U.S. patent number RE39,107 [Application Number 09/665,634] was granted by the patent office on 2006-05-23 for cap operated retractable medical device.
This patent grant is currently assigned to Retractable Technologies, Inc.. Invention is credited to Thomas J. Shaw.
United States Patent |
RE39,107 |
Shaw |
May 23, 2006 |
**Please see images for:
( Certificate of Correction ) ** |
Cap operated retractable medical device
Abstract
A cap operated retractable medical device has an outer body with
a hingedly connected outer cap which moves between an open and a
closed position. The device is used as a blood sampler with a
conventional collection tube normally used in such devices. A
movable member is entirely enclosed within the outer body. A
sliding interference or friction fit holds a retraction body within
the mouth of the movable member and also holds the front end of the
movable member within the outer body positioned within the
retraction body adjacent a stop. A double ended needle is installed
in the retraction body. Camming protrusions on the cap engage the
back of the movable member to move it forward as the cap is closed
thereby triggering retraction of the retraction body and its double
ended needle entirely within the outer body. Once the cap is closed
with the double ended needle safely inside, the device can be
safely handled. The device is compact. It can be as short as the
needles it will safely contain.
Inventors: |
Shaw; Thomas J. (Little Elm,
TX) |
Assignee: |
Retractable Technologies, Inc.
(Little Elm, TX)
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Family
ID: |
25339534 |
Appl.
No.: |
09/665,634 |
Filed: |
September 19, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
08862849 |
May 23, 1997 |
05810775 |
Sep 22, 1998 |
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Current U.S.
Class: |
604/110; 600/576;
604/195 |
Current CPC
Class: |
A61B
5/15003 (20130101); A61B 5/150351 (20130101); A61B
5/150389 (20130101); A61B 5/150496 (20130101); A61B
5/150732 (20130101); A61B 5/150656 (20130101); A61B
5/154 (20130101); A61M 5/3232 (20130101); A61B
5/150572 (20130101) |
Current International
Class: |
A61M
5/00 (20060101) |
Field of
Search: |
;604/110,195,192,198,187,263,181,403,411-413 ;222/325
;215/234-236,238,240,354 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 539 634 |
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May 1993 |
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EP |
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H02-502076 |
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Jul 1990 |
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JP |
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H03-504209 |
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Sep 1991 |
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JP |
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H07-246196 |
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Sep 1995 |
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JP |
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WO 95/08358 |
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Mar 1995 |
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WO |
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WO 95/16389 |
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Jun 1995 |
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WO |
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WO 96/05879 |
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Feb 1996 |
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WO |
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WO 98/48869 |
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Nov 1998 |
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WO |
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WO 98/52630 |
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Nov 1998 |
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WO |
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Primary Examiner: Rodriguez; Cris L.
Attorney, Agent or Firm: Locke Liddell & Sapp LLP
Claims
What is claimed is:
1. A cap operated retractable medical device combination
comprising: a long thin walled tubular outer body having a back end
with an opening and a front end which incorporates a centered hub;
an elongated movable member closely fitting entirely within the
outer body, the movable member having a back end with an opening
and a front end and front portion wherein the front portion has a
radially enlarged inner surface and an outer surface; a retraction
body having a laterally extending wall with an outwardly facing
edge, releasably held at a forward position with respect to the
movable member by means of the radially enlarged inner surface of
the front portion of the movable member; the movable member being
held in position with the retraction body adjacent the hub of the
outer body by means of a tight area created between the outer
surface of the front portion of the movable member and the inside
surface of the wall of the outer body near its front end; a cap
hinged at the back end of the outer body and selectively movable
between an open position and a closed position relative to the
opening at the back end of the outer body, said cap having a cam
surface confined to engage the back end of the movable member
inside the outer body and move it forward as the cap is moved to
the closed position; and whereby closing the cap causes the movable
member to move forward while the retraction body is restrained by
the hub in the outer body thereby releasing the retraction body
from the movable member.
2. The combination of claim 1 wherein the wall of the tubular outer
body has a portion of the wall behind the front end which is
thickened to create a stepped portion on its inner surface which
cooperates with the outer surface of the front portion of the
movable member to create said tight area whereby the movable member
is held in a forward position.
3. The combination of claim 2 wherein the outer surface of the
front portion of the movable member is radially enlarged relative
to the wall of the movable member to cooperate with the stepped
portion on the inner surface of the outer body to create the tight
area which holds the movable member in a forward position.
4. The combination of claim 2 wherein a rear portion of the wall of
the movable member has an inner surface which is stepped inwardly
to form a constriction which will catch the retraction body when it
retracts and prevent it from escaping from the movable member.
5. The combination of claim 1 wherein the retraction body carries a
needle holder with a needle extended through the front of the outer
body.
6. The combination of claim 5 wherein the retraction body has a
centrally located opening for securing said needle holder which can
be installed from the front of the assembled device.
7. The combination of claim 6 wherein said centrally located
opening is formed by a forwardly extending tubular wall which in
cooperation with the hub serves to confine said biasing means
between the hub and the retraction body.
8. The combination of claim 5 wherein said cap has an outer rim
larger than the opening in the back of the outer body and an inner
rim comprising two camming protrusions which are spaced apart and
positioned to enter said opening when the cap is moved to the
closed position.
9. The combination of claim 8 wherein said protrusions are
oppositely positioned along the inner rim about half-way from the
hinged connection.
10. A cap operated retractable medical device combination
comprising: an elongated outer body having a partially closed
front, an open back and an intermediate wall portion connecting the
front and back; wherein the intermediate wall portion has an inner
surface that defines a hollow interior and an opening at the back;
a cap which is selectively positionable with respect to said
opening between an open position which allows access to the hollow
interior and a closed position which blocks said opening, said cap
having a camming protrusion which moves through the opening when
the cap is moving to the closed position; an elongated movable
member shorter than the outer body and contained therein, the
movable member having a wall configured to define an external
surface in close proximity to the inner surface of the wall of the
outer body, an internal surface which defines a cavity therein and
an open back end which serves as a control surface for the camming
protrusion on said cap; and there is a front end portion of the
movable member with radially enlarged inner and outer surfaces; a
retraction body releasably held by the movable member at the
radially enlarged inner surface of the front end portion of the
movable member; the radially enlarged surface of the movable member
being slidably held by a portion of the inner surface of the outer
body at a location spaced behind the partially closed front of the
outer body; means for preventing forward movement of the retraction
body and biasing means adapted to apply a retraction force to the
retraction body; and whereby the retraction body may be released
from the movable member for retracting by forward movement of the
movable member caused by positioning the cap into the closed
position while the retraction body is restrained by said means for
preventing forward movement.
11. The combination of claim 10 wherein the retraction body carries
a needle holder with a needle extended through the partially closed
front.
12. The combination of claim 11 wherein the partially closed front
comprises a hub centered along the longitudinal axis of the
device.
13. The combination of claim 12 wherein the retraction body has a
laterally extending discoid wall having an outer facing edge which
is held by the radially enlarged inner surface of the front end
portion of the movable member.
14. The combination of claim 13 wherein the retraction body has a
centrally located opening for securing said needle holder wherein
said needle holder can be installed from the front of the assembled
device.
15. The combination of claim 14 wherein said centrally located
opening is formed by a forwardly extending tubular wall which in
cooperation with the hub serves to confine said biasing means
between the hub and the retraction body.
16. The combination of claim 15 wherein the biasing means comprises
a coil spring which closely circumscribes the tubular wall of the
retraction body thereby stabilizing the retraction body as it
retracts.
17. The combination of claim 10 wherein said cap is hingedly
connected at the back of the outer body to pivot at the hinge
between said open and said closed position thereby positioning said
protrusion to engage the contact surface on the movable member to
cause said forward movement of the movable member when the cap is
moved to the closed position.
18. The combination of claim 17 wherein said cap has an outer rim
larger than the opening in the back of the outer body and an inner
rim comprising two camming protrusions which are spaced apart and
positioned to enter said opening when the cap is moved to the
closed position.
19. The combination of claim 18 wherein said protrusions are
oppositely positioned along the inner rim about half-way from the
hinged connection.
.Iadd.20. A cap operated retractable medical device in combination
comprising: a tubular outer body having a front end portion, a back
end portion and an open back end; a movable cap disposed at the
back end portion of the tubular outer body, the movable cap being
movable from an open position to a closed position to close the
open back end of the tubular outer body; a needle bearing
retraction body disposed in the tubular outer body and comprising a
needle projecting outwardly from the front end portion; and a
movable member extending between the closed position and the
retraction body, the movable member disengaged from the movable cap
in its open position; whereby the action of closing the cap causes
initial engagement between the cap and the movable member, closes
the open back end of the tubular outer body and causes the movable
member to release the needle bearing retraction body, retracting
the needle within the tubular outer body and retaining it therein.
.Iaddend.
.Iadd.21. The combination of claim 20 wherein the retraction body
is retractably held by the movable member operated by the action of
closing the cap. .Iaddend.
.Iadd.22. The combination of claim 20 wherein the movable cap is
normally open and movable from the normally open to the closed
position. .Iaddend.
.Iadd.23. The combination of claim 22 wherein the cap is hingedly
supported at the back end of the tubular outer body for movement
from the normally open to the closed position. .Iaddend.
.Iadd.24. The combination of claim 20 wherein the needle bearing
retraction body is retractably held by the movable member which
moves in response to the action of closing said cap. .Iaddend.
.Iadd.25. The combination of claim 24 wherein the movable member
has a mouth having an inner surface which retractably holds the
retraction body. .Iaddend.
.Iadd.26. The combination of claim 25 wherein the needle bearing
retraction body is retractably held within the mouth of the movable
member by means of a sliding interference fit. .Iaddend.
.Iadd.27. The combination of claim 24 wherein the front end portion
of the tubular outer body has a hub which serves to release the
retraction body from the moveable member as the moveable member
moves in response to the action of closing the cap. .Iaddend.
.Iadd.28. The combination of claim 24 wherein the movable member
has an outer surface being slidingly held by means of the inner
wall surface of the tubular outer body. .Iaddend.
.Iadd.29. The combination of claim 24 wherein the movable member
has an outer surface having a sliding interference fit with an
interior surface portion of the front end portion of the tubular
outer body which frictionally supports the moveable member with the
exposed needle in an untreated condition. .Iaddend.
.Iadd.30. The combination of claim 24 wherein the front portion of
the tubular outer body has a hub with an opening for receiving a
forward portion of the unretracted retraction body and a stop for
the retraction body when the movable member moves in response to
the action of closing said cap. .Iaddend.
.Iadd.31. A cap operated retractable medical device, in combination
comprising: a hollow body having a front end portion and an open
back end; a pivotably connected cap associated with the hollow body
which closes the open back end of said body by the action of
closing the cap; a retractably mounted needle being releasably held
in a pre-retraction position by a hollow movable member which is
operated by the action of closing the cap to release the needle;
and the needle being retracted into the hollow movable member by
the action of closing the cap, the needle being retained within
said movable member thereby preventing needle sticks. .Iaddend.
.Iadd.32. The combination of claim 31 wherein the movable member is
a tubular member within the hollow body which is operated by the
action of closing the cap. .Iaddend.
.Iadd.33. The combination of claim 31 wherein the retractably
mounted needle is mounted in a retraction body releasably held by
the movable member. .Iaddend.
.Iadd.34. The combination of claim 33 wherein the movable member is
a tubular member having a front end portion and an open back end.
.Iaddend.
.Iadd.35. The combination of claim 34 wherein the retraction body
is a discoid shaped member releasably held in the front end portion
of the movable member. .Iaddend.
.Iadd.36. The combination of claim 35 wherein the discoid shaped
member has an outer edge which is releasably held by means for a
sliding interference fit at the front end portion of the movable
member. .Iaddend.
.Iadd.37. The combination of claim 34 wherein the front end portion
of the movable member is releasably held by means of a sliding
interference fit at the front end portion of the hollow body.
.Iaddend.
.Iadd.38. A cap operated retractable medical device combination
comprising: a tubular outer body having a back end having an
opening and a front end portion; a cap mounted at the back end of
the outer body for movement between an open position and a closed
position relative to the opening at the back end of the outer body;
a movable member slidingly positioned in the tubular outer body,
the movable member being responsive to movement of the cap from its
open to its closed position; a retraction body associated
retractably with one end of the movable member; and whereby the
retraction body is dissociated from the movable member and retained
in the tubular outer body by the act of moving the cap to its
closed position. .Iaddend.
.Iadd.39. A method of operating a retractable medical device,
comprising the steps of: providing a tubular outer body having a
front end containing a retraction mechanism with a retractable
needle and an open back end having a closeable cap attached by a
hinge to the outer body; retracting the needle by the action of
closing the cap; and retaining the retracted needle within the
tubular outer body. .Iaddend.
.Iadd.40. The method of claim 39 wherein the step of retracting the
needle is performed by pressing the closeable cap against a movable
member associated with the retractable needle. .Iaddend.
.Iadd.41. The method of claim 40 wherein the retractable needle
comprises a retraction body removably holding the needle, the
retraction body being removably associated with the movable member
and the step of pressing the closeable cap against the movable
member includes the step of dissociating the retraction body from
the movable member. .Iaddend.
.Iadd.42. The method of claim 41 wherein the step of dissociating
the retraction body from the movable member is accomplished by the
steps of stopping the retraction body from moving forward while the
movable member is moving forward in response to the step of
pressing the closeable cap against the moveable member.
.Iaddend.
.Iadd.43. The method of claim 42 wherein the step of stopping the
retraction body from moving forward while the movable member is
moving forward is accomplished by the step of bringing the
retraction body into contact with a structure in the front end of
the tubular outer body. .Iaddend.
.Iadd.44. The method of claim 42 wherein the step of stopping the
retraction body from moving forward while the movable member is
moving forward is accomplished by the step of slidingly separating
an interface between the retraction body and the movable member.
.Iaddend.
.Iadd.45. In a medical device having a tubular outer body with an
open end, a needle retraction body disposed opposite the open end,
and a movable member slidably axially in the outer body, the
improvement comprising a cap pivotably connected to the outer body
to close the open end and thereby initiate retraction of a needle
into the tubular outer body by operation of the retraction body.
.Iaddend.
.Iadd.46. The medical device of claim 45 wherein the movable member
is disposed between the cap and the retraction body, the retraction
body being releasable when the movable member is displaced by
movement of the cap during closure of the open end of the tubular
outer body. .Iaddend.
.Iadd.47. The medical device of claim 45 wherein the medical device
is a fluid collection device. .Iaddend.
.Iadd.48. The medical device of claim 47 wherein the fluid
collection device is a blood sampler. .Iaddend.
.Iadd.49. In a medical device having a tubular outer body with an
open end, a needle retraction body disposed opposite the open end,
and a movable member slidably axially in the outer body, the
improvement comprising a cap hinged to the outer body to close the
open end and thereby initiate retraction of a needle into the
tubular outer body by operation of the retraction body.
.Iaddend.
.Iadd.50. In a medical device having a tubular outer body with an
open end, a needle retraction body disposed opposite the open end,
and a movable member slidably axially in the outer body, the
improvement comprising a cap unitarily molded to the outer body to
close the open end and thereby initiate retraction of a needle into
the tubular outer body by operation of the retraction body.
.Iaddend.
.Iadd.51. In a blood sampler having a tubular outer body with an
open end, a needle retraction body disposed opposite the open end,
and a movable member slidable axially in the outer body, the
improvement comprising an end obstruction attached to the tubular
outer body having a position independent of the movable member, the
end obstruction initially contacting the movable member to move the
movable member forward until retraction of a needle into the
tubular outer body by operation of the retraction body.
.Iaddend.
.Iadd.52. In a blood sampler having a tubular outer body with an
open end, a needle retraction body disposed opposite the open end,
and a movable member slidable axially in the outer body, the
improvement comprising a blocking member attached to the outer body
adjacent its open end, the attached blocking member being
selectively movable from a first position in which the blocking
member does not traverse the open end to a second position in which
the blocking member traverses the open end and also initiates
retraction of a needle into the outer body by operation of the
retraction body. .Iaddend.
.Iadd.53. In a blood sampler having a tubular outer body with an
open end, a needle retraction body disposed opposite the open end,
and a movable member slidable axially relative to the outer body,
the improvement comprising an end closure for the tubular outer
body, the end closure having an open position providing access to
the hollow interior of the movable member, a blocking position with
respect to the open end that initiates contact with the movable
member and a closed position preventing access to the hollow
interior of the movable member and initiating retraction of a
needle into the tubular outer body by operation of the retraction
body. .Iaddend.
.Iadd.54. The blood sampler of claim 53 wherein the end closure is
attached to the outer body to close the open end of the outer body
and also initiate retraction of a needle into the outer body by
operation of the retraction body. .Iaddend.
.Iadd.55. The blood sampler of claim 54 wherein the end closure is
attached by a hinge to the outer body to close the open end and
thereby initiate retraction of a needle into the tubular outer body
by operation of the retraction body. .Iaddend.
.Iadd.56. The blood sampler of claim 53 wherein the end closure is
attached to the outer body to close the open end and thereby
initiate retraction of a needle into the tubular outer body by
operation of the retraction body, the end closure and outer body
being unitarily molded. .Iaddend.
.Iadd.57. The blood sampler of claim 53 wherein the movable member
is disposed between the end closure and the retraction body, the
retraction body being releasable when the movable member is
displaced by movement of the end closure during closure of the open
end of the tubular outer body. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the invention
The invention pertains to a retractable medical device which in the
preferred embodiment is useful for collecting body fluids from a
patient. It is primarily useful as a blood collection device.
2. Background of the Prior Art
Prevention of needle sticks has become a paramount concern of the
healthcare industry because of serious and deadly risk factors
associated with AIDS and other serious communication diseases.
Blood collection devices utilize a needle inserted into a patient's
vein so as to draw blood through the needle into an associated
separate collection reservoir. Accidental needle sticks from
previously used needles can occur during the fluid withdrawing
process and subsequent handling and disposal operation. Until such
used medical devices are destroyed, they remain potentially
lethal.
Illustrative of the type of device used for blood sampling is a
collection device sold under the trademark Vacutainer.RTM. by
Becton Dickinson Corporation, which has been the conventional
standard for this type of device. It has a tubular syringe-like
body with a needle in the front end, part of which extends back
into a tubular syringe-like shell. Part of the needle extends
externally for punching the skin. An evacuated collection tube with
a rubber stopper is placed into the open back of the syringe-like
shell with the rubber stopper against the internal end of the
needle. After the skin is punctured, the collection tube is pushed
forward to cause the needle to enter the evacuated tube. Vacuum
helps draw blood into the collecting tube. When a sufficient sample
has been obtained, the collecting tube and the stopper are simply
withdrawn from the tubular shell and sent to the laboratory. This
particular device has a permanently extended needle and an opening
in the back for the collection tube which remains open after the
collection tube is removed, leaving small quantities of blood and
an internally exposed needle.
Retractable medical devices which are used for collecting fluid
samples from patients are known. While they offer retraction of the
needle, they suffer from high manufacturing and assembly cost. They
lack simplicity which results in a multiplicity of difficult to
manufacture and assemble parts. An early example of such a device
is Haber U.S. Pat. No. 4,813,426 which employs a mechanically
translatable insert holding a double-ended needle. It has a
position which compresses a spring portion of the holder. When
buttons extending from opposite sides of the outer tube are
compressed, the needle carrier can be mechanically moved to the
position of us or to a rearward safe position. Allard U.S. Pat. No.
4,838,863 describes a spring loaded double ended needle carrier in
a T-shaped housing having an opening behind for the sample tube.
The needle holder is locked in a use position with a removable pin
which is withdrawn to retract the needle. Alternately, breakable
tabs on the needle holder extend laterally under a shelf with pins
which may be pushed down when the sample tube is inserted to
fracture the breakable tabs thereby releasing the needle holder
which is withdrawn into the interior as the sample tube is removed.
Subsequently, a cap is provided to close the back. Allard does not
explain how one could assemble the device without making the outer
body in two or more pieces.
In addition, a number of devices attach the double ended needle to
a partially withdrawable plunger with an opening in back for the
sample tube. Shaw U.S. Pat. No. 5,423,758 discloses a tubular outer
body with a partially removable plunger. The plunger has a
separable needle holding portion for a double ended needle and an
opening in the back of the plunger for a sample tube. It utilizes a
two position end cap from which the sample tube extends. The
plunger is used to position and retract the needle assembly.
By in large, the prior art fails to take into account the need for
a single one-handed required and controlled action that will
simultaneously close the back of the main body of the device and
initiate retraction of the exposed needle after the sample tube is
removed. If the inner needle which punctures the collection tube is
not covered with a rubber sheath, blood will continue to flow into
the device. This blood provides a source of contamination during
subsequent handling of the device. If the internal needle is
covered with a rubber sheath to prevent the blood from continuing
to flow after the collection tube is removed, the rubber sheath
serves to hide a sharp needle which can result in unintended
punctures. Since the sheathed needle looks safe, people tend to put
their finger into the open end without thinking. Even if a cap were
to be provided, it use requires a separate operation and it is easy
to forget or simply fail to use it. Consequently, an improvement in
safety is possible with a device that caps the back of the device
while it is retracting.
SUMMARY OF THE INVENTION
The invention is a retractable medical device in the form of a
blood sampler which can be operated by one hand without removing
the device from the patient after one or more collection tubes are
filled. While one hand holds a gauze pad over the puncture site,
the other hand is used to manipulate a cap hingedly connected to
the back of the device. As the cap is moved to the closed position,
it moves a movable member forward releasing a retraction body with
the needle which is retracted entirely within the walls of the now
closed body. Once retracted, the sharp double ended needle is
confined and cannot be used. Safety is assured because the act of
closing the cap is the same act which causes retraction of the
needle. It is the only way retraction can take place.
The cap operated retractable medical device includes a long thin
walled tubular outer body having a back end with an opening and a
front end which incorporates a centered hub which provides an
opening for a needle holder. A long thin walled tubular movable
member closely fits entirely within the outer body. The movable
member has a back end with an opening and a front portion wherein
the front portion has a radially enlarged inner surface and an
outer surface. A retraction body having a disk-like laterally
extending wall with an outwardly facing edge is releasably held
within the movable member at a forward position by means of
cooperation between the radially enlarged inner surface of the
front portion of the movable member and the outwardly facing
edge.
A thickened or stepped in portion of the wall of the outer body is
provided for a short distance behind the front wall. The hub,
preferably in the form of an annular ring, serves as a stop for the
retraction body spaced behind the front wall of the outer body. It
also serves to hold the front end of the compression spring which
is placed between the front wall of the outer body and the
retraction body. The movable member is held in position within the
outer body, with the retraction body adjacent the hub, by means of
a tight area created between the outer surface of the movable
member and the stepped in or thickened inside surface of the wall
of the outer body near its front end. The retraction body carries a
double ended needle.
A cap which is hinged at the back end of the outer body is
selectively movable between an open position and a closed position
relative to the opening of the back of the outer body. The cap
includes a cam surface configured to engage the back end of the
movable member inside the outer body and move it forward as the cap
is moved to the closed position. Closing the cap causes the movable
member to move forward while the retraction body is restrained by
the hub in the outer body thereby releasing the retraction body
from the movable member. A spring compressed under the retraction
body expands to drive the retraction body and double ended needle
backward within the movable member just as the cap is fully closed.
Another stepped in portion of the wall of the movable member near
the back end catches the retraction body before the needle behind
the retraction body can reach the area of the cap.
The tight area between the outer surface of the movable member and
the inner surface of the outer body near the front of the device is
in the nature of an interference fit which still allows the movable
member to go forward when the cap is closed. Since the forwardly
extending needle of the blood sampler does not need to puncture a
rubber seal as does a syringe, the retraction body and movable
member do not have to resist large forces before releasing. The
rearward facing portion of the needle in the device does have to
puncture the seal of a collection tube, but since the retraction
body is positioned against a hub or stop at the front of the outer
body and cannot move forward, impaling the collection tube on the
interior end of the needle cannot disassociate the retraction body
from the movable member.
The needle holder is carried by the retraction body with the needle
extended in both directions. In the assembled condition, the
conjunction of the retraction body and the hub provide a convenient
means for installing the already assembled needle holder and needle
through the opening in the front wall of the outer body. The needle
holder is threaded into a centrally located opening in the
retraction body. The centrally located opening of the retraction
body has a forwardly extending tubular wall which cooperates with
the hub to confine the spring between the hub and the retraction
body. Since the spring closely circumscribes the tubular wall of
the retraction body, it serves to stabilize the retraction body so
that it tends to move straight back without tilting during its
retraction.
The cap has an outer rim larger than the opening at the back of the
outer body and an inner rim containing one or more camming
protrusions which cam the back of the movable member when the cap
is closed. The inner rim preferably comprises two camming
protrusions which are spaced apart and positioned to enter the
opening when the cap is moving to the closed position. The
protrusions are oppositely positioned along the inner rim about
half way from the hinged connection. The protrusions actually
contact the back of the movable member before the cap is closed and
continue moving the movable member until retraction occurs just as
the cap is becoming fully closed.
A fail-safe design is provided. The needle can only retract when
the cap is closed. Since the cap is hinged to the device, it cannot
be lost or misplaced. There is little chance of premature
retraction since retraction can only be initiated by closing the
cap. Even if retraction is forced by pushing the needle against a
solid object, the needle does not come out of the body. Once the
cap is closed to retract the needle, no special handling is
required. A sound is made when the retraction occurs. The fact that
the cap is closed together with the sound assures that the needle
is no longer exposed, even without looking. An additional visual
indication is also provided by the clear plastic walls of the outer
body and movable member which enables the user to visually observe
the extended spring that proves retraction has occurred.
The parts are fewer in number than other retractable devices
comprising only an outer body which can be molded as one together
with the cap, the movable member, the retraction body and the
needle assembly. Due to the fact that the movable member is
contained entirely within the outer body, a more compact device is
made possible, limited in length only by the space required to
enclose the double ended needle. The parts are suitable for
fabrication in multiple cavity high speed plastic injection molding
machines. No special materials are utilized apart from the usual
plastic materials employed in the syringe industry.
Assembly is simplified by sliding interference fitting of the parts
in a straight line direction. First the retraction body is inserted
from the rear of the movable member and moved forward to fit within
its mouth. The back end of the compression spring is placed over
the tubular extension and into a spring groove of the retraction
body while the outer end is dropped into a hub at the front of the
outer body as the movable member is moved forward to compress the
spring. Then the movable member is moved forward until the front
end slidingly engages the stepped in portion of the outer body
which creates a tight area where the movable member is held and the
retraction body is positioned just above the hub which serves as a
stop. The needle assembly is then screwed into the retraction body
through the opening in the front wall of the outer body. A
removable protective cap can be placed over the exposed needle
until the device is ready for use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away view on the center line of the assembled
medical device in the form of a blood collection sampling device in
the ready-to-use position without the collection tube in place;
FIG. 2 is a view of the device of FIG. 1 after the cap has been
moved from the open to the closed position thereby triggering
retraction of the retractable member and closing the rear of the
outer tube;
FIG. 3 is a perspective view of the outer tube and cap with the
movable member in place in the position of use;
FIG. 4 is a front view of the medical device of FIGS. 1-3 showing
the back of the cap when it is laid out level with the place of the
flange at the back of the device;
FIG. 5 is a plan view of the retraction body seen from behind
looking forward towards the front of the device;
FIG. 6 is a view of the retraction body of FIG. 5 cut-away on the
line 6--6 of FIG. 5;
FIG. 7 is a partially cut-away view of the movable member showing
preferred details of the wall structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The medical device is generally referred to by the reference
numeral 10 in FIG. 1. The device 10 is a fluid collection device,
ore particularly a blood sampler. Device 10 has an elongated body
12 having a partially closed front 14 and an open back 16. There is
an intermediate wall portion 18 connecting front 14 and back 16.
Intermediate wall portion 18 has an outer wall surface 20 and an
inner wall surface 22 which defines a hollow interior 24. Inner
wall 22 together with open back 16 forms opening 26 at the back of
outer body 12. A flange 17 is positioned at the back of outer body
12 to serve as a grip. It may be noted that flange 17 could be
moved forward along body 12 if desired and is not necessarily
located at the back of the body 12. In this regard, the forward
direction is the direction in which the external needle 88 is
extended.
FIG. 4 is a front view of elongated body 12 of FIG. 3 showing the
flange 17 at the back and a hub 28 having a chamfered opening 86 in
front. A selectively positionable cap designed to close opening 26
generally referred to by reference numeral 30 is hingedly connected
at hinge 32 to back 16 of body 12. FIG. 4 shows cap 30 having a
solid back 31. It is shown laid out fully from the position of FIG.
3.
Cap 30 is positionable between an open position as shown in FIG. 1
and FIG. 3 and a closed position as shown in FIG. 2. The open
position allows access to hollow interior 24 while the closed
position blocks opening 26 from outside access. Cap 30 has an outer
rim 34 larger than opening 26 in the back of outer body 12 and an
inner rim 36 which constitutes a camming protrusion which moves
through opening 26 when the cap is moving to the closed position.
The preferred form of the inner rim is two camming protrusions 38
which are spaced apart and positioned to enter opening 26 close to
inner wall surface 22 when the cap is moved to the closed position.
The preferred protrusions are oppositely positioned along the inner
rim about half way from hinged connection 32. Protrusions 38 could
take different forms. As will be seen, they are designed to operate
the movable member. FIG. 3 shows the orientation of body 12 as it
would be placed above a patient's arm during use. The lobe of the
protrusions of this preferred arrangement are not in the way of a
conventional collection tube which will be inserted from the rear.
The collection tube slides between the protrusions into opening 24.
This means that cap 30 does not require an open position more open
than a right angle with respect to back end 16. An additional
advantage is that the cap closes more fully before it contacts the
movable member and contacts it at opposite points which avoids any
tendency to bind. The outer surface of inner rim 36 friction fits
into opening 26 so that the cap stays closed.
An elongated movable member generally designated 40 in FIG. 1 is
shorter than outer body 12 and is contained entirely therein.
Movable member 40 is a long thin walled tubular member having a
wall 42 with an external surface 44 and an internal surface 46.
Wall 42 is configured to define the external surface 44 in close
proximity to inner surface 22 of outer body 12. The wall and
internal surface 46 defines a cavity 48 therethrough and an open
back end 50 which serves as a contact surface for one or more
camming protrusions 38 on cap 30. Open back end 50 defines an
opening 52, which as will be seen, accepts a conventional evacuated
collection tube with a rubber stopper in front, not shown in the
Figures. The collection tube occupies most of cavity 48 and its
closed back end extends some distance beyond back 16.
Referring now to FIG. 7, movable member 40 has a front end portion
54 which preferably had a radially enlarged inner surface 56 and an
outer surface 58 which may also be radially enlarged as shown. It
has a front end 59. A retraction body 60 seen in FIGS. 5 and 6 is
releasably held by movable member 40 at the radially enlarged inner
surface 56 of front end portion 54.
Retraction body 60 is best seen in FIGS. 5 and 6. Retraction body
60 has a laterally extending wall 62 in a discoid shape with an
outwardly facing edge 64 which is held by the radially enlarged
inner surface 56 of wall 42 as shown in FIG. 1. The radially
enlarged surface 56 nee not be a continuous surface, although that
is preferred. It could be radially enlarged sectors or lands which
project inwardly from inner surface 46 sufficient to hold
retraction body 60 during use. There is no need for a seal at edge
64.
Retraction body 60 further includes a forwardly extending tubular
wall 66 having a centrally located opening 68 which extends
longitudinally along the central axis of the assembled device.
Longitudinally extending opening 68 has an inner wall surface 70
which may have threads or a plurality of angularly spaced sets of
radial protrusions 72. Radial protrusions 72 can serve as a thread
substitute for securing a threaded needle holder 74 best seen in
FIGS. 1 and 2. A spring groove 76 is formed around tubular wall 66
to receive the end portion of a spring 77. The front of retraction
body 60 is designated 78 as a transition zone which connects
tubular wall 66 with laterally extending wall 62. An angular
extension 80 between front 78 and wall 62 provides an offset for
wall 62 behind front 78 in the vertical direction such that
compressive force applied to edges 64 can cause flexing of angular
extension 80. Angular extension 80 can act somewhat like a very
stiff spring especially if radial slots 82 are provided at one or
several locations through wall 62. Such slots are indicated
schematically by dotted lines in FIG. 5 as radial slots 82. A
number of such slots could divide discoid wall 62 into sectors
which are slightly compressible toward the center, independently of
each other. This could facilitate fitting retraction device 60
within front portion 54 of movable member 40.
Returning to FIGS. 1 and 2, it can be seen that hub 28 has a
flanged wall portion 84 which extends forwardly from wall 14 and
forms an opening 86 for threaded needle holder 74. In addition,
wall portion 84 extends rearwardly behind front 14 to form a stop
86. Needle holder 74 has a portion which extends forwardly of hub
28 and a threaded portion behind which screws into opening 68 of
retraction body 60. Double ended needle 88 is securely held
extending forwardly and rearwardly from needle holder 74. A
collapsible rubber sheath 90 sealingly covers the rearwardly
extending portion of needles 88. It is designed to seal the flow
passage through needle 80 after a collection tube is removed in
preparation for collection of another sample in a second collection
tube. Stop 86 constitutes a means for preventing forward movement
of retraction body 60 which is spaced behind the back of front wall
14. Stop 86 is preferably an annular ring which is a rearward
extension of wall 84 behind wall 14. Stop wall 86, together with
the inwardly extending flanges of wall 84 which form opening 86,
create a well for holding spring 77.
The radially enlarged surface 58 of front end portion 54 of movable
member 40 is slidably held by a portion of inner surface 22 of
outer body 12 at a location spaced behind partially closed front
wall 14 of the outer body. Intermediate wall 18 has a thickened
portion 92 which extends a short distance behind front wall 14.
This creates an inner surface portion 94 which extends radially
inwardly from inner surface 22 of intermediate wall 18. This
creates a constricted area in a band around the inside of outer
body 12 adjacent front wall 14. A smooth ramp 96 leads into
thickened area 92 whereby movable member 40 can be moved forwardly
until outer surface 58 slidably engages surface 94 thereby creating
a tight area in a band between surfaces 58, 94 which holds movable
member 40 in the position shown in FIG. 1. The tight area is a
sliding interference fit between the front portion of the movable
member and the inner surface of the outer tube. Alternately,
thickened area 92 could be a plurality of angularly arranged land
areas which engage portions of outer surface 58. A great degree of
holding force is not needed since the front portion of needle 88 is
primarily designed to puncture skin and it not normally used to
pass through rubber stoppers commonly used in vials.
Thickened area 92 may be regarded as creating a stepped in portion
on the inner surface of body 12 which cooperates with outer surface
58 of the front portion of the movable member to create the tight
area whereby the movable member is held in its forward position
shown in FIG. 1. The stepped surface creates a smaller diameter for
a short distance behind front wall 14 which clamps radially
enlarged outer surface 58 when the movable member is introduced
through opening 26 and moved forward until the cooperating surfaces
58 and 94 slidingly engage. Some compressive force is directed
around the mouth of member 40 toward retraction body 60 which is
held inside. The forwardly extending tubular wall 66 in cooperation
with hub 28 serves to confine biasing spring 77 between the hub and
the retraction body. The flanged wall portion 84 forms the opening
86 for needle holder 74 which is smaller than the diameter of the
spring. Flanged portion 84 thus supports the spring at its forward
end. In its use position in FIG. 1, the surface 63 of retraction
body 60 wall 62 lies closely adjacent to stop 86 A plurality of
guide bumps 102 on wall surface 22 help stabilize and locate
movable member 40 within outer body 12 as it moves.
Assembly of device 10 is simple and well suited for automated
assembly. First retraction body 60 without the needle holder is
pushed through the open back end of movable member and moved
forward with a tool until cooperating edge 64 and inwardly facing
surface 56 are engaged at the mouth of movable member 40. The back
end of spring 77 is positioned circumscribing tubular wall 66 of
retraction body 60 and the front of the movable member holding the
retraction body and the spring are pushed into opening 26 at the
back of outer body 12. The front end of spring 77 is seated into a
well-like opening 104 within hub 28 at the front of the outer body.
A tool may be inserted through opening 86 to serve as a guide for
the spring as it moves forward and prevent lateral buckling of the
spring as it is compressed. Movable member 40 is moved entirely
within outer body 12 until the outwardly facing surface 58 engages
the cooperating stepped in surface 94 and moved forward until
surface 63 of the retraction body reaches stop 86. Threaded needle
holder 74 together with needle 88 is then placed into opening 86
and turned to secure it in place in retraction body 60. Finally, a
removable protective cap (not shown) is placed over the exposed
portion of needle 88 and device 10 is ready for sterilization and
packaging.
In operation, the cap operated retractable medical device is
supplied as shown in FIG. 1 except that a conventional removable
cap is placed over the extended needle with its back end
frictionally held by the protruding portion of needle holder 74.
The protective cap is removed and needle 88 is inserted into a
vein. A conventional rubber stopper collection tube (not shown) is
inserted into the open back of device 10 and pushed forward while
holding device 10 until the rearwardly extending portion of needle
88 punctures the rubber stopper and the needle passes through
rubber sheath 90. The outer tube is held while a blood sample is
collected in the collection tube. When the collection tube is
filled sufficiently, it is removed from device 10 and put down.
Sheath 90 restricts further flow of blood. Typically, a gauze pad
is placed over the patient's entry point with one hand and the
other hand is used to grasp device 10 while manipulating cap 30
towards the closed position with the thumb of the other hand. Thus,
retraction with one hand is possible before the needle is removed
from the patient.
As cap 30 is pivoted into a blocking position with respect to the
opening 26, protrusions 38 come in contact with back end 50. As the
thumb pushed cap 30 further into cavity 24, movable member 40 moves
forward along surface 94 toward front wall 14. An annular stop 86
prevents retraction body 60 from moving forward with movable member
40. Stop 86 disassociates retraction body 60 from the mouth of the
movable member. Retraction body 60 is freed from front portion 54
of the movable member by relative movement between edge 64 and
surface 56. When retraction body 60 comes free, spring 77 acting on
retraction body 60 then drives retraction body 60 backward carrying
needle 88 into outer body 12. Constriction 98 which constitutes a
stepped in portion 100 of the wall of the movable member prevents
retraction body from further rearward movement beyond the retracted
position of FIG. 2. Cap 30 completely closes the back of the outer
body 12 in a friction fit. Coil spring 77 which closely
circumscribes the tubular wall 66 of retraction body 60 tends to
stabilize the retraction body as it is retracting so that it moves
straight back without tilting. In the retracted position of FIG. 2,
the sharp needle points are entirely enclosed within outer body 12
and not accessible. The opening in hub 28 is too small to insert a
finger and cap 30 prevents access from behind. Consequently, the
danger from needle sticks during subsequent handling and disposal
of this single use medical device are greatly reduced once the cap
is closed. The device cannot be retracted without closing the cap.
Once retracted, the device is not reusable without considerably
effort.
In the best mode, it is anticipated that only about 1/8 of a pound
needs to be generated by spring 77 in its fully compressed position
since retraction body 60 is essentially free from restraint once it
is dissociated from the mouth of the movable member. The outer body
12 in cap 30 can be molded as a single unit. Hinge 32 is preferably
a so-called "living hinge" which is connected to the body 12 during
the molding process. Body 12 would preferably come out of the mold
with cap 30 in the orientation shown in FIG. 4.
* * * * *