U.S. patent application number 15/912168 was filed with the patent office on 2018-09-27 for shroud deployment in automatic injection devices.
The applicant listed for this patent is AbbVie Inc.. Invention is credited to Edwin Chim, Vincent DiPalma, Esra Ozdaryal, David Post, Vivek Rao, Sherwin Shang, Eduard Tsvirko.
Application Number | 20180272076 15/912168 |
Document ID | / |
Family ID | 45937673 |
Filed Date | 2018-09-27 |
United States Patent
Application |
20180272076 |
Kind Code |
A1 |
Rao; Vivek ; et al. |
September 27, 2018 |
SHROUD DEPLOYMENT IN AUTOMATIC INJECTION DEVICES
Abstract
Exemplary embodiments provide automatic injection devices in
which a shroud is automatically deployed to protectively sheath a
needle after an injection is performed. Exemplary embodiments also
provide shroud deployment assemblies including a shroud and a
syringe carrier that, when cooperatively configured in an automatic
injection device, ensure that the shroud is automatically and
completely deployed after an injection is performed using the
automatic injection device. Exemplary embodiments are also
configured to ensure that, once the shroud is deployed to an
extended position to sheath the needle, accidental forces applied
to the shroud do not succeed in subsequently retracting the shroud
to a retracted position in which the needle would become
exposed.
Inventors: |
Rao; Vivek; (Alameda,
CA) ; Shang; Sherwin; (Vernon Hills, IL) ;
Ozdaryal; Esra; (Deerfield, IL) ; Tsvirko;
Eduard; (Arlington Heights, IL) ; Chim; Edwin;
(Vernon Hills, IL) ; Post; David; (Kenosha,
WI) ; DiPalma; Vincent; (Hayward, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AbbVie Inc. |
North Chicago |
IL |
US |
|
|
Family ID: |
45937673 |
Appl. No.: |
15/912168 |
Filed: |
March 5, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14007849 |
Dec 11, 2013 |
9956353 |
|
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PCT/US2012/031260 |
Mar 29, 2012 |
|
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15912168 |
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61469077 |
Mar 29, 2011 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2005/3267 20130101;
A61M 5/326 20130101; A61P 37/06 20180101; Y10T 29/49826 20150115;
A61P 1/04 20180101; A61P 29/00 20180101; A61M 5/3204 20130101; A61M
2005/2073 20130101; A61M 5/2033 20130101; A61M 5/3245 20130101;
A61P 19/06 20180101; A61P 43/00 20180101; A61M 2005/206
20130101 |
International
Class: |
A61M 5/32 20060101
A61M005/32; A61M 5/20 20060101 A61M005/20 |
Claims
1. A syringe carrier assembly for use in an automatic injection
device, the syringe carrier assembly comprising: a proximal tubular
portion having a first outer diameter; a distal tubular portion
having a second outer diameter less than the first diameter; and a
chamfer formed between the proximal and distal tubular portions to
create a relief extending between the proximal tubular portion and
the distal tubular portion; wherein the syringe carrier assembly is
disposed partly within a tubular member of a shroud; wherein, as
the shroud moves from a retracted position to an extended position,
distal arms of the shroud move forwardly within a constrained space
formed between an inner portion of the housing of the automatic
injection device and an external portion of the proximal tubular
portion of the syringe carrier; and wherein the proximal tubular
portion and/or a chamfered edge of the syringe carrier assembly are
cooperatively coupled to exhibit a gradual downward force slope
substantially along a distance from a retracted position to a
deployed position.
2. The syringe carrier assembly of claim 1, wherein the height of
the constrained space is configured to be at least equal to a
thickness of the distal arms of the shroud.
3. The syringe carrier assembly of claim 1, wherein an outer
diameter of the proximal tubular portion of the syringe carrier
assembly is configured to range from about 13.0 mm to about 14.0
mm.
4. The syringe carrier assembly of claim 1, wherein the chamfered
edge has an angle ranging from about 5 degrees to about 60
degrees.
5. The syringe carrier assembly of claim 1, wherein the proximal
tubular portion of the syringe carrier assembly comprises: a slot
formed in an outer surface of the proximal tubular portion to
create a depression or trough in the outer surface.
6. The syringe carrier assembly of claim 1, wherein the slot has a
depth ranging from about 0.1 mm to about 0.5 mm.
7. An automatic injection device, comprising: a housing having an
internal bore extending between a proximal end and a distal end,
the internal bore including a flange having diametrically opposed
openings therein; and a shroud disposed within the internal bore at
the proximal end of the housing of the automatic injection device,
the shroud movable between a retracted position and an extended
position relative to the housing, the shroud comprising: a tubular
member extending between a proximal end and a distal end, and one
or more arms extending from the distal end of the tubular member;
and wherein, as the shroud is deployed from the retracted position
to the extended position, the arms of the shroud move forwardly
through the diametrically opposed openings in the flange of the
housing, wherein the flange is configured to minimize engagement of
the arms with an edge of the flange to facilitate movement of the
arms of the shroud through the opening of the flange during
deployment of the shroud.
8. The automatic injection device of claim 7, wherein the flange is
configured to minimize bending of the arms of the shroud.
9. The automatic injection device of claim 7, wherein the portion
of the flange abutting the opening is removed to increase the width
of the opening.
10. The automatic injection device of claim 9, wherein a length of
the removed portion of the flange ranges from 0.05 mm to 0.6
mm.
11. The automatic injection device of claim 7, wherein, once the
shroud is deployed to the extended position, the shroud is
configured to withstand a force of at least 80 N without retracting
to the retracted position.
12. The automatic injection device of claim 7, wherein the
automatic injection device comprises a dose of a TNF.alpha.
inhibitor.
13. The automatic injection device of claim 7, further comprising:
a syringe carrier coupled to and disposed partly within the tubular
member of the shroud, the syringe carrier comprising a cylindrical
portion having a slot formed in an outer surface of the cylindrical
portion to create a depression or trench in the outer surface
extending along a length of the syringe carrier; wherein the slot
increases a constrained space formed between an inner portion of
the housing of the automatic injection device and an external
portion of the cylindrical portion of the syringe carrier.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/007,849, filed on Dec. 11, 2013, which is
incorporated herein by reference in its entirety. U.S. patent
application Ser. No. 14/007,849 is a National Stage Entry of
International Patent Application No. PCT/US2012/031260, filed on
Mar. 29, 2012, which claims priority to U.S. Provisional Patent
Application No. 61/469,077, filed on Mar. 29, 2011, each of which
is incorporated herein by reference in their entirety. This
application is also related to U.S. patent application Ser. No.
12/770,557, filed on Apr. 29, 2010, which is also incorporated
herein by reference in its entirety.
BACKGROUND
[0002] Automatic injection devices offer an alternative to
manually-operated syringes for delivering therapeutic agents into
patients' bodies and allow patients to self-administer injections.
Automatic injection devices have been used to deliver medications
under emergency conditions, for example, to administer epinephrine
to counteract the effects of a severe allergic reaction. Automatic
injection devices have also been described for use in administering
anti-arrhythmic medications and selective thrombolytic agents
during a heart attack (See, e.g., U.S. Pat. Nos. 3,910,260;
4,004,577; 4,689,042; 4,755,169; and 4,795,433). Various types of
automatic injection devices are also described in, for example,
U.S. Pat. Nos. 3,941,130; 4,261,358; 5,085,642; 5,092,843;
5,102,393; 5,267,963; 6,149,626; 6,270,479; and 6,371,939; and
International Patent Publication No. WO/2008/005315.
[0003] Conventionally, an automatic injection device includes a
housing that houses a syringe and, when operated, causes the
syringe to move forwardly within the housing and a needle to
project from the housing so that a therapeutic agent contained in
the syringe is ejected into a patient's body. An automatic
injection device typically includes a plunger with a distal end
that is seated on a firing body before firing. In order to fire the
device, a patient depresses a firing button which disengages the
distal end of the plunger from the firing body and allows the
plunger to move the syringe forwardly. An automatic injection
device may include a lockout shroud that is deployed during or
after an injection to provide a protecting covering over the needle
and to thereby prevent accidental needle stick injuries to the
user.
[0004] Certain conventional automatic injection devices experience
problematic shroud deployment including, but not limited to,
complete failure in shroud deployment, incomplete shroud
deployment, and complete or incomplete shroud deployment after an
unacceptably long delay, and the like. Each of these problematic
shroud deployment patterns may be referred to as shroud deployment
failure or failure in shroud deployment. Shroud deployment failure
is undesirable in automatic injection device as they can introduce
the risk of accidental needle stick injury caused by an exposed
needle.
SUMMARY
[0005] Exemplary embodiments provide automatic injection devices in
which a shroud is automatically deployed to protectively sheath a
needle after an injection is performed. Exemplary embodiments also
provide shroud deployment assemblies including a shroud and a
syringe carrier that, when cooperatively configured in an automatic
injection device, ensure that the shroud is automatically and
completely deployed after an injection is performed using the
automatic injection device. Exemplary embodiments are also
configured to ensure that, once the shroud is deployed to an
extended position to sheath the needle, accidental forces applied
to the shroud do not succeed in subsequently retracting the shroud
to a retracted position in which the needle would become
exposed.
[0006] In accordance with one exemplary embodiment, a shroud
deployment assembly is provided for use in an automatic injection
device. The shroud deployment assembly includes a shroud and a
syringe carrier. The shroud is disposed within an internal bore of
a housing of the automatic injection device, and is movable between
a retracted position relative to the housing and an extended
position relative to the housing. The shroud includes a tubular
member extending between a proximal end and a distal end, and one
or more arms extending from the distal end of the tubular member.
The syringe carrier is coupled to and disposed partly within the
tubular member of the shroud, and includes a cylindrical portion.
As the shroud is deployed from the retracted position to the
extended position, the arms of the shroud move forwardly within a
constrained space formed between an inner surface of the housing of
the automatic injection device and an outer surface of the
cylindrical portion of the syringe carrier. The constrained space
is maximized and configured to facilitate smooth movement of the
arms of the shroud within the constrained space during deployment
of the shroud, while ensuring proper lockout of the shroud in the
extended position.
[0007] In accordance with another exemplary embodiment, an
automatic injection device is provided. The automatic injection
device includes a housing having an internal bore extending between
a proximal end and a distal end. The automatic injection device
also includes a shroud disposed within the internal bore at the
proximal end of the housing of the automatic injection device. The
shroud is movable between a retracted position relative to the
housing and an extended position relative to the housing. The
shroud includes a tubular member extending between a proximal end
and a distal end, and one or more arms extending from the distal
end of the tubular member. The automatic injection device also
includes a syringe carrier disposed partly within the tubular
member of the shroud, the syringe carrier comprising a tubular
member. As the shroud is deployed from the retracted position to
the extended position, the arms of the shroud move forwardly within
a constrained space formed between an inner surface of the housing
of the automatic injection device and an outer surface of the
tubular member of the syringe carrier. The constrained space is
maximized to facilitate movement of the arms of the shroud within
the constrained space during deployment of the shroud, while
ensuring proper lockout of the shroud in the extended position.
[0008] In accordance with another exemplary embodiment, a method is
provided for forming an automatic injection device. The method
includes providing a housing having an internal bore extending
between a proximal end and a distal end, and disposing a shroud
within the internal bore at the proximal end of the housing of the
automatic injection device. The shroud is movable between a
retracted position and an extended position relative to the
housing, and includes a tubular member extending between a proximal
end and a distal end, and one or more arms extending from the
distal end of the tubular member. The method also includes
disposing a syringe carrier partly within the tubular member of the
shroud, the syringe carrier comprising a tubular member. The method
further includes configuring a constrained space formed between the
housing of the automatic injection device and the tubular member of
the syringe carrier to minimize a pinching effect of the arms
during its movement in the constrained space when moving from the
retracted position to the extended position.
[0009] In accordance with another exemplary embodiment, a method is
provided for using an automatic injection device for delivering an
injection. The method includes providing a shroud having one or
more arms within a housing of the automatic injection device, the
shroud being in a retracted position relative to the housing to
expose a needle through an open proximal end of the shroud. The
method includes delivering an injection using the automatic
injection device through the needle. The method also includes
deploying the shroud from the retracted position to an extended
position relative to the housing of the automatic injection device
to protectively sheath the needle after the injection, the arms of
the shroud moving forwardly within a constrained space formed
between an inner portion of the housing of the automatic injection
device and an outer portion of a tubular member of a syringe
carrier. The constrained space and/or the arms of the shroud are
configured to minimize a pinching effect of the arms during its
movement in the constrained space.
[0010] In accordance with another exemplary embodiment, a syringe
carrier assembly is provided for use in an automatic injection
device. The syringe carrier assembly includes a proximal tubular
portion having a first outer diameter, a distal tubular portion
having a second outer diameter less than the first diameter, and a
chamfered edge formed between the proximal and distal tubular
portions. The syringe carrier assembly is disposed partly within a
tubular member of a shroud. As the shroud moves from a retracted
position relative to the housing to an extended position relative
to the housing, distal arms of the shroud move forwardly within a
constrained space formed between an inner portion of the housing of
the automatic injection device and an external portion of the
proximal tubular portion of the syringe carrier. The proximal
tubular portion and/or the chamfered edge of the syringe carrier
assembly are cooperatively coupled to exhibit a gradual downward
force slope substantially along a distance as the shroud moves from
the retracted position to the extended position.
[0011] In accordance with another exemplary embodiment, an
automatic injection device is provided. The device includes a
housing having an internal bore extending between a proximal end
and a distal end, the internal bore including a flange having at
least one opening. The device also includes a shroud disposed
within the internal bore at the proximal end of the housing of the
automatic injection device. The shroud is movable between a
retracted position and an extended position relative to the
housing. The shroud includes a tubular member extending between a
proximal end and a distal end, and one or more arms extending from
the distal end of the tubular member. As the shroud is deployed
from the retracted position to the extended position, the arms of
the shroud move forwardly through the opening in the flange of the
housing. The flange is configured to minimize engagement of the
arms with an edge of the flange to facilitate movement of the arms
of the shroud through the opening of the flange during deployment
of the shroud.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and other objects, aspects, features and
advantages of exemplary embodiments will be more fully understood
from the following description when read together with the
accompanying drawings, in which:
[0013] FIG. 1 illustrates a perspective view of an exemplary
automatic injection device in which caps that cover proximal and
distal ends of the housing are removed from the housing.
[0014] FIG. 2 illustrates a perspective view of the exemplary
automatic injection device of FIG. 1 in which the housing is capped
using proximal and distal caps.
[0015] FIG. 3 (prior art) illustrates a cross-sectional schematic
view of an exemplary automatic injection device before use.
[0016] FIG. 4 (prior art) illustrates a cross-sectional schematic
view of the exemplary automatic injection device of FIG. 3 during a
subsequent stage of operation.
[0017] FIG. 5 illustrates a perspective view of an exemplary
automatic injection device including a syringe housing sub-assembly
and a firing mechanism sub-assembly.
[0018] FIG. 6 illustrates an exploded perspective view of the
firing mechanism sub-assembly of the exemplary automatic injection
device of FIG. 5.
[0019] FIG. 7 illustrates a perspective view of a syringe actuation
component of the exemplary firing mechanism sub-assembly of FIG.
6.
[0020] FIG. 8 illustrates an exploded perspective view of the
syringe housing sub-assembly of the exemplary automatic injection
device of FIG. 5.
[0021] FIG. 9 illustrates a perspective view of a syringe carrier
of the exemplary syringe housing sub-assembly of FIG. 8.
[0022] FIGS. 10A and 10B illustrate cross-sectional views of an
exemplary assembled automatic injection device offset by 90.degree.
angles from each other, in which the syringe housing sub-assembly
and the firing mechanism sub-assembly are coupled together.
[0023] FIG. 11 illustrates a cross-sectional view of an exemplary
assembled automatic injection device.
[0024] FIG. 12 illustrates a cross-sectional view of an exemplary
automatic injection device housing an exemplary syringe.
[0025] FIG. 13A illustrates a perspective view of a syringe housing
sub-assembly in which the shroud is assembled over the syringe
carrier.
[0026] FIG. 13B is a transverse sectional view of the syringe
housing sub-assembly of FIG. 13A, showing contact regions at which
the grooves in the shroud contact with and move relative to the
rails of the syringe carrier.
[0027] FIG. 13C shows a measurement of the inner diameter between
two oppositely-positioned grooves of the shroud.
[0028] FIG. 13D shows a measurement of the outer diameter between
two oppositely-positioned rails of the syringe carrier.
[0029] FIG. 14A illustrates a perspective view of a syringe housing
sub-assembly in which the shroud is fully or partially disposed in
the proximal housing component.
[0030] FIG. 14B illustrates a longitudinal sectional view of the
syringe housing sub-assembly of FIG. 14A, showing the engagement of
the distal arms of the shroud with the flange in the proximal
housing component.
[0031] FIG. 14C shows a measurement of the distance between two
oppositely-positioned openings in the flange that may accommodate
the distal arms of the shroud as the arms pass through the
flange.
[0032] FIG. 14D shows a measurement of the span of the distal arms
of the shroud (i.e., the distance between the terminal ends of the
distal arms taken perpendicular to the length of the shroud).
[0033] FIG. 15A illustrates a perspective view of a syringe housing
sub-assembly in which the syringe carrier and the shroud are
assembled and positioned within the proximal housing component.
[0034] FIG. 15B illustrates a transverse sectional view of the
syringe housing sub-assembly of FIG. 15A, showing the pinching of
the distal arms of the shroud within the constrained space between
the proximal housing component and the syringe carrier.
[0035] FIG. 15C shows a measurement of the inner diameter of the
proximal housing component.
[0036] FIG. 15D shows a measurement of the thickness of a distal
arm of the shroud.
[0037] FIG. 15E shows a measurement of the inner diameter between
two oppositely-positioned distal arms of the shroud.
[0038] FIG. 15F shows a measurement of the outer diameter of the
proximal housing component of the syringe carrier.
[0039] FIG. 16A illustrates a perspective view of a syringe housing
sub-assembly in which the biasing mechanism is disposed between the
syringe carrier and the shroud.
[0040] FIG. 16B illustrates a longitudinal sectional view of the
syringe housing sub-assembly in which the biasing mechanism is
disposed between the syringe carrier and the shroud.
[0041] FIG. 16C shows a measurement of the inner diameter of the
shroud.
[0042] FIG. 16D shows a measurement of the outer diameter of the
biasing mechanism.
[0043] FIGS. 17A and 17B are extension force profile of forces in N
(y-axis) generated during the deployment of a shroud against the
deployment distance in mm (x-axis).
[0044] FIG. 18 illustrates an exemplary retraction and extension
force profile of forces in N (y-axis) against the deployment
distance in mm (x-axis) during the retraction and deployment of a
shroud.
[0045] FIG. 19 illustrates an exemplary retraction and extension
force profile of forces in N (y-axis) against the distance in mm
(x-axis) during the retraction and deployment of a shroud.
[0046] FIG. 20 illustrates an exemplary retraction and extension
force profile of forces in N (y-axis) against deployment distances
in mm (x-axis) in which a downward peak appears in the later stages
of shroud deployment.
[0047] FIG. 21 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during deployment of exemplary shrouds.
[0048] FIG. 22A is a longitudinal sectional view taken through a
proximal housing component housing a shroud, in which the proximal
housing component lacks a flange cut.
[0049] FIG. 22B is a longitudinal sectional view taken through the
proximal housing component, showing the pocket on the proximal side
of the flange.
[0050] FIG. 23A is a longitudinal sectional view taken through a
proximal housing component housing a shroud, in which the proximal
housing component includes a flange cut.
[0051] FIG. 23B is a longitudinal sectional view taken through the
proximal housing component, showing the pocket on the proximal side
of the flange.
[0052] FIG. 24 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during shroud deployment associated with conventional
automatic injection devices that are not configured to improve the
shroud deployment process.
[0053] FIG. 25 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during shroud deployment associated with housing
components with a 0.1 mm flange cut.
[0054] FIG. 26 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during shroud deployment associated with housing
components with a 0.3 mm flange cut.
[0055] FIG. 27 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during shroud deployment associated with housing
components with a 0.3 mm flange cut.
[0056] FIG. 28A illustrates a graph plotting retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis), for an exemplary syringe carrier with a
proximal tubular portion that has been reduced in outer diameter
from about 14.17 mm to about 13.17 mm.
[0057] FIG. 28B illustrates a graph plotting retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis), for an exemplary syringe carrier with a
proximal tubular portion that has been reduced in outer diameter
from about 14.17 mm to about 14.00 mm.
[0058] FIG. 29 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) for a control proximal housing component formed of a
repsol-grade polypropylene material with an inner diameter of about
17.53 mm to about 17.63 mm.
[0059] FIG. 30 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) for an exemplary test proximal housing component formed
of a polycarbonate material with an increased inner diameter of
about 17.72 mm to about 17.85 mm.
[0060] FIG. 31A illustrates a perspective view of an exemplary
syringe carrier having an exemplary chamfer formed between the
proximal tubular portion and the distal tubular portion.
[0061] FIG. 31B illustrates a side view of the exemplary syringe
carrier of FIG. 31A.
[0062] FIG. 32 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in automatic injection devices including ten exemplary
syringe carriers configured as shown in FIGS. 31A and 31B.
[0063] FIG. 33A illustrates a perspective view of an exemplary
syringe carrier having an exemplary chamfer formed between the
proximal tubular portion and the distal tubular portion.
[0064] FIG. 33B illustrates a side view of the exemplary syringe
carrier of FIG. 33A.
[0065] FIG. 34 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIGS. 33A and
33B.
[0066] FIG. 35A illustrates a perspective view of an exemplary
syringe carrier having an exemplary chamfer formed between the
proximal tubular portion and the distal tubular portion.
[0067] FIG. 35B illustrates a side view of the exemplary syringe
carrier of FIG. 35A.
[0068] FIG. 36 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIGS. 35A and
35B.
[0069] FIG. 37 illustrates a perspective view of an exemplary
syringe carrier 2700 having an exemplary chamfer formed between the
proximal tubular portion and the distal tubular portion and an
exemplary slot formed in the proximal tubular portion.
[0070] FIG. 38 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIG. 37.
[0071] FIG. 39 illustrates a perspective view of an exemplary
syringe carrier 2900 having an exemplary chamfer formed between the
proximal tubular portion and the distal tubular portion and an
exemplary slot formed in the proximal tubular portion.
[0072] FIG. 40 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIG. 39.
[0073] FIG. 41 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices in which a slot
having a depth of about 0.3 mm is introduced to the syringe
carriers and a 0.1 mm flange cut is introduced to the flanges in
the proximal housing components.
[0074] FIG. 42 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices in which a slot
having a depth of about 0.3 mm is introduced to the syringe
carriers and a 0.3 mm flange cut is introduced to the flanges in
the proximal housing components.
[0075] FIG. 43 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers in which a slot having a depth of about
0.3 mm and a chamfer having an exemplary width of about 0.7 mm and
an exemplary angle of about 10 degrees are introduced to the
syringe carriers.
[0076] FIG. 44 illustrates a perspective view of an exemplary
syringe carrier having an exemplary chamfer formed between the
proximal tubular portion and the distal tubular portion.
[0077] FIG. 45 illustrates a perspective view of an exemplary
syringe carrier having an exemplary slot formed in the proximal
tubular portion of the syringe carrier to create a depression in
the surface of the proximal tubular portion.
[0078] FIGS. 46-48 illustrate graphs of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary syringe carriers of a first type, a second
type, and a third type.
[0079] FIG. 49 illustrates a perspective view of an exemplary
syringe carrier in which the living hinge includes a draft in the
proximal anchor portion of the syringe carrier.
[0080] FIG. 50 illustrates a perspective view of an exemplary
syringe carrier including a rail extending between a proximal end
and a distal end.
[0081] FIG. 51 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary COF values of about 0.000, about 0.125, and
about 0.300.
[0082] FIG. 52 illustrates a graph of shroud override forces in N
(y-axis) against override distance in mm (x-axis) for the control
and exemplary test syringe carriers.
[0083] FIG. 53 illustrates a histogram of peak shroud override
forces in N (y-axis) for the control and exemplary test syringe
carriers.
DETAILED DESCRIPTION
[0084] Exemplary embodiments provide automatic injection devices in
which a needle shroud is automatically deployed in a reliable and
consistent manner to protectively sheath a needle after an
injection is delivered using the automatic injection device.
Exemplary embodiments also provide shroud deployment assemblies
including a needle shroud and a syringe carrier that when
cooperatively configured in an automatic injection device ensure
that the needle shroud is automatically deployed in a reliable and
consistent manner after an injection is delivered using the
automatic injection device. Exemplary embodiments thereby avoid the
risk of accidental needle injury caused by an exposed needle.
[0085] Exemplary embodiments are also configured to ensure that,
once the shroud is deployed to an extended position to sheath the
needle, accidental forces applied to the shroud do not succeed in
subsequently retracting the shroud to a retracted position in which
the needle would become exposed. Exemplary embodiments thereby
avoid re-introduction of the risk of accidental needle stick
injury. In some exemplary embodiments, the maximum force that an
exemplary shroud, once deployed to an extended position, can
reliably withstand without retracting back to a retracted position
(referred to as the "override force") is about 80 N to about 120
N.
[0086] Exemplary embodiments may implement one or a combination of
two or more of the structural, functional and operational
configurations taught herein to minimize the risk of shroud
deployment failure. Exemplary embodiments may also modify one or
more conventional components of an automatic injection device in
accordance with the teachings provided herein in order to minimize
the risk of shroud deployment failure in the modified conventional
components.
[0087] Automatic injection devices provided in accordance with
exemplary embodiments may be used for administering any type of
substance into a patient's body including, but not limited to,
liquid therapeutic agents, e.g., adalimumab (HUMIRA.RTM.),
golimumab, etc.
I. DEFINITIONS
[0088] Certain terms are defined in this section to facilitate
understanding of exemplary embodiments.
[0089] The terms "automatic injection device," "autoinjector" and
"autoinjector pen" refer to a device that enables a patient to
self-administer a dose of a substance, such as a liquid medication,
wherein the automatic injection device differs from a standard
syringe by the inclusion of a firing mechanism sub-assembly for
automatically delivering the substance into the patient's body by
injection when the firing mechanism sub-assembly is engaged. In an
exemplary embodiment, the automatic injection device may be
wearable on the patient's body.
[0090] The automatic injection device, e.g., autoinjector pen, of
exemplary embodiments may include a "therapeutically effective
amount" or a "prophylactically effective amount" of an antibody or
antibody portion of the invention. A "therapeutically effective
amount" refers to an amount effective, at dosages and for periods
of time necessary, to achieve the desired therapeutic result. A
therapeutically effective amount of the antibody, antibody portion,
or other TNF.alpha. inhibitor may vary according to factors such as
the disease state, age, sex, and weight of the patient, and the
ability of the antibody, antibody portion, or other TNF.alpha.
inhibitor to elicit a desired response in the patient. A
therapeutically effective amount is also one in which any toxic or
detrimental effects of the antibody, antibody portion, or other
TNF.alpha. inhibitor are outweighed by the therapeutically
beneficial effects. A "prophylactically effective amount" refers to
an amount effective, at dosages and for periods of time necessary,
to achieve the desired prophylactic result. Typically, since a
prophylactic dose is used in patients prior to or at an earlier
stage of disease, the prophylactically effective amount will be
less than the therapeutically effective amount.
[0091] The term "substance" refers to any type of drug,
biologically active agent, biological substance, chemical substance
or biochemical substance that is capable of being administered in a
therapeutically effective amount to a patient employing exemplary
automatic injection devices. Exemplary substances include, but are
not limited to, agents in a liquid state. Such agents may include,
but are not limited to, adalimumab (HUMIRA.RTM.) and proteins that
are in a liquid solution, e.g., fusion proteins and enzymes.
Examples of proteins in solution include, but are not limited to,
Pulmozyme (Dornase alfa), Regranex (Becaplermin), Activase
(Alteplase), Aldurazyme (Laronidase), Amevive (Alefacept), Aranesp
(Darbepoetin alfa), Becaplermin Concentrate, Betaseron (Interferon
beta-1b), BOTOX (Botulinum Toxin Type A), Elitek (Rasburicase),
Elspar (Asparaginase), Epogen (Epoetin alfa), Enbrel (Etanercept),
Fabrazyme (Agalsidase beta), Infergen (Interferon alfacon-1),
Intron A (Interferon alfa-2a), Kineret (Anakinra), MYOBLOC
(Botulinum Toxin Type B), Neulasta (Pegfilgrastim), Neumega
(Oprelvekin), Neupogen (Filgrastim), Ontak (Denileukin diftitox),
PEGASYS (Peginterferon alfa-2a), Proleukin (Aldesleukin), Pulmozyme
(Dornase alfa), Rebif (Interferon beta-1a), Regranex (Becaplermin),
Retavase (Reteplase), Roferon-A (Interferon alfa-2), TNKase
(Tenecteplase), and Xigris (Drotrecogin alfa), Arcalyst
(Rilonacept), NPlate (Romiplostim), Mircera (methoxypolyethylene
glycol-epoetin beta), Cinryze (C1 esterase inhibitor), Elaprase
(idursulfase), Myozyme (alglucosidase alfa), Orencia (abatacept),
Naglazyme (galsulfase), Kepivance (palifermin) and Actimmune
(interferon gamma-1b).
[0092] A protein in solution may also be an immunoglobulin or
antigen-binding fragment thereof, such as an antibody or
antigen-binding portion thereof. Examples of antibodies that may be
used in an exemplary automatic injection device include, but are
not limited to, chimeric antibodies, non-human antibodies, human
antibodies, humanized antibodies, and domain antibodies (dAbs). In
an exemplary embodiment, the immunoglobulin or antigen-binding
fragment thereof, is an anti-TNF.alpha. and/or an anti-IL-12
antibody (e.g., it may be a dual variable domain immunoglobulin
(DVD) IgTM). Other examples of immunoglobulins or antigen-binding
fragments thereof that may be used in the methods and compositions
of exemplary embodiments include, but are not limited to, 1D4.7
(anti-IL-12/IL-23 antibody; Abbott Laboratories); 2.5(E)mg1
(anti-IL-18; Abbott Laboratories); 13C5.5 (anti-IL-13 antibody;
Abbott Laboratories); J695 (anti-IL-12; Abbott Laboratories);
Afelimomab (Fab 2 anti-TNF; Abbott Laboratories); HUMIRA.RTM.
(adalimumab) Abbott Laboratories); Campath (Alemtuzumab); CEA-Scan
Arcitumomab (fab fragment); Erbitux (Cetuximab); Herceptin
(Trastuzumab); Myoscint (Imciromab Pentetate); ProstaScint
(Capromab Pendetide); Remicade (Infliximab); ReoPro (Abciximab);
Rituxan (Rituximab); Simulect (Basiliximab); Synagis (Palivizumab);
Verluma (Nofetumomab); Xolair (Omalizumab); Zenapax (Daclizumab);
Zevalin (Ibritumomab Tiuxetan); Orthoclone OKT3 (Muromonab-CD3);
Panorex (Edrecolomab); Mylotarg (Gemtuzumab ozogamicin); golimumab
(Centocor); Cimzia (Certolizumab pegol); Saris (Eculizumab); CNTO
1275 (ustekinumab); Vectibix (panitumumab); Bexxar (tositumomab and
1131 tositumomab); and Avastin (bevacizumab).
[0093] Additional examples of immunoglobulins, or antigen-binding
fragments thereof, that may be used in the methods and compositions
of exemplary embodiments include, but are not limited to, proteins
comprising one or more of the following: the D2E7 light chain
variable region (SEQ ID NO: 1), the D2E7 heavy chain variable
region (SEQ ID NO: 2), the D2E7 light chain variable region CDR3
(SEQ ID NO: 3), the D2E7 heavy chain variable region CDR3 (SEQ ID
NO:4), the D2E& light chain variable region CDR2 (SEQ ID NO:
5), the D2E7 heavy chain variable region CDR2 (SEQ ID NO: 6), the
D2E7 light chain variable region CDR1 (SEQ ID NO: 7), the D2E7
heavy chain variable region CDR1 (SEQ ID NO: 8), the 2SD4 light
chain variable region (SEQ ID NO: 9), the 2SD4 heavy chain variable
region (SEQ ID NO: 10), the 2SD4 light chain variable CDR3 (SEQ ID
NO: 11), the EP B12 light chain variable CDR3 (SEQ ID NO: 12), the
VL10E4 light chain variable CDR3 (SEQ ID NO: 13), the VL100A9 light
chain variable CDR3 (SEQ ID NO: 14), the VLL100D2 light chain
variable CDR3 (SEQ ID NO: 15), the VLL0F4 light chain variable CDR3
(SEQ ID NO: 16), the LOE5 light chain variable CDR3 (SEQ ID NO:
17), the VLLOG7 light chain variable CDR3 (SEQ ID NO: 18), the
VLLOG9 light chain variable CDR3 (SEQ ID NO: 19), the VLLOH1 light
chain variable CDR3 (SEQ ID NO: 20), the VLLOH10 light chain
variable CDR3 (SEQ ID NO: 21), the VL1B7 light chain variable CDR3
(SEQ ID NO: 22), the VL1C1 light chain variable CDR3 (SEQ ID NO:
23), the VL0.1F4 light chain variable CDR3 (SEQ ID NO: 24), the
VL0.1H8 light chain variable CDR3 (SEQ ID NO: 25), the LOE7. A
light chain variable CDR3 (SEQ ID NO: 26), the 2SD4 heavy chain
variable region CDR (SEQ ID NO: 27), the VH1B11 heavy chain
variable region CDR (SEQ ID NO: 28), the VH1D8 heavy chain variable
region CDR (SEQ ID NO: 29), the VH1A11 heavy chain variable region
CDR (SEQ ID NO: 30), the VH1B12 heavy chain variable region CDR
(SEQ ID NO: 31), the VH1E4 heavy chain variable region CDR (SEQ ID
NO: 32), the VH1F6 heavy chain variable region CDR (SEQ ID NO: 33),
the 3C-H2 heavy chain variable region CDR (SEQ ID NO: 34), and the
VH1-D2. N heavy chain variable region CDR (SEQ ID NO: 35).
[0094] The term "human TNF.alpha." (abbreviated herein as
hTNF.alpha., or simply hTNF) refers to a human cytokine that exists
as a 17 kD secreted form and a 26 kD membrane associated form, the
biologically active form of which is composed of a trimer of
noncovalently bound 17 kD molecules. The structure of hTNF.alpha.
is described further in, for example, Pennica, D., et al. (1984)
Nature 312:724-729; Davis, J. M., et al. (1987) Biochem.
26:1322-1326; and Jones, E. Y., et al. (1989) Nature 338:225-228.
The term human TNF.alpha. is intended to include recombinant human
TNF.alpha. (rhTNF.alpha.), which can be prepared by standard
recombinant expression methods or purchased commercially (R & D
Systems, Catalog No. 210-TA, Minneapolis, Minn.). TNF.alpha. is
also referred to as TNF.
[0095] The term "TNF.alpha. inhibitor" refers to an agent that
interferes with TNF.alpha. activity. The term also includes each of
the anti-TNF.alpha. human antibodies (used interchangeably herein
with TNF.alpha. antibodies) and antibody portions described herein
as well as those described in U.S. Pat. Nos. 6,090,382; 6,258,562;
6,509,015; 7,223,394; and 6,509,015. In one embodiment, the
TNF.alpha. inhibitor used in the invention is an anti-TNF.alpha.
antibody, or a fragment thereof, including infliximab
(Remicade.RTM., Johnson and Johnson; described in U.S. Pat. No.
5,656,272); CDP571 (a humanized monoclonal anti-TNF-alpha IgG4
antibody); CDP 870 (a humanized monoclonal anti-TNF-alpha antibody
fragment); an anti-TNF dAb (Peptech); CNTO 148 (golimumab;
Centocor, See WO 02/12502 and U.S. Pat. No. 7,521,206 and U.S. Pat.
No. 7,250,165); and adalimumab (HUMIRA.RTM. Abbott Laboratories, a
human anti-TNF mAb, described in U.S. Pat. No. 6,090,382 as D2E7).
Additional TNF antibodies that may be used in the invention are
described in U.S. Pat. Nos. 6,593,458; 6,498,237; 6,451,983; and
6,448,380. In another embodiment, the TNF.alpha. inhibitor is a TNF
fusion protein, e.g., etanercept (Enbrel.RTM., Amgen; described in
WO 91/03553 and WO 09/406476). In another embodiment, the
TNF.alpha. inhibitor is a recombinant TNF binding protein (r-TBP-I)
(Serono).
[0096] In one embodiment, the term "TNF.alpha. inhibitor" excludes
infliximab. In one embodiment, the term "TNF.alpha. inhibitor"
excludes adalimumab. In another embodiment, the term "TNF.alpha.
inhibitor" excludes adalimumab and infliximab.
[0097] In one embodiment, the term "TNF.alpha. inhibitor" excludes
etanercept, and, optionally, adalimumab, infliximab, and adalimumab
and infliximab.
[0098] In one embodiment, the term "TNF.alpha. antibody" excludes
infliximab. In one embodiment, the term "TNF.alpha. antibody"
excludes adalimumab. In another embodiment, the term "TNF.alpha.
antibody" excludes adalimumab and infliximab.
[0099] The term "treatment" refers to therapeutic treatment, as
well as prophylactic or suppressive measures, for the treatment of
a disorder, such as a disorder in which TNF.alpha. is detrimental,
e.g., rheumatoid arthritis.
[0100] The term "patient" or "user" refers to any type of animal,
human or non-human, that may be injected a substance using
exemplary automatic injection devices.
[0101] The terms "pre-filled syringe/device" and "pre-fillable
syringe/device" encompass a syringe/device that is filled with a
substance immediately prior to administration of the substance to a
patient and a syringe/device that is filled with a substance and
stored in this pre-filled form for a period of time before
administration of the substance to a patient.
[0102] The term "plunger" refers to a structural member in an
automatic injection device for selectively moving and actuating a
syringe to inject a dose contained in the syringe into a patient's
body.
[0103] The term "firing mechanism" refers to a mechanism that, when
engaged by a firing engagement mechanism, automatically delivers a
substance contained in an automatic injection device into a
patient's body. A firing engagement mechanism may be any type of
mechanism that engages and triggers the firing mechanism including,
but not limited to, a firing button that may be pushed by a patient
to trigger the firing mechanism. In an exemplary embodiment, the
firing mechanism may be engaged once to automatically deliver one
dose of a substance contained in an automatic injection device. In
another exemplary embodiment, the firing mechanism may be engaged
more than once to automatically deliver more than one dose of a
substance, e.g., insulin, contained in an automatic injection
device. In this exemplary embodiment, the automatic injection
device may be re-filled with the substance between doses.
[0104] The term "syringe housing assembly" refers to a collection
of components in an automatic injection device that are
cooperatively configured to house a syringe, facilitate actuation
of the syringe to perform an injection, hold a lockout shroud in a
retracted position during an injection, and automatically deploy
the shroud to an extended position during or after an
injection.
[0105] The term "syringe carrier" refers to a structural member in
an automatic injection device that envelopes a portion of a syringe
used in the device. In an exemplary embodiment, the syringe carrier
may be configured to hold and guide the syringe within the housing
of the device in order to move the syringe forward to an injecting
position.
[0106] The term "shroud" or "lockout shroud" refers to a protective
covering for a needle that, when deployed, covers the needle and
prevents accidental needle stick injury that may be caused by an
exposed needle.
[0107] The term "retracted position" relating to a shroud refers to
a position of the shroud relative to the syringe that allows the
needle to extend through a proximal opening of the shroud. In an
exemplary embodiment, the retracted position of the shroud may be
achieved by using a force from a biasing member to push the shroud
distally relative to the housing or relative to the syringe.
[0108] The term "extended position" or "deployed position" relating
to a shroud refers to a position of the shroud relative to the
syringe that allows the shroud to protectively cover the needle and
prevents the needle from extending through a proximal opening of
the shroud. In an exemplary embodiment, the extended position of
the shroud may be achieved by using the force exerted by a biasing
mechanism to push the shroud in the proximal direction relative to
the housing or relative to the syringe.
[0109] The term "shroud deployment mechanism" refers to a mechanism
that includes and automatically deploys a shroud to protectively
cover a needle. In exemplary embodiments, the shroud may be
deployed during and/or after an injection is delivered using the
device. In an exemplary embodiment, the shroud deployment mechanism
may hold the shroud in a retracted position during use of the
needle in an injection, and may automatically deploy the shroud to
an extended position to cover the needle during and/or after the
needle is removed from the injection site. An exemplary shroud
deployment mechanism may include a shroud, a biasing mechanism and
part of a housing, all cooperatively engaged to hold the shroud
retracted in the retracted position during a first time period (for
example, during an injection) and to deploy the shroud to the
extended position during a second time period (for example, during
and/or after an injection).
[0110] The term "shroud deployment failure" or "failure in shroud
deployment" refers to a problematic deployment of a shroud of an
automatic injection device that provides a protective covering over
a needle. Shroud deployment failure may include, but is not limited
to, non-deployment of the shroud, partial deployment of the shroud,
complete or partial deployment of the shroud after an unacceptably
long delay, and the like. In an exemplary embodiment, an acceptable
delay may range from about zero to about two seconds. In this
exemplary embodiment, shroud deployment with a delay greater than
about two seconds may constitute a shroud deployment failure.
[0111] The term "extension force" refers to the force with which an
exemplary shroud of an automatic injection device is deployed from
a retracted position to an extended position.
[0112] The term "retraction force" refers to the force with which
an exemplary shroud of an automatic injection device is moved from
an extended position to a retracted position.
[0113] The term "residual extension force" refers to the forces
experienced at or near the end of the shroud deployment process
when the shroud is at or is approaching its fully extended
position.
[0114] The term "override force" refers to the maximum force that
an exemplary shroud, once deployed to an extended position, can
reliably resist or withstand without retracting back toward a
retracted position and exposing the needle. Exemplary shroud
override forces may include, but are not limited to, about 80 N to
about 120 N. In an exemplary embodiment, the needle may be about
7.4 mm from the proximal end of the extended shroud before an
override force is applied to the shroud. In an exemplary
embodiment, the maximum override force may be reached before the
shroud travels about 2-3 mm in the distal direction from its
extended position.
[0115] The term "distal" refers to a portion, end or component of
an exemplary automatic injection device that is farthest from an
injection site on the patient's body when the device is held
against the patient for an injection or for mimicking an
injection.
[0116] The term "proximal" refers to a portion, end or component of
an exemplary automatic injection device that is closest to an
injection site on a patient's body when the device is held against
the patient for an injection or for mimicking an injection.
II. EXEMPLARY AUTOMATIC INJECTION DEVICES
[0117] Exemplary embodiments are described below with reference to
certain illustrative embodiments. While exemplary embodiments are
described with respect to using an automatic injection device to
provide an injection of a dose of a liquid medication, one of
ordinary skill in the art will recognize that exemplary embodiments
are not limited to the illustrative embodiments and that exemplary
automatic injection devices may be used to inject any suitable
substance into a patient. In addition, components of exemplary
automatic injection devices and methods of making and using
exemplary automatic injection devices are not limited to the
illustrative embodiments described below.
[0118] A syringe of an exemplary automatic injections device may
contain a dose of a TNF.alpha. inhibitor. In an exemplary
embodiment, the TNF.alpha. inhibitor may be a human TNF.alpha.
antibody or antigen-biding portion thereof. In an exemplary
embodiment, the human TNF.alpha. antibody or antigen-binding
portion thereof may be adalimumab or golimumab.
[0119] FIGS. 1 and 2 illustrate an exemplary automatic injection
device 10 suitable for injecting a dose of a substance, such as a
liquid drug, into a patient. FIG. 1 illustrates a perspective view
of the exemplary automatic injection device 10 in which caps that
cover proximal and distal ends of the housing are removed. FIG. 2
illustrates a perspective view of the exemplary automatic injection
device 10 of FIG. 1 in which the proximal and distal ends of the
housing are capped using proximal and distal caps.
[0120] Referring to FIG. 1, the automatic injection device 10
includes a housing 12 for housing a container, such as a syringe,
containing a dose of a substance to be injected into a patient's
body. The housing 12 has a tubular configuration, although one of
ordinary skill in the art will recognize that the housing 12 may
have any size, shape and configuration capable of housing a syringe
or other container. While exemplary embodiments will be described
with respect to a syringe mounted in the housing 12, one of
ordinary skill in the art will recognize that the automatic
injection device 10 may employ any other suitable container for
storing and dispensing a substance, for example, a cartridge.
[0121] The exemplary syringe is preferably slidably mounted in the
housing 12, as described in detail below. When the device 10 is in
an inactivated position, the syringe is sheathed and retracted
within the housing 12. When the device 10 is actuated, a needle
coupled to a proximal end of the syringe projects from a proximal
end 20 of the housing 12 to allow ejection of the substance from
the syringe into the patient's body. As shown, the proximal end 20
of the housing 12 includes an opening 28 through which the needle
of the syringe projects when the device 10 is actuated. In an
exemplary embodiment, the opening 28 may be located in the housing
12 itself. In another exemplary embodiment, the opening 28 may be
located in another internal component, e.g., a shroud used to cover
the needle. In another exemplary embodiment, the opening 28 may be
located in the housing 12 and another internal component, e.g., a
shroud.
[0122] Referring still to FIG. 1, a distal end 30 of the housing 12
includes a firing engagement mechanism, e.g., a firing button 32,
configured to actuate a firing mechanism. The housing 12 also
houses the firing mechanism, e.g., one or more actuators,
configured to drive the syringe from a sheathed or retracted
position within the housing 12 (in which the needle does not
project from the housing 12) to a projecting position (in which the
needle projects from the housing 12). The firing mechanism is
configured to subsequently expel the substance from the syringe
through the needle into the patient's body.
[0123] The exemplary automatic injection device 10 may include a
removable proximal cap 24 (or needle cap) for covering the proximal
end 20 of the housing 12 to prevent exposure of the needle prior to
an injection. In the illustrative embodiment, the proximal cap 24
may include a boss 26 for locking and/or joining the proximal cap
24 to the housing 12 until the patient is ready to activate the
device 10. Alternatively, the proximal cap 24 may include a
threaded screw portion, and the internal surface of the housing 12
at opening 28 may include a screw thread. Any suitable mating
mechanism may be used in accordance with the teachings of exemplary
embodiments.
[0124] The exemplary automatic injection device 10 may include a
removable distal cap 34 configured to cover the firing button 32 to
prevent exposure and accidental engagement of the firing button 32
prior to an injection. A step 29 may be formed at the distal end of
the housing 12 to accommodate the distal cap 34. In an exemplary
embodiment, the distal cap 34 may be coupled to the firing button
32 in a snap-fit. In another exemplary embodiment, the distal cap
34 may include a boss for locking and/or joining the distal cap 34
to the firing button 32 of the device 10 until the patient is ready
to activate the device 10. In another exemplary embodiment, the
distal cap 34 may include a threaded screw portion, and a surface
of the firing button 32 may include a screw thread. Any suitable
mating mechanism may be used in accordance with the teachings of
exemplary embodiments.
[0125] The housing 12 and caps 24, 34 may include graphics, symbols
and/or numbers to facilitate use of the automatic injection device
10. For example, the housing 12 may include an arrow 125 on an
outer surface pointing towards the proximal end 20 of the device 10
to indicate how the device 10 should be held relative to the
patient (i.e., with the proximal end 20 placed on the injection
site). In addition, the proximal cap 24 is labeled with a "1" to
indicate that a patient should remove the proximal cap 24 of the
device first, and the distal cap is labeled with a "2" to indicate
that the distal cap 34 should be removed after the proximal cap 24
is removed in preparation for an injection. One of ordinary skill
in the art will recognize that the automatic injection device 10
may have any suitable graphics, symbols and/or numbers to
facilitate patient instruction, or the automatic injection device
10 may omit such graphics, symbols and/or numbers.
[0126] The housing 12 may also preferably include a display window
130 to allow a patient to view the contents of the syringe housed
within the housing 12. The window 130 may include an opening in the
sidewall of the housing 12, or may include a translucent material
in the housing 12 to allow viewing of the interior of the device
10. The housing 12 may be formed of any suitable biocompatible or
surgical material including, but not limited to, plastics and other
known materials.
[0127] FIGS. 3 and 4 (prior art) are cross-sectional schematic
views of the components of an exemplary automatic injection device
10. FIG. 3 (prior art) illustrates a cross-sectional schematic view
of the exemplary automatic injection device 10 prior to use. FIG. 4
(prior art) illustrates a cross-sectional schematic view of the
exemplary automatic injection device 10 of FIG. 3 during a
post-injection stage of operation.
[0128] As illustrated in FIGS. 3 and 4, a syringe 50 or other
suitable container for a substance is disposed within the interior
of the housing 12 of the device 10. An exemplary syringe 50 may
include a hollow barrel portion 53 for holding a dose of a liquid
substance to be injected into a patient's body. An exemplary barrel
portion 53 is substantially cylindrical in shape, although one of
ordinary skill in the art will recognize that the barrel portion 53
may have any suitable shape or configuration. A seal, illustrated
as a bung 54, seals the dose within the barrel portion 53. The
syringe 50 may also include a hollow needle 55 connected to and in
fluid communication with the barrel portion 53, through which the
dose can be ejected by applying pressure to the bung 54. The hollow
needle 55 extends from a proximal end 53a of the barrel portion 53.
A distal end 53b of the barrel portion 53 includes a flange 56, or
other suitable mechanism, for abutting a stop 123 in the housing 12
to limit the movement of the syringe 50 within the housing 12, as
described below. One of ordinary skill in the art will recognize
that exemplary embodiments are not limited to the illustrative
syringe 50 and that any suitable container for containing a dose of
a substance to be injected may be used in accordance with the
teachings of exemplary embodiments.
[0129] Any suitable needle 55 may be used in an exemplary automatic
injection device. In an exemplary embodiment, the needle 55 may be
a fixed twenty-seven gauge one-half inch needle. In another
exemplary embodiment, the needle 55 may be a twenty-nine gauge
one-half inch needle. The tip of an exemplary hollow needle 55 may
include a number of bevels, e.g., five bevels, to facilitate
insertion. However, the needle 55 may have any suitable size, shape
and configuration suitable for piercing a patient's skin to deliver
a substance to the patient's body, and is not limited to the
illustrative embodiment. Suitable types of needles are well-known
in the art.
[0130] The automatic injection device 10 shown in FIGS. 3 and 4 may
include a syringe actuation component 70, illustrated as a plunger,
for selectively injecting the dose contained in the syringe 50 into
a patient's body. The exemplary plunger 70 may include a rod
portion 71 having a first end 71a connected to the bung 54 for
selectively applying pressure to the bung 54 to expel the dose
through the needle 55. The plunger 70 may include a flanged second
end 72. In an exemplary embodiment, the plunger 70 may include more
or fewer components than those illustrated in FIGS. 3 and 4. In an
exemplary embodiment, the device 10 may include more or fewer
actuators than those illustrated in FIGS. 3 and 4.
[0131] The plunger 70 may be biased forward towards the proximal
end 20 of the device 10 by a first biasing mechanism, illustrated
as a coil spring 88, disposed about or above the flanged second end
72 of the plunger 70. A proximal end 88a of the coiled spring 88
may abut the flanged second end 72 of the plunger 70 to selectively
apply pressure to the plunger 70 and to move the plunger 70 toward
the injection site on the patient's body. Alternatively, the
plunger 70 may extend through the center of the spring 88.
[0132] As illustrated in FIG. 3, prior to use of the device 10, the
coil spring 88 (or another suitable mechanism) may be compressed
between the plunger 70 and a component or internal surface of the
device, thus storing energy. A trigger 91, which may be activated
by any suitable actuation means such as an activation mechanism
320, may retain the plunger 70 and the first biasing mechanism 88
in a retracted, latched position before the activation mechanism
320 is activated. The trigger 91 may latch the flanged second end
72 of the plunger 70. When the activation mechanism 320 or other
actuation means is activated, the trigger 91 may release the
flanged second end 72 of the plunger 70, allowing the coil spring
88 to propel the plunger 70 towards the first end of the device
10.
[0133] A second biasing mechanism, illustrated as an exemplary coil
spring 89, may hold the syringe 50 in a retracted position within
the housing 12 prior to use, as shown in FIG. 3. In the retracted
position, the needle 55 may be preferably sheathed entirely within
the housing 12. The exemplary syringe coil spring 89 may be
disposed about the distal portion of the barrel portion 53 and may
be seated in a shelf 121 formed within the housing 12. The distal
end of the coil spring 89 may abut the flanged distal end 56 of the
syringe 50. The spring force of the second biasing mechanism 89 may
push the flanged distal end 56 of the syringe 50 away from the
proximal end 20 of the housing 12, thereby holding the syringe 50
in the retracted position until activated. Other components of the
device 10 may also be used to position the syringe 50 relative to
the housing 12.
[0134] The first biasing mechanism 88 and the second biasing
mechanism 89 may have any suitable configuration and tension
suitable for use in biasing certain components of the device. For
example, the first biasing mechanism 88 may have any suitable size,
shape, energy and properties suitable for driving the plunger 70
and the syringe 50 forward when released or actuated. The second
biasing mechanism 89 may have any suitable size, shape, energy and
properties suitable for retracting the syringe 50 prior to
actuation of the first biasing mechanism 88. Other suitable means
for facilitating movement of the plunger 70 and/or syringe 50 may
also be used. Other suitable means of latching spring 88 may also
be used.
[0135] Referring still to the illustrative embodiment of FIGS. 3
and 4, the plunger 70 may include a rod portion 71 and an exemplary
radially compressible expanded portion 76 at the center of the
plunger 70 between proximal and distal solid portions of the rod
portion 71. In an exemplary embodiment, the expanded portion 76 may
be aligned along the central axis of the rod portion 71. In an
illustrative embodiment, the rod 71 may be split and expanded to
form a pair of projecting elbows 78 that encircle a longitudinal
slit or void and that define the radially compressible expanded
portion 76. The projecting elbows 78 may be pre-formed as part of
the molded plunger 70 or, alternatively, may be attached to the
plunger 70 separately. The projecting elbows 78 may be compressible
so that they can be moved radially inwardly to cause that portion
of the rod 71 to adopt a diameter similar to the rest of the rod
71. The compressible expanded portion 76 facilitates movement of
the syringe 50.
[0136] When an activation mechanism 320 activates the trigger 91 to
release the plunger 70, the spring force of the coil spring 88
propels the plunger 70 forward. The activation mechanism 320 may
have any suitable size, shape, configuration and location suitable
for releasing the plunger 70 or otherwise activating the device 10.
For example, the activation mechanism 320 may include a firing
button formed at a distal end 30 of the housing 12, and/or may
include another suitable device, such as a latch, twist-activated
switch and other devices known in the art. While the illustrative
activation mechanism 320 is located towards a distal end 30 of the
device 10, one of ordinary skill in the art will recognize that the
activation mechanism 320 may be positioned at any suitable location
on the device 10.
[0137] During a first operational stage, the plunger 70 pushes the
syringe 50 forward such that the tip of the needle 55 projects from
the proximal end 20 of the housing 12. The initial biasing force
provided by the first coil spring 88 is sufficient to overcome the
biasing force of the second coil spring 89 to allow movement of the
syringe 50 against the backward biasing force of the second coil
spring 89. In the first operational stage, the expanded region 76
of the plunger 70, formed by the projecting elbows 78 of the
plunger 70, may rest against the flanged distal end 56 of the
syringe 50, or may initially partially enter the barrel portion 53
and, in turn, at least temporarily halt due to stiction forces.
This prevents the plunger 70 from traveling within the syringe
barrel portion 53. In this manner, by stiction or abutment of the
flanged distal end 56, all biasing force from the first coil spring
88 is applied to move the syringe 50 forward towards the proximal
end 20 of the device 10.
[0138] The forward motion of the syringe 50 towards the proximal
end 20 of the device 10 may continue against the biasing force of
the coil spring 89 until the flanged distal end 56 of the barrel
portion 53 abuts the stop 123 in the housing 12, thereby forming a
stopping mechanism 56, 123. One of ordinary skill in the art will
recognize that other stopping mechanisms may be employed and that
exemplary embodiments are not limited to the illustrative stopping
mechanism.
[0139] The first operational stage may propel the tip of the needle
55 through the opening 28 at the proximal end 20 of the device 10,
so that the needle 55 may pierce the patient's skin. During this
stage, the syringe barrel portion 53 may preferably remain sealed
without expelling the substance through the needle 55. The
interference caused by the stopping mechanism 56, 123 may maintain
the needle 55 in a selected position extending from the proximal
open end 28 of the device 10 during subsequent steps. Until the
stopping mechanism 56, 123 stops the movement of the syringe 50,
the compressible expanded portion 76 of the plunger 70 may prevent
movement of the plunger 70 relative to the barrel portion 53. The
stopping mechanism 56, 123 may be positioned at any suitable
location relative to the open proximal end 20 to allow the syringe
50 to penetrate the skin by any suitable depth suitable for an
injection.
[0140] The second operational stage commences after the stop 123 of
the housing 12 catches the flanged portion 56, stopping farther
movement of the barrel portion 53. During this stage, the continued
biasing force of the coil spring 88 may continue to push the
plunger 70 relative to the housing 12, as shown in FIG. 5. The
biasing force may cause the elbows 78 of the plunger 70 to compress
radially inward and slide into the interior of the barrel portion
53. While the interference between components 123 and 56 may retain
the barrel portion 53 in a selected position (with the needle 55
exposed) and with the elbows 78 in a collapsed stage, the coil
spring 88 may push the plunger 70 within the barrel portion 53.
After the plunger 70 overcomes the necessary force to allow the
elbows 78 to compress and extend into the barrel portion 53, the
plunger 70 may apply pressure to the bung 54, causing ejection of
the substance contained in the syringe 50 through the projecting
needle 55. Because the needle 55 was made to penetrate the
patient's skin in the first operational stage, the substance
contained in the barrel portion 53 of the syringe 50 is injected
directly into a portion of the patient's body.
[0141] FIG. 5 illustrates a perspective view of an exemplary
automatic injection device 10 including an exemplary syringe
housing sub-assembly 121 and an exemplary firing mechanism
sub-assembly 122. In an exemplary embodiment, the automatic
injection device 10 may include two interlocking components: a
syringe housing sub-assembly 121 containing the proximal components
of the device 10 (e.g., proximal housing component 12a, syringe
barrel 53, coil spring 89, needle 55 and other proximal components,
etc.), and a firing mechanism sub-assembly 122 containing the
distal components of the device 10 (e.g., firing body 12b, syringe
actuation component 700' having a pressurizer 754' extending out of
an opening 228 at the proximal end 122a of the firing mechanism
sub-assembly 122, etc.). The syringe housing sub-assembly 121 and
the firing mechanism sub-assembly 122 may be coupled through any
suitable means. In an exemplary embodiment, a proximal end 122a of
the firing mechanism sub-assembly 122 may be sized and configured
to be inserted into a distal end 121b of the syringe housing
sub-assembly 121. In addition, one or more tabs 127 at the proximal
end 122a of the firing mechanism sub-assembly 122 may snap-fit into
corresponding openings 126 at the distal end 121b of the syringe
housing assembly 122 to ensure alignment and coupling of the two
assemblies 121, 122 and the components housed therein.
[0142] FIG. 6 illustrates an exploded perspective view of the
firing mechanism assembly 122 of the exemplary automatic injection
device of FIG. 5. FIG. 7 illustrates a perspective view of an
exemplary syringe actuation component 700' included in the firing
mechanism assembly 122. The firing mechanism sub-assembly 122 may
include the firing body 12b (also called the distal housing
component) having a hollow internal bore for housing the biasing
mechanism 88 and a distal portion of the syringe actuation
component 700'. The firing body 12b may include an opening 228 at
the proximal end 122a to allow entry of the biasing mechanism 88
and the syringe actuation component 700' during assembly of the
firing mechanism sub-assembly 122. The firing body 12b may have one
or more ridges or grooves on its outer surface 128 to identify it
and to facilitate gripping of the device 10. The firing body 12b
may include one or more tabs 127 at or near the proximal end 122a
of the firing mechanism sub-assembly 122 configured to snap-fit
into corresponding openings 126 on the distal end 121b of the
syringe housing assembly 122. The firing body 12b may also include
a narrowed distal wall 1234 for supporting the distal end of the
spring 88. The firing body 12b may also include a distal anchoring
cap 12c over which the anchoring portion 789' of the syringe
actuation component 700' may be supported.
[0143] The firing mechanism sub-assembly 122 may also include a
syringe actuator, illustrated as a syringe actuation component
700', which extends from the proximal end 122a of the firing body
12b for driving the syringe 50 forward within the housing 12 in a
first operational stage, and for actuating the bung 54 to expel the
contents of the syringe 50 in a second operational stage. The
proximal end of the syringe actuation component 700' may include be
configured as a pressurizer 754' for engaging and driving the bung
54. Distal to the pressurizer 754', a pair of elbows 76 may be
provided with a central longitudinal slit or void. The elbows 76
may be aligned along a central axis of the syringe actuation
component 700' and may extend between the pressurizer 754' and a
solid rod portion 70 of the syringe actuation component 700'. The
syringe actuation component 700' may include an indicator 190 at
the solid rod portion 70 distal to the elbows 78. During operation
of the device 10 and after completion of an injection, the
indicator 190 is configured to align with the window 130 on the
housing 12 to indicate at least partial completion of the
injection. The indicator 190 preferably has a distinctive color or
design to represent completion of an injection.
[0144] The illustrative syringe actuation component 700' further
includes a retaining flange 720' for holding the actuating coil
spring 88 in a compressed position until actuation. The retaining
flange 720' is sized, dimensioned and formed of a material that
preferably allows the syringe actuation component 700' to slidably
and easily move within the housing 12 when the device 10 is
actuated. Extending distally from the retaining flange 720', the
syringe actuation component 700' forms a base 788', for the
actuating coil spring 88. The base 788' terminates in a trigger
anchoring portion 789'. The illustrative base 788' may comprise
flexible arms 788a', 788b' around which the spring 88 coils. The
trigger anchoring portion 789' may comprise tabbed feet 7891'
extending from the base 788' and configured to selectively engage
the anchoring cap 12c of the firing body 12b. The firing button 32
coupled to the distal end of the firing body 12b is configured to
hold the trigger anchoring portion 789' retracted until activation.
When activated, the firing button 32 releases the trigger anchoring
portion 789', allowing the coil spring 88 to propel the syringe
actuation component 700' towards the proximal end 20 of the device
10.
[0145] In a retracted, anchored position shown FIGS. 6 and 7, the
trigger anchoring portion 789' interacts with the housing 12, which
holds the tabbed feet 7891' in a latched position against the
biasing force of the coil spring 88, to maintain the syringe
actuation component 700' in a retracted position. In this position,
the flange 720' retracts the spring 88 against the distal wall 1234
of the firing body 12b. An opening in the anchoring cap 12c allows
the firing button 32 access to the anchoring portion 789' of the
syringe actuation component 700'. In the retracted position, the
pressurizer 754' of the syringe actuation component 700' extends
out of an opening 228 at the proximal end 122a of the firing body
12b.
[0146] When the firing body 12b couples to a corresponding syringe
actuation mechanism 700', the pressurizer 754' extends into the
barrel portion of a syringe housed therein. The pressurizer 754'
may be integral with, the same as, connected to, or otherwise in
communication with the bung 54 of a syringe 50 housed in the device
10 and may have any suitable size, shape and configuration suitable
for applying pressure to the bung 54. In one embodiment, the
pressurizer 754' has a cross-section corresponding to the shape of
the barrel portion 53 of a corresponding syringe 50 so as to
substantially seal the barrel portion 53, and the pressurizer 754'
is configured to slidably move within the barrel portion 53 to
apply pressure to the bung 54 and actuate the syringe 50.
[0147] In the illustrative embodiment of FIGS. 6 and 7, the syringe
actuation component 700' constitutes a single, integrated mechanism
for anchoring a corresponding syringe 50, spring 88 and other
components, actuating and moving the syringe 50 to a protracted
position, and separately expelling the contents of the syringe
50.
[0148] FIG. 8 is an exploded perspective view of an exemplary
syringe housing sub-assembly 121 configured to be assembled and
interact with the firing mechanism sub-assembly 122 of FIG. 7. The
components of the syringe housing sub-assembly 121 are
cooperatively configured to house a syringe 50 containing a
substance to be injected and to facilitate operation of the device
10 in the two different operational stages as described above. The
syringe housing sub-assembly 121 includes a syringe carrier 1000
configured to movably hold a syringe. FIG. 9 illustrates a
perspective view of an exemplary syringe carrier 1000. The syringe
housing sub-assembly 121 also includes a shroud 1110 configured to
protectively cover a needle 55 before, during or after use in an
injection. The syringe carrier 1000 and the shroud 1110 may be
coupled together with a second biasing member 89 positioned
therebetween. The syringe carrier 1000, the shroud 1110 and the
biasing member 89 may be placed within the hollow bore of a
proximal housing component 12a whose proximal end may be covered by
the proximal cap 24.
[0149] The proximal housing component 12a is a portion of the
syringe housing 12 that provides a hollow structural member for
accommodating the second biasing mechanism 89, the syringe carrier
1000 and the shroud 1110 of the syringe housing sub-assembly 121.
The proximal housing component 12a may be a tubular member having a
tubular side wall, i.e., may have a substantially cylindrical shape
with a substantially circular cross-section. The proximal housing
component 12a may extend from a proximal end to a distal end along
the longitudinal axis of the automatic injection device. The
proximal housing component 12a may be coupled to the firing body
12b at or near the distal end, and may be coupled to the proximal
cap 24 at or near the proximal end. The proximal housing component
12a may include one or more windows 130 formed or provided in its
side wall to allow a user to view the contents of the syringe 50
disposed inside the proximal housing component 12a.
[0150] The shroud 1110 is a structural member that, when deployed,
provides a protective covering for the needle before, during and/or
after the use of the needle in an injection. The components of the
syringe housing sub-assembly 121 are cooperatively configured to
hold the shroud 1110 in a retracted position relative to the
proximal housing component 12a during an injection and to
automatically deploy the shroud 1110 relative to the proximal
housing component 12a during or after an injection. In an exemplary
embodiment, the shroud 1110 may be positioned at or may form the
proximal end 20 of the housing 12. The shroud 1110 may include a
main tubular body portion 1116 having a tubular side wall, i.e.,
may have a substantially cylindrical shape with a substantially
circular cross-section. The main tubular body portion 1116 may
extend from a proximal end to a distal end along the longitudinal
axis of the automatic injection device.
[0151] The main tubular body portion 1116 may include one or more
slots 1118 extending longitudinally along the body portion. In an
exemplary embodiment, the slot 1118 may provide a longitudinal
track for the movement of a raised rail edge or tabbed foot 1006 of
the syringe carrier 1000 as the syringe carrier 1000 and/or the
shroud 1110 move relative to each other. When the shroud 1110 moves
toward the syringe carrier 1000 during retraction of the shroud,
the tabbed foot 1006 of the syringe carrier 1000 may travel toward
the proximal end of the device along the slot 1118. Conversely,
when the shroud 1110 moves away from the syringe carrier 1000
during deployment of the shroud, the tabbed foot 1006 of the
syringe carrier 1000 may travel toward the distal end of the device
along the slot 1118.
[0152] The distal end of the main tubular body portion 1116 may be
configured as a rim and may be coupled to one or more distal arms
1114 that are spaced apart from each other. In an exemplary
embodiment, two spaced-apart distal arms 1114 are coupled to the
distal end of the main tubular body portion 1116. The distal arms
1114 may take any suitable shape including, but not limited to, a
substantially cylindrical shape with a circular cross-section, a
substantially extended box shape with a rectangular or square
cross-section, etc. In an exemplary embodiment, the distal arms
1114 may extend substantially parallel to each other and to the
longitudinal axis of the device. In another exemplary embodiment,
the distal arms 1114 may extend at an angle to the longitudinal
axis of the device such that they diverge from each other relative
to attachment points on the shroud 1110.
[0153] The proximal end of the main tubular body portion 1116 may
be coupled to a proximal tubular portion 1112. In an exemplary
embodiment, the proximal tubular portion 1112 may cover part or all
of the needle 55 after an injection. In an exemplary embodiment,
the main tubular portion 1116 may cover part or all of the needle
55 after an injection. The proximal tubular portion 1112 of the
shroud 1110 may be a tubular member having a tubular side wall,
i.e., may have a substantially cylindrical shape with a
substantially circular cross-section. The proximal tubular portion
1112 may extend from a proximal end to a distal end along the
longitudinal axis of the automatic injection device. The proximal
end of the proximal tubular portion 1112 may have a proximal
opening 28. The proximal opening 28 may allow the needle 55 to
project outwardly and to penetrate an injection site during
operation of the device 10. The distal end of the proximal tubular
portion 1112 may be coupled to or may extend from the proximal end
of the main tubular body portion 1116 of the shroud 1110.
[0154] In an exemplary embodiment, the proximal tubular portion
1112 of the shroud 1110 may have a cross-sectional diameter smaller
than the cross-sectional diameter of the main tubular body portion
1116. In this exemplary embodiment, a stepped portion 1113 may be
formed at the coupling between the distal end of the proximal
tubular portion 1112 and the proximal end of the main tubular body
portion 1116. The stepped portion 1113 may form a forward stop for
the biasing member 89 that is disposed at least partly inside the
shroud 1110. The stepped portion 1113 may confine the biasing
member 89 and prevent farther forward movement of the biasing
member 89 towards the proximal end of the device 10.
[0155] The syringe carrier 1000 is a structural member that
envelopes the distal half of a syringe 50 used in the device 10.
The syringe carrier 1000 may be configured to hold and guide the
syringe 50 within the housing 12 in order to move the syringe 50
forward to an injecting position. The syringe 50 may rest in the
syringe carrier 1000 and both may be contained in the housing 12.
During operation of the device 10, the syringe 50 and the syringe
carrier 1000 move proximally forward within the housing 12. The
flange 256 within the housing 12 stops and limits the movement of
the flange 1063 of the carrier 1000, which in turn stops and limits
the movement of the syringe 50. One of ordinary skill in the art
will recognize that the movement of the carrier 1000 may be stopped
using any suitable stopping mechanism.
[0156] In an exemplary embodiment, the syringe carrier 1000 is
stationary within the proximal housing component 12a and the
syringe 50 selectively and controllably slides within and relative
to the syringe carrier 1000. The side wall of the proximal tubular
portion 1002 of the syringe carrier 1000 may optionally include a
step. In another exemplary embodiment, the syringe carrier 1000 is
slidably disposed within the proximal housing component 12a and
selectively carries the syringe 50 within the housing 12. The
syringe carrier 1000 may have any suitable configuration, shape and
size suitable for carrying or guiding the syringe 50 within the
proximal housing component 12a. The syringe carrier 1000 is also
configured to cooperate with the shroud 1110 in order to
automatically deploy the shroud 1110 during and/or after an
injection.
[0157] The syringe carrier 1000 may include a proximal tubular
portion 1002 that is substantially tubular and has a tubular side
wall, i.e., has a substantially cylindrical shape with a
substantially circular cross-section. The side wall of the proximal
tubular portion 1002 may optionally include one or more raised
structures, e.g., a longitudinally-extending rail 1007. The rail
1007 may include a tabbed foot 1006. When the syringe carrier 1000
is assembled with the shroud 1110, the tabbed foot 1006 may fit
within the slot 1118 of the shroud 1110, such that the two
components cooperatively form a locking mechanism for the syringe
carrier 1000 and the shroud 1110. In the assembled configuration,
the tabbed foot 1006 may travel longitudinally within the slot 1118
but is restricted from disengaging from the slot 1118. That is, a
forward movement of the tabbed foot 1006 of the carrier 1000 may be
stopped by the proximal end of the slot 1118 of the shroud 1100. At
the same time, the rail 1007 fits along internal longitudinal
grooves provided in the main tubular body portion 1116 of the
shroud 1110, and moves longitudinally along the tracks provided by
the grooves. In an exemplary embodiment, the grooves may be
provided near the distal end of the shroud 1110 and may extend for
an exemplary length of about 2 mm.
[0158] The proximal end of the proximal tubular portion 1002 may be
coupled to or may extend into a proximal anchor portion 1003. In an
exemplary embodiment, the proximal tubular portion 1002 may have a
larger outer diameter than the proximal anchor portion 1003. The
proximal anchor portion 1003 may have an exemplary outer diameter
of about 12.60 mm in an exemplary embodiment. The proximal anchor
portion 1003 of the syringe carrier 1000 may limit the movement of
the syringe 50 in a distal, rearward direction. The proximal anchor
portion 1003 may include one or more radial grooves configured to
engage the interior stop or flange 256 of the proximal housing
component 12a. The engagement of the proximal anchor portion 1003
with the interior flange 256 limits the movement of the syringe 50
in the distal, rearward direction. The proximal anchor portion 1003
may have a continuously extending side wall or may be divided into
discontinuous side walls.
[0159] In an exemplary embodiment, the proximal end of the proximal
anchor portion 1003 may include a syringe carrier coupler 1004 that
extends in the proximal direction past the proximal anchor portion
1003 to facilitate coupling of the syringe carrier 1000 with the
distal end of the biasing member 89 and the distal end of the
shroud 1110. In an exemplary embodiment, the proximal anchor
portion 1003 of the syringe carrier 1000 may provide a stopping
mechanism for the distal end of the biasing mechanism 89, and may
prevent farther movement of the biasing mechanism 89 in the distal
direction.
[0160] The distal end of the proximal tubular portion 1002 may be
coupled to a proximal portion of a distal tubular portion 1005 that
is substantially tubular and has a tubular side wall, i.e., has a
substantially cylindrical shape with a substantially circular
cross-section. The distal end of the distal tubular portion 1005
may be coupled to or may extend to form a flanged distal end 1062
that may serve as a damper for the syringe 50. The flanged distal
end 1062 may extend radially from the distal tubular portion 1005,
and may have a larger cross-sectional diameter than the distal
tubular portion 1005.
[0161] The side wall of the distal tubular portion 1005 may include
one or more windows 1001 that allow a user to view the contents of
the syringe 50 disposed inside the housing 12. In some exemplary
embodiments, the windows 1001 may extend into the proximal tubular
portion 1002. In other exemplary embodiments, the windows 1001 may
be restricted to either the proximal tubular portion 1002 or the
distal tubular portion 1005.
[0162] In an exemplary embodiment, the cross-sectional diameter of
the distal tubular portion 1005 may be smaller than the
cross-sectional diameter of the proximal tubular portion 1002. In
this embodiment, there may be transition portion 1064 formed at the
coupling between the distal end of the proximal tubular portion
1002 and the proximal end of the distal tubular portion 1005. The
transition portion 1064 may form a substantially perpendicular
surface between the planes of the tubular portions or may form an
inclined surface at an angle relative to the planes of the tubular
portions. In an exemplary embodiment, the transition portion 1064
may have a larger outer diameter in at least one part of the
transition portion, relative to the outer diameters of the proximal
tubular portion 1002 and the distal tubular portion 1005.
[0163] The region between the proximal 1002 and the distal 1005
tubular portions may include an intermediate flange 1063 that
extends radially from the tubular portions. The intermediate flange
1063 may be a radially continuous structure or a radially
discontinuous structure, and may have a larger cross-sectional
diameter than the tubular portions. The intermediate flange 1063
may be configured to engage with the interior stop or flange 256 of
the proximal housing component 12a to limit the movement of the
syringe 50 in the proximal, forward direction. In an exemplary
embodiment, the flange 1063 may result in an increased outer
diameter of the transition portion 1064 relative to the outer
diameters of the proximal tubular portion 1002 and the distal
tubular portion 1005.
[0164] Upon actuation of the syringe carrier 1000 the syringe
carrier 1000 moves toward the proximal end of the device until the
intermediate flange 1063 of the syringe carrier 1000 abuts against
the interior stop or flange 256 of the proximal housing component
12a. This limits farther movement of the syringe carrier 1000 and
the syringe 50 in the proximal, forward direction.
[0165] In an exemplary embodiment, the shroud 1110 is in a
retracted position prior to performing an injection. In another
exemplary embodiment, the shroud 1110 is in an extended position
prior to performing an injection and is retracted in order to
perform the injection. In this embodiment, in order to expose the
needle for an injection, the shroud 1110 is retracted in the
distal, backward direction against the biasing force of the biasing
member 89. When the needle is in use during an injection, the
shroud 1110 may be pushed to or held in a retracted position toward
the distal end of the device. During retraction, as the shroud 1110
moves relative to the syringe carrier 1000, the tabbed foot 1006 of
the rail 1007 of the syringe carrier 1000 moves in a relative
manner longitudinally toward the proximal end of the device along
the slot 1118 of the shroud 1110. At the same time, the rail 1007
of the syringe carrier 1000 moves in a relative manner
longitudinally along the inner grooves in the shroud 1110. The
shroud retraction process is complete and further movement of the
shroud 1110 is stopped when the tabbed foot 1006 reaches the
proximal end of the slot 1118. Since the tabbed foot 1006 is fit
into the slot 1118 in a locking manner, the tabbed foot 1006 does
not disengage from the slot 1118 and prevents farther backward or
distal motion of the shroud 1110.
[0166] In the retracted position of the shroud 1110, the distal rim
or end of the main tubular body portion 1116 may abut the proximal
side of the stop or flange 256 provided on the inner surface of the
proximal housing component 12a. In an exemplary embodiment, in the
retracted position, the distal arms 1114 may extend in the distal
direction beyond the intermediate flange 1063 of the syringe
carrier 1000.
[0167] In order to cover the needle before, during or after an
injection, the shroud 1110 is deployed in the proximal, forward
direction from its retracted position to an extended position under
the biasing force of the biasing member 89. In the deployed
position, the shroud 1110 protectively covers the needle during or
after use and prevents accidental needle stick injuries. In an
exemplary embodiment, the shroud 1110 may be automatically deployed
by the biasing force of the biasing member 89. During deployment,
as the shroud 1110 moves relative to the syringe carrier 1000, the
tabbed foot 1006 of the rail 1007 of the syringe carrier 1000 moves
in a relative manner longitudinally toward the distal end of the
device along the slot 1118 of the shroud 1110. At the same time,
the rail 1007 of the syringe carrier 1000 moves in a relative
manner longitudinally along the inner grooves in the shroud 1110.
The shroud deployment process is complete and further movement of
the shroud 1110 is stopped when the tabbed foot 1006 reaches the
distal end of the slot 1118. Since the tabbed foot 1006 is fit into
the slot 1118 in a locking manner, the tabbed foot 1006 does not
disengage from the slot 1118 and prevents farther proximal or
forward motion of the shroud 1110.
[0168] After the shroud 1110 is deployed to the extended position,
the distal arms 1114 ensure that the shroud 1110 is not retracted
again due to a backward force applied to the shroud in the distal
direction. In exemplary embodiments, the distal arms 1114 of
exemplary shrouds 1110 may resist shroud retraction against a
maximum force known as the "override force." In an exemplary
embodiment, during deployment, the shroud 1110 moves within the
housing of the device such that the distal end of the distal arms
1114 of the shroud 1110 rest against the interior stop or flange
256 of the housing. The interior stop or flange 256 thus prevents
farther distal or backward movement of the shroud 1110 after the
shroud has been deployed. This locking mechanism ensures that the
needle is protectively covered after the device has been used, and
prevents accidental needle stick injuries caused by accidental
retraction of the shroud. Exemplary shroud override forces may
range from about 80 N to about 200 N, although override forces are
not limited to this exemplary range.
[0169] As illustrated in FIG. 9, the biasing member 89 extends
between the proximal end of the syringe carrier coupler 1004 of the
syringe carrier 1000 and the transition portion 1113 of the shroud
1110. In an exemplary embodiment, the biasing member 89 may hold
the syringe 50 in a retracted position within the housing 12 prior
to use, as shown in FIG. 3. In another exemplary embodiment, the
syringe carrier 1000 holding the syringe 50 may be locked to the
interior flange 256 in the housing. This interaction may hold the
syringe 50 in a retracted position within the housing before. With
the aid of the tube 26 of the first cap 24, this interaction is
able to lock the syringe carrier 1000 and the syringe 50 in place
during shipping, shock, dropping, vibration, and the like. The
biasing member 89 may hold the shroud 1110 forward in this
exemplary embodiment.
[0170] When the shroud 1110 is in the retracted position, the
needle 55 may be preferably sheathed entirely within the housing
12. The exemplary syringe coil spring 89 may be disposed about the
proximal portion of the barrel portion 53 of the syringe 50 and may
be seated in a shelf formed within the housing interior 12. The top
end of the coil spring 89 may abut the flanged second end 56 of the
syringe 50. The spring force of the second biasing mechanism 89 may
push the flanged second end 56 of the syringe 50 away from the
first end 20 of the housing 12, thereby holding the syringe 50 in
the retracted position until activated. Other components of the
device 10 may also position the syringe 50 relative to the housing
12.
[0171] FIGS. 10A and 10B are cross-sectional views at 90.degree.
offset angles from each other, illustrating an assembled automatic
injection device, wherein the syringe housing sub-assembly 121 and
the firing mechanism sub-assembly 122 of FIG. 5 are coupled
together, such that the pressurizer 754' of the syringe actuation
component 700' extends into the barrel portion 53 of a syringe 50
housed in the syringe housing sub-assembly 121 and is in
communication with a bung 54 of the syringe 50. Referring again to
FIGS. 7 and 10B, the syringe actuation component 700' includes, at
its proximal end 700a', a pressurizing end 754' for applying
pressure to the bung 54, a plunger rod portion 70 with a
compressible expanded portion 76 (illustrated as the plunger elbows
78), as well as other components, such as components for anchoring
the coil spring 88 to the syringe actuation component 700', as
described below. The compressible expanded portion 76 facilitates
movement of a corresponding syringe 50 into a projecting position
and expulsion of the contents of the syringe 50. Alternatively, the
syringe actuation component 700' may comprise multiple actuators
for moving and/or promoting actuation of the syringe 50.
[0172] As shown in FIG. 10B, the trigger anchoring portion 789' of
the syringe actuation component 700' is anchored at the distal end
of the housing 12 by the firing button 32. When a patient activates
the firing button 32, driving arms 32a connected to the firing
button 32 compress the tabbed feet 7891' of the trigger anchoring
portion 789' inwards, thereby decreasing the distance (plunger arm
width) between the tabbed feet of the plunger arms 788a', 788b'.
This releases the syringe actuation mechanism 700' and the spring
88.
[0173] In an exemplary embodiment, during a first operational
stage, the plunger 70 advances under the spring force of the spring
88 and enters the bore of the syringe 50. The elbows 78 of the
plunger 70 may compress radially inwardly, at least partly, as the
plunger 70 enters the bore of the syringe 50. In an exemplary
embodiment, the radially inward compression of the elbows 78 may
cause the plunger 70 to elongate or lengthen along the longitudinal
axis. In an exemplary embodiment, the pressurizing end 754' of the
plunger 70 may initially be spaced from the bung 54, and the
plunger 70 may move toward the bung 54 during the first operational
stage until the pressurizing end 754' of the plunger 70 comes into
initial contact with the bung 54.
[0174] During a second operational stage, the pressurizing end 754'
of the plunger 70 pushes against the bung 54. In this stage, the
elbows 78 of the plunger 70 exert frictional forces against the
inner wall of the syringe, which impedes the forward movement of
the pressurizing end 754' against the bung 54. Furthermore, the
incompressible nature of the dose of the liquid therapeutic
substance in the syringe acts against the forward movement of the
pressurizing end 754' against the bung 54. As a result, the
combination of the frictional forces exerted by the elbows 78 and
the resistance force of the liquid inside the syringe 50 impedes
farther movement of the pressurizing end 754' against the bung 54.
When the combination of these forces exceeds the forces holding the
syringe carrier 1000 in place, the syringe 50 and the syringe
carrier 1000 are caused to move forward toward the proximal end of
the device under the force of the spring 88. During the forward
movement of the syringe, the initial biasing force provided by the
first coil spring 88 is sufficient to overcome the biasing force of
the second coil spring 89 to allow movement of the syringe 50
against the backward biasing force of the second coil spring 89.
The forward movement of the syringe 50 causes the tip of the needle
55 to project from the proximal end 20 of the housing 12.
[0175] In this exemplary embodiment, during a third operational
stage, when the syringe carrier 1000 is fully extended in the
housing of the device, the plunger 70 moves farther into the bore
of the syringe 50. In an exemplary embodiment, the radially inward
compression of the elbows 78 may cause the plunger 70 to elongate
or lengthen along the longitudinal axis. As the plunger 70 moves
into the syringe 50, the pressurizing end 754' of the plunger 70
pushes the bung 54 into the syringe 50 and causes the contents of
the syringe 50 to be ejected from the syringe through the needle
55.
[0176] In another exemplary embodiment, after the spring 88 is
released, the plunger 70 may advance under the spring force of the
spring 88 and enter the bore of the syringe 50, and the elbows 78
of the plunger 70 may compress radially inwardly, at least partly,
as the plunger enters the bore of the syringe 50. In an exemplary
embodiment, the radially inward compression of the elbows 78 may
cause the plunger 70 to elongate or lengthen along the longitudinal
axis.
[0177] The pressurizing end 754' of the plunger 70 may initially be
spaced from the bung 54 in an exemplary embodiment, and the plunger
70 may move toward the bung 54 until the pressurizing end 754' of
the plunger 70 comes into initial contact with the bung 54. The
pressurizing end 754' of the plunger 70 may subsequently push
against the bung 54. The elbows 78 of the plunger 70 may exert
frictional forces against the inner wall of the syringe, which
impedes the forward movement of the pressurizing end 754' against
the bung 54. Furthermore, the incompressible nature of the dose of
the liquid therapeutic substance in the syringe acts against the
forward movement of the pressurizing end 754' against the bung 54.
As a result, the combination of the frictional forces exerted by
the elbows 78 and the resistance force of the liquid inside the
syringe 50 may impede farther movement of the pressurizing end 754'
against the bung 54.
[0178] When the combination of these forces exceeds the forces
holding the syringe carrier 1000 in place, the syringe 50 and the
syringe carrier 1000 are caused to move forward toward the proximal
end of the device under the force of the spring 88. During the
forward movement of the syringe, the initial biasing force provided
by the first coil spring 88 is sufficient to overcome the biasing
force of the second coil spring 89 to allow movement of the syringe
50 against the backward biasing force of the second coil spring 89.
The forward movement of the syringe 50 causes the tip of the needle
55 to project from the proximal end 20 of the housing 12. In this
exemplary embodiment, when the syringe carrier 1000 is fully
extended in the housing of the device, the elbows 78 of the plunger
70 may compress radially inwardly to a greater extent and the
plunger 70 may move farther into the bore of the syringe 50. In an
exemplary embodiment, the radially inward compression of the elbows
78 may cause the plunger 70 to elongate or lengthen along the
longitudinal axis. As the plunger 70 moves into the syringe 50, the
pressurizing end 754' of the plunger 70 may push the bung 54 into
the syringe 50 and cause the contents of the syringe 50 to be
ejected from the syringe through the needle 55.
[0179] In another exemplary embodiment, prior to operation, the
compressible expanded portion 76, illustrated as elbows 78, of the
syringe actuation component 700' rests above the flanged distal end
56 of the syringe 50 to allow the compressible expanded portion 76,
when pushed by a released coil spring 88, to apply pressure to the
syringe barrel portion 53, thereby moving the syringe 50 forward
within the housing 12 when actuated. In this exemplary embodiment,
in the first operational stage, the expanded region 76 of the
plunger 70, formed by the projecting elbows 78, rests against the
flanged distal end 56 of the barrel portion 53. This prevents the
plunger 70 from traveling within the syringe barrel portion 53.
[0180] In this manner, all biasing force from the first coil spring
88 is applied to move the syringe 50 and the syringe carrier 1000
forward towards the proximal end 20 of the device 10. The forward
motion of the syringe 50 and the syringe carrier 1000 towards the
proximal end 20 of the device 10 may continue against the biasing
force of the coil spring 88 until the flanged distal end 56 of the
barrel portion 53 abuts a stopping mechanism, such as a stop 256 on
the proximal housing component 12a shown in FIG. 10B. One of
ordinary skill in the art will recognize that alternate stopping
mechanisms may be employed and that exemplary embodiments are not
limited to the illustrative stopping mechanism.
[0181] The first operational stage may propel the tip of the needle
55 through the opening 28 at the proximal end 20 of the device 10,
so that the needle 55 may pierce the patient's skin. During this
stage, the syringe barrel portion 53 may preferably remain sealed
without expelling the substance through the needle 55. The
interference caused by the stopping mechanism may maintain the
needle 55 in a selected position extending from the proximal open
end 28 of the device 10 during subsequent steps. Until the stopping
mechanism stops the movement of the syringe 50, the compressible
expanded portion 76 of the plunger 70 may prevent movement of the
plunger 70 relative to the barrel portion 53. The stopping
mechanism may be positioned at any suitable location relative to
the open proximal end 20 to allow the syringe 50 to penetrate the
skin by any suitable depth suitable for an injection.
[0182] In this exemplary embodiment, the second operational stage
commences after the stopping mechanism of the housing 12 catches
the flanged portion 56, stopping further movement of the barrel
portion 53. During this stage, the continued biasing force of the
spring 88 continues to move the syringe actuation component 700'
forward, causing the compressible expanded portion 76 to compress
radially inwardly and move into the barrel portion 53 of the
syringe 50. In an exemplary embodiment, the radially inward
compression of the elbows 78 may cause the plunger 70 to elongate
along the longitudinal axis. The forward motion of the syringe
actuation component 700' within the barrel portion 53 causes the
pressurizer 754' to apply pressure to the bung 54, causing
expulsion of the syringe contents into an injection site. Because
the needle 55 was made to penetrate the patient's skin in the first
operational stage, the substance contained in the barrel portion 53
of the syringe 50 is injected directly into a portion of the
patient's body.
[0183] As also shown in FIGS. 10A and 10B, the distal cap 34 may
include a stabilizing protrusion 340 that extends through the
firing button 32 and between the tabbed feet 7891' of the syringe
actuation component 700' to stabilize the components of the device
prior to activation.
[0184] In the exemplary embodiment shown in FIG. 10A, a removable
rigid needle shield 1406 is coupled to the proximal end of the
syringe 50 for protectively covering the needle 55. The rigid
needle shield 1406 covers and protects a soft needle shield which
keeps the needle 55 sterile before use. Together, the rigid needle
shield 1406 and the soft needle shield are meant to prevent
accidental needle stick injuries that could be caused by an exposed
needle. In an exemplary embodiment, the rigid needle shield 1406 is
a hollow tubular member with a substantially cylindrical wall
having an inner bore with a substantially circular cross-section.
The outer cross-sectional diameter of the cylindrical wall may be
substantially constant over the length of the rigid needle shield
1406 or may vary over the length of the rigid needle shield 1406.
An exemplary rigid needle shield 1406 may be formed of one or more
rigid materials including, but not limited to, polypropylene.
[0185] In an exemplary embodiment, a removable soft needle shield
(not shown) is provided within the bore of the rigid needle shield
1406 to provide a sealing layer between the needle 55 and the rigid
needle shield 1406. An exemplary soft needle shield may be formed
of one or more resilient materials including, but not limited to,
rubber.
[0186] In the needle assembly shown in FIGS. 10A and 10B, the
needle 55 is covered by the soft needle shield and the rigid needle
shield 1406. The rigid needle shield 1406 is, in turn, covered by
the proximal removable cap 24 of the automatic injection device.
The proximal removable cap 24 is provided in the automatic
injection device for covering the proximal end of the housing of
the automatic injection device to prevent exposure of the needle
prior to an injection.
[0187] FIG. 11 is a cross-sectional view of an assembled automatic
injection device 10'. The illustrative embodiment of the automatic
injection device 10' includes proximal and distal housing
components 12a, 12b. The proximal and distal housing components
12a, 12b are assembled together to form a complete housing. As
shown, a proximal housing component 12a, forming a proximal end of
the housing, receives a proximal end of the distal housing
components 12b.
[0188] A removable rigid needle shield 1406 is coupled to the
proximal end of the syringe 50' for protectively covering the
needle (not shown).
[0189] A cooperating projection 312 and groove 313, or a plurality
of cooperating projections 312 and grooves 313, facilitate assembly
and coupling of the proximal and distal housing components 12a, 12b
in the illustrative embodiment. Other suitable assembly mechanisms
may alternatively be employed. A shelf 29 formed on an outer
surface of the distal housing component 12b to form a stop for the
removable distal cap 34.
[0190] As shown, the firing button 32' may be a cap covering the
distal end of the distal housing component 12b. The illustrative
firing button 32' slides relative to the distal housing component
12b to actuate a syringe actuator, such as the plunger 70. The
illustrative firing button 32' releasably retains flexible
anchoring arms 172 of the plunger 70'. When depressed, the firing
button 32' releases the flexible anchoring arms 172 to allow a
first biasing mechanism, illustrated as spring 88' to propel the
plunger 70' towards the proximal end of the device 10'.
[0191] In the embodiment of FIG. 11, the plunger 70' further
includes a flange 72' located between the compressible expanded
portion 78' and the distal end of the plunger rod 71'. A first
biasing mechanism 88' is seated between an interior distal end of
the housing and the flange 72' to bias the plunger 70 towards the
proximal end of the housing. When the firing button 34' releases
the anchoring arms 172, the coil spring 88', or other suitable
biasing mechanism propels the plunger 70' towards the proximal end
20 of the device 10.
[0192] The plunger 70' further includes an indicator 190 formed at
an intermediate portion of the plunger rod 71 between the flange
72' and the compressible expanded portion, illustrated as flexible
elbows 78'. The indicator 190 may indicate to the patient of the
device 10' when the dose from the syringe 50 has been fully or
substantially fully ejected. In the illustrative embodiment, the
indicator 190 is formed on a portion of the plunger rod 71' between
the compressible expanded central portion 76 and the flange 72'. As
the plunger rod 71 moves during operation, the indicator 190
advances towards and aligns with window 130 in the housing as the
dose empties from the syringe. The indicator 190, which is
preferably a different color or pattern from the substance being
injected, fills the window 130 entirely to indicate that the dosage
has been ejected. Any suitable indicator may be used.
[0193] The syringe 50' of FIG. 11 may include protrusions or other
suitable component to facilitate controlled movement of the syringe
within the housing 12'. For example, with reference to FIG. 11, the
syringe 50' includes a sleeve 157 forming a proximal protrusion 158
for abutting a proximal side of a first protrusion 168 formed on an
inner surface of the housing 12' for limited movement of the
syringe 50' in the distal direction within the housing 12'. The
sleeve 157 may also form a flange 159 that may abut the distal side
of the first protrusion 168 to limit movement of the syringe 50' in
the proximal direction during an injection.
[0194] In the embodiment of FIG. 12, the second biasing mechanism,
illustrated as coil spring 89' is disposed about a proximal portion
of the syringe 50'. A shelf 169 formed at a proximal inner surface
of the housing 12' receives a proximal end of the coil spring 89'.
The proximal protrusion 158 of the syringe sleeve 157, or another
suitably disposed mechanism, receives the distal end of the coil
spring 89'. As described above, the second biasing mechanism 89'
biases the syringe 50' in a retracted position within the housing
12' until activation of the device 10.
[0195] FIG. 12 illustrates a cross-sectional view taken along the
longitudinal axis L of the housing 1300 of an automatic injection
device housing an exemplary syringe 1400. The housing 1300 of the
automatic injection device extends substantially along the
longitudinal axis L between a proximal end 1302 and a distal end
1304. The housing 1300 includes a hollow internal bore 1306 for
accommodating the syringe 1400 and other related components, e.g.,
the needle, a soft needle shield covering the needle, a rigid
needle shield 1406 covering the needle and the soft needle shield,
etc.
[0196] The proximal end 1302 of the housing 1300 includes or is
fitted with a removable proximal cap 1308. The proximal cap 1308
extends substantially along the longitudinal axis L between a
proximal end 1310 and a distal end 1312. The proximal cap 1308
includes a hollow internal bore 1314 for accommodating part or the
entire length of a rigid needle shield 1406. In an exemplary
embodiment, the hollow internal bore 1314 of the proximal cap 1308
may also accommodate a proximal portion of the syringe body
1400.
[0197] The syringe 1400 extends substantially along the
longitudinal axis L between a proximal end 1402 and distal end
1404. The proximal end 1402 of the syringe 1400 is coupled to a
needle that may be covered by the removable rigid needle shield
1406. In some exemplary embodiments, the needle may be covered by a
removable soft needle shield that is, in turn, covered by the rigid
needle shield 1406. The rigid needle shield 1406 extends
substantially along the longitudinal axis L between a closed
proximal end 1408 and an open distal end 1410 that abuts the
proximal end 1402 of the syringe 1400. Exemplary lengths of rigid
needle shields 1406 range from about 5 mm to about 30 mm, but are
not limited to this range. In exemplary embodiments, the syringe
1400 may be housed within the housing 1300 of the automatic
injection device such that the rigid needle shield 1406 is disposed
partly or entirely within the proximal cap 1308.
III. EXEMPLARY COMPONENT INTERACTIONS AFFECTING SHROUD
DEPLOYMENT
[0198] The deployment of a shroud 1110 from a retracted position to
an extended position involves the components of the syringe housing
sub-assembly 121 illustrated in FIG. 8. Certain interactions among
the components of the syringe housing sub-assembly 121 during the
shroud deployment process give rise to forces that tend to impede
the deployment process. Exemplary embodiments configure one or more
components of the syringe housing sub-assembly 121 in order to
minimize the interactions so that shroud deployment is
consistently, reliably and completely achieved.
[0199] A first type of interaction occurs between the rails 1007 of
the syringe carrier 1000 and the internal longitudinal grooves
provided in the main tubular body portion 1116 of the shroud 1110.
During shroud deployment, the grooves in the shroud 1110 contact
and move relative to the rails 1007 of the syringe carrier 1000
toward the needle. This interaction between the grooves in the
shroud 1110 and the rails 1007 of the syringe carrier 1000 gives
rise to frictional forces that tend to impede the shroud deployment
process and may result in shroud deployment failure in some
instances.
[0200] FIG. 13A illustrates a perspective view of a syringe housing
sub-assembly 121 in which the shroud 1110 is assembled over the
syringe carrier 1000. FIG. 13B is a transverse sectional view of
the syringe housing sub-assembly 121 of FIG. 13A, showing contact
regions at which the grooves in the shroud 1110 contact with and
move relative to the rails 1007 of the syringe carrier 1000. FIG.
13C shows a measurement of the inner diameter between two
oppositely-positioned grooves of the shroud 1110. An exemplary
inner diameter is about 15.60 mm, although other sizes are
possible. FIG. 13D shows a measurement of the outer diameter
between two oppositely-positioned rails 1007 of the syringe carrier
1000. An exemplary outer diameter is about 15.51 mm, although other
sizes are possible.
[0201] A second type of interaction occurs between the distal arms
1114 of the shroud 1110 and the flange 256 provided in or adjacent
to the inner surface of the proximal housing component 12a. The
flange 256 includes one or more openings 255 that allow the distal
arms 1114 of the shroud 1110 to pass through the flange 256 during
shroud deployment. In an early stage in the shroud deployment
process, the sides of the distal arms 1114 come into contact with
the flange 256 (at the edge of the opening 255) in the proximal
housing component 12a, and are caused to bend by the engagement
with the flange 256. This engagement of the distal arms 1114 of the
shroud 1110 with the flange 256 gives rise to frictional forces
that tend to impede the shroud deployment process and may result in
shroud deployment failure in some instances.
[0202] FIG. 14A illustrates a perspective view of a syringe housing
sub-assembly 121 in which the shroud 1110 is fully or partially
disposed in the proximal housing component 12a. FIG. 14A highlights
an area of the proximal housing component 12a at which the distal
arms 1114 of the shroud 1110 engage with the flange 256 in the
proximal housing component 12a. FIG. 14B illustrates a longitudinal
sectional view of the syringe housing sub-assembly 121 of FIG. 14A,
showing the engagement of the distal arms 1114 of the shroud 1110
with the flange 256 in the proximal housing component 12a. FIG. 14C
shows a measurement of the distance between two
oppositely-positioned openings 255 in the flange 256 that may
accommodate the distal arms 1114 of the shroud 1110 as the arms
pass through the flange 256. An exemplary distance of the flange
openings is about 3.10 mm, although other sizes are possible. FIG.
14D shows a measurement of the span of the distal arms 1114 of the
shroud 1110 (i.e., the distance between the terminal ends of the
distal arms taken perpendicular to the length of the shroud). An
exemplary span is about 6.13 mm, although other sizes are
possible.
[0203] A third type of interaction occurs among the distal arms
1114 of the shroud 1110, the proximal housing component 12a, and
the syringe carrier 1000, as the distal arms 1114 pass through the
constrained space provided between the proximal housing component
12a and the syringe carrier 1000. The distal arms 1114 of the
shroud 1110 are pinched within the constrained space between the
outer diameter of the proximal tubular portion 1002 of the syringe
carrier 1000 and the inner diameter of the proximal housing
component 12a. In a later stage in the shroud deployment process,
the distal arms 1114 bend due to engagement with the flange 256 of
the proximal housing component 12a, which causes the arms 1114 to
twist within the constrained space between the syringe carrier 1000
and the proximal housing component 12a of the automatic injection
device. Movement of the distal arms 1114 within the constrained
space causes pinching of the distal arms 1114, i.e., causes reverse
twisting of the arms so that they can fit between the syringe
carrier 1000 and the proximal housing component 12a. This pinching
effect of the distal arms 1114 of the shroud 1110 gives rise to
frictional forces that tend to impede the shroud deployment process
and may result in shroud deployment failure in some instances.
[0204] In another exemplary embodiment, the constrained space may
be provided by a combination of components different from the outer
diameter of the proximal tubular portion 1002 of the syringe
carrier 1000 and the inner diameter of the proximal housing
component 12a. For example, the constrained space may be provided
between two housing components, or between the inner surface of a
housing component and the outer surface of a component different
from the syringe carrier 1000.
[0205] FIG. 15A illustrates a perspective view of a syringe housing
sub-assembly 121 in which the syringe carrier 1000 and the shroud
1110 are assembled and positioned within the proximal housing
component 12a. FIG. 15A highlights an area of the proximal housing
component 12a at which the distal arms 1114 of the shroud 1110 are
pinched within the constrained space between the proximal housing
component 12a and the syringe carrier 1000. FIG. 15B illustrates a
transverse sectional view of the syringe housing sub-assembly 121
of FIG. 15A, showing the pinching of the distal arms 1114 of the
shroud 1110 within the constrained space between the proximal
housing component 12a and the syringe carrier 1000. FIG. 15C shows
a measurement of the inner diameter of the proximal housing
component 12a. An exemplary inner diameter is about 17.60 mm,
although other sizes are possible. FIG. 15D shows a measurement of
the thickness of a distal arm 1114 of the shroud 1110. An exemplary
thickness is about 1.45 mm, although other sizes are possible. FIG.
15E shows a measurement of the inner diameter between two
oppositely-positioned distal arms 1114 of the shroud 1110. An
exemplary inner diameter is about 14.40 mm, although other sizes
are possible. FIG. 15F shows a measurement of the outer diameter of
the proximal housing component 1002 of the syringe carrier 1000. An
exemplary outer diameter is about 14.00 mm, although other sizes
are possible.
[0206] A fourth type of interaction occurs among the syringe
carrier 1000, the shroud 1110, and the biasing mechanism 89 (e.g.,
a compression spring) disposed between the assembled syringe
carrier 1000 and shroud 1110. Defects in the biasing mechanism 89
(due, for example, to material and/or fabrication defects) may give
rise to frictional forces that tend to impede the shroud deployment
process and may result in shroud deployment failure in some
instances. FIG. 16A illustrates a perspective view of a syringe
housing sub-assembly 121 in which the biasing mechanism 89 is
disposed between the syringe carrier 1000 and the shroud 1110. FIG.
16B illustrates a longitudinal sectional view of the syringe
housing sub-assembly 121 in which the biasing mechanism 89 is
disposed between the syringe carrier 1000 and the shroud 1110. FIG.
16C shows a measurement of the inner diameter of the shroud 1110.
An exemplary inner diameter is about 13.70 mm, although other sizes
are possible. FIG. 16D shows a measurement of the outer diameter of
the biasing mechanism 89. An exemplary outer diameter is about
13.30 mm, although other sizes are possible.
[0207] FIGS. 17A and 17B are extension force profile of forces in N
(y-axis) generated during the deployment of a shroud against the
deployment distance in mm (x-axis). At an early stage 1702 in the
shroud deployment process, the first type of interaction (i.e.,
between the rails 1007 of the syringe carrier 1000 and the internal
longitudinal grooves provided in the shroud 1110) and the fourth
type of interaction (i.e., among the syringe carrier 1000, the
shroud 1110, and the biasing mechanism 89) dominate. These
interactions do not give rise to high frictional forces to impede
the shroud deployment process, and result in a small and gradual
decrease in the forces generated.
[0208] At a subsequent stage 1704 in the shroud deployment process,
the second type of interaction (i.e., between the distal arms 1114
of the shroud 1110 and the flange 256 in the proximal housing
component 12a) dominates. In this stage, the distal arms 1114 are
bent by engagement with the flange 256, which gives rise to
frictional forces that impede the shroud deployment process. This
is exhibited as a sharp and large drop in the forces generated. The
first and fourth types of interactions are also operative in this
stage of the shroud deployment process.
[0209] At a subsequent stage 1706 in the shroud deployment process,
the third type of interaction (i.e., among the distal arms 1114 of
the shroud 1110, the proximal housing component 12a, and the
syringe carrier 1000) dominates. In this stage, movement of the
distal arms 1114 within the constrained space causes pinching of
the distal arms 1114, i.e., causes reverse twisting of the arms so
that they can fit between the syringe carrier 1000 and the proximal
housing component 12a. The pinching effect of the distal arms 1114
of the shroud 1110 gives rise to frictional forces that tend to
impede the shroud deployment process. This is exhibited as a drop
or downward peak in the forces generated. The first, second and
fourth types of interactions are also operative in this stage of
the shroud deployment process.
IV. CONFIGURATION OF EXEMPLARY AUTOMATIC INJECTION DEVICES TO
IMPROVE SHROUD DEPLOYMENT
[0210] Exemplary embodiments may configure one or more features of
an automatic injection device in order to ensure consistent,
reliable and complete shroud deployment within an acceptably short
period of time after an injection is performed. Exemplary
configurations may include, but are not limited to, one or more
configurations of the proximal housing component 12a, the shroud
1110, the syringe carrier 1000, combinations of the aforementioned
configurations, and the like.
[0211] FIG. 18 illustrates an exemplary retraction and extension
force profile of forces in N (y-axis) against the deployment
distance in mm (x-axis) during the retraction and deployment of a
shroud 1110. Different forces combine to generate the force profile
illustrated in FIG. 18. Exemplary forces include, but are not
limited to, the force exerted by the biasing member 89, the force
bending the distal arms 1114 of the shroud 1110, the force twisting
the distal arms 1114, and the like. In an exemplary embodiment, a
shroud 1110 may travel a distance from about 12 mm to about 18 mm
during the shroud deployment process, but is not limited to this
exemplary range. In an exemplary embodiment, a shroud 1110 may
travel about 15.2 mm during the shroud deployment process.
[0212] Portion 1802 of FIG. 18 illustrates exemplary forces
generated during the shroud retraction process in which the shroud
is moved from an extended position to a retracted position to allow
the needle to be exposed through a proximal opening in the shroud.
Upon retraction of the shroud, the needle may be used to administer
an injection at an injection site. The shroud retraction process
begins at point 1804 (at which the shroud is extended toward the
proximal end of the device) and ends at point 1806 (at which the
shroud is retracted toward the distal end of the device).
[0213] Portion 1808 of FIG. 18 illustrates exemplary forces
generated during the shroud deployment process in which the shroud
is moved from the retracted position to the extended position to
allow the shroud to cover the needle after an injection, and to
thereby avoid the risk of accidental needle stick injuries. The
forces are measured by a force sensor as the deployed shroud pushes
on the sensor during the shroud deployment process. The shroud
deployment process begins at point 1810 (at which the shroud is
retracted toward the distal end of the device) and ends at point
1812 (at which the shroud is extended toward the proximal end of
the device). The extension force decreases significantly at an
earlier stage of shroud deployment, e.g., at an x-axis distance
range from about 13 mm to about 8 mm. The extension force reaches a
plateau at a later stage of shroud deployment, e.g., at an x-axis
distance range from about 6.0 mm to about 0.0 mm. In some exemplary
embodiments, there is a residual extension force near and at the
end of the shroud deployment process. Exemplary residual extension
forces may range from about 0.0 N to about 2.0 N in some exemplary
embodiments. In FIG. 18, the residual extension force is about 1.00
N.
[0214] In exemplary embodiments, lower extensions forces
experienced during shroud deployment and lower residual extension
forces may correspond to a slowdown in the shroud deployment
process. Exemplary embodiments provide structural, functional and
operational improvements to the components of the syringe housing
sub-assembly 121 to maximize the extension forces during shroud
deployment to prevent failures in shroud deployment, for example,
non-deployment or incomplete deployment of the shroud.
[0215] In exemplary embodiments, decreases in the extension forces
during an early stage in the shroud deployment process may be
attributable to bending of the distal arms 1114 of the shroud 1110.
In the early stage in the shroud deployment process, the distal
arms 1114 engage with the flange 256 in the housing 12a of the
automatic injection, and are caused to bend by the engagement with
the flange 256. The bending effect of the distal arms 1114 is
dominant in region 1814 of the extension force profile, and is
reflected in the decreases in the extension forces at an x-axis
range of between about 13 mm and about 8 mm shown in FIG. 18 in an
exemplary embodiment. The decreases in the extension forces may
correspond to a slowing down of the shroud deployment process in
the early stage.
[0216] In exemplary embodiments, decreases in the extension forces
during a later stage in the shroud deployment process may be
attributable to a pinching effect of the distal arms 1114 of the
shroud 1110 within a constrained space between the proximal tubular
portion 1002 of the syringe carrier 1000 and the internal diameter
of the proximal housing component 12a. In the later stage in the
shroud deployment process, the distal arms 1114 bend due to
engagement with the flange 256 of the proximal housing component
12a, which causes the arms 1114 to twist within the constrained
space between the syringe carrier 1000 and the proximal housing
component 12a of the automatic injection device. Movement of the
distal arms 1114 within the constrained space causes pinching of
the distal arms 1114, i.e., causes reverse twisting of the arms so
that they can fit between the syringe carrier 1000 and the proximal
housing component 12a. The pinching effect of the distal arms 1114
is dominant in region 1816 of the extension force profile, and is
reflected in decreases in the extension forces at an x-axis range
of between about 4 mm and about 1 mm. In an exemplary embodiment,
the decreases in the extension forces at the later stages of the
shroud deployment process are reflected in a localized downward
peak in the extension force profile, illustrated as peak 2002 in
FIG. 20.
[0217] In FIG. 18, the downward peak of FIG. 20 is absent in the
later stages of shroud deployment. In the exemplary embodiment
shown in FIG. 18, the structure, function and operation of
exemplary devices is configured to reduce the pinching effect of
the distal arms 1114 within the constrained space between the
syringe carrier 1000 and the proximal housing component 12a. This
maximizes the extension forces experienced during the later stages
of shroud deployment as the shroud is deployed from the retracted
position to the extended position, which results in an elimination
of a downward peak that might otherwise appear in the extension
force profile.
[0218] FIG. 19 illustrates an exemplary retraction and extension
force profile of forces in N (y-axis) against the distance in mm
(x-axis) during the retraction and deployment of a shroud. FIG. 19
also shows the positions of the distal arms 1114 of the shroud 1110
relative to the syringe carrier 1000 as the shroud is deployed. For
example, at a deployment distance of about 13 mm (i.e., at about
the beginning of shroud deployment), the majority of the length of
the distal arms 1114 of the shroud 1110 passes over the distal
tubular portion 1005 of the syringe carrier 1000. At a deployment
distance of about 6.5 mm, the majority of the length of the distal
arms 1114 passes over the proximal tubular portion 1002 of the
syringe carrier 1000, and the terminal end of the distal arms 1114
approaches the transition portion between the proximal and distal
tubular portions of the syringe carrier 1000. Since the outer
diameter of the distal tubular portion 1005 of the syringe carrier
1000 is substantially unchanged between the deployment distances of
about 13 mm and about 6.5 mm, the force profile shows a gradual
decline between these two points.
[0219] At a deployment distance of about 2.1 mm, the terminal end
of the distal arms 1114 passes over the transition portion between
the proximal tubular portion 1002 and the distal tubular portion
1005 of the syringe carrier 1000. In an exemplary embodiment, the
transition portion has a larger outer diameter than the proximal
tubular portion 1002 and the distal tubular portion 1005 of the
syringe carrier 1000. In an exemplary embodiment, the transition
portion has an outer diameter of about 14.17 mm. This impedes the
passage of the terminal end of the distal arms 1114, and thereby
causes a slowdown of the deployment of the shroud. This is
exhibited by the dip in the forces at about 2.1 mm.
[0220] At a deployment distance of about 0 mm, the entire length of
the distal arms 1114 of the shroud 1110 passes over the proximal
tubular portion 1002 of the syringe carrier 1000. In an exemplary
embodiment, the outer diameter of the proximal tubular portion 1002
is smaller than the transition portion between the proximal tubular
portion 1002 and the distal tubular portion 1005 of the syringe
carrier 1000. In an exemplary embodiment, the outer diameter of the
proximal tubular portion 1002 at the deployment distance of 0 mm is
about 14 mm (compared with an outer diameter of the transition
region of about 14.17 mm) The lower outer diameter removes the
impedance to the passage of the terminal end of the distal arms
1114, and thereby facilitates the deployment of the shroud. This is
exhibited by the rise in the forces over deployment distances
between about 2 mm and about 0 mm.
[0221] FIG. 20 illustrates an exemplary retraction and extension
force profile of forces in N (y-axis) against deployment distances
in mm (x-axis) in which a downward peak 2002 appears in the later
stages of shroud deployment at an x-axis range of between about 4
mm and about 1 mm. The downward peak 2002 results from the pinching
effect of the distal arms 1114 within the constrained space between
the syringe carrier 1000 and the proximal housing component 12a. In
the exemplary embodiment shown in FIG. 20, the downward peak causes
a dip of about 0.4 N in the extension force from about 1.0 N in
FIG. 18 to about 0.6 N in FIG. 14.
A. Configuration of the Distal Arms of the Shroud
[0222] In an exemplary embodiment, the structural configuration of
the distal arms 1114 of the shroud 1110 may be modified to maximize
the extension forces during the shroud deployment process.
[0223] In an exemplary embodiment, a rounded or oval structure may
be included at the distal end of the distal arms 1114 of the shroud
1110, or the distal end of the distal arms 1114 may be configured
in a rounded or oval structure to facilitate the shroud deployment
process.
[0224] In an exemplary embodiment, the thickness of the distal arms
1114 of the shroud 1110 may be reduced in order to minimize the
pinching effect of the arms 1114 within the constrained space
provided between the outer surface of the syringe carrier 1000 and
the inner surface of the proximal housing component 12a. The
thickness of the distal arms 1114 of the shroud 1110 may be
configured to be comfortably accommodated within the height of the
constrained space. The thickness of the distal arms 1114 of the
shroud 1110 may be at most the height of the constrained space.
Exemplary thicknesses of the distal arms 1114 may range from about
1.00 mm to about 2.00 mm, but are not limited to this exemplary
range. Exemplary thicknesses may include, but are not limited to,
about 1.3, 1.31, 1.32, 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.39,
1.4, 1.41, 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.49, 1.5 mm,
and the like.
[0225] In an exemplary embodiment, the thickness may be reduced
from about 1.45 mm to about 1.40 mm. In an exemplary embodiment,
the shroud 1110 with the distal arms 1114 having the reduced
thickness of about 1.40 mm may have an inner diameter of about
14.40 mm, and may be accommodated between a proximal housing
component 12a having an exemplary inner diameter of about 17.60 mm
and a syringe carrier 1000 having an exemplary outer diameter of
about 14.00 mm.
[0226] FIG. 21 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during deployment of exemplary shrouds. The thickness
of the distal arms 1114 of the shrouds 1110 was decreased to a
small extent and a rounded structure was included at the distal end
of the arms. FIG. 21 shows that the extension force does not
exhibit a sharp drop unlike in FIG. 18, i.e., the downward slope in
FIG. 21 is more gradual than the downward slope in FIG. 18. This is
due to the structural change in the distal arms, which reduces the
bending effect of the distal arms during the early stages of the
shroud deployment process. The residual extension force in FIG. 21
at the end of the deployment is about 1.5 N, which is higher than
the residual extension of about 1.0 N in FIG. 18. A comparison
between FIGS. 18 and 21 indicates that the configured distal arms
result in a gradual drop in the extension forces over the
deployment process and in an increase in the residual extension
force.
[0227] In an exemplary embodiment, the distal arms 1114 of the
shroud 1110 may be rotated relative to a locating groove on the
shroud 1110. In an exemplary embodiment, the diverging angle of the
distal arms 1114 may be increased or decreased. Exemplary diverging
angles may range from about 0 degrees to about 45 degrees, but are
not limited to this exemplary range.
B. Configuration of the Flange of the Proximal Housing
Component
[0228] In the second type of interaction described above, the sides
of the distal arms 1114 contact the flange 256 (at the edge of the
opening 255) in the proximal housing component 12a, and are caused
to bend by the engagement with the flange 256. In an exemplary
embodiment, the flange 256 provided in or adjacent to the inner
surface of the housing 12a may be modified to increase the size of
the opening 255.
[0229] Exemplary embodiments configure and/or modify the flange 256
to minimize engagement of the distal arms 1114 of the shroud 1110
with the flange 256. Exemplary embodiments also configure and/or
modify the flange 256 to delay the engagement of the distal arms
1114 of the shroud 1110 with the flange 256 during the shroud
deployment process. In this manner, exemplary embodiments maximize
the extension forces generated during the shroud deployment
process, and result in smooth and reliable shroud deployment. In an
exemplary embodiment, the flange 256 is configured to minimize
bending of the distal arms 1114 of the shroud 1110 when the arms
are engaged by the flange 256. In an exemplary embodiment, a
portion of the flange 256 abutting the opening 255 may be cut off
or removed to provide more room for the distal arms 1114 of the
shroud 1110 to slide through the flange 256 and then to catch onto
a small pocket 257 in the flange 256. The pocket 257 of the flange
256 prevents further retraction of the shroud 1110.
[0230] FIG. 22A is a longitudinal sectional view taken through a
proximal housing component 12a housing a shroud 1110, in which the
proximal housing component 12a lacks a flange cut. The proximal
housing component 12a includes a flange 256 with an opening 255 and
a pocket 257. The flange 256 extends into the opening 255 to a
greater extent, denoted as distance D1. The shroud 1110 includes
distal arms 1114 that pass through the opening 255 and that are
bent by the protrusion of the flange 256 into the opening 255. This
bending effect occurs at an earlier time (compared to a proximal
housing component with a flange cut) after the distal arm 1114 has
traveled over distance L1 through the opening 255. After passing
through the opening 255, the terminal end of the distal arm 1114
catches onto the pocket 257. FIG. 22B is a longitudinal sectional
view taken through the proximal housing component 12a, showing the
pocket 257 on the proximal side of the flange 256.
[0231] FIG. 23A is a longitudinal sectional view taken through a
proximal housing component 12a housing a shroud 1110, in which the
proximal housing component 12a includes a flange cut. The proximal
housing component 12a includes a flange 256 with an opening 255 and
a pocket 257. The flange 256 extends into the opening 255 to a
lesser extent, denoted as distance D2. That is, a portion along the
circumferential length of the flange 256 abutting the opening 255
is removed or cut by introducing a flange cut, denoted by a length
(D1-D2), so that the opening 255 is wider. The shroud 1110 includes
distal arms 1114 that pass through the opening 255 and that are
bent by the protrusion of the flange 256 into the opening 255. This
bending effect occurs at a later time (compared to a proximal
housing component without a flange cut) after the distal arm 1114
has traveled over distance L2 through the opening 255. This
exemplary modification to the flange delays and reduces the
engagement of the distal arms 1114 with the flange 256 to reduce
the bending effect and, therefore, maximize the extension forces
during shroud deployment process. After passing through the opening
255, the terminal end of the distal arm 1114 catches onto the
pocket 257. FIG. 23B is a longitudinal sectional view taken through
the proximal housing component 12a, showing the pocket 257 on the
proximal side of the flange 256.
[0232] Exemplary cuts or notches formed in the flange 256 may range
in length from between about 0 mm to about 10 mm in some exemplary
embodiments. Some exemplary lengths of the cuts or notches may
include, but are not limited to, about 0, 0.1, 0.2, 0.3, 0.4, 0.5,
0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5,
7, 7.5, 8, 8.5, 9, 9.5, 10, and the like. Some exemplary lengths of
the cuts or notches may range from about 0.05 mm to about 0.6 mm.
In an exemplary embodiment, the opening distance between two
oppositely-positioned openings 255 in the flange 256 may be abound
3.10 mm, and the span of the distal arms 1114 of the shroud 1110
(i.e., the distance between the terminal ends of the distal arms
taken perpendicular to the length of the shroud) may be about 6.13
mm.
[0233] In an exemplary embodiment, one or more bosses may be added
to the flange 256 to create a backstop for the distal arms 1114 of
the shroud 1110 to lock into place when shroud override forces are
applied in the distal direction to the shroud 1110. In an exemplary
embodiment, one or more chamfers may be added to the edges of the
flange 256 to facilitate its engagement with the distal arms 1114
of the shroud 1110.
[0234] FIG. 24 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) during shroud deployment associated with conventional
automatic injection devices that are not configured to improve the
shroud deployment process. The force profile of FIG. 24 is used as
a control to verify and evidence the improvements in the shroud
deployment process achieved by exemplary embodiments. FIG. 24 shows
a large and sudden drop in the forces generated from about 2.5 N to
about 0.5 N after the shroud has traveled a distance denoted as L1.
This drop in the forces corresponds to the bending effect of the
distal arms 1114 of the shroud 1110 caused by engagement of the
distal arms 1114 with the flange 256 in the proximal housing
component 12a. Since the conventional flange does not include a
flange cut, the bending effect occurs at an earlier time (compared
to a proximal housing component with a flange cut) after the distal
arm 1114 has traveled over distance L1 through the opening 255 in
the flange 256. In the example shown in FIG. 24, the bending effect
starts after the distal arm 1114 has traveled about 2 mm.
Furthermore, a later pinching effect is observed at a deployment
distance of about 2 mm at which a downward peak reduces the forces
from about 0.8 N to about 0 N. The residual extension force at the
end of the shroud deployment process is about 1 N.
[0235] In some exemplary embodiments, a cutout is formed in an
exemplary interior flange 256 of a proximal housing component 12a.
In an exemplary embodiment, the cutout may have a dimension of
about 0.1 mm FIG. 25 illustrates a graph showing retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis) during shroud deployment associated with
housing components with a 0.1 mm flange cut. FIG. 25 shows a drop
in the forces generated from about 2.5 N to about 2 N after the
shroud has traveled a distance denoted as L2. This drop in the
forces corresponds to the bending effect of the distal arms 1114 of
the shroud 1110 caused by engagement of the distal arms 1114 with
the flange 256 in the proximal housing component 12a. Since the
exemplary flange includes a flange cut, the bending effect occurs
at a later time (compared to a conventional proximal housing
component without a flange cut) after the distal arm 1114 has
traveled over a greater distance L2 through the opening in the
flange 256. In the example shown in FIG. 25, the bending effect
starts after the distal arm 1114 has traveled about 5 mm. In
addition, the drop in the forces is more gradual and smaller in
magnitude (i.e., a force difference of about 0.5 N) compared to
that in FIG. 24. The residual extension force in FIG. 25 at the end
of the deployment is about 1.8 N, which is higher than the residual
extension force of about 1.0 N in FIG. 24. A comparison between
FIGS. 24 and 25 indicates that introducing a cutout in the flange
256 reduces the bending effect on the distal arms 1114 of the
shroud 1110 (i.e., the second type of interaction). This results in
a later and more gradual drop in the extension forces over the
deployment process and an increase in the residual extension
force.
[0236] In some exemplary embodiments, a cutout is formed in an
exemplary interior flange 256 formed of a polycarbonate material.
In an exemplary embodiment, the cutout may have a dimension of
about 0.3 mm FIG. 26 illustrates a graph showing retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis) during shroud deployment associated with
housing components with a 0.3 mm flange cut. FIG. 26 shows that the
extension forces do not exhibit a sharp drop, unlike in FIG. 24.
That is, the downward slope in FIG. 24 is more gradual than the
downward slope in FIG. 24. The residual extension force in FIG. 26
at the end of the deployment is about 1.5 N, which is higher than
the residual extension force of about 1.0 N in FIG. 24. A
comparison between FIGS. 24 and 26 indicates that introducing a
cutout in the flange 256 reduces the bending effect on the distal
arms 1114 of the shroud 1110 (i.e., the second type of
interaction). This results in a later and more gradual drop in the
extension forces over the deployment process and an increase in the
residual extension force.
[0237] In some exemplary embodiments, a cutout is formed in an
exemplary interior flange 256 formed of a polypropylene material.
In an exemplary embodiment, the cutout may have a dimension of
about 0.3 mm FIG. 27 illustrates a graph showing retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis) during shroud deployment associated with
housing components with a 0.3 mm flange cut. FIG. 27 shows that the
extension forces do not exhibit a sharp drop, unlike in FIG. 24.
That is, the downward slope in FIG. 27 is more gradual than the
downward slope in FIG. 24. This is due to the design change in the
distal arms, which reduces the bending effect of the distal arms
during the early stages of the shroud deployment process. The
residual extension force in FIG. 27 at the end of the deployment is
about 1.3 N, which is higher than the residual extension force of
about 1.0 N in FIG. 24. A comparison between FIGS. 24 and 27
indicates that introducing a cutout in the flange 256 reduces the
bending effect on the distal arms 1114 of the shroud 1110 (i.e.,
the second type of interaction). This results in a later and more
gradual drop in the extension forces over the deployment process
and an increase in the residual extension force.
C. Configuration of the Proximal Tubular Portion of the Syringe
Carrier
[0238] In an exemplary embodiment, the constrained space between
the syringe carrier 1000 and the proximal housing component 12a may
be increased to reduce the pinching effect on the distal arms 1114
of the shroud 1110 and to, thereby, maximize the extension forces
in a later stage in the shroud deployment process, while ensuring
proper lockout of the shroud in the extended position. In an
exemplary embodiment, the outer diameter of the proximal tubular
portion 1002 of the syringe carrier 1000 may be decreased in order
to increase the constrained space between the syringe carrier 1000
and the proximal housing component 12a, which provides a larger
space for the twisting movement of the distal arms 1114 of the
shroud 1110 and facilitates smooth and reliable shroud
deployment.
[0239] Exemplary outer diameters of the proximal tubular portion
1002 of the syringe carrier 1000 may range from about 13.00 mm to
about 15.00 mm, but are not limited to this exemplary range. An
exemplary outer diameter of the proximal tubular portion 1002 of
the syringe carrier 1000 may be about 13.17 mm, 14.00 mm, 14.17 mm,
and the like. In an exemplary embodiment, the distal arms 1114
(accommodated within the constrained space between the proximal
tubular portion of the syringe carrier and the proximal housing
component 12a) may have a thickness of about 1.40 mm to about 1.45
mm and may have an inner diameter of about 14.40 mm. The proximal
housing component 12a may have an exemplary inner diameter of about
17.60 mm.
[0240] FIG. 28A illustrates a graph plotting retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis), for an exemplary syringe carrier 1000
with a proximal tubular portion 1002 that has been reduced in outer
diameter from about 14.17 mm to about 13.17 mm FIG. 28A shows that
the extension force does not include a downward peak in a later
stage in the shroud deployment process, e.g., at an x-axis range of
between about 4 mm and about 1 mm, unlike in FIG. 24. FIG. 28A also
shows that the residual extension force at the end of the
deployment is about 1.2 N for the 13.17 mm outer diameter, which is
higher than residual extension forces of about 0.5 N to about 1.0 N
for the 14.17 mm outer diameter.
[0241] FIG. 28B illustrates a graph plotting retraction and
extension forces in N (y-axis) generated at different deployment
distances in mm (x-axis), for an exemplary syringe carrier 1000
with a proximal tubular portion 1002 that has been reduced in outer
diameter from about 14.17 mm to about 14.00 mm FIG. 28B shows that
the extension force does not include a downward peak in a later
stage in the shroud deployment process, e.g., at an x-axis range of
between about 4 mm and about 1 mm, unlike in FIG. 24. FIG. 28B also
shows that the residual extension force at the end of the
deployment is above 1 N for the 14.00 mm outer diameter, which is
higher than residual extension forces of about 0.5 N to about 1.0 N
for the 14.17 mm outer diameter.
D. Configuration of the Inner Diameter of the Proximal Housing
Component
[0242] In an exemplary embodiment, the constrained space between
the syringe carrier 1000 and the proximal housing component 12a may
be increased to reduce the bending effect and/or the pinching
effect and to, thereby, maximize the extension forces in the during
the shroud deployment process, while ensuring proper lockout of the
shroud in the extended position. The inner diameter of the proximal
housing component 12a of the automatic injection device may be
increased in order to increase the constrained space between the
syringe carrier 1000 and the proximal housing component 12a, which
provides a larger space for the twisting movement of the distal
arms 1114 of the shroud 1110, which provides a larger space for the
twisting movement of the distal arms 1114 of the shroud 1110 and
facilitates smooth and reliable shroud deployment.
[0243] Exemplary inner diameters of the proximal housing component
12a may range from about 17 mm to about 18 mm, but are not limited
to this exemplary range. An exemplary range of inner diameters is
between about 17.5 mm and about 17.7 mm for a proximal housing
component formed of a repsol-grade polypropylene material. An
exemplary range of inner diameters is between about 17.7 mm and
about 17.85 mm for a proximal housing component formed of a
polycarbonate material.
[0244] At the same time, the exemplary embodiments may impose a
maximum limit on the inner diameter of the proximal housing
component 12a, because inner diameters above the limit may create
syringe alignment problems within the housing of the automatic
injection device. Thus, a problem solved by exemplary embodiments
is increasing the inner diameter of the proximal housing component
12a within a certain maximum limit in order to improve the shroud
deployment process, while limiting the outer and inner diameters of
the automatic injection device and avoiding syringe alignment
problems.
[0245] In an exemplary embodiment, the distal arms 1114
(accommodated within the constrained space between the proximal
tubular portion of the syringe carrier and the proximal housing
component 12a) may have a thickness of about 1.40 mm to about 1.45
mm and may have an inner diameter of about 14.40 mm. An exemplary
outer diameter of the proximal tubular portion 1002 of the syringe
carrier 1000 may be about 13.17 mm, 14.00 mm, 14.17 mm, and the
like. The proximal housing component 12a may have an exemplary
inner diameter of about 17 mm to about 18 mm.
[0246] FIG. 29 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) for a control proximal housing component formed of a
repsol-grade polypropylene material with an inner diameter of about
17.53 mm to about 17.63 mm FIG. 29 shows that the residual
extension force at the end of the deployment is about 1.0 N.
[0247] FIG. 30 illustrates a graph showing retraction and extension
forces in N (y-axis) generated at different deployment distances in
mm (x-axis) for an exemplary test proximal housing component formed
of a polycarbonate material with an increased inner diameter of
about 17.72 mm to about 17.85 mm FIG. 30 shows that the residual
extension force at the end of the shroud deployment process is
about 1.5 N, which is advantageously higher than for the control
proximal housing component of FIG. 29.
[0248] A comparison between FIGS. 29 and 30 shows that increasing
the inner diameter of the proximal housing component 12a reduces
the pinching effect of the distal arms of the shroud, which
maximizes the extension forces during a later stage of the shroud
deployment process. That is, the proximal housing component 12a
corresponding to FIG. 30 results in significant improvements in the
shroud deployment and lockout performance.
E. Other Exemplary Configurations of the Transition Portion of the
Syringe Carrier
[0249] In an exemplary embodiment, the transition portion of the
syringe carrier 2100 may be configured to reduce the pinching
effect and to, thereby, maximize the extension forces in a later
stage in the shroud deployment process. In an exemplary embodiment,
a gradual transition, i.e., a sloped portion, may be introduced at
the transition portion to provide a gradual transition between the
wider proximal tubular portion 2104 and the narrower distal tubular
portion 2106, and to thereby reduce the outer diameter of the
proximal tubular portion 2104 at the critical pinching area of the
transition portion. This provides a larger space for the twisting
movement of the distal arms 1114 of the shroud 1110 and facilitates
smooth and reliable shroud deployment. The gradual transition
between the proximal and distal tubular portions of the syringe
carrier may take the form of a chamfer in an exemplary embodiment.
An exemplary chamfer may fully or partially replace a step at the
transition portion of the syringe carrier.
[0250] An exemplary chamfer may have an angle relative to the
longitudinal axis of the automatic injection device of between
about 5 degrees and about 60 degrees, although the angle is not
limited to this exemplary range. Certain exemplary angles include,
but are not limited to, about 5, 10, 15, 20, 25, 30, 35, 40, 45,
50, 55, 60 degrees, and the like. An exemplary chamfer may have an
exemplary width of between about 0.2 mm and about 0.7 mm, although
the width is not limited to this exemplary range. Exemplary widths
may include, but are not limited to, about 0.2, 0.25, 0.3, 0.35,
0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7 mm, and the like. An exemplary
chamfer may have an exemplary depth (i.e., the vertical distance
between the proximal tubular portion and the distal tubular
portion) of between about 0.6 mm and about 0.9 mm, although the
depth is not limited to this exemplary range. Certain exemplary
depths may include, but are not limited to, about 0.6, 0.65, 0.7,
0.75, 0.8, 0.85, 0.9 mm, and the like. An exemplary chamfer may
have an exemplary length ranging between about 0.1 mm and about 0.5
mm, but is not limited to this exemplary range. Exemplary lengths
may include, but are not limited to, about 0.1, 0.15, 0.2, 0.25,
0.3, 0.35, 0.4, 0.45, 0.5 mm, and the like.
[0251] In an exemplary embodiment, the edge of the transition
portion of the syringe carrier 2100 may include a rounded
structure. An exemplary rounded structure may have an exemplary
width of between about 0.1 mm and about 0.7 mm, although the width
is not limited to this exemplary range.
[0252] FIG. 31A illustrates a perspective view of an exemplary
syringe carrier 2100 having an exemplary chamfer 2108 formed
between the proximal tubular portion 2104 and the distal tubular
portion 2106. FIG. 31B illustrates a side view of the exemplary
syringe carrier 2100 of FIG. 31A. In the exemplary embodiment shown
in FIGS. 31A and 31B, a chamfer 2108 is introduced at the
transition portion 2102 so that the chamfer 2108 creates an angled
relief extending between the wider proximal tubular portion 2104
and the narrower distal tubular portion 2106. The chamfer 2108 may
have an exemplary width of about 0.7 mm, an exemplary length of
about 3 mm, and an exemplary angle of about 15 degrees relative to
the plane of the cylindrical portions. In the exemplary embodiment
shown in FIGS. 31A and 31B, the distal edge 2110 of the chamfer
2108 may be aligned with the distal edge 2112 of the flange 2114 of
the transition portion 2102, and the proximal edge 2116 of the
chamfer 2108 may extend in the proximal direction beyond the
proximal edge 2118 of the flange 2114. In another exemplary
embodiment, the distal edge 2110 of the chamfer 2108 may not be
aligned with the distal edge 2112 of the flange 2114 of the
transition portion 2102.
[0253] FIG. 32 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in automatic injection devices including ten exemplary
syringe carriers configured as shown in FIGS. 31A and 31B. FIG. 32
shows that the pinching effect between about 1.0 mm and about 4.0
mm shown in FIG. 24 is reduced or eliminated by the introduction of
the chamfer as shown in FIGS. 31A and 31B. The residual extension
force is about 1.5 N.
[0254] FIG. 33A illustrates a perspective view of an exemplary
syringe carrier 2300 having an exemplary chamfer 2308 formed
between the proximal tubular portion 2304 and the distal tubular
portion 2306. FIG. 33B illustrates a side view of the exemplary
syringe carrier 2300 of FIG. 33A. In the exemplary embodiment shown
in FIGS. 33A and 33B, a chamfer 2308 is introduced at the
transition portion 2302 between the proximal tubular portion 2304
and the distal tubular portion 2306, so that the chamfer creates an
angled relief extending between the wider proximal tubular portion
2304 and the narrower distal tubular portion 2306. The chamfer 2308
may have an exemplary width of about 0.7 mm and an exemplary angle
of about 10 degrees relative to the plane of the cylindrical
portions. In the exemplary embodiment shown in FIGS. 33A and 33B,
the distal edge 2310 of the chamfer 2308 may be aligned with the
distal edge 2312 of the flange 2314, and the proximal edge 2316 of
the chamfer 2308 may extend in the proximal direction beyond the
proximal edge 2318 of the flange 2314.
[0255] FIG. 34 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIGS. 33A and
33B. FIG. 34 shows that the pinching effect at about 2.5 mm shown
in FIG. 24 is eliminated by the introduction of the chamfer as
shown in FIGS. 33A and 33B. In addition, the residual extension
force is raised to above 1.0 N by the introduction of the chamfer
as shown in FIGS. 33A and 33B.
[0256] FIG. 35A illustrates a perspective view of an exemplary
syringe carrier 2500 having an exemplary chamfer 2508 formed
between the proximal tubular portion 2504 and the distal tubular
portion 2506. FIG. 35B illustrates a side view of the exemplary
syringe carrier 2500 of FIG. 35A. In the exemplary embodiment shown
in FIGS. 35A and 35B, a chamfer 2508 is introduced at the
transition portion 2502 between the proximal tubular portion 2504
and the distal tubular portion 2506, so that the chamfer 2508
creates an angled relief extending between the wider proximal
tubular portion 2504 and the narrower distal tubular portion 2506.
The chamfer 2508 may have an exemplary width of about 0.7 mm and an
exemplary angle of about 10 degrees relative to the plane of the
cylindrical portions. In the exemplary embodiment shown in FIGS.
35A and 35B, the proximal edge 2516 of the chamfer 2508 may be
aligned with the proximal edge 2518 of the flange 2514, and the
distal edge 2510 of the chamfer 2508 may extend in the distal
direction beyond the distal edge 2512 of the flange 2514.
[0257] FIG. 36 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIGS. 35A and
35B. FIG. 36 shows that the pinching effect at about 2.5 mm shown
in FIG. 24 is eliminated by the introduction of the chamfer as
shown in FIGS. 35A and 35B. In addition, the residual extension
force is raised above 1.0 N by the introduction of the chamfer as
shown in FIGS. 35A and 35B.
[0258] FIG. 37 illustrates a perspective view of an exemplary
syringe carrier 2700 having an exemplary chamfer 2708 formed
between the proximal tubular portion 2704 and the distal tubular
portion 2706 and an exemplary slot 2710 formed in the proximal
tubular portion 2704. The slot 2710 is formed in the proximal
tubular portion 2704 to create a depression or trench in the outer
surface of the proximal tubular portion 2704. The slot 2710 may
extend over a portion of the length of the proximal tubular portion
2704 or over the entire length of the proximal tubular portion
2704. During the shroud deployment process, the distal arms 1114 of
the shroud 1110 may engage with the surface of the slot 2710 as the
distal arms move in the proximal direction over the proximal
tubular portion 2704. Introduction of the slot 2710 thus increases
the constrained space between the syringe carrier 2700 and the
proximal housing component 12a available to accommodate the distal
arms 1114 of the shroud 1110. This reduces the pinching effect of
the distal arms 1114 (i.e., the third type of interaction described
above), thereby maximizing extension forces generated during the
shroud deployment process and facilitating smooth and reliable
shroud deployment.
[0259] Exemplary slots may have depths ranging from about 0.05 mm
to about 0.5 mm, but are not limited to this exemplary range.
Certain exemplary depths include, but are not limited to, about
0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 mm, and the
like. The depth of a slot 2710 may be constant or may vary over the
length and/or width of the slot. The width of the slot 2710 may be
constant along its length or may vary.
[0260] In an exemplary syringe carrier including one or more slots,
a chamfer may be absent at the transition portion between the
proximal and distal tubular portions of the syringe carrier.
[0261] In another exemplary syringe carrier include one or more
slots, a chamfer may be introduced at the transition portion
between the proximal and distal tubular portions of the syringe
carrier. In an exemplary embodiment, a chamfer 2708 is introduced
at the transition portion 2702 so that the chamfer creates an
angled relief extending between the slot 2710 and the distal
tubular portion 2706. In an exemplary embodiment, the chamfer 2708
may have an exemplary width of about 0.7 mm and an exemplary angle
of about 10 degrees relative to the plane of the cylindrical
portions.
[0262] FIG. 38 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIG. 37. A slot
having a depth of about 0.1 mm and a chamfer having an exemplary
width of about 0.7 mm and an exemplary angle of about 10 degrees
are introduced in the syringe carriers. The introduction of the
chamfer and the slot reduces the pinching effect at about 2.5 mm
and increases the residual extension force above 1.0 N.
[0263] FIG. 39 illustrates a perspective view of an exemplary
syringe carrier 2900 having an exemplary chamfer 2908 formed
between the proximal tubular portion 2904 and the distal tubular
portion 2906 and an exemplary slot 2910 formed in the proximal
tubular portion 2904. A slot 2910 is formed in the proximal tubular
portion 2904 to create a depression in the surface of the proximal
tubular portion. The slot 2910 may extend over a portion of the
length of the proximal tubular portion 2904 or over the entire
length of the proximal tubular portion 2904. During the shroud
deployment process, the distal arms 1114 of the shroud 1110 may
engage with the surface of the slot 2910 as the distal arms move in
the proximal direction over the proximal tubular portion 2904. The
slot 2910 may have an exemplary depth of about 0.3 mm.
[0264] A chamfer 2908 is introduced at the transition portion 2902
so that the chamfer creates an angled relief extending between the
slot 2910 and the distal tubular portion 2906. The chamfer 2908 may
have an exemplary width of about 0.7 mm and an exemplary angle of
about 10 degrees relative to the plane of the cylindrical
portions.
[0265] FIG. 40 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers configured as shown in FIG. 39. A slot
having a depth of about 0.3 mm is introduced in the syringe
carriers. The forces generated drop at a deployment distance of
about 11 mm due to the bending effect of the distal arms of the
shroud. However, the introduction of the slot reduces the pinching
effect over the deployment distance range of about 4 mm to about 0
mm (i.e., there is no downward peak in the forces), and raises the
residual extension force to about 1.5 N. A comparison between FIGS.
24 and 40 indicates that introducing a slot in the proximal tubular
component of the syringe carrier reduces the pinching effect on the
distal arms 1114 of the shroud 1110 (i.e., the third type of
interaction). This results in increased forces during the later
stages of the shroud deployment process and an increase in the
residual extension force.
[0266] FIG. 41 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices in which a slot
having a depth of about 0.3 mm is introduced to the syringe
carriers and a 0.1 mm flange cut is introduced to the flanges in
the proximal housing components. The bending effect of the distal
arms 1114 of the shroud 1110 is delayed and starts after the distal
arm 1114 has traveled from about 13 mm to about 8.5 mm. In
addition, the drop in the forces is more gradual and smaller in
magnitude compared to that in FIG. 24 (which lacks a flange cut). A
comparison between FIGS. 41 and 24 (which lacks a flange cut)
indicates that introducing a cutout in the flange 256 reduces the
bending effect on the distal arms 1114 of the shroud 1110 (i.e.,
the second type of interaction). This results in a later and more
gradual drop in the extension forces over the deployment process
and an increase in the residual extension force.
[0267] The introduction of the slot reduces the pinching effect
over the deployment distance range of about 4 mm to about 0 mm
(i.e., there is no downward peak in the forces), and raises the
residual extension force to about 2 N. A comparison between FIGS.
24 and 41 (which lacks a slot in the syringe carrier) indicates
that introducing a slot in the proximal tubular component of the
syringe carrier reduces the pinching effect on the distal arms 1114
of the shroud 1110 (i.e., the third type of interaction). This
results in increased forces during the later stages of the shroud
deployment process and an increase in the residual extension
force.
[0268] FIG. 42 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices in which a slot
having a depth of about 0.3 mm is introduced to the syringe
carriers and a 0.3 mm flange cut is introduced to the flanges in
the proximal housing components.
[0269] The bending effect of the distal arms 1114 of the shroud
1110 is delayed and starts after the distal arm 1114 has traveled
from about 13 mm to about 8.5 mm. In addition, the drop in the
forces is more gradual and smaller in magnitude compared to that in
FIG. 24 (which lacks a flange cut). A comparison between FIGS. 42
and 24 (which lacks a flange cut) indicates that introducing a
cutout in the flange 256 reduces the bending effect on the distal
arms 1114 of the shroud 1110 (i.e., the second type of
interaction). This results in a later and more gradual drop in the
extension forces over the deployment process and an increase in the
residual extension force.
[0270] The introduction of the slot reduces the pinching effect
over the deployment distance range of about 4 mm to about 0 mm
(i.e., there is no downward peak in the forces), and raises the
residual extension force to about 1.5 N. A comparison between FIGS.
42 and 24 (which lacks a slot in the syringe carrier) indicates
that introducing a slot in the proximal tubular component of the
syringe carrier reduces the pinching effect on the distal arms 1114
of the shroud 1110 (i.e., the third type of interaction). This
results in increased forces during the later stages of the shroud
deployment process and an increase in the residual extension
force.
[0271] FIG. 43 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) in exemplary automatic injection devices including ten
exemplary syringe carriers in which a slot having a depth of about
0.3 mm and a chamfer having an exemplary width of about 0.7 mm and
an exemplary angle of about 10 degrees are introduced to the
syringe carriers. The introduction of the chamfer and the slot
reduces the pinching effect at about 2.5 mm, and raises the
residual extension force to about 1.5 N.
[0272] FIG. 44 illustrates a perspective view of an exemplary
syringe carrier 3100 having an exemplary chamfer 3102 formed
between the proximal tubular portion 3104 and the distal tubular
portion 3106. The chamfer 3102 may have an exemplary width of about
0.5 mm and an exemplary angle of about 45 degrees relative to the
plane of the cylindrical portions.
[0273] FIG. 45 illustrates a perspective view of an exemplary
syringe carrier 3200 having an exemplary slot 3202 formed in the
proximal tubular portion 3204 of the syringe carrier 3200 to create
a depression in the surface of the proximal tubular portion 3204.
The slot 3202 may extend over a portion of the length of the
proximal tubular portion 3204 or over the entire length of the
proximal tubular portion 3204. During the shroud deployment
process, the distal arms 1114 of the shroud 1110 may engage with
the surface of the slot 3202 as the distal arms move in the
proximal direction over the proximal tubular portion 3204. The slot
3202 may have an exemplary depth of between about 0.1 mm and about
0.7 mm. In an exemplary embodiment, the slot 3202 may have an
exemplary depth of about 0.5 mm.
[0274] FIGS. 46-48 illustrate graphs of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary syringe carriers of a first type, a second
type, and a third type. The three types of syringe carriers were
formed using different production tools. Differences in the
manufacturing tolerances of the different production tools
introduced differences in the geometries of the syringe
carriers.
[0275] FIG. 46 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary syringe carriers of a first type: a control
syringe carrier configured as shown in FIG. 9 having a step at the
transition portion between the proximal tubular portion and the
distal tubular portion; a syringe carrier configured as shown in
FIG. 44 with a chamfer of width about 0.5 mm and an angle of about
45 degrees; and a syringe carrier configured as shown in FIG. 45
with a 0.5 mm deep slot cut. FIG. 46 shows a pinching effect at
about 2 mm at which the extension force shows a downward peak
corresponding to a pinching effect during the later stage of the
shroud deployment process. The control syringe carrier (illustrated
in FIG. 9) shows the greatest downward peak resulting in a residual
extension force of about 1.0 N. The chamfered syringe carrier
(illustrated in FIG. 44) shows an intermediate downward peak
resulting in a residual extension force of about 1.3 N. The slotted
syringe carrier (illustrated in FIG. 45) shows no downward peak
resulting in a residual extension force of about 1.7 N. FIG. 46
indicates that the pinching effect is reduced or eliminated by the
chamfer and the slot, which results in efficient and reliable
shroud deployment.
[0276] FIG. 47 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary syringe carriers of a second type: a control
syringe carrier configured as shown in FIG. 9 having a step at the
transition portion between the proximal tubular portion and the
distal tubular portion; a syringe carrier configured as shown in
FIG. 44 with a chamfer of width about 0.5 mm and an angle of about
45 degrees; and a syringe carrier configured as shown in FIG. 45
with a 0.5 mm deep slot cut. FIG. 34 shows a pinching effect at
about 2 mm at which the extension force shows a downward peak which
corresponds to a pinching effect during the later stage of the
shroud deployment process. The control syringe carrier (illustrated
in FIG. 9) shows the greatest downward peak. The chamfered syringe
carrier (illustrated in FIG. 44) shows an intermediate downward
peak. The slotted syringe carrier (illustrated in FIG. 45) shows no
downward peak. FIG. 47 indicates that the pinching effect is
reduced or eliminated by the chamfer and the slot, which results in
efficient and reliable shroud deployment.
[0277] FIG. 48 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary syringe carriers of a third type: a control
syringe carrier configured as shown in FIG. 9 having a step at the
transition portion between the proximal tubular portion and the
distal tubular portion; a syringe carrier configured as shown in
FIG. 44 with a chamfer of width about 0.5 mm and an angle of about
45 degrees; and a syringe carrier configured as shown in FIG. 45
with a 0.5 mm deep slot cut. FIG. 48 shows a pinching effect at
about 2 mm at which the extension force shows a downward peak which
corresponds to a pinching effect during shroud deployment. The
control syringe carrier (illustrated in FIG. 9) shows the greatest
downward peak. The chamfered syringe carrier (illustrated in FIG.
44) shows an intermediate downward peak. The slotted syringe
carrier (illustrated in FIG. 45) shows no downward peak. FIG. 48
indicates that the pinching effect is reduced or eliminated by the
chamfer and the slot, which results in efficient and reliable
shroud deployment.
[0278] In an exemplary syringe carrier, a rounded step, i.e., a
step with a rounded edge, may be formed at the transition portion
between the proximal tubular portion and the distal tubular portion
of the syringe carrier. However, it was determined from
quantitative experimental results that the rounded edge does not
maximize extension forces (i.e. reduce or substantially eliminate
the localized downward peak near the end of deployment of the
shroud) compared to FIG. 24. As such, in another exemplary syringe
carrier, the transition portion may be left un-rounded.
F. Configuration of the Living Hinge of the Proximal Anchor Portion
of the Syringe Carrier
[0279] In an exemplary embodiment, a draft 3602 may be included in
the living hinge of the proximal anchor portion 3604 of the syringe
carrier 3600 in order to facilitate the molding or formation
process of the syringe carrier. Without the draft 3602, the hinge
at the proximal anchor portion 3604 of the syringe carrier 3600 may
tend to stick to the mold used in molding or forming the syringe
carrier 3600. The introduction of the draft 3602 allows the syringe
carrier 3600 to be released smoothly from the mold after the
syringe carrier is molded or formed in the mold. The introduction
of the draft 3602 may improve the syringe carrier molding process
and avoid warping of the parts of the syringes carrier 3600 that
may otherwise by caused by a defective molding process.
[0280] FIG. 49 illustrates a perspective view of an exemplary
syringe carrier 3600 in which the living hinge includes a draft
3602 in the proximal anchor portion 3604 of the syringe carrier
3600. In exemplary embodiments, the draft 3602 may have exemplary
draft angles of about 1.degree., 2.degree., 3.degree., 4.degree.,
5.degree., 6.degree., 7.degree., 8.degree., 9.degree., 10.degree.,
etc. In the exemplary embodiment illustrated in FIG. 49, the draft
angle is about 5.degree..
[0281] In another exemplary embodiment, a draft may not be included
in the living hinge of the proximal anchor portion 3604 of the
syringe carrier 3600.
G. Configuration of the Rail of the Syringe Carrier
[0282] The rails of an exemplary syringe carrier may be configured
in one or more exemplary ways to decrease the frictional forces
experienced between the rails and the inner grooves of the shroud
as the rails move within the grooves during shroud deployment.
Reduction of the frictional forces increases the extension forces
experienced during the shroud deployment process and facilitates
smooth shroud deployment.
[0283] FIG. 50 illustrates a perspective view of an exemplary
syringe carrier 3700 including a rail 3702 extending between a
proximal end 3704 and a distal end 3706. In an exemplary
embodiment, the width of the rail 3702 of the carrier 3700 (i.e.,
the cross-sectional width of the rail) may be decreased in order to
decrease interaction of the rail 3702 with the inner grooves of the
shroud during the shroud deployment process, which may increase the
extension forces in the shroud deployment process. In an exemplary
embodiment, the width of the rail 3702 may be decreased to the same
width along the length of the rail 3702. In another exemplary
embodiment, the width of the rail 3702 may be decreased to
different widths along the length of the rail 3702. In an exemplary
embodiment, the width of the rail 3702 may be wider at the proximal
end 3704 than at the distal end 3706. In an exemplary embodiment,
the width of the rail 3702 may be wider at the distal end 3706 than
at the proximal end 3704. In an exemplary embodiment, the rail 3702
is a tapered rail having a greater width at one end and a lesser
width at another end. In an exemplary embodiment, the width may
vary over the length of the rail 3702 (for example, material may be
removed to achieve different widths along the length of the rail)
in order to compensate for warpage in the components after
molding.
[0284] In an exemplary embodiment, the length of the rail 3702
along the longitudinal axis of the carrier 3700 may be decreased in
order to decrease interaction of the rail 3702 with the inner
grooves of the shroud during the shroud deployment process, which
may increase the extension forces in the shroud deployment process.
Exemplary lengths of the rail 3702 may range from about 14.00 mm to
about 16.00 mm, but are not limited to this exemplary range. In an
exemplary embodiment, the length of the rail 3702 may be decreased
from about 15.30 mm to about 14.79 mm. In another exemplary
embodiment, the length of the rail 3702 may be decreased from about
15.30 mm to about 14.94 mm.
[0285] In an exemplary embodiment, the distance between the rails
3702 of the carrier 3700 may be decreased.
[0286] In an exemplary embodiment, the top profile of an exemplary
rail 3702 of the carrier 3700 may be configured to match the
curvature of the shroud in order to improve the interlocking of the
rail 3702 and the internal grooves of the shroud Improved
interlocking provides stability to the shroud and carrier assembly
during movement of the components during the shroud deployment
process. The configuration of the top profile of the rail 3702 also
increases the gap between the top of the rail 3702 and the inner
surface of the groove of the shroud. The increased gap increases
the residual extension forces, which facilitates smooth shroud
deployment.
H. Configuration of the Inner Grooves of the Shroud
[0287] The inner grooves of the shroud may be configured in one or
more exemplary ways to decrease the frictional forces experienced
between the rails of the syringe carrier and the inner grooves of
the shroud as the rails move within the grooves during shroud
deployment. Reduction of the frictional forces increases the
extension forces experienced during the shroud deployment process
and facilitates smooth shroud deployment.
[0288] In an exemplary embodiment, the height of the internal
grooves of the shroud 1110 may be increased in order to decrease
frictional forces between the rail 1007 of the syringe carrier 1000
with the inner grooves of the shroud 1110 during the shroud
deployment process, in order to maximize the extension forces in
the shroud deployment process.
[0289] In an exemplary embodiment, a lead-in may be added to the
internal grooves of the shroud 1110 in order to facilitate assembly
of the shroud 1110 and the carrier 1000. The size of the lead-in in
the groove may be configured based, in part, on the diameter of the
groove. For example, for a groove with a larger diameter, the size
of the lead-in may be reduced.
[0290] In an exemplary embodiment, a lead-in may be added to the
rail 1007 of the carrier 1000 in order to facilitate assembly of
the shroud 1110 and the carrier 1000.
I. Configuration of Coefficient of Friction
[0291] The extension forces experienced during the shroud
deployment process may be dependent on, in part, the coefficient of
friction (COF) and the frictional forces experienced among the
different moving components of the automatic injection device,
e.g., components of the shroud 1110 and the syringe carrier 1000.
Higher COF values increase the frictional forces experienced
between the different moving components during the shroud
deployment process, and may thus lead to failed shroud deployment.
Reducing the COF values decreases the frictional forces experienced
during the shroud deployment process and allows the release of the
biasing member 89 to smoothly deploy the shroud.
[0292] FIG. 51 illustrates a graph of retraction and extension
forces in N (y-axis) against shroud deployment distances in mm
(x-axis) for exemplary COF values of about 0.000, about 0.125, and
about 0.300. FIG. 51 shows a pinching effect at about 2 mm at which
the extension force showed a downward peak which corresponds to a
pinching effect during shroud deployment. The downward peak had the
greatest magnitude (extension force of about 0.7 N) for the 0.300
COF, an intermediate magnitude (extension force of about 1.5 N) for
the 0.125 COF, and the lowest magnitude (extension force of about
2.5 N) for the 0.000 COF.
[0293] FIG. 51 indicates that increasing COF values increased the
frictional forces, which resulted in a greater magnitude of the
downward peak at about 2 mm Exemplary embodiments may configure one
or more properties of the different moving parts, e.g., components
of the shroud 1110, the syringe carrier 1000, the automatic
injection device housing, etc., to reduce the frictional forces
experienced during the shroud deployment process. These
modifications improve the shroud deployment process and prevent
shroud deployment failure.
[0294] In exemplary embodiments, one or more properties of the
material forming the moving parts may be configured in reducing the
frictional forces experienced during the shroud deployment process.
These properties may include, but are not limited to, flex modulus,
yield strength, yield elongation, material strength for
functionality and manufacturability, and the like. In an exemplary
embodiment, a polyacetal material may be used to form one or more
moving parts experiencing low frictional forces, e.g., the shroud,
the syringe carrier, etc. In an exemplary embodiment,
polytetrafluoruethylene (PTFE) may be used to form one or more
moving parts, e.g., the shroud, the syringe carrier, etc.
J. Other Exemplary Configurations
[0295] One of ordinary skill in the art will recognize that one or
more other configurations may be implemented and/or one or more
additional features may be included to improve the shroud
deployment process. The configurations and features provided in
exemplary embodiments are not limited to those described below in
this section.
[0296] For example, in an exemplary embodiment, the inner diameter
of the shroud 1110 may be increased to reduce frictional forces
between the biasing member 89 and the shroud 1110.
[0297] In an exemplary embodiment, the width of the tabbed foot
1006 of the carrier 1000 may be decreased to reduce frictional
forces between the tabbed foot 1006 and the slot 1118 of the shroud
1110. In an exemplary embodiment, the width of the slot 1118 of the
shroud 1110 may be increased to reduce frictional forces between
the tabbed foot 1006 and the slot 1118 of the shroud 1110.
[0298] In an exemplary embodiment, one or more sloping portions,
e.g., chamfers, may be added to a side wall of the interior flange
256 in the housing to reduce frictional forces between the flange
256 and components of the shroud deployment assembly, e.g., the
arms 1114 of the shroud 1110. In an exemplary embodiment, the
distal edge of a side wall of the interior flange 256 in the
housing may be rounded to reduce frictional forces between the
flange 256 and components of the shroud deployment assembly, e.g.,
the arms 1114 of the shroud 1110.
K. Summary
[0299] Exemplary embodiments may implement one or a combination of
two or more of the structural, functional and operational
configurations taught herein to minimize the risk of shroud
deployment failure. Exemplary embodiments may also modify one or
more conventional components of an automatic injection device in
accordance with the teachings provided herein in order to minimize
the risk of shroud deployment failure in the modified conventional
components.
[0300] Exemplary embodiments provide automatic injection devices in
which a needle shroud is automatically deployed in a reliable and
consistent manner to protectively sheath a needle during or after
an injection is delivered using the automatic injection device.
Exemplary embodiments also provide shroud deployment assemblies
including a needle shroud and a syringe carrier that when
cooperatively configured in an assembled automatic injection device
ensure that the needle shroud is automatically deployed in a
reliable and consistent manner.
[0301] Exemplary embodiments may provide methods for forming an
automatic injection device. An exemplary method includes providing
a housing having an internal bore extending between a proximal end
and a distal end, and disposing a shroud within the internal bore
at the proximal end of the housing of the automatic injection
device. The shroud may be capable of moving between a retracted
position and an extended position relative to the housing. The
shroud may include a tubular member extending between a proximal
end and a distal end, and one or more arms extending from the
distal end of the tubular member. The method may include disposing
a syringe carrier partly within the tubular member of the shroud,
the syringe carrier comprising a tubular member. The method may
also include configuring a constrained space formed between the
housing of the automatic injection device and the tubular member of
the syringe carrier to minimize a pinching effect of the distal
arms during its movement in the constrained space when moving from
the retracted position to the extended position.
[0302] Exemplary embodiments may provide methods for using an
automatic injection device to deliver an injection. An exemplary
method includes retracting a shroud from an extended position to a
retracted position within a housing of the automatic injection
device before, during or after an injection, the shroud exposing a
needle through an open proximal end of the shroud when the shroud
is in the retracted position, and delivering the injection using
the automatic injection device through the needle. The method may
include deploying the shroud from the retracted position to the
extended position within the housing of the automatic injection
device before, during or after the injection, the shroud
protectively sheathing the needle when the shroud is in the
extended position. The deployment of the shroud comprising moving
distal arms of the shroud in a forward direction within a
constrained space formed between the housing of the automatic
injection device and a tubular member of a syringe carrier. The
constrained space and/or the distal arms of the shroud are
configured to minimize a pinching effect of the distal arms during
its movement in the constrained space.
[0303] Exemplary automatic injection devices have sufficiently high
shroud override forces so that it is difficult to cause the shroud
to retract once it has been deployed. Exemplary shroud override
forces may include, but are not limited to, about 80 N to about 120
N. The high shroud override forces ensure that, once deployed, the
shroud remains deployed against forces exerted to retract the
shroud, which minimizes or eliminates the risk of needle stick
injuries.
[0304] The shroud override forces were monitored and graphed for
the control syringe carrier and for each of the above syringe
carrier design changes. FIG. 52 illustrates a graph of shroud
override forces in N (y-axis) against override distance in mm
(x-axis) for the control and exemplary test syringe carriers. FIG.
53 illustrates a histogram of peak shroud override forces in N
(y-axis) for the control and exemplary test syringe carriers. All
of the exemplary syringe carriers showed shroud override forces of
above 80 N, which indicates that, once deployed, the shroud remain
reliably deployed even when large forces (of about 80 N) attempt to
retract the shroud by pushing on the shroud in the distal
direction.
V. INCORPORATION BY REFERENCE
[0305] The contents of all references, including patents and patent
applications, cited throughout this application are hereby
incorporated herein by reference in their entirety. The appropriate
components and methods of those references may be selected for the
invention and embodiments thereof. Still further, the components
and methods identified in the Background section are integral to
this disclosure and can be used in conjunction with or substituted
for components and methods described elsewhere in the disclosure
within the scope of the invention.
VI. EQUIVALENTS
[0306] In describing exemplary embodiments, specific terminology is
used for the sake of clarity. For purposes of description, each
specific term is intended to at least include all technical and
functional equivalents that operate in a similar manner to
accomplish a similar purpose. Additionally, in some instances where
a particular exemplary embodiment includes a plurality of system
elements or method steps, those elements or steps may be replaced
with a single element or step. Likewise, a single element or step
may be replaced with a plurality of elements or steps that serve
the same purpose. Further, where parameters for various properties
are specified herein for exemplary embodiments, those parameters
may be adjusted up or down by 1/20.sup.th 1/10.sup.th, 1/5.sup.th,
1/3.sup.rd, 1/2, etc., or by rounded-off approximations thereof,
unless otherwise specified. Moreover, while exemplary embodiments
have been shown and described with references to particular
embodiments thereof, those of ordinary skill in the art will
understand that various substitutions and alterations in form and
details may be made therein without departing from the scope of the
invention. Further still, other aspects, functions and advantages
are also within the scope of the invention.
* * * * *