 126 and since its diameter is greater than that
of opening 134 the end wall 126 will at this point prevent any
further axial movement of the needle out of the needle guard.
The spring clip guard of the invention, in the embodiment. illustrated
in FIGS. 12 13A and 13B, includes a resilient portion which comprises
a transverse arm 150 terminating at its distal end at a distal end
wall 152 which includes at its upper end a curved lip 154 and
at its lower end a curved end 156. An elongated rectangular opening
or slot 158 is provided in transverse arm 150. The proximal ends
of transfer arm 150 and opening 158 terminate at an extension 160
extending upwardly at an angle from arm 150 and having a finger
or flap 162 that extends toward opening 158.
The proximal end of extension 160 terminates at a curved end 166
from which a proximal end wall 168 extends downwardly. Wall 168
which includes an opening 170 terminates at its lower end at a
curved section 172 from which extends an upwardly sloping arm 174
that terminates at a clamping edge 176. As can be seen in FIGS.
13A and 13B, a 360.degree. circular groove 178 is formed about the
circumferential wall of needle 16 slightly inwardly from the tip
18 of the needle.
In the ready position of the spring clip guard of FIG. 12 as illustrated
in FIG. 13A, the shaft of the needle passes through aligned opening
170 in the rear wall 168 and opening 158 in the resilient transverse
arm 150 and extends distally beyond the catheter hub. As in the
prior embodiments described hereinabove, the needle shaft in this
position exerts a downward radial force on arm 150 by means of its
engagement with curved lip 154. This downward force urges the curved
end 156 of the spring clip to seat firmly within a groove 164 formed
in the inner wall of the catheter hub at point a.
At the same time, the upper curved end 166 of end wall 168 engages
the inner wall of the catheter hub at point b, and the lower-curved
end 172 of wall 168 engages the inner wall of the catheter hub at
point f. Further engagement between the needle shaft and the spring
clip is provided by the contact of finger 162 with the upper end
of the needle shaft at point e, and between the clamping edge 176
and the lower surface of the needle shaft at point g. In this manner,
the needle is securely but movably retained within the catheter
hub in its ready position.
When the needle is retracted axially, to the right as viewed in
FIGS. 13A and 13B, it eventually moves past its engagement with
lip 154 thereby to suddenly release the radial force it had previously
exerted on the resilient arm 150 of the needle guard. This release
of engagement between the needle shaft and lip 154 allows the distal
curved end 156 of the distal end wall 152 of the spring clip to
be released from its seat in annular groove 164 so that arm 150
and end wall 152 pivot quickly into the interior of the catheter
hub, as seen in FIG. 13B, to a position at which wall 152 forms
a barrier to the needle tip. This positioning of wall 152 prevents
inadvertent contact with the needle tip. The engagement of finger
162 and clamping edge 176 to opposing sides of the needle prevents
further axial movement of the needle in either direction.
If an attempt is thereafter made to pull the needle axially further
to the right, as viewed in FIG. 13B, the finger 162 will enter the
circular groove 178 formed in the needle surface, thereby to prevent
further axial movement of the needle in the proximal direction out
of the needle guard.
It will thus be appreciated that the spring clip needle guard of
the invention as employed in an IV catheter provides automatic and
reliable protection of the needle tip upon needle retraction to
prevent accidental contact with the needle tip by a health care
practitioner. It will also be appreciated that modifications may
be made to the embodiments of the invention specifically described
hereinabove without necessarily departing from the spirit and scope
of the invention. |