U.S. patent application number 10/899923 was filed with the patent office on 2005-02-03 for automatic injector.
This patent application is currently assigned to SID Technologies, LLC. Invention is credited to Lavi, Gilad, Tsals, Izrail.
Application Number | 20050027255 10/899923 |
Document ID | / |
Family ID | 34107966 |
Filed Date | 2005-02-03 |
United States Patent
Application |
20050027255 |
Kind Code |
A1 |
Lavi, Gilad ; et
al. |
February 3, 2005 |
Automatic injector
Abstract
An injector is automatic in that the needle is inserted into the
injection site (e.g., a patient's skin) with user or caregiver
assistance, the delivery is automatically initiated upon needle
insertion, and the needle is retracted automatically after the end
of delivery. Preferably the needle is not seen by the user prior
to, during or after injection. Prior to and after injection, the
needle is hidden in the device so as to avoid any potential injury
or health risk to the user or health care provider. The injector
includes a housing and a shield arranged to slide relative to the
housing and a driver moving during drug delivery. The housing and
shield form a cartridge enclosure. The cartridge is shielded and
locked after delivery is completed. A needle-locking mechanism can
be used in any number of pen-like injectors or safety needles.
Inventors: |
Lavi, Gilad; (Rishon
Letzion, IL) ; Tsals, Izrail; (Newtown, PA) |
Correspondence
Address: |
CAESAR, RIVISE, BERNSTEIN,
COHEN & POKOTILOW, LTD.
11TH FLOOR, SEVEN PENN CENTER
1635 MARKET STREET
PHILADELPHIA
PA
19103-2212
US
|
Assignee: |
SID Technologies, LLC
Newtown
PA
|
Family ID: |
34107966 |
Appl. No.: |
10/899923 |
Filed: |
July 27, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60491196 |
Jul 31, 2003 |
|
|
|
Current U.S.
Class: |
604/135 ;
604/192 |
Current CPC
Class: |
A61M 5/2033 20130101;
A61M 5/3271 20130101; A61M 5/326 20130101; A61M 5/3202 20130101;
A61M 2205/582 20130101; A61M 2005/2418 20130101; A61M 2005/206
20130101; A61M 2005/2073 20130101; A61M 2005/3247 20130101; A61M
2205/581 20130101; A61M 2005/2013 20130101; A61M 5/3157
20130101 |
Class at
Publication: |
604/135 ;
604/192 |
International
Class: |
A61M 005/20 |
Claims
What is claimed is:
1. An injector for automatically injecting and delivering fluids
into a living being, said injector comprising: a housing having a
first proximal end and a first distal end that is open; a cartridge
having a barrel containing a fluid, said cartridge further
comprising a displaceable stopper at a second proximal end and a
needle at a second distal end, said cartridge being fixed within
said housing; a driver engaged within said housing for driving said
stopper to dispense the fluid from said barrel and through said
needle when disengaged from said housing; a needle shield being in
sliding engagement with said first distal end of said housing and
comprising an opening for permitting said needle to pass
therethrough; and a single spring, engaged with said driver, that
is released by a user force, said single spring displacing said
driver for automatically injecting and delivering the fluid into
the living being and for automatically acting against the needle
shield to remove the needle from the living being while concealing
the needle once the fluid delivery is complete.
2. The injector of claim 1 wherein said second distal end of the
barrel comprises a reduced-diameter portion and wherein said driver
comprises members that ride along the barrel when said driver is
disengaged from said housing, said single spring acting against
said needle shield whenever said members contact said
reduced-diameter portion.
3. The injector of claim 1 wherein said driver comprises latches
for engaging said housing and wherein said single spring acts
against said latches to move said driver when said latches are
disengaged from said housing.
4. The injector of claim 3 wherein said needle shield is positioned
against the living being and application of said user force causes
said needle shield to disengage said latches from said housing.
5. The injector of claim 2 further comprising a locking mechanism
that prevents the needle shield from being displaced toward said
housing after said single spring has acted against said needle
shield.
6. The injector of claim 1 wherein said user force is approximately
10 Newtons.
7. The injector of claim 5 wherein said needle shield slides on
said housing.
8. The injector of claim 5 wherein said needle shield slides inside
said housing.
9. The injector of claim 4 wherein said driver comprises a driver
rod that engages said stopper.
10. The injector of claim 2 wherein said single spring acting
against said needle shield provides the user with a tactile and
audible feedback of the end of the fluid delivery.
11. The injector of claim 7 wherein said locking mechanism
comprises leaf springs in said housing that are forced inward of
said housing when said single spring acts against said needle
shield, said needle shield further comprising latches on an inside
surface of said needle shield, said latches on said inside surface
of said needle shield engaging said leaf springs, thereby
preventing said needle shield from being displaced toward said
housing.
12. The injector of claim 8 wherein said locking mechanism
comprises latch members in an inner surface of said housing and
said needle shield comprises corresponding latch members located on
an outside surface of said shield, said corresponding latch member
located on said outside surface engaging said latch members on said
inner surface of said housing, thereby preventing said needle
shield from being displaced toward said housing.
13. The injector of claim 7 wherein said locking mechanism
comprises pins and pin-slots that are used on said housing and
needle shield respectively to prevent said needle shield from being
displaced toward said housing after said single spring has acted
against said needle shield.
14. The injector of claim 8 wherein said locking mechanism
comprises pins and pin-slots that are used on said housing and
needle shield respectively to prevent said needle shield from being
displaced toward said housing after said single spring has acted
against said needle shield.
15. The injector of claim 9 wherein said housing further comprises
an observation window to permit the user to see the contents of the
barrel.
16. The injector of claim 15 further comprising a titrating rod
that passes through an opening in said first proximal end, said
titrating rod passing through a passageway in said driver rod and
contacting said stopper for dispensing the fluid during titration,
said titrating rod not being coupled to said stopper.
17. The injector of claim 16 wherein said titrating rod comprises a
smooth shaft portion for axial movement with respect to a housing
axis.
18. The injector of claim 16 wherein said titrating rod comprises a
threaded shaft portion for rotational axial movement with respect
to a housing axis.
19. The injector of claim 16 wherein said titrating rod comprises a
ratcheted shaft portion for incremental axial movement with respect
to a housing axis.
20. The injector of claim 1 further comprising a safety ring
releasably secured between said housing and said needle shield,
said ring arranged to prevent activation of said injector when said
ring is engaged between said housing and said needle shield.
21. An injector for automatically injecting and delivering fluids
into a living being, said injector comprising: a housing having a
first proximal end and a first distal end that is open; a cartridge
having a barrel containing a fluid, said cartridge further
comprising a displaceable stopper at a second proximal end and a
needle at a second distal end having a reduced-diameter portion,
said cartridge being fixed within said housing; a driver engaged
within said housing for driving said stopper to dispense the fluid
from said barrel and through said needle when disengaged from said
housing, said driver comprising members that slide along said
barrel and detect said reduced-diameter portion; a needle shield
being in sliding engagement with said first distal end of said
housing and comprising an opening for permitting said needle to
pass therethrough; and driving means, engaged with said driver,
that is released by a user force, said driving means displacing
said driver for automatically injecting and delivering the fluid
into the living being, said driving means also automatically acting
against said needle shield to remove the needle from the living
being while concealing said needle when said reduced-diameter
portion is detected.
22. The injector of claim 22 wherein said driving means is a single
spring.
23. The injector of claim 22 wherein said driver comprises latches
for engaging said housing and wherein said single spring acts
against said latches to move said driver when said latches are
disengaged from said housing.
24. The injector of claim 23 wherein said needle shield is
positioned against the living being and application of said user
force causes said needle shield to disengage said latches from said
housing.
25. The injector of claim 22 further comprising a locking mechanism
that prevents the needle shield from being displaced toward said
housing after said single spring has acted against said needle
shield.
26. The injector of claim 21 wherein said user force is
approximately 10 Newtons.
27. The injector of claim 25 wherein said needle shield slides on
said housing.
28. The injector of claim 25 wherein said needle shield slides
inside said housing.
29. The injector of claim 24 wherein said driver comprises a driver
rod that engages said stopper.
30. The injector of claim 22 wherein said single spring acting
against said needle shield provides the user with a tactile and
audible feedback of the end of the fluid delivery.
31. The injector of claim 27 wherein said locking mechanism
comprises leaf springs in said housing that are forced inward of
said housing when said single spring acts against said needle
shield, said needle shield further comprising latches on an inside
surface of said needle shield, said latches on said inside surface
of said needle shield engaging said leaf springs, thereby
preventing said needle shield from being displaced toward said
housing.
32. The injector of claim 28 wherein said locking mechanism
comprises latch members in an inner surface of said housing and
said needle shield comprises corresponding latch members located on
an outside surface of said shield, said corresponding latch member
located on said outside surface engaging said latch members on said
inner surface of said housing, thereby preventing said needle
shield from being displaced toward said housing.
33. The injector of claim 27 wherein said locking mechanism
comprises pins and pin-slots that are used on said housing and
needle shield respectively to prevent said needle shield from being
displaced toward said housing after said single spring has acted
against said needle shield.
34. The injector of claim 28 wherein said locking mechanism
comprises pins and pin-slots that are used on said housing and
needle shield respectively to prevent said needle shield from being
displaced toward said housing after said single spring has acted
against said needle shield.
35. The injector of claim 29 wherein said housing further comprises
an observation window to permit the user to see the contents of the
barrel.
36. The injector of claim 35 further comprising a titrating rod
that passes through an opening in said first proximal end, said
titrating rod passing through a passageway in said driver rod and
contacting said stopper for dispensing the fluid during titration,
said titrating rod not being coupled to said stopper.
37. The injector of claim 36 wherein said titrating rod comprises a
smooth shaft portion for axial movement with respect to a housing
axis.
38. The injector of claim 36 wherein said titrating rod comprises a
threaded shaft portion for rotational axial movement with respect
to a housing axis.
39. The injector of claim 36 wherein said titrating rod comprises a
ratcheted shaft portion for incremental axial movement with respect
to a housing axis.
40. The injector of claim 21 further comprising a safety ring
releasably secured between said housing and said needle shield,
said ring arranged to prevent activation of said injector when said
ring is engaged between said housing and said needle shield.
41. A method for automatically injecting and delivering a fluid
into a living being, said method comprising the steps of: disposing
a cartridge inside an injector housing having a first proximal end
and a first distal end, said cartridge having a barrel having a
second proximal end and a second distal end, said second proximal
end having a movable stopper thereat and said second distal end
having a reduced-diameter portion having a needle thereat;
providing a needle shield to be in sliding engagement with said
injector housing at said first distal end, said needle shield
comprising an opening to permit said needle to pass therethrough;
latching a driver inside said injector housing against the bias of
a single spring, said driver having a driver rod engaged with said
stopper; positioning said needle shield and opening against the
living being; applying a sufficient force to said injector housing
to de-latch said driver while driving said needle shield towards
said housing and inserting said needle into the living being;
displacing said stopper by said driver under the action of said
single spring to dispense the fluid into the living being; and
detecting said reduced-diameter portion and permitting said single
spring to act directly against said needle shield to withdraw said
needle from the living being while concealing said needle.
42. The method of claim 41 further comprising the step of latching
the needle shield to said injector housing thereby preventing said
needle shield from being displaced and re-exposing said needle
after the needle has been withdrawn from the living being.
43. The method of claim 41 wherein said step of detecting said
reduced-diameter portion comprises members that ride along said
barrel during driver displacement.
44. The method of claim 41 wherein said sufficient force comprises
approximately 10 Newtons.
45. The method of claim 43 wherein said step of displacing said
stopper by said driver comprises said single spring acting against
a portion of said driver adjacent said members that ride along said
barrel.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] This invention relates to the preparation and administration
of a product into a living organism (e.g. the human body), and more
particularly to an apparatus for automatically and safely
delivering the product.
[0003] 2. Description of Related Art
[0004] Previously, various devices have been developed for the
delivery of medications into and through the skin of living
organisms. These devices include syringes in which a liquid drug
solution is delivered through the skin of a user from a syringe
chamber by movement of a syringe plunger to move the drug solution
from a syringe chamber through a syringe needle inserted under the
skin. The drug solution is generally in liquid form, and can be a
mixture of the drug (e.g. powdered, lyophilized, concentrated
liquid) and a diluent (e.g. dextrose solution, saline solution,
water).
[0005] It is well known that many people are apprehensive about
receiving an injection from a needle. This problem is even more
significant for those who must administer their own medication. It
is known that needle phobia can be minimized by hiding the needle
before, during and after delivery. It is therefore preferable that
the person who receives the drug should not see the needle, which
often triggers the fear of needle insertion.
[0006] It is also preferable for the needle to be protected before
and after delivery of the drug. While a needle can be protected
with a removable cap, it is preferable for the needle to be secured
within the delivery device before the needle is inserted through
the patient's skin and after the needle is shielded. Preferably the
needle is enclosed in the device after use and locked into final
position after injection. The needle insertion is assisted by the
user or caregiver while its shielding is automatic, so that the
user does not prematurely expose the needle for injection or have
to guess when delivery is completed.
[0007] It is also preferable for such a device to provide
indications for assisting in the correct use of the automatic
injector. Indications could be visual, audible or tactile and are
provided at the start or completion of any stage of system use.
[0008] A user or patient could be injured if an injection device
were activated prematurely. Generally, such a device projects its
needle from the end of a barrel and ejects the dose. Such actions
can cause injury if the needle pierces another person or is
injected into an undesired area of the patient (e.g., an eye).
Accordingly, it is advantageous if the needle is in a safe location
before and after use to prevent accidental injury or
contamination.
[0009] It is further desirable to have a simple, reliable system
that facilitates safe preparation and delivery of a drug. Dosage
amounts may vary from one patient to another. At present, there is
no easy way for a patient to self-administer a dosage of drug via
an automatic injection system where the dosage amount may be easily
changed prior to delivery and easily delivered. Moreover, there is
a need to further improve the ability of the user to minimize
residual drug in the container or system. Also, there is a need to
enable the user to eliminate any air bubbles that may be trapped in
the drug container prior to use.
[0010] It is also desirable to provide a delivery system where the
dosage for delivery is easily viewed by the patient prior and after
use. The user's inability to see the dosage form prior to use
creates a significant sense of unease in the user in that the user
wants to ensure that the proper dosage is in the system and ready
for delivery. More importantly, the user's inability to see the
dosage form prior to use leaves the user concerned that the dosage
may be faulty, or, for example, have foreign particles trapped and
if present, may result in injury or harm to the user. The user's
inability to view the dosage being delivered and the end of
delivery leaves the user with a level of uncertainty as to the
amount delivered and the delivery being completed. Thus, it is
extremely important to the user's peace of mind to provide an area
in which to view the dosage prior to and after delivery. As will be
discussed in detail later, the injection device of the present
application provides this opportunity.
[0011] Further, it is desirable to provide a delivery system that
is easy to use at a low cost. Moreover, it is desirable to provide
a system that is easy to integrate with the drug container, thereby
providing flexibility in meeting the requirements of different drug
containers like pre-filled syringes/cartridges. For example, it is
important to accommodate standard cartridges with a needle cover
including a rigid plastic cover. Moreover, it is desirable to have
a system that can accommodate cartridges filled on standard filling
lines. It is desirable to provide a system characterized by a small
number of components indicating low product costs.
[0012] The following are exemplary existing automatic
injectors.
[0013] U.S. Pat. No. 5,114,406 (Gabriel, et al.); and U.S. Pat. No.
6,544,234 (Gabriel) disclose a plunger which is telescopically
received within a tubular element causing the needle penetration,
drug delivery and securing the needle. Beside it being a telescope
type mechanism the system is using two springs and the detection of
end of delivery is controlled by packaging parts and not by the
cartridge only.
[0014] U.S. Pat. No. 5,599,309 (Marshall, et al.) discloses an
injector having a drive member held in a rearward primed position
by a detent provided in the body of the device. When the device is
applied to a patients skin and a rear end cap is pressed forwardly,
the forward ends of ribs wedge tongues inward (or pivot) until they
clear the detents formed by the forward ends of the slots. A coil
spring shoots a cylinder forward for injection and delivery. This
invention is involving the packaging parts in order to detect end
of delivery and is using two springs--one to penetrate and deliver
and the second to shield.
[0015] U.S. Pat. No. 6,159,181 (Crossman, et al.) and U.S. Patent
Publication No. 2003/0093036 (Crossman, et al.) are mechanisms to
deliver drugs in a parenteral method and to shield the penetrating
needle after use. Both mechanisms use double springs and do not use
the cartridge to detect the end of delivery. In 2003/0093036
(Crossman, et al.) the user is expected to manually trigger the
needle shield and to decide when to do that. The evolution between
these two applications is in making the device simpler and more
accurate. Nevertheless, the basic principles remain the same.
[0016] The following exemplary patents are mentioned as they relate
to needle retraction mechanisms. Several disclose axially-aligned
spring-driven needle extenders and retractors. These include U.S.
Pat. No. 5,779,677 (Frezza); U.S. Pat. No. 6,210,369 (Wilmot, et
al); U.S. Pat. No. 5,391,151 (Wilmot); U.S. Pat. No. 5,637,094
(Stewart, Jr., et al.) and U.S. Patent Publication No. 2001/0005781
(Bergens et al.). In all of these references, the function is
served by a set of axially-positioned springs; in some, two springs
are in use and in others, such as Stewart's and Bergens, even three
springs are used. None of the references includes a mechanism for
cartridge-shape detection.
[0017] In U.S. Patent Publication No. 20030105430 (Lavi, et al.),
the functions are served by a mechanism of ten parts, including two
springs. The mechanism performs a combination of slide and rotate
move, the end of delivery is detected by the packaging parts and
not by the shape of the cartridge. The design is characterized by
high complexity and costs.
[0018] U.S. Pat. No. 6,743,203 (Pickhard) discloses a device for
automatically injecting liquids and comprises an axially-divided
housing wherein the parts can be removably assembled. The design
employs a cartridge with a separate needle assembly and three
springs resulting in high complexity.
[0019] However, to the best of Applicants' knowledge, none of the
exemplary references discussed previously discloses or suggests the
mechanism of the present invention. This invention implements the
triggering of the mechanism by pushing on the injection site,
insertion of the needle by advancing the housing and cartridge,
automatic delivery using the driving means, automatic end of
delivery sensing mechanism using the shape of the cartridge for
detection, and automatic needle extraction and shielding using the
same driving means. Simplicity in implementing these functions
within the discussed invention is a major difference as compared to
other known devices.
[0020] All references cited herein are incorporated herein by
reference in their entireties.
BRIEF SUMMARY OF THE INVENTION
[0021] In an exemplary embodiment, an automatic injector for
delivering a fluid includes only five components: a housing, a
cartridge, a shield, a driver and a spring. The housing has a
proximal end and a distal end, and includes means arranged to
activate the injector. The drug cartridge is positioned within the
housing and the shield and includes a barrel, a stopper, and a
needle extending toward the distal end of the housing. The barrel
is arranged to contain a fluid in communication with the needle.
The stopper is slidingly located within the barrel for forcing the
fluid through the needle upon activation of the injector. The
driver is in communication with the housing and the shield. The
driver is arranged to act on the stopper when disengaged from the
housing.
[0022] The injector also includes a mechanism that automatically
shields the cartridge with the needle upon the end of delivery. In
addition, this exemplary embodiment of an injector may also include
a needle-locking device that locks the needle within the housing
after use; further, this exemplary embodiment may include a rod
arranged for moving the stopper for titration before delivery; this
exemplary embodiment may include a window that allows a user to
inspect the dosage before delivery and titrate.
[0023] The shield mechanism in this exemplary embodiment might
require a well defined force to insert the needle into the tissue.
This required force is prolonged in time and travel and is designed
to assure the user fully inserts the needle into the tissue based
on the inertia of human motion.
[0024] The completion of the un-shielding and insertion of the
needle results in this exemplary embodiment in an automatic
triggering of the injection process. The injection is driven by the
energy of the driving means. The injection in this exemplary
embodiment is continued until the full content of the cartridge is
delivered.
[0025] The completion of the delivery results an automatic
shielding of the cartridge needle. In this exemplary embodiment the
spring bypasses the driver and forces the extraction and shielding
of the needle. The shield is automatically moved to a locked
position shielding the cartridge needle. An excessive force would
be required to overpower the shield retention feature after the
shield is placed in the locked, discard position.
[0026] Further scope of applicability of the present invention will
become apparent in the description given hereafter. However, it
should be understood that the detailed description and specific
examples, while indicating preferred embodiments of the invention,
are given by way of illustration only, since the invention will
become apparent to those skilled in the art from this detailed
description.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0027] The invention will be described in conjunction with the
following drawings in which like reference numerals designate like
elements and wherein:
[0028] FIG. 1 is an external view showing an injector construed in
accordance with an exemplary embodiment of the invention and the
shield sliding on the housing;
[0029] FIG. 2 is an external view showing an injector construed in
accordance with another exemplary embodiment of the invention and
the shield sliding inside the housing;
[0030] FIG. 3 is a longitudinal section view showing an injector
construed in accordance with an exemplary embodiment of the
invention, shield on the housing, illustrating the cartridge
support by the housing;
[0031] FIG. 4 is a longitudinal section view showing an injector
construed in accordance with an exemplary embodiment of the
invention, shield inside the housing, illustrating the cartridge
support by the housing, and the observation window;
[0032] FIG. 5 is a longitudinal section view showing an injector
construed in accordance with an exemplary embodiment of the
invention, shield on the housing, illustrating the driver;
[0033] FIG. 6 is a view similar to that of FIG. 5, but showing the
injector in a state wherein the protective cap is removed;
[0034] FIG. 7 is a force profile with respect to the shield
displacement for an injector construed in accordance with an
exemplary embodiments of the invention;
[0035] FIG. 8 is a force profile with respect to the injector
operation timing for an injector construed in accordance with an
exemplary embodiments of the invention;
[0036] FIG. 9 is a partial external view of the injector, shield on
the housing, showing the injector in a state wherein the shield is
slightly depressed and a section of the cylindrical part of the
shield obscuring the driver is removed;
[0037] FIG. 10 is a partial sectional view of the injector as
illustrated in FIG. 6, but showing the injector in a state wherein
the shield is slightly depressed
[0038] FIG. 11 is a partial external view of the injector showing
the injector in a state wherein the shield is further depressed and
a section of the cylindrical part of the shield obscuring the
driver is removed;
[0039] FIG. 12 is a partial external view of the injector showing
the injector in a state wherein the shield is fully depressed and a
section of the cylindrical part of the shield obscuring the driver
is removed;
[0040] FIG. 13 is a partial sectional view of the injector as
illustrated in FIG. 6, but showing the injector in a state wherein
the shield is fully depressed;
[0041] FIG. 14 is an isometric view of the driver of the exemplary
embodiment with shield on the housing, when engaged with the
housing;
[0042] FIG. 15 is a partial isometric view of the deformed driver
section of the exemplary embodiment with shield on the housing,
which latches during disengagement from the housing;
[0043] FIG. 16 is a partial isometric view of the deformed driver
section shield on the housing, which latches during delivery;
[0044] FIG. 17 is an external isometric view of the housing, of the
exemplary embodiment with shield on the housing;
[0045] FIG. 18 is an isometric view of the housing with a removed
section, of the exemplary embodiment with shield on the
housing;
[0046] FIG. 19 is an isometric view of the shield from the proximal
end, of the exemplary embodiment with shield on the housing;
[0047] FIG. 20 is an isometric view of the shield from the distal
end, of the exemplary embodiment with the shield on the housing,
with a cylindrical section partially removed;
[0048] FIG. 21 is a view similar to that of FIG. 6, but showing the
injector during the beginning of drug delivery;
[0049] FIG. 22 is a view similar to that of FIG. 6, but showing the
injector during the middle of drug delivery;
[0050] FIG. 23 is a view similar to FIG. 6, but showing the
injector at the end of delivery;
[0051] FIG. 24 is a view similar to FIG. 3, but showing the
injector at the end of delivery;
[0052] FIG. 25 is a partial sectional view of the injector
illustrating the details of the shield locking mechanism of the
automatic injector of the exemplary embodiment with the shield on
the housing;
[0053] FIG. 26 is an isometric view of the driver, of the exemplary
embodiment with the shield inside the housing, when engaged with
the housing;
[0054] FIG. 27 is a partial isometric view of the driver of the
exemplary embodiment with the shield inside the housing, with
latches deformed during delivery;
[0055] FIG. 28 is an external isometric view of the housing of the
exemplary embodiment with shield inside the housing;
[0056] FIG. 29 is an isometric view of the housing with a removed
section, of the exemplary embodiment with shield inside the
housing;
[0057] FIG. 30 is an isometric view of the shield from the proximal
end, of the exemplary embodiment with shield inside the
housing;
[0058] FIG. 31 is an isometric view of the shield from the distal
end, of the exemplary embodiment with the shield inside the
housing, with a cylindrical section partially removed;
[0059] FIG. 32 is a partial sectional view of the injector, shield
inside the housing, showing the injector in a state wherein the
shield is slightly depressed and the section shown through the
middle of the latch;
[0060] FIG. 33 is a partial sectional view of the injector as
illustrated in FIG. 32, but showing the injector section through a
side of the driver latch;
[0061] FIG. 34 is a partial sectional view of the injector as
illustrated in FIG. 32 but showing the injector in a state wherein
the shield is further depressed and the driver is disengaged from
the housing;
[0062] FIG. 35 is a partial sectional view of the injector
illustrated in FIG. 33 but showing the injector in a state wherein
the shield is further depressed and the driver is disengaged from
the housing;
[0063] FIG. 36 is a partial sectional view of the injector
illustrating the details of the shield locking mechanism of the
shielded automatic injector of the exemplary embodiment with the
shield inside the housing;
[0064] FIG. 37 is illustrating an exemplary embodiment of the
filled cartridge of the present invention;
[0065] FIG. 38 is an isometric view of the shield from the proximal
end illustrating an alternative embodiment of the mechanism for
generating the force profile defined in FIG. 7 and FIG. 8;
[0066] FIG. 39 is an isometric view of the housing illustrating an
alternative embodiment of the mechanism for generating the force
profile defined in FIG. 7 and FIG. 8 with the shield inside the
housing;
[0067] FIG. 40 also illustrates the alternative embodiment of the
mechanism for generating the force profile defined in FIG. 7 and
FIG. 8 whereby the driver, driving means, and the cartridge are
removed;
[0068] FIG. 40A illustrates the arrangement prior to use;
[0069] FIG. 40B illustrates the automatic injector with a deployed
shield;
[0070] FIG. 40C illustrates shielded discard position.
[0071] FIG. 41 is a view similar to that of FIG. 6, of an exemplary
embodiment of the invention and the shield sliding on the housing
but showing the titration mechanism employing a threaded rod;
[0072] FIG. 42 is a view of an alternative titration mechanism of
an exemplary embodiment of the invention and the shield sliding on
the housing employing a smooth rod;
[0073] FIG. 43 is a view of an alternative titration mechanism of
an exemplary embodiment of the invention with the shield sliding
inside the housing but showing the titration employing a ratchet
mechanism;
[0074] FIG. 44 is a view similar to that of FIG. 37, but showing an
alternative approach for creating flanges;
[0075] FIG. 45 is a view similar to that of FIG. 37, but showing an
alternative cartridge with double sided needle;
[0076] FIG. 46 is a view of the automatic injector of an exemplary
embodiment of the invention with the shield sliding on the housing
with the safety clip;
[0077] FIG. 47 is a view of the automatic injector of an exemplary
embodiment of the invention with the shield sliding on the housing
with the safety clip removed;
[0078] FIG. 48 is a view of the cartridge and driver
sub-assembly;
[0079] FIG. 49 is a view of the assembly process of the
cartridge/driver and housing/spring sub-assemblies merger; and
[0080] FIG. 50 is a view of the final assembly step of merging the
shield with the sub-assembly from FIG. 49.
DETAILED DESCRIPTION OF THE INVENTION
[0081] The present invention is directed to automatic injectors and
needle-locking devices. The injector is automatic in that the
needle at a distal end of the injector is unshielded with the user
assistance; the needle is inserted into the injection site (e.g., a
patient's skin) with the user assistance; delivery is automatically
initiated upon insertion of the needle, and the needle is
automatically shielded after the end of delivery. The exemplary
injectors include a tight relationship between the position of the
shield and the force required for its displacement. Moreover, the
exemplary injectors include a rod that provides titration as
described below.
[0082] The term distal refers to the end or direction of the
injector that is applied to an injection site for delivery. The
term proximal refers to the end of the injector that is opposite
the distal end. The exemplary embodiments show each injector having
a distal end from which the needle is exposed for delivery, and a
proximal end opposite the distal end.
[0083] Preferably the needle is not seen by the user prior to,
during or after injection. Prior to and after injection, the needle
is covered and/or protected by the shield so as to avoid any
potential injury or health risk to the user or health care
provider.
[0084] Without being limited to any particular theory, the
needle-shielding mechanism can be used in any number of pen-like
injectors or other types of injectors or syringes. The
needle-shielding mechanism includes a position-dependent controlled
shield force that insures a needle assembly is shielded within an
injector before use and is in a shielded and locked position after
use. For purposes of illustration, the needle-locking device is
shown in combination with a drug cartridge inserted in the
injector.
[0085] Without being limited to a particular theory, the disclosed
exemplary embodiments include: (a) a disposable device having a
disposable pre-filled cartridge; (b) a disposable pre-filled
injector with drug titration (needle concentric to housing), an
automatic injector with the shield sliding on the housing and an
automatic injector with the shield sliding inside the housing.
[0086] Referring to FIGS. 1-50, there is shown at 10 an automatic
injector constructed in accordance with exemplary embodiment of
this invention. In particular, the injector 10 includes a housing
100, a shield 200, a driver 300 (FIG. 3), a cartridge 500, and a
driving unit 400 (FIG. 3). Preferably, examples of the injector 10
also include a leaf spring 131 (FIG. 3) extending from the housing
100, as will be described in more detail below. In this embodiment,
the shield 200 slides on the housing 100.
[0087] Referring to FIGS. 1-50, there is shown also at 30 (FIG. 2)
an automatic injector constructed in accordance with another
exemplary embodiment of this invention whereby the shield 250
slides inside the housing 160. In particular, the injector 30
includes a housing 160, a shield 250, a driver 350, a cartridge
500, and a driving unit 450. Preferably, examples of the injector
30 also include a leaf spring 285 (FIG. 4) extending from the
shield 250, as will be described in more detail below.
[0088] The housing 100 is interfaced with the shield 200 forming
enclosure for the cartridge 500 as is shown in FIG. 3. Externally,
the automatic injector 10 represents a pen-like cylindrical
structure as is illustrated in FIG. 1. The injector 10 has a distal
end 11 from which the needle is exposed for delivery, and a
proximal end 12 opposite the distal end 11. Without being limited
to a particular theory, the term distal refers to the end or
direction of the injector that is applied to the injection site for
delivery, and the term proximal refers to the end or direction
opposite the distal end or direction.
[0089] In the exemplary embodiment with the shield 250 sliding in
the housing 160, the housing 160 is interfaced with the shield 250
forming enclosure for the cartridge 500, as is shown in FIG. 4.
Externally, the automatic injector 30 represents a pen like
cylindrical structure as is illustrated in FIG. 2. The injector 30
has a distal end 31 from which the needle is exposed for delivery,
and a proximal end 32 opposite the distal end 31. Without being
limited to a particular theory, the term distal refers to the end
or direction of the injector that is applied to the injection site
for delivery, and the term proximal refers to the end or direction
opposite the distal end or direction. Both embodiments 10/30,
either with the shield sliding on the housing or with the shield
sliding inside the housing, retain the basic mechanisms.
[0090] In the exemplary embodiment 10 with the shield 200 sliding
on the housing 100, the housing 100 has a proximal surface equipped
with finger like extensions 104 (FIG. 3). These extensions have
latches 105 and 106 intended to capture the flanges 513 of the
cartridge 500 barrel (see FIG. 3). Furthermore, the housing 100 and
the shield 200 form an enclosure that houses the driver 300 and the
driving means 400. By way of example only, the driving means may
comprise a spring 400, as illustrated in FIG. 3 and FIG. 5. The
driver 300 is maintained in its initial position while interlocked
with the housing 100. The driver 300 is preloaded by the compressed
spring 400.
[0091] In the exemplary embodiment 30 with the shield 250 sliding
inside the housing 160 the housing 160 has a proximal end surface
equipped with finger like extensions 164 (FIG. 4). These extensions
have latches 165 and 166 intended to capture the flanges 513 of the
cartridge 500 barrel (see FIG. 4). Furthermore, the housing 160 and
the shield 250 form an enclosure which is housing the driver 350
and the driving means 450. Preferably, the driving means may
comprise a spring 450, as illustrated in FIG. 4. The driver 350 is
maintained in its initial position while interlocked with the
housing 160. The driver 350 is preloaded by the compressed spring
450.
[0092] The first step in the use of the automatic injector is the
removal of the protective cap 540 (needle cover) of the needle 512
illustrated for the shield on housing embodiment. The cap may
comprise one component, e.g., an elastomeric protective cap 541.
Alternatively, the protective cap 540 may further comprise a second
component, e.g., a rigid plastic protective cap 542. The protective
cap 540 of the needle 512 protrudes through the distal end of the
auto injector (see FIG. 1 and FIG. 2). It is removed from the
injector in the first step of use to open the fluid path as
illustrated in FIG. 6. The protective cap 540 also protects the
shield 200 from accidental impact before use.
[0093] The automatic injector of the exemplary embodiments have a
minimal number of parts. To achieve the minimal number of
components, the initial step of needle deployment (the needle
insertion into the tissue) is implemented by the user while pushing
the injector toward the injection site. The insertion of the needle
automatically triggers the release of the driver and initiates the
injection.
[0094] The displacement of the shield while pushing the shield
toward the injection site results in the disengagement of the
driver from the housing. The displacement of the shield over the
initial part of the shield travel requires a substantial force over
a short distance as shown in FIG. 7. The force 700 required to
displace the shield increases rapidly with the initial displacement
711 of the shield. It remains high during the initial segment of
the travel 712 and then rapidly decreases over a short travel
distance 713. The shield displacement force remains low over the
second part of the travel 714. The force applied by the user to the
automatic injector drops to close to zero after the shield is
displaced and the needle is fully inserted at 715.
[0095] The high initial shield displacement force over a short
distance assures that the shield is fully displaced and the needle
fully inserted due to the inertia of the human motion. The
automatic injector requires from the user about 1 kg of force for
the shield displacement over the initial part of the shield
travel.
[0096] The profile of the shield displacement force as a function
of time 750 is illustrated in FIG. 8. Applied forces of 731, 732,
733, 734 and 735 correspond respectively to displacements 711, 712,
713, 714 and 715.
[0097] The driver 300, housing 100 and the shield 200 have a set of
features intended to facilitate the disengagement of the driver
from the housing at a force defined above. The operation of the
automatic injector will become clear from a detailed description of
the automatic injector components and component interactions.
[0098] The driver in the exemplary embodiment of the invention with
the shield sliding on the housing is initially engaged to the
housing as illustrated in FIG. 9 and FIG. 10. The secure engagement
prevents an accidental release of the spring due to a potential
impact during storage or transportation. The action of shield
displacement by the user is preformed in three stages. Initially,
the shield rails 221 apply a tangential force to driver fingers
pads 316 bringing these together. The direction of the applied
force is illustrated in FIG. 15 with arrows. During further motion
the shield rail 222 is pushing radially on the latch finger pads
316 (see FIG. 11). The direction of the force is also illustrated
in FIG. 16 with arrows. Latch fingers 314 are bent radially
eventually disengaging the driver 300 from the housing 100.
[0099] The driver movement relative to housing is initiated. The
drug delivery starts as illustrated in FIG. 12 and FIG. 13. At this
stage the tangential force applied to latch fingers 314 is
substantially reduced. The fingers 314 spread to an unloaded
position while the bending of the fingers 314 toward the barrel 511
(FIG. 23) persists through delivery time
[0100] The driver 300 is slidingly located within the housing. When
the driver 300 is disengaged from the housing 100, the injector 10
is activated. The driver is biased by the spring 400. The spring
400 causes the driver to slide forward towards the distal end of
the automatic injector 11 (FIG. 21). The driver 300 moves the
stopper through the barrel 511 forcing the fluid in the barrel
through the needle 512 to be delivered into an injection site. An
intermediate position of the driver is illustrated in FIG. 22.
[0101] The driver 300 (see FIG. 14) of the exemplary embodiment of
the invention with the shield sliding on the housing is comprised
of a base 330, driver rod 320 and side fingers 310. The side
fingers 310 have a core 311 attached to the base 330. On the
opposite end fingers 311 have protrusions 312 abating the barrel
and latches 313 engaged with the housing. The latches consist of
two latch fingers 314 equipped with protruding sections 315. These
sections 315 have an overhang section 316.
[0102] After the driver is disengaged from the housing the latch
fingers are deflected radially as illustrated in FIG. 16. The latch
finger 314 deflection allows the driver to slide in the
housing.
[0103] The housing 100 (see FIG. 17 and FIG. 18) is a cylindrical
part with two primary areas: a cylindrical section 101 and a second
cylindrical section 102 with a reduced outside circumference
matching the internal circumference of the shield 200. The housing
100 also has a base 103. The base 103 has two fingers 104 with
latches 105 and 106. The latches 105 and 106 capture and hold the
barrel of the cartridge after assembly.
[0104] The housing 100 has two symmetrical slits 120 with a long
narrow section 121 and a wide opening 122. The wide opening 122
accepts the driver latch fingers 314 to engage the driver and the
housing in the assembly. Overhang sections 316 in an unstressed
state are wider than the opening 122 additionally securing the
driver to the housing.
[0105] The housing contains two symmetrical openings 130 with built
in leaf springs 131. These leaf springs are attached to the housing
100 at the base 132. The leaf springs serve to secure the shield in
a shielded position after completion of delivery as is described
below.
[0106] The automatic injector has an observation window 800 (see
FIG. 9) and a reduced-length observation window 820 (see FIG. 12).
This window is located in section 102 of the housing and is formed
by the housing slots 113 jointly with the matching slots 225 in the
shield 200. The observation window exposes the barrel to the user.
The housing area 111 with an increased diameter extends onto and
envelops the shield with its extensions 112 to provide an improved
holding ability and support for the user during the operation of
the injector.
[0107] The housing also has two flattened areas 123. These areas
accommodate protrusions on the inner shield surface.
[0108] The shield 200 (see FIG. 19 and FIG. 20) is a cylindrical
part with a cylindrical section 201. Its internal circumference
corresponds to the external circumference of the housing 100 in
section 102. The shield 200 has two external flats 202.
Furthermore, the shield has a base 204 with an opening 205 to
accept the cartridge needle. The base 204 has two elevated
ring-like features 206 and 207 to improve interface with the
subcutaneous site.
[0109] The shield has furthermore two elevated areas 220 on the
inner surface. These form outer fingers 221 engaging the overhang
sections 316 of the latch fingers of the driver and during
operation push the protruding latch fingers 314 together. The
elevated section also forms the central finger 222 for disengaging
the driver from the housing. Shield latches 223 prevent disassembly
of the device and secondary exposure of the needle after shielding
of the cartridge.
[0110] Toward the end of injection, protrusions 312 of the driver
fingers 311 slide off the barrel 511 allowing the fingers 311 to
deflect toward the reduced-diameter neck N of the cartridge 500.
This motion allows the spring 400 to slide over the latches 313 and
engage the base of the shield 204 as illustrated in FIG. 24.
Simultaneously the spring 400 deflects the leaf spring 131 as
illustrated in FIG. 24. Thus, these protrusions 312 form a "change
of barrel diameter"detector for the driver 300.
[0111] The spring acting on the base of the shield 204 provides a
substantial force resulting in an extraction of the cartridge
needle from the subcutaneous tissue and the return of the shield to
its extended position as illustrated in FIG. 25. Furthermore, the
spring impacting the base of the shield provides a clear tactile
and audible indication of the end of drug delivery.
[0112] The spring 400 forces the leaf springs 131 attached to the
housing 100 outward. The latch of the shield 223 interacts with the
leaf spring 131, thereby preventing a repeated displacement of the
shield 200. The shield 200 of the automatic injector is further
prevented from moving off the housing 100 by a ring like feature
136. The automatic injector now has a shielded needle and is ready
for disposal.
[0113] Another exemplary embodiment with the shield inside the
housing is further described in FIG. 26 through FIG. 36. The driver
350 (see FIG. 26) of the exemplary embodiment of the invention with
the shield sliding inside the housing is comprised of a base 380,
driver rod 371 and side fingers 360. The side fingers 360 have a
core 361 attached to the base 380. On the opposite end, fingers 361
have protrusions 362 abutting the barrel 511 and latches 363
engaged with the housing. The latches consist of two latch regions
365 of lower height and an elevated section 364.
[0114] The housing/driver disengagement mechanism is different in
this exemplary embodiment. The latch 363 deflects only in the
radial plane being forced inward by the shield 250 wedged between
the housing and the driver as will be described below.
[0115] The housing 160 (see FIG. 28 and FIG. 29) is a cylindrical
part with two primary areas: a knurled section 161 and a
cylindrical section 162. The internal circumference 181 is matched
to the external circumference of the shield 250. The housing 160
also has a base 163. The base 163 has two fingers 164 with latches
165 and 166. The latches 165 and 166 capture and hold the barrel of
the cartridge after assembly.
[0116] The housing 160 has a pair of symmetrical latches 172. These
latches interact with the shield after use to lock it in a shielded
position. Housing latches 172 prevent disassembly of the device and
secondary exposure of the needle after delivery. The other pair of
latches 173 releasably attaches the driver 350 to the housing
160.
[0117] The housing 160 further has a pair of symmetrical openings
171. These openings together with openings in the shield 250 form
observation windows.
[0118] The shield 250 (see FIG. 30 and FIG. 31) is a cylindrical
part with a cylindrical section 251. Its external circumference
matches the internal circumference of the housing 160 in section
162. The shield contains two symmetrical openings 280 with built-in
leaf springs 281. These leaf springs are attached to the shield 250
at the base 282. The leaf springs serve to secure the shield in a
shielded position after completion of delivery as is discussed
below. Furthermore, the shield has a base 254 with an opening 253
to accept the cartridge needle. The base 254 has two elevated
ring-like sections 256 and 257 to improve interface with the
subcutaneous site.
[0119] The shield has furthermore two elongated openings 270. These
form an observation window in conjunction with the housing openings
171. The shield furthermore has ribs 291. These ribs support the
spring 450.
[0120] The shield 250 has symmetrical slits 271. These slits have a
wide section 272 followed by a narrower section 273. The front of
the narrower section is tapered 274. This taper 274 of the shield
disengages the driver from the housing during activation, as
illustrated in FIG. 32 through FIG. 35.
[0121] The beginning of the driver 350 and housing 250
disengagement process is illustrated in FIG. 32 and FIG. 33. The
driver latch 363 extensions 364 are engaged to the housing pins
173. The shield disengagement taper 274 is pushed between the latch
365 and the housing 160. Eventually, the driver latch 364 is
deflected and disengaged from the housing as illustrated in FIG. 34
and FIG. 35.
[0122] The operation of the automated shielding process of the
embodiment with the shield inside the housing is similar to that of
the shield on the housing. The spring 450 acting on the base of the
shield 254 provides a substantial force resulting in an extraction
of the cartridge needle from the subcutaneous tissue and the return
of the shield to its extended position as illustrated in FIG.
36.
[0123] The typical Hypak cartridge 500 is illustrated in FIG. 37.
It has a barrel 510 consisting of a glass barrel 511 with a staked
needle 512. The glass barrel 511 has flanges 513. The barrel is
filled with drug 530. The drug is sealed by a stopper 520 which is
in a sliding relationship with the barrel. The needle is shielded
by a protective cap 540 made from an elastomeric component 541
abutting the needle. The needle protective cover 540 frequently has
a rigid plastic protective cup 542 simplifying the cap removal.
[0124] Device with Titration:
[0125] The titration is made feasible by the observation window.
Only when the cartridge is observed can the user titrate the
content of the cartridge and expel the air. Three examples for
implementing the titration are detailed in FIG. 41, FIG. 42 and
FIG. 43.
[0126] The injector 20 of the exemplary embodiment of the invention
with the shield sliding on the housing includes a rod 600
protruding through the opening 197 in the base of the housing at
the proximal end of the injector as illustrated in FIG. 41. The
driver 325 has an internal rod passageway 322 to accommodate
titration rod 600. The titration rod has a threaded section 610
engaged with the threaded section of housing 198 of the opening in
the housing 197. Rod also has an unthreaded section 620 abutting
the stopper 520 and a knurled knob 630 for hand operation.
[0127] Alternative to the threaded titration rod is a rod without a
thread in FIG. 42. The rod 601 extends through an opening 199 of a
rear wall 193 at the proximal end of the injector 21. The rod 601
has an unthreaded section 621 abutting the stopper 520 for pushing
it during titration.
[0128] Another alternative is a titration rod with a ratcheted
surface. The injector 40 of the exemplary embodiment of the
invention with the shield sliding on the housing includes a rod 602
protruding through the opening 192 in the base of the housing at
the proximal end of the injector as illustrated in FIG. 43. The
driver 375 has a rod 322 hollow internally 325 to accommodate
titration rod 602. The titration rod has a toothed section 612
engaged with the ratchet 187 and no-back latch 186 of the housing
185. Rod 602 also has a section without ratchets 622 acting on the
stopper 520. The ratcheting mechanism is formed as part of the
housing 185. It is fixed at the hinge 191 with the tooth 189
engaging the housing. The travel of the ratchet 187 is limited by a
limiter 180. The titration mechanism with a ratchet allows for an
incremental propulsion of the rod toward the stopper.
[0129] Use of the Device:
[0130] As shown in FIG. 6 of the preferred embodiment, the first
step in the use of the injector 10 is to remove the safety cap 540.
Then the automatic injector 10 is applied to the injection site and
depressed by pushing on the housing 100. This action results in the
exposure and insertion of the needle 512. It also releases the
driver 300 automatically initiating the injection.
[0131] During the injection time, the holding force is minimal as
illustrated by element 736 in FIG. 8. Upon completion of the
injection the spring 400 moves toward the shield 200. The force
acting on the shield increases to the level of the spring force as
illustrated by 721 and 737, respectively, in FIG. 7 and FIG. 8.
This force leads to the extraction of the needle from the tissue
and shielding of the needle by the shield 200. The spring force
somewhat decays through the motion (see displacement 722 and force
738). At the end of the shielding, the shield is locked. The
injector is ready for disposal.
[0132] Without being limited to a particular theory, as an example
of the balances of forces working in the injector, it generally
takes about 1.0 kgf (10 Newtons) to displace the shield 200 by
about 5 mm. The initial injection force of the driving unit 400 is,
for example, about 1.5 kgf (15 Newtons), and the final pushing
force during shielding is about 1 kgf. Dynamic friction takes, for
example, 0.2 kgf (2 Newtons), at maximum.
[0133] The leaf spring 131 does not affect the operation of the
injector 10 before or during delivery. However, during retraction,
the spring 400 bypasses the leaf spring 131 and deflects it. The
shield 200 is locked between the leaf spring 131 and the latch 223
preventing potential axial movement of the shield and consequential
re-exposure of the needle 512. In other words, the shield 200 is
locked to the housing 100 and unable to move.
[0134] Use of the Device with Titration:
[0135] The first step in using this injector 20 (or 21 or 40) is to
remove the safety cap 542 out of the opening 205 at the distal end
of the injector. Then any residual air in the cartridge 500 could
be purged and the amount of liquid in the syringe can be adjusted
to the required dosage by titration. The titration is achieved by
positioning the injector 10 vertically so that the needle 512 is
upright and by moving the titration rod 600 (or 601 or 602) toward
the stopper and thus, moving the unwanted air and drug out of the
injector through the needle.
[0136] Titration solves the problem of removing residual air
commonly included in pre-filled syringes, which is a by-product of
the filling technology. Titration also releases potential high
static friction between the stopper 520 and the barrel 511 caused
by non-movement over a long period of time (e.g., storage).
[0137] In order to minimize the amount of drug collected inside the
injector during titration, the injector could be turned needle down
after the residual air is purged as observed through the
window.
[0138] The housing 100 and the shield 200 of the exemplary
embodiment of the invention with the shield sliding on the housing
preferably include a window that allows a user to view the contents
and amount of dosage in the cartridge 500 before, during and after
delivery. This window is also essential for the titration. FIGS. 9
and 12 are isometric views of the injector 10. FIG. 9 corresponds
to the injector 10 at the stages before the injection and during
titration. It is important to have a full window to observe the
barrel contents during preparation to injection. FIG. 12 shows the
injector 10 during injection when the size of the observation
window is substantially reduced. At this stage the drug is not
observed. After delivery, the observation window 800 of the
injector 10 is again at the original length with the empty
cartridge and spring being visible through the window for
inspection.
[0139] In summary, a user looking through the window 800 of
injector 10 can observe the amount of dosage in the cartridge 500.
During storage, the cartridge 500 is filled with the drug solution.
During titration, extra solution and air bubbles are pushed out of
the barrel 500.
[0140] The injector 30 of the exemplary embodiment of the invention
with the shield sliding inside the housing has a full size
observation window also during injection as illustrated in FIG. 4.
The opening 171 in the housing 160 is matched to the length of the
active cartridge area. The opening 270 in the shield 250 is
substantially longer providing for a consistent cartridge
visualization before, during and after injection.
[0141] The injectors constructed in accordance with the exemplary
embodiments provide a safe and efficient approach to delivering a
drug into a patient. The injector would be used as a disposable
device and can incorporate various combinations of the features
described herein.
[0142] Alternative Embodiments:
[0143] An alternative embodiment of the present invention could
have a different latching mechanism as illustrated in FIG. 40A,
FIG. 40B and FIG. 40C of the exemplary embodiment of the invention
with the shield sliding on the housing. The cutouts of the housing
form a pattern providing locking of the shield for disposal and
preventing second shield displacement.
[0144] The shield 240 has two pins 233 interacting with a slotted
housing 150. The housing cutouts are illustrated in FIG. 40A and
are defined by numerals 140 through 147. Housing 150 contains two
cutouts 140. Cutout 140 creates a shaped latch 141. Latch 141 is
attached to housing section 152 at base 144. Latch 141 is formed
from two sections 142 and 147 connected by 143. The latches 141 are
separated by a gap 145.
[0145] FIG. 40A illustrates the operation of this alternative
latching mechanism. Only housing 150 and shield 240 are shown for
clarity. Furthermore a section of the shield 240 and housing 150
are removed. FIG. 40A illustrates assembly before displacement.
FIG. 40B illustrates a displaced shield. FIG. 40C illustrates a
discard position. Pressing the shield 240 against injection site
causes bending of latches 142 and closing of the air gap 145. At
the end of shield 240, displacement latch 142 is released and
returns to its original shape as illustrated in FIG. 40B. Once
delivery is completed, action of spring 400 forces shield 240 to
retract. Pins 233 move into the gap between latches 142 and expand
the air gap 145 by a bending latch elements 142 and 147. The pins
233 reach their final position as shown in FIG. 40C. These pins 233
prevent re-exposure of the needle. Protrusion 146 of latches 121
further increase the holding force provided by the housing 150 and
shield 240.
[0146] In summary, prior to the shield 240 displacement, the pins
233 are located inside the hooks 142 formed by the cutouts in the
housing (see FIG. 40A). During shield 240 displacement the hooks
deflect and allow the pins 233 to move axially inside the housing
cutouts 140 to a position illustrated in FIG. 40B. During the
return of the shield 240 the pins 233 deflect the hooks 142 and end
up at the base of the hooks. The hook protrusions 146 further
assist the locking function of the hook and pins.
[0147] An alternative embodiment of the present invention could
have a different cartridge as illustrated in FIG. 44. The barrel
510 of the cartridge is lacking the flange. A flange 514 is added
to the cartridge assembly.
[0148] Another alternative embodiment of the present invention
could have a different cartridge as illustrated in FIG. 45. The
barrel 510 of the cartridge is lacking the flange. A flange 514 is
added to the cartridge assembly. Furthermore, the needle is
activated (pushed to penetrate the stopper 522 for titration and
drug delivery).
[0149] The exemplary embodiments show each injector having a distal
end from which the needle is exposed, and a proximal end opposite
the distal end. In the exemplary embodiments, the injector deploys
its needle with user assist, delivers the drug in the cartridge and
shields the needle. Preferably the injector provides a distinct end
of delivery indication (e.g., a "click-type" effect and associated
tactile feedback). The injector can be assembled around a
cartridge. As a further feature of some exemplary embodiments, the
cartridge includes a stopper that can be moved within the syringe
barrel for titration by a rod, a threaded back rod, or a ratcheted
rod. The rod can be moved in one direction only for titration. It
is not connected to the stopper or the driver and allows for
unimpeded delivery.
[0150] The injector provides various safety features for minimizing
potential exposure of the needle. These features include false
activation prevention mechanisms. In particular, a safety ring 900
is illustrated in FIG. 46 and FIG. 47 and provides this function.
The ring 900 prevents activation of the automatic injector. Only
after the ring is removed is the activation possible.
[0151] Alternatively, the high force for moving the shield at the
beginning of use prevents premature displacement of the shield.
Furthermore, the needle-locking mechanism locks the needle after
use. The injector optionally includes damping material (e.g., the
bushing, shock absorbing tab) for shock and noise reduction. The
injector provides linear rate control using a low elasticity
constant spring, preferably in the form of an expansion spring. The
expansion spring can be made longer so that the cartridge stopper
moves over a small longitudinal range compared to the length of the
spring, thereby allowing the force of the spring to be consistent
over the smaller range.
[0152] The delivery devices of the exemplary embodiments allow for
accurate titration and measurement of the amount of compound to be
injected. Moreover, since the end of delivery is clear, no eye
contact is required for indication of the end of delivery, thus
making the delivery easier when the user cannot see the observation
window.
[0153] As a person skilled in the art would readily understand,
delivery of the fluid drug is determined not only by the driving
unit or spring. It also depends on fluid properties and the fluid's
path geometry. Therefore, delivery curves will not be identical to
spring reaction curves. The fluid acts as a hydraulic damper and
its resistance to flow is related to the force applied to it.
[0154] The driving unit in the exemplary embodiments can be a
spring. The compression spring is preferably used in the
embodiments having a substantially symmetrical housing
cross-section. The required motion range and the accumulated
thickness of the coils limit this initial compression.
[0155] The driving spring is the most available element to control
delivery. The main feature provided from the spring is a low
elasticity constant. A low constant provides a more uniform
delivery profile, more flexibility in controlling delivery
duration, spring load reduction during shelf life, and it provides
sufficient force at the end of the injection cycle. Using long
springs provides the benefit of improving delivery time control and
profile by changing the spring's constant of elasticity and by
allowing preloads.
[0156] Moreover, this invention overcomes other problems associated
with the prior art. For example, the driver and springs overcome
the problems of needle phobia and needle injury. In addition, the
injectors include a rod that provides the advantage of titration to
allow a patient to measure and self-administer a dosage via an
automatic injection system, with the rod automatically separating
from the stopper before delivery. The injectors with a rod also
enable the user to minimize residual drug in the system and to
eliminate air bubbles that may otherwise be trapped in the
automatic system prior to use. Further, the window provides the
user with the ability to see dosage formulation prior to use, and
to see that the drug has been delivered after use.
[0157] It should be apparent from the aforementioned description
and attached drawings that the concept of the present application
may be readily applied to a variety of preferred embodiments,
including the exemplary embodiments disclosed herein. For example,
other driving and retraction units, such as elastomeric "O" rings
or compressed gas may be used in place of the compression springs
disclosed herein to bias the driver, as readily understood by a
skilled artisan.
[0158] The assembly process for the exemplary embodiment is
illustrated in FIG. 48 through FIG. 50. The initial step includes
the assembly of the cartridge 500 with the driver 300. The spring
400 is assembled with the housing 100. The driver/cartridge
subassembly is merged with housing/spring subassembly. Adding the
shield completes the automatic injector. The assembly process is
simple due to the small number of components.
[0159] It is further appreciated that the present invention may be
used to deliver a number of drugs. The term "drug" used herein
includes but is not limited to peptides or proteins (and mimetic
thereof), antigens, vaccines, including DNA vaccines, hormones,
analgesics, anti-migraine agents, anti-coagulant agents,
medications directed to the treatment of diseases and conditions of
the central nervous system, narcotic antagonists,
immunosuppressants, agents used in the treatment of A/DS, chelating
agents, anti-anginal agents, chemotherapy agents, sedatives,
anti-neoplastics, prostaglandins, antidiuretic agents and DNA or
DNA/RNA molecules to support gene therapy.
[0160] Typical drugs include peptides, proteins or hormones (or any
memetic or analogues of any thereof) such as insulin, calcitonin,
calcitonin gene regulating protein, atrial natriuretic protein,
colony stimulating factor, betaseron, erythropoietin (EPO),
interferons such as alpha., .beta., or .gamma. interferon,
somatropin, somatotropin, somastostatin, insulin-like growth factor
(somatomedins), luteinizing hormone releasing hormone (LHRH),
tissue plasminogen activator (TPA), growth hormone releasing
hormone (GHRH), oxytocin, estradiol, growth hormones, leuprolide
acetate, factor VIII, interleukins such as interleukin-2, and
analogues or antagonists thereof, such as IL-1 ra, thereof;
analgesics such as fentanyl, sufentanil, butorphanol, bup
renorphine, levorphanol, morphine, hydromorphone, hydrocodone,
oxymorphone, methadone, lidocaine, bupivacaine, diclofenac,
naproxen, paverin, and analogues thereof; anti-migraine agents such
as sumatriptan, ergot alkaloids, and analogues thereof;
anti-coagulant agents such as heparin, hirudin, and analogues
thereof; antiemetic agents such as scopolamine, ondansetron,
domperidone, metoclopramide, and analogues thereof; cardiovascular
agents, anti-hypertensive agents and vasodilators such as
diltiazem, clonidine, nifedipine, verapamnil,
isosorbide-5-mononitrate, organic nitrates, agents used in
treatment of heart disorders, and analogues thereof; sedatives such
as benzodiazepines, phenothiozines, and analogues thereof;
chelating agents such as deferoxamine, and analogues thereof;
anti-diuretic agents such as desmopressin, vasopressin, and
analogues thereof; anti-anginal agents such as nitroglycerine, and
analogues thereof; anti-neoplastics such as fluorouracil,
bleomycin, and analogues thereof; prostaglandins and analogues
thereof; and chemotherapy agents such as vincristine, and analogues
thereof, treatments for attention deficit disorder,
methylphenidate, fluoxamine, Bisolperol, tactolimuls, sacrolimus
and cyclosporin.
[0161] While the invention has been described in detail and with
reference to specific examples thereof, it will be apparent to one
skilled in the art that various changes and modifications can be
made therein without departing from the spirit and scope
thereof.
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