U.S. patent application number 17/382536 was filed with the patent office on 2021-11-11 for medical injection device with a cleaning chamber.
The applicant listed for this patent is Novo Nordisk A/S. Invention is credited to Morten Revsgaard Frederiksen, Roshan Hakkim, Mie Haraldsted, Graham Hinde, Bas Kamp, Matias Melander, Christian Hoejris Nielsen.
Application Number | 20210346594 17/382536 |
Document ID | / |
Family ID | 1000005728106 |
Filed Date | 2021-11-11 |
United States Patent
Application |
20210346594 |
Kind Code |
A1 |
Haraldsted; Mie ; et
al. |
November 11, 2021 |
MEDICAL INJECTION DEVICE WITH A CLEANING CHAMBER
Abstract
The invention relates to an injection device for injecting a
liquid drug. The injection device comprises a housing assembly
supporting a non-removable cartridge having an interior chamber
containing the liquid drug to be injected and a reusable needle
cannula connected to the cartridge. A needle shield assembly
provided with a cleaning chamber containing a volume of a cleaning
agent for cleaning at least the distal tip of the needle cannula
between subsequent injections is further provided. The needle
shield assembly is axially movable in a proximal direction in
relation to the housing assembly from a first position to a second
position upon rotation of at least a part of the needle shield
assembly, wherein the first position is a position in which the
distal tip of the needle cannula is located inside the cleaning
chamber thereby cleansing the distal tip of the needle cannula, and
the second position is a position in which the distal tip of the
needle cannula is located outside and distal to the cleaning
chamber for equalizing the pressure in the cartridge.
Inventors: |
Haraldsted; Mie;
(Helsingoer, DK) ; Frederiksen; Morten Revsgaard;
(Copenhagen K, DK) ; Melander; Matias;
(Copenhagen, DK) ; Nielsen; Christian Hoejris;
(Copenhagen NV, DK) ; Hinde; Graham; (Eindhoven,
NL) ; Kamp; Bas; (Eindhoven, NL) ; Hakkim;
Roshan; (Eindhoven, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Novo Nordisk A/S |
Bagsvaerd |
|
DK |
|
|
Family ID: |
1000005728106 |
Appl. No.: |
17/382536 |
Filed: |
July 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15754332 |
Feb 22, 2018 |
11097046 |
|
|
PCT/EP2016/069004 |
Aug 10, 2016 |
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17382536 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 5/286 20130101;
A61M 2005/3267 20130101; A61M 2005/2073 20130101; A61M 5/3257
20130101; A61M 5/31573 20130101; A61M 5/001 20130101; A61M 5/3271
20130101; A61M 2005/3284 20130101; A61M 5/326 20130101 |
International
Class: |
A61M 5/00 20060101
A61M005/00; A61M 5/32 20060101 A61M005/32; A61M 5/315 20060101
A61M005/315; A61M 5/28 20060101 A61M005/28 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2015 |
EP |
15182290.5 |
Claims
1. An injection device for injecting a liquid drug, comprising: a
housing assembly supporting a non-removable cartridge having an
interior chamber containing a liquid drug to be injected, a needle
cannula connected to the cartridge and having a distal tip for
penetrating the skin (S) of a user and a longitudinal lumen, a
needle shield assembly which is provided with a cleaning chamber
containing a volume of a cleaning agent for cleaning at least the
distal tip of the needle cannula between subsequent injections,
wherein the needle shield assembly is movable in a proximal
direction in relation to the housing assembly from a first position
to a second position, wherein; the first position is a position in
which the distal tip of the needle cannula is located inside the
cleaning chamber, the second position is a position in which the
distal tip of the needle cannula is located outside and distal to
the cleaning chamber for equalizing the pressure in the cartridge,
wherein the at least one part of the needle shield assembly is
helically guided in relation to the housing assembly, such that the
at least one part of the needle shield assembly performs helical
movement in relation to the housing assembly upon rotation of the
at least one part of the needle shield assembly relatively to the
housing assembly, and wherein the needle shield assembly moves from
the first position to the second position thereby exposing at least
the distal tip of the needle upon rotation of at least one part of
the needle shield assembly.
2. An injection device for injecting a liquid drug according to
claim 1, wherein one of the needle shield assembly or the housing
assembly is provided with a protrusion and the other of the needle
shield assembly or the housing assembly is provided with a helical
track, and wherein the protrusion engages the helical track, such
that the at least one part the needle shield assembly moves
helically in relation to the housing assembly upon rotation of the
at least one part of the needle shield assembly relatively to the
housing assembly.
3. An injection device for injecting a liquid drug according to
claim 2, wherein the helical track terminates in an axial track
allowing the needle shield assembly to be moved in the proximal
direction during expelling of a set dose.
4. An injection device for injecting a liquid drug according to
claim 1, wherein a compression spring is operational between the
needle shield assembly and the housing assembly urging the needle
shield assembly in the distal direction.
5. An injection device for injecting a liquid drug according to
claim 1, wherein the needle shield assembly comprises at least a
distal shield part and a proximal shield part rotatable in
unison.
6. An injection device for injecting a liquid drug according to
claim 1, wherein the needle shield assembly comprises a rotatable
ring.
7. An injection device for injecting a liquid drug according to
claim 6, wherein the rotatable ring is rotatable in relation to the
proximal shield part and axially secured to the distal shield
part.
8. An injection device for injecting a liquid drug according to
claim 7, wherein one of the rotatable ring or the housing assembly
is provided with a protrusion and the other of the rotatable ring
or the housing assembly is provided with a helical track, such that
the rotatable ring moves helically in relation to the housing
assembly upon rotation of the rotatable ring relatively to the
housing assembly.
9. An injection device for injecting a liquid drug according to
claim 1, wherein the needle shield assembly or the housing assembly
is provided with a protrusion and the other of the needle shield
assembly or the housing assembly is provided with a helical track
such that the needle shield assembly moves helically in relation to
the housing assembly upon rotation of the needle shield assembly
relatively to the housing assembly.
10. An injection device for injecting a liquid drug according to
claim 9, wherein the needle shield assembly is provided with a
window and the housing assembly is provided with an opening and
which window is brought into alignment with the opening when the
needle shield assembly is rotated relatively to the housing
assembly.
11. An injection device for injecting a liquid drug according to
claim 1, wherein the needle shield assembly carries a cleaning unit
comprising the cleaning chamber.
12. An injection device for injecting a liquid drug according to
claim 1, wherein the cleaning agent contained in the cleaning
chamber is the same liquid drug as contained in the cartridge and
wherein the liquid drug comprises a preservative.
13. An injection device for injecting a liquid drug according to
claim 1, wherein the needle shield assembly distally is provided
with a distal surface having an opening surrounded by a recess.
14. An injection device for injecting a liquid drug according to
claim 13, wherein the distal tip of the needle cannula in the
second position is positioned in the recess.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is continuation of U.S. application Ser.
No. 15/754,332, filed Feb. 22, 2018, which is a .sctn. 371 National
Stage application of International Application PCT/EP2016/069004
(published as WO 2017/032599), filed Aug. 10, 2016, which claims
priority to European Patent Application 15182290.5, filed Aug. 25,
2015; the contents of which are incorporated herein by
reference.
THE TECHNICAL FIELD OF THE INVENTION
[0002] The invention relates to a medical injection device for
injecting a liquid drug and especially to a pre-filled injection
device for apportioning a multiple number of doses, the doses
preferably being individual settable by the user. The invention
especially relates to such pre-filled injection device wherein the
same needle cannula is used for a multiple number of injections and
wherein the tip of the needle cannula is cleaned between subsequent
injections.
DESCRIPTION OF RELATED ART
[0003] Injection devices wherein the tip of the needle cannula is
maintained in a cleaning solvent between subsequent injections are
disclosed in U.S. Pat. Nos. 3,354,881, 4,416,663 and in U.S. Pat.
No. 4,666,436. As can be seen from these prior art injection
devices, the cleaning chamber is usually carried on a retractable
needle shield covering the distal tip of the needle cannula between
subsequent injections.
[0004] Further WO2014/064100 discloses a pre-filled disposable
injection device which has a telescopically shield covering the
distal tip of the needle cannula between subsequent injections.
This telescopically shield is urged into a distal covering position
by a spring. Further, in one embodiment, the shield is provided
with a hollow chamber containing a liquid solvent such as a
chemical disinfectant or biocide which cleans the tip of the needle
cannula between subsequent injections.
[0005] Examples on such cleaning solvents are provided in WO
2014/029018. However, as disclosed in WO 2015/062845 it is
preferred to use the preservative contained in the liquid drug as
the cleaning solvent. This can e.g. be done by filling the cleaning
chamber with preservative containing liquid drug directly from the
cartridge and thus use a quantum of the preservative containing
liquid drug itself as the cleaning solvent.
[0006] However, when filling the cleaning chamber with preservative
containing liquid drug from the cartridge there is a risk of
creating an overpressure inside the liquid system which comprises
the interior space of the cartridge, the lumen of the needle
cannula and the cleaning chamber which together forms a closed
liquid system.
[0007] Further, no matter which cleaning agent is used there is
always a risk of an overpressure being build up inside the liquid
system especially due to temperature changes in the liquid drug
caused by different storing conditions for the injection
device.
[0008] Such overpressure in the liquid system and especially inside
the cartridge can have the unfortunate effect that the liquid
volume ejected is larger than the volume (the doses) set by the
user.
[0009] It is therefore important to equalize the pressure in the
liquid system or at least in the cartridge prior to making an
injection. Otherwise the dose size expelled can be different from
the set and intended dose due to these pressure differences.
DESCRIPTION OF THE INVENTION
[0010] It is thus an object of the present invention to provide an
injection device in which any overpressure in the liquid system can
be easily vented prior to performing an injection.
[0011] Accordingly, in one aspect, the present invention relates to
an injection device for injecting a liquid drug. The injection
device comprises: [0012] a housing assembly supporting a
non-removable cartridge having an interior chamber containing the
liquid drug to be injected: The housing assembly can be assembled
from several parts which together makes up an outer shell of the
injection device, [0013] a needle cannula which is connected to the
interior of the cartridge at least during injection and which
needle cannula has a longitudinal lumen through which the liquid
drug flows during injection and which lumen connects a distal part
of the needle cannula having a distal tip with a proximal part of
the needle cannula, [0014] a needle shield assembly which is
provided with a cleaning chamber containing a volume of a cleaning
agent for cleaning at least the distal tip of the needle cannula
between subsequent injections.
[0015] Further, the needle shield assembly is movable in a proximal
direction in relation to the housing assembly from a first position
to a second position.
[0016] The first position being a position in which the distal tip
of the needle cannula is located inside the cleaning chamber, and
the second position being a position in which the distal tip of the
needle cannula is located outside and distal to the cleaning
chamber and the needle shield assembly is movable from the first
position to the second position upon rotation of at least a part of
the needle shield assembly.
[0017] The needle shield assembly is preferably made up from a
number of parts whereof one or more parts are rotatable relatively
to the housing. The other parts not being rotatable in relation to
the housing assembly can be axially connected to the rotating part
or parts such that the non-rotating parts moves axially together
with the rotating part but do not rotate together with the rotating
part or parts.
[0018] Thus upon rotation of at least a part of the needle shield
assembly i.e. as a consequence of rotating the at least one part of
the needle shield assembly, the needle shield assembly moves from
the first position to the second position such that at least the
distal tip of the needle cannula is moved outside the cleaning
chamber and exposed to the surroundings.
[0019] The liquid system comprises at least the interior of the
cartridge, the lumen of the needle cannula and the interior of the
cleaning chamber. Once the distal tip of the needle cannula is
brought to a position just distal to the cleaning chamber, any
overpressure present at least inside the cartridge and in the lumen
of the needle cannula will equalize with the pressure of the
surroundings.
[0020] Any overpressure present inside the cleaning chamber will
not be equalized at once by exposing the distal tip of the needle
cannula, but once the distal tip of the needle cannula is moved
back into the cleaning chamber such overpressure will equalise with
the pressure inside the cartridge and after the distal tip of the
needle cannula has been moved in and out of the cleaning chamber a
few number of times any overpressure present in the cleaning
chamber will slowly disappear. Further, an overpressure inside the
cleaning chamber does not influence on the dose sizes as the distal
tip of the needle cannula is moved directly from the exposed
position and into the skin of the user during injection.
[0021] Further a part of the needle shield assembly is helically
guided in relation to the housing assembly such that when the user
rotates the specific part of the needle shield assembly it performs
a helical movement in relation to the housing assembly.
[0022] The needle shield assembly is preferably made up from a
number of different parts which together forms the needle shield.
Once the entire needle shield or at least a part of the needle
shield is rotated it is thus guided helically in the proximal
direction such that the needle shield or the part of the needle
shield moves proximally in order to expose the distal tip of the
needle cannula in front of the needle shield.
[0023] The helical guidance is preferably created by having one of
the needle shield assembly or the housing assembly to be provided
with a protrusion and the other of the needle shield assembly or
the housing assembly to be provided with a helical track. The
protrusion thus operates in the helical track, such that at the
least one part the needle shield assembly move helically in
relation to the housing assembly upon rotation of the at least one
part of the needle shield assembly relatively to the housing
assembly.
[0024] Only one single protrusion and one helical track are needed
in order to secure the helical guidance. However, any number of
protrusions and helical tracks can be provided.
[0025] The helical track in which the protrusion is guided
preferably terminates into an axial track allowing the needle
shield assembly to be moved in the proximal direction during
expelling of the set dose. Once the needle shield assembly or the
part of the needle shield assembly has been rotated through the
helical track and into the axial track, the needle shield assembly
is able to move in a straight axial direction following the axial
track. The needle shield assembly can further be provided with a
"parking position" in which it is not possible to move the needle
shield assembly in the axial direction at all. When not in this
"parking position", the needle shield assembly or part thereof is
bound to move helically until the protrusion enters into the axial
track. Only when the protrusion is positioned in the axial track,
the needle shield can move purely axially and not helically.
[0026] As a consequence the user thus has to rotate the needle
shield assembly or part thereof before it is possible to perform an
injection.
[0027] In order to return the needle shield after an injection has
been performed, a compression spring is operational provided
between the needle shield assembly and the housing assembly. This
compression spring can be any kind of spring providing an axial
force. The spring can made from either steel or a polymeric
material, it can in one example be moulded as a part of the needle
shield assembly. However, the spring does not necessarily have to
abut neither the needle shield assembly nor the housing assembly,
it merely has to operate between the needle shield assembly and the
housing thus moving these parts away from each other.
[0028] The needle shield assembly can be assembled from any number
of individual parts, however in the disclosed two embodiments the
needle shield assembly comprises a distal shield part and a
proximal shield part which are rotatable in unison.
[0029] In one example, the needle shield assembly also comprises a
rotatably ring which is connected to the remaining parts of the
needle shield assembly such that these parts travels axially
together with the rotatable ring but without rotating.
[0030] In one specific example the rotatable ring is rotatable in
relation to the proximal shield part but axially secured to the
proximal shield part. The rotatable ring whenever guided for
helical movement in relation to the housing assembly thus brings
the proximal shield part along with it in the axial direction but
without transferring rotation to the proximal shield part.
[0031] In a specific example the helical movement of the rotatable
ring is introduced by providing either the rotatable ring or the
housing assembly with a protrusion and the other of the rotatable
ring or the housing assembly with a helical track. The protrusion
can be shaped as a thread segment to further provided a helical
guidance.
[0032] In a different example a helical rotation of the needle
shield assembly is introduced by providing the needle shield
assembly or the housing assembly with a protrusion and the other of
the needle shield assembly or the housing assembly with a helical
track such that the needle shield assembly move helically in
relation to the housing assembly upon rotation of the needle shield
assembly relatively to the housing assembly.
[0033] In the latter example the needle shield assembly is provided
with a window and the housing assembly is provided with an opening.
When the user thus rotate the needle shield assembly to equalize
the pressure, the window is brought into alignment with the opening
which in the second position of the needle shield assembly makes it
possible for the user to inspect the liquid drug in the
cartridge.
[0034] Both the window in the needle shield assembly and the
opening can have any shape but when implemented in a longitudinal
pen-shaped injection device, the window is preferably a
longitudinal window and the opening is thus made to accommodate the
window.
[0035] Henceforth, as the needle shield assembly is rotated into
the second position, the longitudinal window is brought into
alignment with the longitudinal opening of the cartridge holder
which gives the user the possibility to view the cartridge or at
least part of the cartridge and thus the content of the cartridge
which gives the user an indication that the pressure has been
equalized. Further, in this second position the needle shield
assembly is free to move in the proximal direction thus it is only
possible to perform an injection after having rotated the needle
shield assembly. The indication given by the alignment of the
longitudinal window with the longitudinal opening is henceforth
further an indication that the injection device is unlocked and
ready to inject.
[0036] In a further example, the cleaning chamber is provided in a
cleaning unit which is carried by the needle shield assembly. When
manufactured as a cleaning unit it can be properly sterilized and
handled separately thereby providing excellent manufacturing
options.
[0037] The cleaning agent contained in the cleaning chamber can be
any kind of liquid that is able to rinse the distal tip of the
needle cannula from bacteria and which prevents the further growth
of bacteria. In one example the cleaning agent could be an alcohol,
however in order to minimize the risk of contaminating the liquid
drug in the cartridge by cleaning agent flowing through the lumen
of the needle cannula and into the cartridge it is preferred to use
a preservative already present in the liquid drug formulation. A
suitable cleaning agent would therefore be phenol or meta-cresol
which are broadly used as preservatives in liquid drugs.
[0038] In one specific example, the liquid drug, when containing a
preservative, can be used as the cleaning agent as disclosed in WO
2015/062845.
[0039] The distal end surface of the needle shield assembly is
preferably provided with a countersunk opening or a recess such
that the distal tip of the needle cannula can be concealed in a
position inside this countersunk opening or recess during
equalizing of the pressure. The user is then able to lay the distal
end surface of the needle shield assembly on the surface of the
skin without the distal tip of the needle cannula touching the
surface of the skin. Only as the user presses the injection device
against the skin with a certain force will the needle shield
assembly slide in the proximal direction and the needle cannula
penetrate the skin. The force needed to move the needle shield
assembly is mainly determined by the force of the compression
spring urging the needle shield in the distal direction.
[0040] In a further example the countersunk area or recess is
formed as a concave recess preferably surrounding an opening
through which the needle cannula can pass. The opening is
preferably made with a rather narrow diameter such that the distal
tip of the needle cannula is prevented from passage if bended.
Definitions
[0041] An "injection pen" is typically an injection apparatus
having an oblong or elongated shape somewhat like a pen for
writing. Although such pens usually have a tubular cross-section,
they could easily have a different cross-section such as
triangular, rectangular or square or any variation around these
geometries.
[0042] The term "Needle Cannula" is used to describe the actual
conduit performing the penetration of the skin during injection. A
needle cannula is usually made from a metallic material such as
e.g. stainless steel and connected to a hub to form a complete
injection needle all though the needle cannula could also be
connected directly to the housing structure without using a needle
hub
[0043] As used herein, the term "drug" is meant to encompass any
drug-containing flowable medicine capable of being passed through a
delivery means such as a hollow needle in a controlled manner, such
as a liquid, solution, gel or fine suspension. Representative drugs
includes pharmaceuticals such as peptides, proteins (e.g. insulin,
insulin analogues and C-peptide), and hormones, biologically
derived or active agents, hormonal and gene based agents,
nutritional formulas and other substances in both solid (dispensed)
or liquid form.
[0044] "Cartridge" is the term used to describe the container
actually containing the drug. Cartridges are usually made from
glass but could also be moulded from any suitable polymer. A
cartridge or ampoule is preferably sealed at one end by a
pierceable membrane referred to as the "septum" which can be
pierced e.g. by the non-patient end of a needle cannula. Such
septum is usually self-sealing which means that the opening created
during penetration seals automatically by the inherent resiliency
once the needle cannula is removed from the septum. The opposite
end is typically closed by a plunger or piston made from rubber or
a suitable polymer. The plunger or piston can be slidable moved
inside the cartridge. The space between the pierceable membrane and
the movable plunger holds the drug which is pressed out as the
plunger decreased the volume of the space holding the drug.
However, any kind of container--rigid or flexible--can be used to
contain the drug.
[0045] Since a cartridge usually has a narrower distal neck portion
into which the plunger cannot be moved not all of the liquid drug
contained inside the cartridge can actually be expelled. The term
"initial quantum" or "substantially used" therefore refers to the
injectable content contained in the cartridge and thus not
necessarily to the entire content.
[0046] "Cleaning chamber" is in the present description broadly
meant to be any kind of reservoir containing a cleaning solvent to
clean at least the distal tip of the needle cannula between
subsequent injections. Such cleaning chamber is preferably both
distally and proximally sealed by a pierceable septum. However, the
pierceable septums could be replaced by any kind of sealing which
would seal against the outer surface of the needle cannula. The
distal septum and the proximal septum or seal of the cleaning
chamber defines a confinement containing the cleaning solvent which
cleaning solvent in a preferred embodiment is identical to the
preservatives contained in the liquid drug used in the specific
injection device. In a most preferred solution, the same
preservative containing liquid drug is present in both the cleaning
chamber and in the cartridge of the injection device thereby
avoiding contamination of the preservative containing drug inside
the cartridge.
[0047] By the term "Pre-filled" injection device is meant an
injection device in which the cartridge containing the liquid drug
is permanently embedded in the injection device such that it cannot
be removed without permanent destruction of the injection device.
Once the pre-filled amount of liquid drug in the cartridge is used,
the user normally discards the entire injection device. This is in
opposition to a "Durable" injection device in which the user can
himself change the cartridge containing the liquid drug whenever it
is empty. Pre-filled injection devices are usually sold in packages
containing more than one injection device whereas durable injection
devices are usually sold one at a time. When using pre-filled
injection devices an average user might require as many as 50 to
100 injection devices per year whereas when using durable injection
devices one single injection device could last for several years,
however, the average user would require 50 to 100 new cartridges
per year.
[0048] Using the term "Automatic" in conjunction with injection
device means that, the injection device is able to perform the
injection without the user of the injection device delivering the
force needed to expel the drug during dosing. The force is
typically delivered--automatically--by an electric motor or by a
spring drive. The spring for the spring drive is usually strained
by the user during dose setting, however, such springs are usually
prestrained in order to avoid problems of delivering very small
doses. Alternatively, the spring can be fully preloaded by the
manufacturer with a preload sufficient to empty the entire drug
cartridge though a number of doses. Typically, the user activates a
latch mechanism e.g. in the form of a button on, e.g. on the
proximal end, of the injection device to release--fully or
partially--the force accumulated in the spring when carrying out
the injection.
[0049] The term "Permanently connected" as used in this description
is intended to mean that the parts, which in this application is
embodied as a cartridge and a needle assembly, requires the use of
tools in order to be separated and should the parts be separated it
would permanently damage at least one of the parts.
[0050] All references, including publications, patent applications,
and patents, cited herein are incorporated by reference in their
entirety and to the same extent as if each reference were
individually and specifically indicated to be incorporated by
reference and were set forth in its entirety herein.
[0051] All headings and sub-headings are used herein for
convenience only and should not be constructed as limiting the
invention in any way.
[0052] The use of any and all examples, or exemplary language (e.g.
such as) provided herein, is intended merely to better illuminate
the invention and does not pose a limitation on the scope of the
invention unless otherwise claimed. No language in the
specification should be construed as indicating any non-claimed
element as essential to the practice of the invention. The citation
and incorporation of patent documents herein is done for
convenience only and does not reflect any view of the validity,
patentability, and/or enforceability of such patent documents.
[0053] This invention includes all modifications and equivalents of
the subject matter recited in the claims appended hereto as
permitted by applicable law.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] The invention will be explained more fully below in
connection with a preferred embodiment and with reference to the
drawings in which:
[0055] FIG. 1 show a cross sectional view of the distal part of the
injection device with the needle shield in the first position.
[0056] FIG. 2 show the cross sectional view of the distal part of
the injection device with the needle shield in the second
position.
[0057] FIG. 3 show a cross sectional view of the distal part of the
injection device during injection.
[0058] FIG. 4 show a perspective view of a part of the needle
shield assembly.
[0059] FIG. 5 show a perspective view of the rotatable ring.
[0060] FIG. 6 show a perspective view of the cartridge holder.
[0061] FIG. 7 show a perspective view of the engagement between
part of the needle shield, the rotatable ring and the cartridge
holder.
[0062] FIG. 8 show a cross sectional view of the distal part of the
injection device with a damaged needle cannula.
[0063] FIG. 9 show a cross sectional view of the distal part of the
injection device with a damaged needle cannula and the needle
shield in the first position.
[0064] FIG. 10 show a cross sectional view of the distal part of
the injection device according to another embodiment with the
needle shield in the first position.
[0065] FIG. 11 show a cross sectional view of the distal part of
the injection device according to another embodiment with the
needle shield in the second position.
[0066] FIG. 12 show a cross sectional view of the distal part of
the injection device according to another embodiment during
injection.
[0067] FIG. 13 show a perspective view of the engagement between
part of the needle shield (in the first position) and the cartridge
holder.
[0068] FIG. 14 show a perspective view of the engagement between
part of the needle shield (in the second position) and the
cartridge holder.
[0069] The figures are schematic and simplified for clarity, and
they just show details, which are essential to the understanding of
the invention, while other details are left out. Throughout, the
same reference numerals are used for identical or corresponding
parts.
DETAILED DESCRIPTION OF EMBODIMENT
[0070] When in the following terms as "upper" and "lower", "right"
and "left", "horizontal" and "vertical", "clockwise" and "counter
clockwise" or similar relative expressions are used, these only
refer to the appended figures and not to an actual situation of
use. The shown figures are schematic representations for which
reason the configuration of the different structures as well as
there relative dimensions are intended to serve illustrative
purposes only.
[0071] In that context it may be convenient to define that the term
"distal end" in the appended figures is meant to refer to the end
of the injection device which usually carries the injection needle
whereas the term "proximal end" is meant to refer to the opposite
end pointing away from the injection needle and usually carrying a
dose dial button.
[0072] Distal and proximal are meant to be along an axial
orientation extending along the longitudinal axis "X" of the
injection device and is further indicated in the figures.
First Embodiment
[0073] The distal part of the injection device is disclosed in the
FIGS. 1 to 3. A cartridge 5 containing the liquid drug to be
expelled is secured in a cartridge holder 10 which is coupled to
the housing 20.
[0074] The cartridge 5 is proximally sealed by a movable plunger 6
and distally closed by a pierceable septum 7.
[0075] The housing 20 proximally encapsulates the dose setting and
injection mechanism which comprises a drive mechanism for driving
forward a piston rod 1. The piston rod 1 is distally provided with
a piston rod foot 3 which abuts a plunger 6 provided inside the
cartridge 5. The piston rod 1 has an outer thread 2 which is
engaged by a similar thread 21 formed in the housing 20 such that
the piston rod 1 is moved helically whenever the piston rod 1 is
rotated.
[0076] The cartridge holder 10 which internally secures the
cartridge 5 is secured to the housing 20 by having a plurality of
outwardly pointing protrusions 11 engaging openings 22 provided in
the housing 20. The cartridge holder 10 is thus both rotational and
axially locked to the housing 20 and could alternatively be formed
as an integral part of the housing 20. Henceforth the cartridge
holder 10 could in many aspects be considered a part of the housing
20 here after referred to as a housing assembly 10, 20.
[0077] As depicted in FIG. 1, a needle cannula 30 is penetrated
through the pierceable septum 7 of the cartridge 5. The needle
cannula 30 has a proximal part 31 inserted into the cartridge 5 and
a distal part 32 with a sharp tip 33 for penetrating the skin (S)
of user during injection (FIG. 3). Once the proximal part 31 has
penetrated through the septum 7 and into the cartridge 5, the
liquid drug can flow through the lumen 34 of the needle cannula
30.
[0078] The needle cannula 30 is secured in a hub 35 which can be
axially moved during initiation of the injection device as e.g.
disclosed in PCT application No. PCT/EP2016/057233.
[0079] Further, the distal tip 33 of the needle cannula 30 is
hidden by an axially movable needle shield assembly 40. In the
first embodiment depicted in the FIGS. 1 to 7, the needle shield
assembly 40 is assembled from two parts, a distal shield part 40A
and a proximal shield part 40B. However, the needle shield assembly
40 could easily be moulded as one unitary part. As best seen in
FIG. 4, the proximal shield part 40B has a circumferential track 43
provided on the inside of the distal end for securing therein the
distal shield part 40A such that the distal shield part 40A and the
proximal shield part 40B operates as one needle shield assembly
40.
[0080] The proximal shield part 40B is further provided with two
proximal extending axial extensions 46 which terminate in
proximally pointing arms 47. These two arms 47 are preferably
provided with a radial extension at their respective proximal ends.
These radial extensions abut a compression spring 55 which
proximally abuts the housing 20 (e.g. via the cartridge holder 10
as depicted in FIGS. 1 to 3). The proximal extensions 46 are
further provided with an outwardly pointing protrusion 44 for
axially securing a rotatable ring 60 as will be explained.
[0081] The distal shield part 40A is distally provided with an
opening 41 through which the needle cannula 30 can penetrate as
disclosed in FIGS. 2 and 3. The most distal surface 42 of the
distal shield part 40A is further provided with a concave recess 45
such that the distal tip 33 of the needle cannula 30 can be brought
to a position outside the cleaning chamber 51 but still within the
boundaries of the distal shield part 40A, the function of which
will be apparent from the further explanation.
[0082] In the situation disclosed in FIG. 1 a quantum of the liquid
drug contained in the cartridge 5 has been filled into the cleaning
chamber 51.
[0083] The cleaning chamber 51 is provided in a cleaning unit 50
which is carried by the distal shield part 40A. The cleaning
chamber 51 is defined by a through-going opening in the cleaning
unit 50 distally being sealed by a pierceable septum 52 and
proximally closed by a rubber piston 53. This rubber piston 53
seals against the outer surface of the needle cannula 30.
[0084] The cleaning chamber 51 is preferably filled with the liquid
drug from the cartridge 5 such that the same preservative
containing liquid drug is present both inside the cartridge 5 and
inside the cleaning chamber 51. However, the cleaning chamber 51
could alternatively be filled with a cleaning agent such as an
alcohol.
[0085] When filling the cleaning chamber 51, the proximal rubber
piston 53 moves proximally to the position disclosed in the
figures. Alternatively, the proximal rubber piston 53 can be
constructed as a septum in a permanent position in which case a
valve is required to let the air out as the preservative containing
liquid drug flows into the cleaning chamber 51.
[0086] The liquid system which comprises of the interior volume of
the cartridge 5, the lumen 34 of the needle cannula 30 and the
cleaning chamber 51 is relatively sensitive to pressure changes
which can occur both when filling the cleaning chamber 51 and also
afterwards especially due to temperature changes.
[0087] In order to obtain a correct dose expelling i.e. the number
of units set by the user must in fact also be expelled during
injection, it is necessary to equalize the pressure of the
cartridge 5 with the pressure outside the liquid system prior to
performing an injection.
[0088] Equalizing the pressure in the cartridge 5 is done by moving
the distal tip 33 of the needle cannula 30 just outside the
cleaning chamber 51 such that an overpressure inside the cartridge
5 (and inside the lumen 34 of the needle cannula 30) can
escape.
[0089] In order to move the needle shield assembly 40 in the
proximal direction to expose the tip 33 of the needle cannula 33, a
rotatable ring 60 is in a first embodiment provided. This rotatable
ring 60 is disclosed in details in FIG. 5 and comprises an outer
serrated surface 61 and an internal helical track 62. This
rotatable ring 60 is herein considered to be a part of the needle
shield assembly 40.
[0090] The rotatable ring 60 is axially locked to the proximal
shield part 40B which has a number of protrusions 44 (see FIG. 4)
which engages the rotatable ring 60 e.g. by engaging behind the
serrated surface 61. The rotatable ring 60 is thus rotatable in
relation to the proximal shield part 40B but the rotatable ring 60
and the proximal shied part 40B are axially locked such that they
move together in the axial direction.
[0091] The cartridge holder 10 is depicted in FIG. 6 and comprises
outwardly pointing protrusions 11 which secures the cartridge
holder 10 to the housing 20. These outwardly pointing protrusions
11 also form rotational stops for the rotatable ring 60 by engaging
a rotational stop surface 63 provided in the rotatable ring 60. In
FIG. 7, the rotatable ring 60 is depicted in a parking position
wherein the rotatable ring 60 axially abuts the protrusion 11 such
that any axial movement of the needle shield assembly 40 is
prevented. The cartridge holder 10 further has a protrusion formed
as a thread segment 12 which engages a helical track 62 provided
inside the rotatable ring 60 such that the rotatable ring 60 moves
axially when rotated i.e. the rotational ring 60 performs a helical
movement.
[0092] The helical track 62 terminates in an axial track 64 which
allows the rotational ring 60 to move purely axially when the
thread segment 12 is located in this axial track 64.
[0093] As best seen in FIG. 1 and FIG. 5, the stop surface 63 of
the rotatable ring 60 is provided on a proximal extension. In a
preferred example, two such proximal extensions are provided each
carrying a stop surface 63 which thus limits the angular rotation
of the rotatable ring 60 to less than 180 degrees.
[0094] FIG. 7 discloses the cartridge holder 10, the proximal
shield part 40B and the rotatable ring 60 together. In this shown
example, the rotational stop surface 63 of the rotatable ring 60
engages one of the outwardly pointing protrusions 11. Further, the
proximal extensions 46 are guided in longitudinal openings 13
provided in the cartridge holder 10 such that the proximal shield
part 40B can only move axially without rotation.
[0095] The shield part 40B is further provided with a longitudinal
extending window 39 such that a user can inspect the content of the
cartridge 5 by looking through this longitudinal window 39 which is
aligned with the longitudinal opening 13. Such window 39 is usually
formed as an opening but can be covered by a well-known transparent
material.
[0096] The rotatable ring 60 is thus axially locked to the proximal
shield part 40B and helically guided by the thread segment 12 on
the cartridge holder 10 which again is secured to the housing
20.
[0097] When a user rotates the rotatable ring 60 in the
anti-clockwise direction as indicated by the arrow "A" in FIG. 7,
this rotation forces the rotatable ring 60 to move helically in the
proximal direction due to the thread segment 12 engaging the
helical track 62 and since the proximal shield part 40 B is axially
coupled to the rotatable ring 60, the proximal shield part 40B
moves axially in the proximal direction as indicated by the arrow
"B" in FIG. 7.
[0098] Further, since the proximal shield part 40B and the distal
shield part 40A is coupled together to operate as one needle shield
assembly 40, the complete needle shield assembly 40 moves
proximally into the position disclosed in FIG. 2 upon rotation of
the rotatable ring 60.
[0099] As the rotatable ring 60 is rotated it also travels in the
proximal direction together with the proximal shield part 40B. This
is illustrated in FIG. 1 and FIG. 2.
[0100] As also seen in the FIGS. 1 to 3, the distal shield part 40A
is at the end surface 42 provided with a concave recess 45 in which
the distal tip 33 of the needle cannula 30 is positioned when the
pressure is being equalized. In this way unnecessary physical
contact with the distal tip 33 of the needle cannula 30 can be
prevented.
[0101] After the pressure has been equalized an injection can be
performed by pressing the distal surface 42 of the distal shield
part 40A against the skin S. This axial movement of the distal
shield part 40A will be conveyed to the proximal shield part 40B
which will also move axially to the position disclosed in FIG.
3.
[0102] The helical track 62 leads to an axial track 64 allowing the
rotatable ring 60 to move axially during injection as disclosed in
FIGS. 2 and 3. As long as the thread segment 12 is located inside
the helical track 62 only helical movement of the proximal shield
part 40B is possible, however once the thread segment 12 is in the
axial track 64 purely axial movement of the proximal shield part
40B is allowed.
[0103] The injection can either be performed as a shield-triggered
injection i.e. a not-shown strained spring is released upon
activation of the shield 40, or it can be a traditional injection
in which the user needs to push a not-shown injection button. The
activation of this not-shown injection button can in one example
release a strained torsion spring which drives the piston rod 1 in
the distal direction.
[0104] During axial movement of the needle shield assembly 40 in
the proximal direction, the compression spring 55 will be
compressed and once the injection is over and the distal surface 42
of the distal shield part 40A is removed from the skin S of the
user, the compression spring 55 will urge the shield 40 in the
distal direction to the position disclosed in FIG. 2. In order to
transform to the first position depicted in FIG. 1, the user has to
rotate the rotatable ring 60 in a clock-wise direction i.e.
opposite the direction indicated by the arrow "A" in FIG. 7, or
alternatively, the compression spring 55 has to supply a force
sufficient to drive the thread segment 12 through the helical track
62.
[0105] In the end position, after injection and after the rotatable
ring 60 has been rotated back, the distal tip 33 of the needle
cannula 30 is once again positioned inside the cleaning chamber 51
and the protrusion 11 prevents any axial movement of the needle
shield assembly 40
[0106] Should the distal part 32 of the needle cannula 30 be bended
or damaged during use as depicted in FIG. 8, the bended portion
will enter into the cleaning chamber 51 as the needle shield
assembly 40 I s moved back to its initial after injection. However,
next time the user rotates the rotatable ring 60 to equalize the
liquid system, the distal part 32 of the needle cannula 30 will
remain bended to an off-centre position and the distal tip 33 of
the needle cannula will abut the inside surface of the needle
shield assembly 40 as disclosed in FIG. 9. This abutment will
further damage e.g. break off the distal part 32 of the needle
cannula 30 and prevent further injections. It is thus not possible
to perform an injection with a bended needle cannula 30.
[0107] Obviously, the diameter of the opening 41 can be adjusted to
accommodate the allowable degree of needle bend. This "needle trap"
is usable in both the described embodiments.
Second Embodiment
[0108] A second embodiment is disclosed in the FIGS. 10 to 14.
Similar parts have been indexed with the same numbers with a "1" in
front. Thus the housing is numbered 120, the cartridge holder 110
and the needle shield assembly 140.
[0109] In the second embodiment, the needle shield assembly 140
comprises a distal shield part 140A and a proximal shield part 140B
and there is no rotatable ring in the second embodiment. The two
parts 140A, 140B could alternatively be moulded as one unitary
part.
[0110] The distal shield part 140A carries the cleaning unit 150
having a cleaning chamber 151 which is either filled with the same
preservative containing drug as present inside the cartridge 105 or
with any different cleaning agent.
[0111] FIG. 10 discloses the injection device with the needle
shield assembly 140 in the first position. Liquid drug has e.g.
been filled from the cartridge 105 into the cleaning chamber 151
and as in the first embodiment the user must actively equalize the
pressure before performing an injection.
[0112] FIG. 11 disclose the injection device with the needle shield
assembly 140 in the second position and FIG. 12 disclose the
injection device during injection of a dose.
[0113] As can be seen from the FIGS. 10 to 12, the needle shield
assembly 140 distally carries the cleaning unit 150 which--as in
the first embodiment--comprises a cleaning chamber 151 distally
sealed by a pierceable septum 152 and proximally sealed by a
sealing piston 153.
[0114] As in the first embodiment, the needle cannula 130 is
secured in a hub 135 and the proximal part 131 is penetrated into
the cartridge 105. The liquid system, in this second embodiment,
also consist of the interior of the cartridge 105, the lumen 134 of
the needle cannula 130 and the cleaning chamber 151.
[0115] In the second embodiment, the housing assembly 110, 120
comprises at least two parts, a regular housing 120 and a cartridge
holder 110. The cartridge holder 110 is provided with a number of,
preferably two, protrusions 111 for securing the cartridge holder
110 to the housing 120 to form one, at least operational, unit.
[0116] The corporation between the needle shield assembly 140 and
the cartridge holder 110 is disclosed in FIGS. 13 and 14. As in the
first embodiment, the distal shield part 140A and the proximal
shield part 140B is both axially and rotational secured to each
other.
[0117] The proximal shield part 140B of the needle shield assembly
140 is provided with a helical track 148 which is engaged by the
outwardly pointing protrusion 111. This is best seen in FIG. 14.
The result being that once the user rotate the needle shield
assembly 140 counter clockwise (indicated by the arrow "A" in FIG.
13), the needle shield assembly 140 simultaneously travels in the
proximal direction (as indicated by the arrow "B") in relation to
the cartridge holder 110 thus performing a helical movement in
relation to the housing assembly 110, 120.
[0118] The helical track 148 can as depicted in FIGS. 13 and 14 be
provided with a radial extension making up the "parking position".
When the protrusion 111 is positioned in this radial extension as
depicted in FIG. 13 axial movement of the needle shield assembly
140 is prevented.
[0119] FIG. 13 depicts the situation of FIG. 10 wherein the needle
shield assembly 140 is in the first extended position with the tip
133 of the needle cannula 130 inside the cleaning chamber 151.
However, the cleaning unit 150 and the cleaning chamber 151 are not
disclosed in FIG. 13 and FIG. 14.
[0120] As in the first embodiment, the needle shield assembly 140
is provided with a longitudinal window 139. When the pressure has
not been equalized, this longitudinal window 139 is located above
the solid part of the cartridge holder 10 such that the user cannot
view the content of the cartridge 105.
[0121] Further, as in the first embodiment, the cartridge holder
110 is provided with longitudinal openings 113 such that the
content of the cartridge 105 can be visually inspected when the
longitudinal window 139 of the needle shield assembly 140 is
aligned with the longitudinal opening 113 of the cartridge holder
110 forming part of the housing assembly 120, 110.
[0122] In the non-equalized position disclosed in FIG. 13, a
protrusion 114 on the cartridge holder 110 abuts a first side of
the longitudinal window 139 thus defining the possible rotational
direction of the needle shield assembly 140.
[0123] Now, in order to equalize the pressure inside the cartridge
105, the user manually rotates the needle shield assembly 140
counter clock-wise (arrow "A") until the protrusion 114 provided on
the cartridge holder 110 abuts the opposite side of the
longitudinal window 139 in the needle shield assembly 140
[0124] Due to the rotation of the needle shield assembly 140
relatively to the housing assembly 120, 110, the needle shield
assembly 140 moves helically in the proximal direction as the
outwardly pointing protrusion 111 travels in the helical track 148
of the needle shield assembly 140
[0125] The needle shield assembly 140 simultaneously travels
rotational as indicated by the arrow "A" and axially as indicted by
the arrow "B" (FIG. 13), the combined movement thus being a helical
movement.
[0126] When the outwardly pointing protrusion 111 arrives at the
end of the helical track 148 as depicted in FIG. 14, the needle
shield assembly 140 is in the equalizing position disclosed in FIG.
11 and the pressure has been equalized.
[0127] Once the needle shield assembly 140 has been moved to this
second position (FIG. 11 and FIG. 14), the distal tip 133 of the
needle cannula 130 is located just distal to the pierceable septum
152 but still within the parameters of the concave depression 145
at the distal end 142 of the distal shield part 140A. Further, in
this position the outwardly pointing protrusion 111 is located in
the longitudinal track 149 such that an injection can be performed
as the shield 140 is now allowed to move purely proximally as
depicted in FIG. 12.
[0128] As in the first embodiment, the distal shield part 140A is
at the end surface 142 provided with a concave recess 145 in which
the distal tip 133 of the needle cannula 30 is positioned when the
pressure is being equalized i.e. when the needle shield assembly
140 is in the second position.
[0129] As the needle shield assembly 140 is rotated the
longitudinal window 139 is brought into alignment with the
longitudinal opening 113 of the cartridge holder 110. The
possibility to view the cartridge 105 and thus the content of the
cartridge 105 in the second, equalized, position is thus an
indication to the user that the pressure has been equalized and an
injection can be performed.
[0130] Further, in this second position depicted in FIG. 14 the
needle shield assembly 140 is free to move in the proximal
direction thus it is only possible to perform an injection after
having rotated the needle shield assembly 140. The indication given
by the alignment of the longitudinal window 139 with the
longitudinal opening 113 is further an indication that the
injection device is unlocked and ready to inject.
[0131] Some preferred embodiments have been shown in the foregoing,
but it should be stressed that the invention is not limited to
these, but may be embodied in other ways within the subject matter
defined in the following claims.
* * * * *