U.S. patent application number 13/902564 was filed with the patent office on 2016-06-16 for fluid flow control device with retractable cannula.
The applicant listed for this patent is Retractable Technologies, Inc., Thomas J. Shaw. Invention is credited to Thomas J. Shaw, Mark Small, Ni Zhu.
Application Number | 20160166778 13/902564 |
Document ID | / |
Family ID | 41400967 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160166778 |
Kind Code |
A9 |
Shaw; Thomas J. ; et
al. |
June 16, 2016 |
Fluid Flow Control Device with Retractable Cannula
Abstract
A device having a housing; a cannula projecting forwardly from
the housing; a connector useful for attaching the device to a fluid
source or receptacle; a fluid flow path establishing fluid
communication between the cannula and the connector; a retraction
mechanism biasing the cannula away from its projecting position;
and an actuator supported by the housing and configured to modify
the fluid flow path so as to terminate fluid flow through the
device, seal off the fluid flow path, and release the retraction
mechanism to retract the cannula into the housing. The subject
device is particularly preferred for use in the medical field, for
example, as part of an infusion set or as a collection device for
blood, or other fluids or flowable matter.
Inventors: |
Shaw; Thomas J.; (Frisco,
TX) ; Small; Mark; (Leonard, TX) ; Zhu;
Ni; (Plano, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shaw; Thomas J.
Retractable Technologies, Inc. |
Frisco
Little Elm |
TX
TX |
US
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20130261551 A1 |
October 3, 2013 |
|
|
Family ID: |
41400967 |
Appl. No.: |
13/902564 |
Filed: |
May 24, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13470855 |
May 14, 2012 |
8469927 |
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13902564 |
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12136462 |
Jun 10, 2008 |
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13470855 |
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Current U.S.
Class: |
604/110 |
Current CPC
Class: |
A61M 5/158 20130101;
A61M 5/3257 20130101; A61M 25/0631 20130101; A61M 5/50 20130101;
A61M 25/0637 20130101; A61M 5/3232 20130101 |
International
Class: |
A61M 5/50 20060101
A61M005/50 |
Claims
1-20. (canceled)
21. A device comprising: a housing; a cannula; a connector
attachable to a fluid source or receptacle external to the device;
a fluid flow path in fluid communication with the connector; a
retraction mechanism biasing the cannula rearwardly; a retraction
cavity having a front portion, wherein the retraction cavity is
connected to the housing such that at least the front portion of
the retraction cavity can move laterally from a first position to a
second position, and wherein the retraction mechanism is separate
from and not coaxial with the fluid flow path; wherein when the
front portion of the retraction cavity is in the first position,
the cannula projects forwardly from the housing, the cannula is in
fluid communication with the connector through the fluid flow path,
and the retraction cavity is not coaxial to or aligned with the
cannula; wherein when the front portion of the retraction cavity is
in the second position the front portion of the retraction cavity
is aligned with the cannula and the retraction mechanism retracts
the cannula into the retraction cavity such that it no longer
projects forwardly from the housing and the cannula is no longer in
fluid communication with the connector.
22. The device of claim 21 further comprising at least one sealing
element configured to prevent fluid leakage into or out of the
fluid flow path.
23. The device of claim 21 wherein at least a portion of the
retraction activity is slidably disposed within the housing.
24. The device of claim 21 wherein the retraction cavity is
pivotally connected to the housing.
25. The device of claim 21 wherein the fluid flow path is
substantially parallel to eh retraction cavity.
26. The device of claim 21 wherein the entire retraction cavity is
moved laterally to move the front portion from the first to the
second portion.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of pending U.S. patent
application Ser. No. 12/136,462 filed on Jun. 10, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a fluid flow control device and,
in a preferred embodiment, to a medical device having a cannula,
often a needle, that is insertable into a patient for use in
infusing, collecting or extracting fluids. One aspect of the
invention relates to a medical device having an actuator that is
manipulated to modify a fluid flow path between the cannula and an
external fluid source or receptacle following the infusion or
extraction. Another aspect of the invention relates to a mechanism
that functions as a clamp when attached to a fluid flow line.
Another aspect of the invention relates to a mechanism that
retracts the cannula inside the device to prevent accidental
needlesticks following use and to prevent reuse of the contaminated
cannula. Although the subject invention is particularly preferred
for use in intravascular ("IV") applications, it can also be used
beneficially, for example, in epidural, intraosseous and
intraocular applications, and with any body fluid.
[0004] 2. Description of Related Art
[0005] Intravascular ("IV") infusion sets are well-known in the art
for delivering fluids and/or medications to a patient by means of a
cannula connected to tubing. IV infusion devices frequently have
attached wings that facilitate handling during insertion of the
cannula, help stabilize the device, and can be secured to limit
movement of the device during use. Blood collection devices operate
on the same principle, but in reverse. Blood is collected from a
vein or artery through a cannula that is connected through the body
of the device to a blood collection receptacle. Following use of a
conventional infusion or fluid collection system, the cannula is
contaminated with blood and/or other bodily fluid, and care must be
taken to avoid reusing the device and to avoid accidentally
sticking either healthcare workers or patients, and thereby
spreading blood-borne pathogens. The use of caps or covers that
must be replaced over the cannula after withdrawal from a patient
are not a satisfactory solution because they increase the risk for
an accidental stick, or can become loose and fall off, thereby
again exposing the contaminated cannula.
[0006] U.S. Pat. No. 5,779,679 to Shaw, entitled "Winged IV Set
With Retractable Cannula," and U.S. Pat. No. 6,210,371 to Shaw,
entitled "Winged IV Set," both disclose an IV infusion set with a
retractable cannula. In both of these patents, the retractable
cannula is held by a retraction member having a tubing connector on
its back end portion that establishes fluid communication between
the cannula and an IV tube. The retraction member is held in its
non-retracted position against the force of a compressed spring by
a pair of releasable latches disposed on opposite sides of the
housing. Once the latches are released, the spring forces the
retraction member, and consequently the cannula, back into the
housing. However, because an IV tube is connected directly to the
retraction member, retraction of the cannula causes the IV tube to
move rearwardly as well. If the tube is not free to move rearwardly
during retraction, the retraction member and the cannula may not be
fully retracted.
[0007] An infusion and fluid collection device are needed in which
the cannula can be retracted without causing or relying upon
rearward movement of the connected tubing, and in such manner that
the device is rendered non-reusable and that the fluid flow path is
interrupted, relocated and sealed off in conjunction with
retraction of the cannula.
SUMMARY OF THE INVENTION
[0008] The apparatus of the invention comprises a device that is
particularly well suited for use in the medical field, but is not
necessarily limited to medical use. According to one preferred
embodiment of the invention, a medical device is disclosed that has
a cannula and can be configured and used for fluid injection,
infusion or extraction. Depending upon its configuration, the
subject device can be used, for example: As part of an infusion set
or as a collection device for venous or arterial blood; for other
body fluids such as spinal fluid, cerebral fluid, amniotic fluid,
and the like that are well known to healthcare workers; or for
solid matter contained in suspensions or slurries such as, for
example, medications, lipids or bone marrow. When the device is
used for infusing fluids or medication, the fluid source can be,
for example, an IV drip bag or a syringe. When the device is used
for collecting blood, the fluid receptacle can be, for example, a
blood collection bag, an evacuated tube or a syringe. When the
device is attached to a fluid flow line, it can also be used as a
clamp. Prior to retraction of the cannula, the device prevents
fluid leakage into or out of the fluid flow path. The cannula is
typically a needle having a front end that is beveled to facilitate
insertion into tissue or into another medical device such as a
port.
[0009] According to one embodiment of the invention, the device
comprises an offset fluid flow path and a retraction chamber fixed
in a position that is in-line with the cannula. Retraction is
initiated by an actuator that can be repositioned axially in
relation to the cannula, thereby also blocking the fluid flow
path.
[0010] According to another embodiment of the invention, the device
comprises an in-line fluid flow path and an offset retraction
cavity. Retraction is initiated by an actuator that can be
repositioned laterally in relation to the cannula, thereby blocking
and sealing off the fluid flow path.
[0011] According to another embodiment of the invention, the device
comprises an in-line fluid flow path and an offset retraction
chamber. Retraction is initiated by an actuator that can be
repositioned arcuately in relation to the cannula, thereby blocking
and sealing off the fluid flow path.
[0012] According to a preferred embodiment of the invention, a
device is disclosed that preferably comprises a housing; a cannula
projecting forwardly from the housing; a connector useful for
attaching the device to a fluid source or receptacle; a fluid flow
path establishing fluid communication between the cannula and the
connector; a retraction mechanism biasing the cannula away from its
projecting position; and an actuator supported by the housing and
configured to modify the fluid flow path so as to terminate fluid
flow through the device, seal off the fluid flow path, and release
the retraction mechanism to retract the cannula into the housing.
Laterally extending finger grips and/or stabilization wings with
finger pads are desirably provided to facilitate manipulation of
the device by a user, to resist rolling of the device on an
underlying surface, and to provide surfaces that can be secured to
a patient during use.
[0013] According to another preferred embodiment of the invention,
the actuator portion of the device comprises two elongate, most
preferably cylindrical, cavities, including one cavity that defines
a portion of the fluid flow path and another that is a retraction
cavity configured to receive a portion of the retraction mechanism
and cannula following retraction. The retraction mechanism
preferably comprises a holder for the needle or cannula, and a
biasing member such as a compression spring. The actuator is
preferably movable by the user from a first position to a second
position to modify the fluid flow path by interrupting, displacing,
redirecting or reconfiguring at least part of the path, thereby
cutting off fluid flow along the original flow path through the
device. At least part of the actuator is either slidably mounted or
rotatably, most preferably pivotally, connected inside the housing.
Movement of the actuator from the first position to the second
position also desirably releases the retraction mechanism, allowing
the biasing member to force the cannula holder and at least part of
the cannula back inside the retraction cavity, and to force all of
the cannula back inside the housing to prevent accidental needle
sticks and to prevent reuse of the device. The use of devices
having retractable needles, the avoidance of accidental
needlesticks and disabling the device to prevent reuse are
important to significantly reducing the spread of disease by
blood-borne pathogens to healthcare workers, other patients, and
those who may handle such devices following use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The apparatus of the invention is further described and
explained in relation to the following figures of the drawings
wherein:
[0015] FIG. 1 is a front elevation view of an embodiment of the
invention having an interruptable fluid flow path, a retractable
cannula projecting forwardly out of the housing, a rearwardly
slidable actuator, and stabilization wings;
[0016] FIG. 2 is a cross-sectional side elevation view taken along
line 2-2 of FIG. 1;
[0017] FIG. 3 is an enlarged view of the device of FIG. 2 following
interruption of the fluid flow path and retraction of the
cannula;
[0018] FIG. 4 is a cross-sectional front elevation view of another
embodiment of the invention having an interruptible fluid flow
path, a retractable cannula projecting forwardly out of the
housing, and a laterally slidable actuator;
[0019] FIG. 5 is a cross-sectional front elevation view of the
embodiment of FIG. 4 following interruption of the fluid flow path
and retraction of the cannula into the retraction cavity;
[0020] FIG. 6 is a perspective view of another embodiment of the
invention having an interruptable fluid flow path, a retractable
cannula projecting forwardly out of the housing, and a pivotable
actuator;
[0021] FIG. 7 is an exploded perspective view of the embodiment of
FIG. 6;
[0022] FIG. 8 is an enlarged top plan view (oppositely directed) of
the embodiment of FIG. 6;
[0023] FIG. 9 is an enlarged cross-sectional plan view, partially
broken away, of the embodiment of FIG. 8, with the cannula
projecting forwardly and a tubing segment (shown in phantom
outline) disposed in fluid communication with the fluid flow path
through the actuator, cannula holder and cannula;
[0024] FIG. 10 is an enlarged cross-sectional plan view of the
embodiment of FIG. 9 following interruption of the fluid flow path
and retraction of the cannula;
[0025] FIG. 11 is a perspective view of another embodiment of the
invention having an interruptable fluid flow path, a retractable
cannula projecting forwardly out of the housing (shown covered by a
protective guard), and an actuator pivotably connected to the
housing;
[0026] FIG. 12 is an exploded perspective view of the embodiment of
FIG. 11;
[0027] FIG. 13 is an enlarged top plan view of the embodiment of
FIG. 11;
[0028] FIG. 14 is a front elevation view of the embodiment of FIG.
13, with the protective cover shown in phantom outline;
[0029] FIG. 15 is an enlarged cross-sectional plan view, partially
broken away, of the embodiment of FIG. 13, with the cannula
projecting forwardly and the protective cover shown in phantom,
showing the fluid flow path through the cannula, cannula holder and
actuator;
[0030] FIG. 16 is a cross-sectional plan view of the embodiment of
FIG. 15 following interruption of the fluid flow path and
retraction of the cannula into the retraction cavity;
[0031] FIG. 17 is a perspective view of another embodiment of the
invention having an interruptable fluid flow path that is
particularly useful with liquid fluids, a retractable cannula
projecting forwardly out of the housing (hidden from view by a
removable protective cover), and an actuator pivotably connected to
the housing;
[0032] FIG. 18 is an exploded perspective view of the embodiment of
FIG. 17;
[0033] FIG. 19 is an enlarged cross-sectional plan view, partially
broken away, of the embodiment of FIG. 17, with the cannula
projecting forwardly and the protective cover shown in phantom
outline, and showing the fluid flow path through the cannula,
cannula holder, actuator and Luer connector set; and
[0034] FIG. 20 is a cross-sectional plan view of the embodiment of
FIG. 19 following interruption of the fluid flow path and
retraction of the cannula into the retraction cavity.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Referring to FIG. 1, device 10 can be used, for example, as
part of a medical apparatus for collecting blood, blood gases or
other bodily fluids from a patient, or for infusing a patient with
fluids of the type typically administered intravenously or
otherwise. As shown, device 10 comprises housing 12 and forwardly
projecting cannula 14 attached to cannula holder 16, which is more
visible in FIGS. 2 and 3. Prior to use of device 10, the beveled
point of cannula 14 is desirably shielded by a protective cover.
Actuator 18 is slidably supported by housing 12 and comprises a
plurality of opposed flexible latches that secure the end opposite
handle 44 inside housing 12. Handle 44 at the front of actuator 18
facilitates manual manipulation of actuator 18 relative to housing
12 to terminate fluid flow through device 10 and initiate
retraction of cannula 14 inside housing 12 as described in greater
detail below.
[0036] Optional stabilization wings 20 extend laterally from
housing 12 and facilitate handling of device 10 by the user. When
used, wings 20 also provide a surface that will restrict rotation
of housing 12 when device 10 is secured to a patient using tape,
sutures, or other similarly effective means. After a desired volume
of fluid has been administered to or withdrawn from a patient as
therapeutically prescribed, the fluid flow through cannula 14 can
be terminated and cannula 14 can be retracted inside housing 12 by
applying rearwardly directed manual pressure to the front side of
handle 44 of actuator 18 while simultaneously grasping housing 12.
If desired, cannula 14 can be retracted into housing 12 without
first withdrawing it from the patient. Usage of device 10 and
retraction of cannula 14 are discussed more fully below in relation
to FIGS. 2 and 3.
[0037] Referring to FIG. 2, device 10 is shown without the optional
stabilization wings attached. Housing 12 of device 10 comprises two
elongated portions including lower section 26 and upper section 28.
Lower section 26 further comprises smaller diameter front end 32
and a larger diameter back end 34 with transition zone defined by
shoulder 30 disposed between front end 32 and back end 34. Upper
section 28 extends rearwardly from a point above shoulder 30 to an
open back end above back end 34 of lower section 26, and comprises
a longitudinal bore that serves as a connector into which tubing
segment 24 is insertable. The end of tubing segment 24 is desirably
maintained inside upper section 28 of housing 12 by any suitable
means such as, for example, frictional engagement or by using a
clamping device, adhesive, or the like. Depending upon the desired
use of device 10, tubing segment 24 can be of any desired length
that is suitable for connecting device 10 to a fluid source, such
as an IV bag, or to a fluid receptacle, such as a blood collection
system. Lower section 26 preferably further comprises a retraction
cavity 36 disposed between back end 34 and transition zone shoulder
30. As shown, back end 34 of retraction cavity 36 comprises an
opening that is closed by end cap 42. Lower section 26 further
comprises aperture 38 disposed in the top wall, slightly forward of
transition zone shoulder 30. Hole 38 aligns with hole 40 in the
bottom of upper section 28, and the alignment of holes 38, 40 helps
establish a fluid flow path between cannula 14 and tubing segment
24.
[0038] The opening at front end 32 of lower section 26 is closed by
slidably engaged tubular actuator 18, which comprises handle 44
extending upwardly from the front edge. Actuator 18 is movable from
a first position, where handle 44 is spaced apart from front end 32
of lower section 26, to a second position, where handle 44 abuts
and is adjacent to front end 32 of lower section 26. Actuator 18 is
desirably sized lengthwise to extend into lower section 26 of
housing 12 a sufficient distance to cover and close hole 38 in
lower section 26 when actuator 18 is moved to the second position
abutting against front end 32. Actuator 18 also desirably comprises
a pair of diametrically opposed latches extending outwardly from
the rear end of actuator 18. As sliding end cap 18 is moved towards
its second position, the latches slide over and engage a projection
shoulder on the inside wall of lower section 26, thereby locking
actuator 18 in its second position and preventing its removal from
housing 12.
[0039] Retraction mechanism 13 supports cannula 14 and comprises
cannula holder 16, cannula holder plug 46, and spring 22. Following
installation of actuator 18 in the front of lower section 26,
cannula holder 16, spring 22 and cannula holder plug 46 are
desirably preassembled and inserted into lower section 26 through
the opening in back end 34 and through retraction cavity 36. Prior
to insertion, resilient cannula holder plug 46 is desirably
inserted into frictional engagement with a recess inside the larger
diameter section 58 of cannula holder 16. Spring 22 is desirably
placed over the smaller diameter front section of cannula holder
16, where it slides rearwardly into abutting engagement with
annular shoulder 52. The assembled unit is then oriented so that
fluid passageway 60 is aligned with aperture 38 in the top wall of
lower section 26, and advanced past transition zone shoulder 30. As
the forwardly extending tip of cannula holder 16 projects forwardly
of actuator 18, spring 22 seats against the annular shoulder inside
the front opening of actuator 18 and is compressed to the position
shown in FIG. 2. Actuator 18 resists the force of the compressed
spring and is prevented from moving forwardly away from housing 12
under the spring force by the resilient latches securing actuator
18 to housing 12 as previously described. This configuration of
elements allows cannula 14 to be in fluid communication with tubing
24, as fluid flows through hollow cannula 14 and cannula holder 16
into cannula holder plug 46, through hole 60 in the top of cannula
holder plug 46, through hole 38 in top of retraction cavity housing
26, through hole 40 in the bottom of tubing assembly housing 28 and
into tubing 24. Similarly, fluid can flow in the opposite direction
and pass from tubing 24, through aligned holes 40, 38 and 60 and
out cannula 14. Rear end cap 42 is installed in the open end of
lower section 26 following installation of cannula 14 and cannula
holder plug 46, and is frictionally held inside rear end 34 of
lower section 26.
[0040] Although cannula 14 can be secured in fixed relation to
cannula holder 16 prior to insertion of retraction mechanism 13
into housing 12, cannula 14 is desirably inserted into the bore of
projecting tip of cannula holder 16 after cannula holder 16 is
installed inside housing 12. As seen in FIG. 2, the opening at the
forwardly extending end of cannula holder 16 is tapered to
facilitate the insertion and attachment of cannula 14. Cannula 14
can be frictionally held inside the bore of cannula holder 16 but
is desirably attached in fixed relation to cannula holder 16 using
glue or any other similarly effective means known to those of
ordinary skill in the art. The open portion of the beveled point of
cannula 14 desirably faces upwardly to facilitate insertion into a
patient. As shown in FIG. 2, open back end 62 of hollow cannula 14
extends through back end 58 of cannula holder 16 into open front
section 54 of cannula holder plug 46. It should be appreciated,
however, that cannula 14 needs only extend into cannula holder 16 a
sufficient distance to facilitate reliable engagement between
them.
[0041] When device 10 is assembled as described above, compressed
spring 22, or any other similarly effective biasing means, biases
cannula 14 and cannula holder 16 rearwardly. The frictional holding
force exerted against inside surface 50 of the smaller diameter
front portion of lower section 26 by cannula holder plug 46 should
be great enough to resist the biasing force exerted against annular
shoulder 52 by spring 22 in combination with the force exerted back
against cannula holder plug 46 through cannula 14 and cannula
holder 16 during insertion of cannula 14 into a patient. Otherwise,
cannula 14 could retract prematurely without movement of actuator
18 relative to housing 12.
[0042] When the fluid infusion or extraction procedure is complete
and retraction of cannula 14, the user can initiate retraction by
applying rearwardly directed pressure to handle 44 while
maintaining housing 12 in a stationary position, either by gripping
its textured outside surface portion (visible in FIG. 1) or by
pressing down on the optional wings (likely already secured to the
patient). The manual pressure applied to handle 44 causes actuator
18 to move backwards relative to housing 12. Desirably, retraction
is initiated while the cannula, typically a needle, is still
inserted in the patient. As actuator 18 moves backwards, cannula
holder 16 and cannula holder plug 46 are also forced backwards due
to the contact between back end 64 of actuator 18 and annular
shoulder 52 of cannula holder 16. It can be observed in FIG. 2 that
back end 64 of actuator 18 abuts the adjacent portion of forwardly
facing annular shoulder 52 of cannula holder 16, while the rear end
of that part of actuator 18 as depicted beneath spring 22 is
slightly separated from annular shoulder 52. This slight separation
causes the rearwardly directed force exerted by the user on handle
44 to be concentrated against one side of annular shoulder 52
rather than being evenly distributed around the circumference, and
is believed to reduce the manual force required to initiate
retraction.
[0043] Referring to FIG. 3, in response to the rearward movement of
actuator 18, cannula holder plug 46 passes through the transition
zone (past shoulder 30) and into larger diameter retraction cavity
36 of lower section 26. As cannula holder plug 46 moves, the
friction force between outside surface 48 of cannula holder plug 46
and inside wall 50 of lower section 26 is reduced, and as cannula
holder plug 46 passes the transition zone and enters retraction
cavity 36, the frictional holding force is completely eliminated.
At the point where the frictional holding force is sufficiently
reduced by the combined finger force of the user as applied through
handle 44 of actuator 18 and the biasing force of compressed spring
22, spring 22 forces cannula holder 16 and cannula holder plug 46
backwards into retraction cavity 36, thereby simultaneously causing
cannula holder 16 to draw the beveled tip of cannula 14 inside
housing 12. It will be apparent to those of skill in the art upon
reading this disclosure that actuator 18 should be long enough that
its range of travel relative to housing 12 is sufficient to force
cannula holder plug 46 past shoulder 30.
[0044] As shown in FIG. 3, following retraction, cannula holder
plug 46 desirably abuts, or nearly abuts, rear end cap 42 of lower
section 26. Lower section 26 is desirably sized such that the
entirety of cannula 14 is contained within lower section 26 and
does not protrude from front end 32. After retraction, the top edge
of actuator 18 blocks the fluid flow path between cannula 14 and
hole 38 in the top of lower section 26. This prevents fluid from
escaping tubing 24 that is still connected to upper section 28 of
housing 12.
[0045] Another embodiment of the invention is disclosed and
described in relation to FIGS. 4 and 5. Referring to FIG. 4, device
70 is preferred for use as part of a blood collection apparatus or
an IV infusion set. Device 70 comprises a substantially rectangular
housing having front wall 72 with forwardly projecting conical nose
74; rear wall 92 with open slot 88; side wall 98; and cooperating,
substantially flat bottom wall 104 and a corresponding top wall
(not visible in the cross-sectional view) that interconnect walls
72, 92 and 98. The edges of bottom wall 104 and the corresponding
top wall (not visible) that are opposite side wall 98 are not
visible in FIG. 4, but extend between front wall 72 and back wall
92 at a point slightly beyond the side of slot 88 that is farthest
removed from wall 98. Sliding track 94, seen behind front wall 72,
is preferably unitarily formed as part of front wall 72.
[0046] As shown and described, the housing of device 70 defines a
structure into which retraction mechanism 76 and actuator 96 are
installable. Retraction mechanism 76 preferably further comprises
cannula holder 78 having a larger diameter head 80, and a biasing
member exerting a rearwardly directed force against cannula holder
78. A preferred biasing member is compression spring 86. Retraction
mechanism 76 is installable into front wall 72, nose 74 and sliding
track 94 of the housing from the rear, preferably prior to the
installation of cannula 84 and actuator 96. Coil spring 86 is
placed over the forwardly extending end of cannula holder 78 and
cannula holder 78 is then inserted into nose 74 until the forwardly
facing end of spring 86 seats against the annular shoulder inside
the front opening of nose 74 that is disposed around cannula holder
78. As spring 86 is compressed, a portion of annular shoulder 82 on
the forwardly facing surface of head 80 abuts against the
rearwardly facing surface of front wall 72 that is adjacent to the
opening through nose 74. While retraction mechanism 76 is held in
place (as by temporarily clamping the portion of cannula holder 78
extending forwardly out of nose 74), actuator 96 is desirably
inserted into sliding track 94 from the side of the housing
opposite wall 98, and is moved laterally to a position as shown in
FIG. 4 where sealing member 95 provides a fluid-tight seal
permitting fluid flow between head 80 of cannula holder 78 into
fluid flow path 100 of actuator 96.
[0047] Actuator 96 is preferably an elongate, substantially
rectangular body made to slidably engage at least one guide or
sliding track 94 on the inside of the housing to facilitate lateral
movement of actuator 96 within the housing. The interior of
actuator 96 preferably comprises an in-line fluid flow path 100
defined by wall sections 106, 108, and a retraction chamber 102
that is offset from cannula 84 while actuator 96 is in the use
position. Resilient sealing member 95, preferably an elastomeric
0-ring or another similarly effective sealing member, is disposed
in a recess at the forward end of fluid flow path 100 through
actuator 96, where it can provide sealing engagement with the
rearwardly facing surface of enlarged head 80 of cannula holder 78.
It will be observed that resilient sealing member 95 seals against
fluid leakage either into or out of fluid flow path 100.
[0048] When actuator 96 is positioned as shown in FIG. 4, spring 86
is maintained in its compressed state and continuously biases
cannula holder 78 in a rearward direction until such time as
actuator 96 is selectively repositioned following use of device 70.
Once retraction mechanism 76 and actuator 96 are installed inside
the housing, the rear end of cannula 84 can be inserted into the
axial bore of cannula 78 and glued or otherwise secured in place.
Although not shown, a frictionally engageable, removable protective
cover is desirably provided for cannula 84 following its
installation in cannula holder 78.
[0049] Prior to use, device 70 is preferably connected to a fluid
source or fluid receptacle by means of a flexible tubing segment 90
that is insertable into or otherwise attachable to tubing connector
103 through slot 88 by conventional means. When actuator 96 is
positioned as shown in FIG. 4, a substantially linear fluid flow
path is established between cannula 84 and tubing segment 90.
Tubing connector 103 can be a section of the bore inside actuator
96 that is tapered slightly to receive and frictionally engage a
free end of tubing segment 90, or can be configured for attachment
of a tubing segment by other known means such as, for example, luer
connectors, threaded connectors, clamps, adhesive, and the like.
Tubing segment 90 is preferably flexible polymeric tubing of any
length and material that are suitable for the intended use. When
configured as shown in FIG. 4, device 70 can be used to transfer
fluids from an external source to be discharged through the
cannula, or can be extracted or withdrawn from an external source
through the cannula and subsequently discharged from the end of
tubing segment 90 that is opposite to tubing connector 103.
[0050] Following use, retraction is initiated by moving actuator 96
from its use position to its retraction position by applying manual
force to actuator 96 in a direction that is substantially
perpendicular to the longitudinal axis through cannula 84 and
cannula holder 78. Referring to FIG. 5, as actuator 96 is moved
laterally toward wall 98, fluid flow path 100 through actuator 96
is shifted laterally into a position where it is no longer opposed
to head 80 of cannula holder 78. Simultaneously, head 80 is acted
upon by the biasing force of compressed spring 86 to propel cannula
holder 78 into retraction cavity 102 of actuator 96, thereby
withdrawing cannula 84 inside the housing. To produce this result,
it will be apparent that the distance between back wall 92 and the
front tip of nose 74 must be sufficiently great to receive the
pointed end of cannula 84 at least into nose 74. Also, the length
of uncompressed spring 86 is desirably such that head 80 will be
maintained a sufficient distance from the front opening of nose 74
that the tip of cannula 84 does not again protrude from the front
of device 70 following retraction, particularly if device 70 is
rotated to a vertical position with the cannula pointing down.
[0051] Another embodiment of the invention, in which the actuator
is repositioned arcuately relative to the housing to initiate
retraction, is described in relation to FIGS. 6-10. Referring first
to FIGS. 6-8, medical device 110 is disclosed that comprises
housing 112, actuator 114, a retraction mechanism 118, and a
forwardly projecting cannula, preferably needle 122. Housing 112
further comprises a hollow body having substantially flat top and
bottom surfaces, an inclined finger pad 134, a forwardly extending,
open neck 136, open side and back sections including actuator stop
rail 140, recessed wall section 168, and aligned, oppositely
disposed apertures 126 for pivotably attaching actuator 114 to
housing 112.
[0052] Actuator 114 preferably comprises actuator contact surface
132, contact surface 166, actuator positioning rail 138, outwardly
projecting mounting bosses 128 insertable into mating engagement
with apertures 126 of housing 112, and tubing aperture 130.
Retraction mechanism 118 preferably comprises a needle holder
having a forwardly extending, small diameter portion 106 and a
larger-diameter head 108 disposed rearwardly of small diameter
portion 106. Compression spring 116 is configured to slide over
small diameter portion 106 and to abut against the forwardly facing
annular surface of head 108. A sealing member, preferably 0-ring
120, is further described below.
[0053] Referring to FIG. 9, the retraction mechanism is inserted
into neck 136 of housing 112 from the rear, with small diameter
portion 106 of the needle holder projecting forwardly through the
opening in the front. Spring 116 slidably engages small diameter
portion 106 and the forward end of spring 116 is seated against an
annular shoulder adjacent to the front opening inside neck 136. The
other end of spring 116 abuts against an annular shoulder of head
108. Spring 116 is compressed, and is maintained in the
pre-retraction position by an opposing force exerted against head
108 by actuator 114, Actuator 114 is disposed in its use position
relative to housing 112, with mounting bosses 128 pivotably
inserted into apertures 126 and with contact surface 166 abutting
against the inside surface of housing 112 that is adjacent to
recessed wall section 168. Actuator 114 comprises fluid flow path
154 bounded by walls 150, 152, and retraction cavity 164. Space 124
in housing 112 is provided to receive a portion of actuator 114
when it is repositioned to terminate fluid flow and initiate
retraction.
[0054] With actuator 114 in this position, fluid flow path 154
through actuator 114 is disposed in fluid communication with axial
passageway 144 through the needle holder and with the inside of
needle 122. Sealing member 120, seated in recess 148, desirably
provides fluid-tight sealing engagement between the forward end of
walls 150, 152 and head 108 of the needle holder. This sealing
engagement is facilitated by an annular shoulder 146 of head 108.
Tubing connector 156 desirably comprises outwardly tapering walls
142 at the rear end of fluid flow path 154 and is adapted to
receive and engage an end of tubing segment 162 (shown in phantom
outline). Projecting boss 158 of housing 112, located adjacent to
the forwardly facing end of retraction cavity 164 is provided to
prevent actuator 114 from inadvertently being moved from the
pre-retraction position to the retraction position. In practice,
the spacing between boss 158 and facing surface 160 of actuator 114
is desirably less than that shown for illustrative purposes in FIG.
9.
[0055] After the transfer of fluids through device 110 in either
direction has been completed to the extent desired, the fluid flow
is easily terminated by repositioning actuator 114 relative to
housing 112 by applying pressure against actuator contact surface
132, which causes actuator 114 to pivot in the direction shown by
arrow 160. Although some manual pressure is required to overcome
the resistance of pushing surface 160 over boss 158 and to move
sealing member 120 past head 108, the required force is desirably
such that it can easily be applied by an adult user. It will again
be observed that resilient sealing member 120 seals against fluid
leakage either into or out of fluid flow path 154.
[0056] Referring to FIG. 10, after actuator 114 is repositioned
relative to housing 112 as shown, fluid flow between needle 122 and
tubing segment 162 is blocked, fluid flow path 154 is offset from
the opening through neck 136 and from passageway 144 through head
108. Furthermore, as soon as wall 150 clears head 108, retraction
cavity 164 is pivoted into coaxial alignment with the opening
through neck 136, and the biasing force of compressed spring 122
projects the needle holder into the retraction cavity,
simultaneously withdrawing the tip of needle 122 from the patient
and into housing 112 to avoid accidental needle sticks and prevent
reuse of device 110.
[0057] Another embodiment of the invention is described in relation
to FIGS. 11-16. This embodiment is particularly preferred for use
in collecting fluids comprising gases, such as arterial blood
gases, intended for subsequent analysis, and also comprises an
actuator that is repositioned arcuately relative to the housing to
initiate retraction. Referring first to FIGS. 11-14, medical device
200 is disclosed that comprises housing 226, actuator 204, needle
holder 220, spring 222, hermetic sealing element 218 and forwardly
projecting needle 224. Housing 226 further comprises a hollow body
having substantially flat top and bottom surfaces 202, oppositely
disposed and integrally formed finger grips with textured gripping
surfaces 206, a forwardly extending, tapered neck 238 with opening
228, an open side and back, and aligned, oppositely disposed
apertures 230 for pivotably attaching actuator 204 to housing 226.
Protective cover 232 is desirably provided to protect needle 224
prior to use, and should be removed from needle 224 prior to
use.
[0058] Actuator 204 preferably comprises actuator contact surface
234, outwardly projecting mounting bosses 212 insertable into
mating engagement with apertures 230 of housing 204, retraction
cavity 216, recess 214 around the opening of the fluid flow path,
and a tubing connector 208 that extends rearwardly from housing
226. Referring to FIGS. 13 and 14, tubing connector 208 further
comprises half of a Luer connector 236 to facilitate attachment of
device 200 to another fluid source or receptacle, depending upon
the intended use.
[0059] Referring to FIGS. 15-16, the retraction mechanism is
installed by inserting it into axial passageway 250 through neck
238 of the housing from the rear, with small diameter portion 221
of needle holder 220 projecting forwardly through opening 228 in
the front. Spring 222 slidably engages small diameter portion 221
and the forward end of spring 222 is seated against an annular
shoulder 252 adjacent to front opening 228 of neck 238. The other
end of spring 222 abuts against an annular shoulder of larger
diameter head 223 of needle holder 220. Spring 222 is compressed,
and is maintained in the pre-retraction position by an opposing
force exerted against head 223 by actuator 204. Actuator 204 is
disposed in its use position relative to housing 226 with mounting
bosses 212 pivotably inserted into apertures 230 (FIG. 12) and with
actuator contact surface 234 abutting against the inside surface of
housing 226 that is underneath the nearest adjacent textured
gripping surface 206. Actuator 204 comprises fluid flow path 242
and retraction cavity 216. Space 244 in housing 226 is provided to
receive a portion of actuator 204 when it is repositioned to
terminate fluid flow and initiate retraction.
[0060] With actuator 204 in the position shown in FIG. 15, fluid
flow path 242 through actuator 204 is disposed in fluid
communication with axial passageway 225 through the needle holder
and with axial passageway 258 inside needle 224. Hermetic sealing
member 246, seated in recess 214, desirably provides fluid-tight
sealing engagement between the forward end of fluid flow path 242
and head 223 of the needle holder. Tubing connector 208 desirably
comprises stepped bore 240 providing fluid communication with fluid
flow path 242. Projecting boss 235 of housing 226, located adjacent
to the forwardly facing end of retraction cavity 216 is provided to
prevent the actuator from being moved inadvertently from the
pre-retraction position to the retraction position shown in FIG.
16.
[0061] Referring to FIG. 16, after the transfer of fluids through
device 200 in either direction has been completed to the extent
desired, the fluid flow is easily terminated by repositioning the
actuator relative to housing 226 by applying pressure against
actuator contact surface 234, which causes the actuator to pivot in
the direction shown by arrow 260. Although some manual pressure is
required to overcome the resistance of pushing surface 237 (FIG.
15) over boss 235 and to move sealing member 246 past head 223, the
required force is desirably within the range that can be applied
smoothly by an adult user. After the actuator is repositioned
relative to housing 112 as shown in FIG. 16, fluid flow between
needle 224 and tubing connector 208 is blocked, fluid flow path 242
is offset from the opening through passageways 248, 250.
Furthermore, as soon as retraction cavity 164 is pivoted into
coaxial alignment with the passageways 248, 250, the biasing force
of compressed spring 224 projects needle holder 221, 223 into the
retraction cavity, simultaneously withdrawing the tip of needle 224
from the patient and into housing 226 to avoid accidental needle
sticks and prevent reuse.
[0062] Another embodiment of the invention is described in relation
to FIGS. 17-20. This embodiment, which is particularly preferred
for use in extracting, collecting or infusing fluids, also
comprises an actuator that is repositioned rotationally, most
preferably arcuately, relative to the housing to initiate
retraction. Referring first to FIGS. 17-18, medical device 300 is
disclosed that comprises housing 304, actuator 316, needle holder
312, spring 310, sealing element 314 and forwardly projecting
needle 308. Housing 304 further comprises a hollow body having
substantially flat top and bottom surfaces, oppositely disposed and
integrally formed finger grips with textured gripping surfaces 340,
a forwardly extending, tapered neck 306 with a forwardly extending
opening, an open side and back, and aligned, oppositely disposed
apertures 324 for pivotably attaching actuator 316 to housing 304.
Protective cover 302 is desirably provided to protect needle 308
prior to use, and should be removed from needle 308 prior to
use.
[0063] Referring to FIGS. 18 and 19, in this embodiment of the
invention, an external connector body 322 is provided that is
attachable to fluid flow passage 328 through actuator 316 by means
of tubing segment 318 having a length that is appropriate for
attachment of another device (not shown) that is either a source
of, or receptacle for, fluids to be infused into or extracted from,
a patient. Referring to FIG. 19, tubing segment 318 (which can
range in length, for example, from one to four feet or more) is
preferably inserted into the rear of actuator 316 and glued,
welded, clamped or otherwise secured in place to establish fluid
communication with fluid flow path 328, and is likewise attachable
to connector body 322 through an opening in nose 320, thereby
establishing fluid communication with stepped axial bore 332
through connector body 322. Connector 334 at the rear of connector
body 322 is desirably provided, most preferably with half of a
standard Luer connector, to facilitate attachment to another
device, preferably a fluid source or receptacle. The end of tubing
segment inserted into nose 320 of connector body 322 is also
preferably attached using an adhesive or by any other suitable
conventional means. Connector body 322 can also optionally be
provided with oppositely directed stabilization wings 336 if
desired for use in securing connector body 322 to another surface
or article.
[0064] Prior to the installation of actuator 316 inside housing
304, the retraction mechanism comprising needle holder 312 and
spring 310 is preferably installed by inserting it into neck 306 of
housing 304 from the rear as previously described in relation to
the embodiment of FIGS. 11-17, with the smaller diameter portion of
needle holder 312 projecting forwardly through the opening in the
front of neck 306. Spring 310 is compressed during installation,
and is maintained in the pre-retraction position by an opposing
force exerted against the head of needle holder 312 by actuator
316. In FIG. 19, actuator 316 is disposed in its use position
inside housing 304 as previously described for actuator 204 in
relation to housing 226 of FIG. 15. Actuator 316 comprises fluid
flow path 328 and retraction cavity 330. Space 326 in housing 304
is provided to receive a portion of actuator 316 when it is
repositioned to terminate fluid flow and initiate retraction.
[0065] With actuator 316 in the position shown in FIG. 19, fluid
flow path 328 through actuator 316 is disposed in fluid
communication with axial passageway through needle holder 312 and
with the axial passageway 258 inside needle 308. Elastomeric
sealing member 314 desirably provides fluid-tight sealing
engagement between the forward end of fluid flow path 328 and the
head of needle holder 312. The rear portion of fluid flow path 328
desirably comprises tapering walls to receive and engage an end of
tubing segment 318 as previously described. A projecting boss as
previously described in relation to boss 235 of housing 226 of FIG.
15 is desirably located adjacent to the forwardly facing end of
retraction cavity 330 to prevent actuator 316 from being moved
inadvertently from the pre-retraction position of FIG. 19 to the
retraction position shown in FIG. 20.
[0066] Referring to FIG. 20, after the transfer of fluids through
device 300 in either direction has been completed to the extent
desired, the fluid flow is easily terminated by repositioning
actuator 316 relative to housing 304 by applying pressure against
the actuator contact surface as indicated by arrow 338, which
causes actuator 316 to pivot in the direction shown by arrow 338.
After the actuator is repositioned relative to housing 304 as shown
in FIG. 20, fluid flow between needle 308 and tubing connector body
322 is blocked, and fluid flow path 328 is offset from the opening
through nose 306. Furthermore, as soon as retraction cavity 330 is
pivoted into coaxial alignment with the opening through neck 306 of
housing 304, the biasing force of compressed spring 308 forces
needle holder 312 into retraction cavity 330, simultaneously
withdrawing the tip of needle 308 from the patient and into housing
304 to avoid accidental needlesticks and prevent reuse, thereby
reducing the related potential for spreading fluid-borne pathogens
to another person.
[0067] As disclosed herein, all housings, actuators, cannula
holders, protective covers, end caps and tubing connectors can be
made of any suitable material such as, for example, plastic, metal,
ceramic, glass, or the like. For medical application such as IV
infusion and blood collection, the use of molded polypropylene is
preferred. Similarly, depending upon the intended use or
application, cannulas suitable for use in the invention can be made
of metal, plastic or ceramic materials, with metal being preferred.
Resilient parts used as fluid sealing members or cannula holder
plugs are desirably made of rubber, other elastomeric polymers, or
rubber-modified plastic.
[0068] When using the devices disclosed in relation to FIGS. 1-5,
and assuming that the housing is maintained in a stationary
position during retraction, a tubing segment connected to the rear
of the device is not moved axially, laterally or directionally when
the actuator is repositioned to terminate the fluid flow and
withdraw the cannula into the housing. When using the devices of
FIGS. 6-20, wherein flow is terminated and the cannula is retracted
by arcuate repositioning of the actuator as it pivots relative to
the housing, the axial, lateral and directional movements of an
attached tubing segment are slight compared to the travel distance
previously associated with the use of conventional devices.
[0069] Other alterations and modifications of the invention will
likewise become apparent to those of ordinary skill in the art upon
reading the present disclosure, and it is intended that the scope
of the invention disclosed herein be limited only by the broadest
interpretation of the appended claims to which the inventors are
legally entitled.
* * * * *