WO2010084113A1

WO2010084113A1 - Drug delivery device with reservoir comprising window coverable by needle magazine

Info

Publication number: WO2010084113A1
Application number: PCT/EP2010/050566
Authority: WO
Inventors: Karsten Dupont Nielsen; Philip Wulff Eckert; Kristian GLEJBØL; Bastian Gaardsvig Kjeldsen; Salim Bouaidat
Original assignee: Novo Nordisk A/S
Priority date: 2009-01-20
Filing date: 2010-01-19
Publication date: 2010-07-29

Abstract

A drug delivery device comprising (a) a generally cylindrical central portion comprising a drug delivery assembly with a drug reservoir (125) having a window (124) allowing inspection of the interior thereof, and (b) a generally ring-formed needle assembly adapted to be arranged around the central portion and comprising a plurality of drug delivery needles. The needle assembly and the drug delivery assembly comprise releasable mating coupling means allowing the needle assembly to be secured to the drug delivery assembly in a situation of use, the needle assembly thereby covering the window.

Description

DRUG DELIVERY DEVICE WITH RESERVOIR COMPRISING WINDOW COVERABLE BY NEEDLE MAGAZINE

The present invention generally relates to medical devices adapted for administration of a fluid drug as well as components for use in such devices. In specific embodiments the invention relates to medical delivery devices and components therefore adapted to provide ease of use in a cost-effective way.

BACKGROUND OF THE INVENTION

In the disclosure of the present invention reference is mostly made to the treatment of diabetes by delivery of insulin, however, this is only an exemplary use of the present invention.

Medical injection devices are used to deliver selected doses of medication to patients. Some medication, such as insulin is self-administered. The typical diabetes patient will require injections of insulin several times during the course of the day. In order to prevent infections it is recommended to use a sterile needle assembly for each injection. Needle assemblies are often delivered in magazines where each magazine contains only one needle assembly in a sterile compartment. Such a magazine is described in US 5,971 ,966. Using a needle assembly of this kind requires the patient to open the magazine and to fasten the needle assembly on to the injection device prior to each injection. The storage of sterile needle assemblies of this type and the final disposal of used needle assemblies present a problem since new ster- ile needle assemblies are often carried loosely in purses or briefcases. Furthermore, used needle assemblies are often disposed of unsafely.

To overcome these problems needle magazines for storing and dispensing a plurality of needle assemblies has been proposed. A first type of needle magazine is adapted to be used with a traditional pen-formed injection device as an add-on instead of traditional single needles.

For example, in US 5,829,589 a needle magazine is provided as a container having a plurality of cavities each accommodating a needle assembly. A cover is rotatably mounted on top of the container. When aligning a slot in the cover with one of the cavities, the user can access the cavity. The needle assembly is connected to the injection device by forcing the tip of the injection device into the cavity where the needle assembly is force fitted, e.g. by a well- known luer coupling, onto the distal end of the injection device. The needle assembly can then be detached from the magazine. When the used needle is to be returned to the maga- zine the user has to conduct a reverse procedure. The above prior art needle magazine is attached to the injection device by fitting the entire magazine into an open end of the remov- able cap of a pen-shaped injection device. Due to the dimensions of a pencil-shaped injection device only five needle assemblies can be contained in the magazine. An ordinary disposable injection device usually contains 300 IU of insulin. For many diabetes patients this is sufficient for 10 to 20 injections, therefore one magazine of needle assemblies are not enough for the lifetime of one disposable injection device, which is very inconvenient.

US 2002/0020646 discloses another needle magazine which is intended to be mounted onto the dispensing distal end portion of an injection device. The needle magazine includes a ro- tatable cassette holding a plurality of needles in a circular array configuration. By sequentially rotating the cassette, each of the needles can be brought into alignment with the distal end of the injection device. By moving the injection device in the distal direction, the back needle of the particular selected needle penetrates a septum in the cartridge. Further distal movement causes the front needle to penetrate a seal in a distal face of the needle container to bring the selected needle into an injection position. Even though the needle magazine according to US 2002/0020646 may include a large number of needles, this needle magazine is rather bulky and takes up much space in the plane which includes the array. If the needle magazine is dimensioned to hold several needles, the circular array extends quite far in a direction transverse to the needle which is aligned with the cartridge, particular in the direction which intersects the centre axis of the circular array. Thus, the geometric form of the needle maga- zine according to US 2002/0020646 is practically not adaptable to all kinds of injection devices, in particular not to injection devices of the pen-shaped form factor. From US 2008/0312604 is known a pen-formed injection device provided with a relative compact needle magazine.

Thus, as appears, it is difficult to provide a pen-shaped device with a needle magazine which comprises a relatively large number of needles and at the same time fits the general pen- shaped form-factor of a traditional drug injection device.

A second type of needle magazine is not adapted to be used as an add-on to a traditional pen-shaped injection device but is provided as part of a drug delivery system specifically designed for use only with a custom-designed needle magazine.

Such a system is known from WO 2005/097237 which discloses a computer controlled and motor actuated drug injection apparatus comprising a needle cassette, and from WO 2008/150715 disclosing a needle cassette. Such an apparatus is relatively expensive and would not be suitable as a pre-filled device. Having regard to the above, it is a first object of the present invention to provide a drug injection device comprising a plurality of needles, the device being convenient to carry and operate, yet allowing for cost-effective manufacturing.

In order to provide a drug injection device which combines a needle magazine with a compact and pocket-friendly form-factor it is a second object of the present invention to provide components for a drug injection device which allows for a compact design without relying on a pre-determined outer form factor as may be the case if the injection device would be based on traditional dose setting and dose expelling principles and mechanisms used in prior art pen-shaped devices.

DISCLOSURE OF THE INVENTION

In the disclosure of the present invention, embodiments and aspects will be described which will address one or more of the above objects or which will address objects apparent from the below disclosure as well as from the description of exemplary embodiments.

Thus, in a first aspect of the invention a drug delivery device is provided comprising (a) a drug delivery assembly having a drug reservoir comprising a window allowing inspection of the interior thereof, a drug outlet, and drug expelling means for expelling an amount of drug from the reservoir through the drug outlet, as well as (b) a needle assembly comprising a plurality of drug delivery needles arranged in a ring-formed configuration, whereby the needles consecutively can be moved into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted sealed position and an extended position in which a distal end of the needle projects from the device and fluid communication is established between the needle and the drug outlet. The drug delivery device further comprises (c) needle actuation means for moving a needle positioned in its actuatable position from its retracted to its extended position. The ring-formed arrangement of the needles defines a central space in which the drug delivery assembly generally is arranged in a situation of use, and the needle assembly and the drug delivery assembly comprise releasable mating coupling means allowing the needle assembly to be secured to the drug delivery assembly in the situation of use, the needle assembly thereby covering the window.

By this arrangement a user can inspect the drug in the reservoir when a new drug unit is taken use, whereas the window will be covered by the needle assembly during normal use.

As the needle assembly can be disconnected from the drug unit the user can inspect the res- ervoir when desired. Optionally the coupling means may be adapted to be arranged in an intermediate position where the needle assembly is secured to the drug delivery assembly with the window visible for inspection.

US 2007/0233001 discloses a motor-doser with a releasable circular needle magazine, the doser comprising an exposed window allowing inspection of a reservoir. Alternatively, the window may be provided with an openable door. WO 2006/077262 discloses a patch-pump comprising a needle patch unit and a reservoir unit having an open window on a lower surface, the window being covered by the needle patch when the two units are assembled.

The needle assembly may have a generally ring-formed configuration allowing the needles to be moved around the central space, e.g. the needle assembly may comprise a plurality of needle units (e.g. each comprising a needle carrier and a needle) connected to each other in a conveyer belt configuration allowing the needle units to be moved "around corners" when the needle assembly has a non-circular configuration, the conveyer belt allowing the needles to move non-circularly relative to the central space. Alternatively, the needle assembly may have a generally circular configuration allowing the needles to be rotated relative to the central space.

In an exemplary embodiment a drug delivery device is provided comprising (a) a generally cylindrical central portion comprising a drug delivery assembly with a drug reservoir having a window allowing inspection of the interior thereof, and (b) a generally ring-formed needle assembly adapted to be arranged around the central portion and comprising a plurality of drug delivery needles. The needle assembly and the drug delivery assembly comprise releasable mating coupling means allowing the needle assembly to be secured to the drug delivery assembly in a situation of use, the needle assembly thereby covering the window. As also described above, the needle actuation means may comprise a user actuatable element arranged peripherally relative to a needle in its actuatable position.

In a second aspect of the invention a drug delivery assembly is provided comprising a drug reservoir containing a fluid drug comprising a given component, a drug metering chamber, a fluid communication between the drug reservoir and the drug metering chamber, a drug outlet, and drug expelling means for expelling an amount of drug from the metering chamber through the drug outlet. The assembly further comprises first valve means having an initial position in which the fluid communication is sealed by the first valve means, and an actuated position in which the fluid communication is not sealed by the first valve means, and second valve means having an initial position in which the fluid communication is not sealed by the second valve means, and an actuated position in which the fluid communication is sealed by the second valve means. The permeability of the second valve means to the given component contained in the fluid drug is higher than the permeability of the first valve means to the given component, whereby a high barrier for diffusion of the given component from the reservoir is provided when the fluid communication is closed by the first valve means, whereas the higher permeability for the given component when the fluid communication is closed by the second valve means assures that an intended amount of diffusion will take place between drug in the drug metering chamber and drug in the reservoir. As appears, the first valve means works as a blocking means.

By this arrangement it can be prevented to a high degree that during storage essential components of the drug, e.g. insulin preservatives such as phenol or meta-cresol, will not diffuse out of the reservoir. On the other hand, preservatives may be absorbed in the metering chamber during operation. To compensate for this absorption the second valve means can serve to replenish preservatives from a much larger reservoir by allowing diffusion through the second valve member and into the metering chamber.

WO 2009/001350 discloses a roller-type pump with a "metering chamber" formed between two rollers, one-way valves being provided on each side of the roller portion. Only the inlet valve is arranged between the metering chamber and the reservoir, the outlet valve being arranged down-stream of the metering chamber.

In an exemplary embodiment the first and second valve means are coupled to each other and moveable between an initial position in which the fluid communication is sealed by the first valve means, and an actuated position in which the fluid communication is sealed by the second valve means. The second valve means may in its actuated position be controlled to allow a flow of fluid from the reservoir to the metering chamber, yet preventing a flow of fluid from the metering chamber to the reservoir, e.g. the second valve means may allow a flow of fluid from the reservoir to the metering chamber when a pressure gradient is established across the second valve means, or the valve may be actuated by external actuator and control means.

The valve means may be provided in the form of a valve member having a first portion pro- viding the first valve means and a second portion providing the second valve means. The metering chamber may be in the form of a cylindrical bore in which the valve member is slid- ingly arranged, the valve member having a general tubular configuration comprising a distal closed end portion forming the first valve means and a proximal open portion forming the second valve means, where the distal and proximal portions are formed at least partially from first and second polymers providing the desired permeability.

In an exemplary embodiment the first valve means provides an outlet seal for the drug outlet in both its initial and actuated position. The outlet seal may be controlled to allow a flow of fluid from the metering chamber, e.g. when in the form of a needle-penetratable self-sealing membrane.

A method of controlling the permeability between two chambers is also provided, comprising the steps of: (a) providing first and second chambers, the first chamber comprising a fluid having a given component, the second chamber being initially empty, a first seal being arranged between the two chambers, (b) arranging a second seal between the two chambers replacing the first seal, the permeability of the second seal to the given component contained in the fluid being higher than the permeability of the first seal to the given component, (c) transferring an amount of fluid from the first to the second chamber, and (d) allowing diffusion of the given component between two chambers through the second seal. The method may be adapted corresponding to the above-described features of the drug delivery assembly.

In a third aspect of the invention a reservoir is provided comprising a generally rigid reservoir member in which a first generally concave cavity is formed, and a flexible foil member forming a second oppositely and generally concave cavity. The first and second cavities are sealed to each other at the peripheries thereof thereby forming a closed reservoir, with the portion of the flexible foil member forming the second concave cavity being collapsible into the first concave cavity thereby providing a variable volume reservoir. The foil material is essentially non-transparent, with at least a portion of the first concave portion being transparent allowing visual inspection of a fluid contained in the reservoir. By this design the foil material can be selected without having regard to its transparency properties. The reservoir member may be made fully or partly from a transparent polymeric material.

A method of manufacturing a reservoir as described above is also provided, comprising the steps of: (a) providing a generally rigid reservoir member in which a first generally concave cavity is formed, (b) providing a generally planar flexible foil member, (c) sealing the rigid reservoir member and the flexible foil member to each other thereby forming a closed reservoir, and (d) moving the flexible foil member into contact with the concave cavity to thereby form a generally concave cavity in the flexible foil member. The flexible form may be either cold- or warm-formed into its concave shape. The method may comprise the further step of introducing a fluid into the reservoir to thereby force the flexible form into an opposed concave shape relative to the shape of the concave cavity of the reservoir member. The method may be adapted corresponding to the above-described features of the reservoir.

In a fourth aspect of the invention a method for operating a drug delivery device is provided, comprising the steps of: (a) providing a drug chamber having a closed outlet, (b) pressurizing an amount of drug contained in the drug chamber, (c) moving a drug delivery needle from a retracted to an intermediately extended position, and (d) moving the drug delivery needle to a further extended position in which fluid communication is established with the drug chamber via the drug outlet. By pressurizing the drug chamber before connection is established with the needle, it is prevented that body fluids at a slightly elevated pressure can flow into and contaminate the dose chamber.

A drug delivery device is also provided, comprising (a) a housing having a contact portion adapted to be arranged in contact with a skin surface of a patient, (b) a drug delivery assembly comprising a drug chamber, an initially closed drug outlet, and drug expelling means for pressurizing an amount of drug contained in the drug chamber, (c) a drug delivery needle having a distal end arranged in an initially retracted position relative to the contact portion, and (d) actuation means for moving the drug delivery needle from its retracted to an intermediate position in which the distal end extends relative to the contact portion, and to a further extended position in which fluid communication is established with the drug chamber via the drug outlet.

In a fifth aspect of the invention an actuator system is provided comprising a housing, a setting member selectively adjustable to a set position, an actuation member moveable between an initial position and a set position determined by the set position of the setting member, as well as first spring means for moving the actuation member from its initial position to its set position, and second spring means for moving the actuation member from the set position back to its initial position, wherein the first and second spring means are actuated from an initial condition to an actuated condition when the setting member is adjusted to a set position. The system further comprises first release means for releasing the first spring means, and second release means for releasing the second spring means, the second release means being independently operatable relative to the first release means, wherein the first spring means acts between the setting member and the actuation member, the second spring means acts between the housing and the setting member, and the setting member acts on the actuation member when the setting member and the actuation member are arranged in their respective set positions, whereby the actuation member can be moved back to its initial position by the second spring means. By this arrangement it can be secured that fluid drug is not moved into a dosing chamber before the setting member has been properly set by a user. In the below description of an exemplary embodiment the actuator system is disclosed incorporated into a fluid dispensing device, however, the actuator may be used in any context in which the defined pattern of movement is relevant.

GB 2 288 539 discloses an injection device comprising a setting and actuation members as well as first and second springs for moving the actuation member, the setting member being adapted to be set to a single pre-determined position. When the dose is set the first spring means is immediately released, this preventing a "dial down" of the set dose.

In an exemplary embodiment the first and second spring means are in the form of a common elastic member having first and second portions attached to the actuation member and housing respectively, and an intermediate portion engaging the setting member, whereby the portion between the first and intermediate portion provides the first spring means, and the portion between the intermediate portion and the second portion provides the first spring means. The intermediate portion may be attached to the setting member and the common elastic member may be in the form of a rubber band having first and second end portions providing the first and second portions respectively. By using a single rubber band a simple design is achieved avoiding the need for e.g. two traditional springs.

The invention also provides a drug delivery device in combination with an actuator system as described above, the drug delivery system further comprising a drug reservoir, a drug metering chamber, a fluid communication between the drug reservoir and the drug metering chamber, valve means controlling a flow of fluid through the fluid communication, and an initially closed drug outlet. In such a device the actuation member is arranged to draw an amount of fluid contained in the drug reservoir from the drug reservoir to the metering chamber via the fluid communication when the actuation member is moved from its initial position to its set position, and expel an amount of fluid from the metering chamber through the drug outlet when the actuation member is moved from its set position back to its initial position.

In an exemplary embodiment the drug delivery device further comprises a portion adapted to be arranged in contact with a skin surface of a user, a drug delivery needle having a distal end arranged in an initially retracted position relative to the contact portion, and actuation means for (i) releasing the second release means to thereby pressurize the drug contained in the metering chamber, and for (ii) moving the drug delivery needle from its retracted to an intermediate position in which the distal end extends from the drug delivery device, and (iii) to a further extended position in which fluid communication is established between the drug delivery needle and the pressurized metering chamber via the drug outlet. The actuation member may comprise a piston, and the metering chamber may comprise a cylindrical portion in which the piston is slidingly arranged.

In a sixth aspect of the invention a needle assembly is provided comprising (a) a housing having a first initially sealed opening and a second opening defined by a cylindrical tube portion, (b) a drug delivery needle having a distal end and a proximal end, and (c) a guide member mounted on the needle between the distal and proximal ends, the guide member being mounted in and in sealing engagement with the cylindrical tube portion, this providing a sealed interior space in which the distal end of the needle is arranged in an initial position. By allowing the guide member to be axially displaced in the cylindrical tube portion from the initial sealed position to an extended position in which the distal end of the needle protrudes through the first opening a simple yet reliable needle guide and seal arrangement is provided. The first opening may initially be covered by a needle-penetratable membrane allow- ing a sterilizing gas, e.g. steam, to penetrate. Also the proximal end of the needle may be arranged in an initially sealed enclosure, e.g. the sealed enclosure may comprise a collapsible member adapted to collapse axially around the proximal end of the needle.

The guide member may have a general cylindrical form corresponding to the cylindrical tube portion with a sealing lip being arranged on one or both of the members. The needle may be straight or have a general U-shaped form. In an exemplary embodiment a needle magazine is provided comprising a plurality of needle assemblies. The needle magazine may comprise a magazine member in which a plurality of housings is integrally formed, or the needle assemblies may be individually formed and arranged in a common carrier or common housing allowing the individual needle assemblies to be moved relative to the common carrier or common housing, and thereby relative to a drug delivery device to which the needle magazine may be adapted to be connected to. In such a common carrier the needle assemblies may be arranged in a ring-formed configuration which may have a circular or non-circular configuration. The individual needle assembly housings may be detached from each other or they may be connected to each other by flexible hinges in a conveyer belt like fashion. By providing a non-circular form of the needle assembly a more "square" central space can be provided allowing more efficient packaging of a drug delivery device.

WO 2008/150715 discloses a U-formed needle with a distal portion arranged in a cavity with a distal opening. Although the needle is mounted in a guide member, the guide member provides no seal with the structure in which it is moved. US 2007/0233001 discloses a U-formed needle with a distal portion arranged in a cavity with a distal opening, a collapsible shroud providing a seal between the cavity and a needle carrier body. US 2008/0312604 and US 2004/0260270 show needles carried by a member arranged in a bore but with no sealing en- gagement between the member and the bore.

In a seventh aspect of the invention a drug delivery device is provided comprising (a) a drug delivery assembly comprising a drug reservoir, a drug outlet, and drug expelling means for expelling an amount of drug from the reservoir through the drug outlet, and (b) a needle as- sembly having a ring-shaped configuration defining a central space, e.g. a through-going opening, comprising a housing, a plurality of drug delivery needles arranged in a ring-shaped configuration relative to the central space, whereby the needles consecutively can be moved into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted position and an extended position in which a pointed end of the needle projects from the device and fluid communication is established between the needle and the drug outlet. The drug delivery device further comprises (c) needle actuation means for moving a needle positioned in its actuatable position from its retracted to its extended position. In such a device the drug delivery assembly is arranged generally in the central space and thereby being surrounded by the plurality of drug delivery needles, and the needle actuation means comprises a user actuatable needle inserter button arranged generally peripherally relative to the needle assembly housing. The needle assembly and the drug delivery assembly are may comprise corresponding coupling means allowing the two units to be coupled and un-coupled to each other. The button may be part of the needle assembly unit.

By arranging the needle inserter button peripherally outside of the needles instead of on top of the needles, a drug injection device is provided which combines a needle magazine with a compact and flat pocket-friendly form-factor.

In an exemplary embodiment the user actuatable needle inserter button can be moved between an initial upper position and an actuated lower position corresponding to the needle being moved to its extended position, wherein the user actuatable needle inserter button comprises a finger portion allowing a finger of a user to fully move the user actuatable needle inserter button to its extended position, e.g. having a width of at least 15 mm. The needle assembly may comprise a peripheral nose-like extension adapted to receive the user ac- tuatable needle inserter button, such a configuration allowing a user to fast and easily identify the button area.

The needles may have a general U-formed configuration comprising a first distal leg portion adapted to be connected to the drug outlet, a second distal leg portion comprising the pointed end, and a proximal portion connecting the two legs.

The user actuatable needle inserter button may comprise an actuation surface moveable between an initial upper position and an actuated lower position corresponding to the needle being moved to its extended position, wherein the actuation surface in the actuated lower position is arranged distally relative to the proximal portions of the needles in their retracted position.

The needle assembly may have a generally ring-formed configuration allowing the needles to be moved around the central space, e.g. the needle assembly may comprise a plurality of needle units, e.g. each comprising a needle carrier and a needle, connected to each other in a conveyer belt configuration allowing the needle units to be moved "around corners" when the needle assembly has a non-circular configuration, the conveyer belt allowing the needles to move non-circularly relative to the central space. Alternatively, the needle assembly may have a generally circular configuration allowing the needles to be rotated relative to the cen- tral space.

In an exemplary embodiment a drug delivery device is provided comprising: (a) a drug delivery assembly comprising a drug reservoir, a drug outlet, and drug expelling means for expelling an amount of drug from the reservoir through the drug outlet, (b) a needle assembly comprising a plurality of drug delivery needles arranged in a generally circular configuration allowing each needle to rotate about a common axis of rotation, whereby the needles consecutively can be rotated into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted sealed position and an extended position in which a distal end of the needle projects from the device and fluid communication is established between the needle and the drug outlet. The device further comprises (c) needle actuation means for moving a needle positioned in its actuatable position from its retracted to its extended position, the needle actuation means comprising a user actuatable element.

Further, the circular arrangement of the needles defines a central space, e.g. a through- going opening, in which the drug delivery assembly generally is arranged, and with the user actuatable element arranged peripherally relative to a needle in its actuatable position.

In an eight aspect of the invention a drug delivery device is provided comprising: (a) a drug delivery assembly comprising a drug reservoir, a drug outlet, and drug expelling means for expelling an amount of drug from the reservoir through the drug outlet, as well as (b) a needle assembly comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted position and an extended position in which a distal end of the needle projects from the device and fluid communication is established between the needle and the drug outlet. The drug delivery device further comprises (c) needle actuation means for moving a needle positioned in its actuatable position from its retracted to its extended position, and (d) control means for controlling movement of the needle assembly relative to the drug delivery assembly. In such a device the control means can be configured in either a first state or a second state, where the first state allows a given needle to be moved from its retracted to its extended position only once when positioned in its actuatable position for the first time, and the second state allows a given needle to be moved from its retracted to its extended position more than once when positioned in its actuatable position for the first time.

By configuring the control means in such a way that a small change of form in e.g. a single component would turn on an off the blocking functionality, it is made possible in a simple way to provide both alternatives which then may be offered on relevant markets.

In an exemplary embodiment the control means is configured to, in the first state, to move a second needle into an actuatable position after a first needle has been moved from its retracted to its extended position, thereby providing automatic forwarding of a new needle. The control means may comprise a control portion that can be configured to determine whether the control means will be configured in either the first state or the second state. The control portion may be arranged on either the drug delivery assembly or the needle assembly.

In an exemplary embodiment a drug delivery device is provided comprising (a) a drug deliv- ery assembly having a drug outlet, (b) a needle assembly comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, and (c) needle actuation means for moving a needle positioned in its ac- tuatable position from a retracted to an extended position in which fluid communication is established with the drug outlet. The drug delivery device can be configured in either a first state or a second state, where the first state allows a given needle to be moved from its re- tracted to its extended position only once when positioned in its actuatable position for the first time, and the second state allows a given needle to be moved from its retracted to its extended position more than once when positioned in its actuatable position for the first time.

The invention also provides a drug delivery system comprising (a) a drug delivery assembly having a drug outlet, (b) a first needle assembly mountable on the drug delivery assembly and comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, the first needle assembly being configured to allow given needle to be moved from its retracted to its extended position only once when positioned in its actuatable position for the first time, (c) a second needle assem- bly mountable on the drug delivery assembly and comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, the second needle assembly being configured to allow a given needle to be moved from its retracted to its extended position more than once when positioned in its actuatable position for the first time, and (d) needle actuation means, associated with either the drug delivery assembly or a needle assembly, for moving a needle positioned in its actuatable position from a retracted to an extended position in which fluid communication is established with the drug outlet. The system may be adapted corresponding to the above-described features of the drug delivery device. By such a system a device system is provided which can be tailored to a given market.

In an ninth aspect of the invention a pump assembly comprising a fluid metering chamber, a fluid inlet, and a fluid communication structure between the fluid inlet and the drug metering chamber. The fluid communication structure comprises flow control means operatable between an open state in which fluid is allowed to flow between the fluid inlet and the drug me- tering chamber, and a closed state in which fluid is not allowed to flow between the drug metering chamber and the fluid inlet. The fluid communication structure further comprises a needle-penetratable outlet portion. The pump assembly is further provided with outlet control means comprising a hollow needle having an inlet portion and an outlet, the inlet portion being adapted to penetrate the needle-penetratable outlet portion, and actuation means adapted to operate the flow control means between the open and closed state. The outlet control means is operatable between an initial state in which the flow control means is in the open state and there is no fluid communication between the fluid communication structure and the needle, and an actuated state in which the actuation means has operated the flow control means to the closed state, and in which the needle has penetrated the needle- penetratable outlet portion thereby providing fluid communication between the needle and the fluid metering chamber via the fluid communication structure. As appears, by this arrangement a simple means of providing a fluid outlet via a needle and actuation of a valve is provided.

In an exemplary embodiment the hollow needle and the actuation means may be provided as an actuatable unit, e.g. with actuation means arranged circumferentially relative to the hollow needle, the hollow needle having an inlet opening arranged distally of the actuation means.

In a further exemplary embodiment the flow control means may comprise a flexible control portion operatable between an open and an actuated closed state, this providing the open and closed state of the flow control means, the needle-penetratable outlet portion being formed integrally with the flexible control portion, whereby operation of the outlet control means between the initial and actuated state moves the needle through the needle- penetratable outlet portion and thereby into fluid communication with the fluid metering chamber, and moves the actuation means into actuating engagement with the flexible control portion to thereby prevent a flow of fluid between the drug metering chamber and the fluid inlet. The flow control means may comprise a flexible control portion operatable between an open and an actuated closed state, this providing the open and closed state of the flow control means. The needle-penetratable outlet portion may be formed integrally with the flexible control portion. Further, the flow control means may comprise a valve formed between a valve seat and the flexible control portion, the flow control means being in the open state when the flexible control portion does not fully engage the valve seat, and in the closed state when the flexible control portion fully engages the valve seat when actuated by the actuation means. In such an arrangement the valve seat may circumferentially surround an opening in fluid communication with the fluid inlet, the flexible control portion engaging the valve seat comprising the needle-penetratable outlet portion, the opening being adapted to receive the needle inlet portion to thereby establish the fluid communication between the needle and the fluid metering chamber.

In the above different aspects of the invention have been described individually, however, it will be appreciated that the features corresponding to the individual aspects can be com- bined, e.g. the features of the dosing mechanism, the reservoir, the needle actuation, and the needle magazine.

As used herein, the term "drug" is meant to encompass any drug-containing flowable medi- cine capable of being passed through a delivery means such as a cannula or hollow needle in a controlled manner, such as a liquid, solution, gel or fine suspension. Representative drugs include pharmaceuticals such as peptides, proteins, and hormones, biologically derived or active agents, hormonal and gene based agents, nutritional formulas and other substances in both solid (dispensed) or liquid form. In the description of the exemplary embodi- ments reference will be made to the use of insulin. Correspondingly, the term "subcutaneous" infusion is meant to encompass any method of transcutaneous delivery to a subject.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be further described with reference to the drawings, wherein

fig. 1 shows a drug delivery unit and a thereto attachable needle magazine, fig. 2 shows the drug delivery unit and the needle magazine attached to each other, fig. 3 shows an exploded view of the drug delivery unit seen from above, fig. 4 shows an exploded view of the drug delivery unit seen from below, fig. 5 shows a rubber band, fig. 6 shows the expelling mechanism of fig. 3 assembled in an assembled state, fig. 7 shows a cross-sectional view of the expelling mechanism of fig. 6, fig. 8 shows an exploded view of the needle magazine seen from above, fig. 9 shows an exploded view of the needle magazine seen from below, fig. 10 shows a cross-section view of a needle unit in an initial position, fig. 1 1 shows a cross-section view of a needle unit in an actuated position, figs. 12A and 12B show schematic cross-sectional views of a drug reservoir in a filled respectively collapsed state, fig. 13A shows a pump assembly with a fluid communication structure, and fig. 13B shows a cross-sectional view through the fluid communication structure.

In the figures like structures are mainly identified by like reference numerals.

DESCRIPTION OF EXEMPLARY EMBODIMENTS When in the following terms such as "upper" and "lower", "right" and "left", "horizontal" and "vertical" 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. In the below described embodiment the lower planar surface is described as being arranged horizontally for the purpose of descrip- tion only.

Fig. 1 shows an embodiment of a drug infusion device 1 comprising a generally cylindrical drug delivery unit 10 and a thereto attachable ring-formed needle magazine or needle storage unit 20 in which a plurality of needles are mounted. When assembled as seen in fig. 2 the device has a general flat and oval configuration providing a "pocket friendly" form for the user. As will be explained in greater detail below, the assembled device comprises a dose- setting dial, a priming button, a combined needle insertion and drug expelling button, as well as a needle advancing button.

With reference to figs. 3-7 the structure and functionality of the drug delivery unit 10 will be described. More specifically, the drug delivery unit comprises a generally circular base member 100 in which a piston 200 and a piston stop member 300 are slidingly received, a valve member 190 mounted in the base member, a piston ring 290 mounted on the piston, a circular dose setting member 400 rotationally arranged relative to the base member, a coupling member 500 rotationally arranged relative to both the dose setting member and the base member, a priming button 490 arranged axially moveable relative to the base member, and an end-of-content (EOC) indicator 590 arranged between the dose setting member 400 and the coupling member 500. A rubber band 280 is attached between the piston, the piston stop member and the base member. A ring-formed drug unit housing 600 (see fig. 1) is attached to the base member, thereby enclosing and holding together the different components of the drug delivery unit.

Turning to the individual components, the base member 100 comprises a generally circular base plate portion 110 with a peripheral edge 11 1 and a generally planer lower surface 112, first and second cavities 120, 130 surrounded by half moon-shaped outer walls 121 , 132, a central space 140 being formed between the two cavities. In the first cavity a reservoir 125 is arranged, the reservoir comprising a half moon-shaped wall 126 and an upper opening closed by a flexible foil (not shown, see below). The outer wall 121 may be provided with a cut-out window 124 allowing inspection of the drug in the reservoir (which indeed would re- quire the reservoir wall to be transparent). The second cavity is intended for use by optional components such as an electronic module. Between the two cavities a dose cylinder por- tioni 50 is arranged, the dose cylinder having a bore 154 with a distal opening 151 , in which a valve member 190 is arranged, and a proximal opening 152 receiving the piston 200, thereby creating a dose (or metering) chamber 129 between the valve member and the piston. A channel 128 connects the reservoir and the distal end of the dose cylinder. On top of the dose cylinder a flexible locking finger 155 with a detent 156 is arranged, as well as a short axle 157 having a central bore 158 in communication with the bore of the cylinder. Opposite (or behind) the dose cylinder portion the two opposed walls 121 , 131 are provided with a pair of guiding grooves 122, 132 adapted to slidingly engage the piston 200 and the piston stop member 300.

The valve member 190 comprises a distal head portion 191 serving as a needle penetratable septum between the exterior and the dose cylinder, as well as proximal cylindrical and flexible skirt portion 192 serving as a flap valve for controlling a flow of fluid through channel 128 into the dose chamber. Further details for the design and functions of the valve member can be found below.

The piston comprises a partly hollow body 210 adapted to receive and lock a distal end of the rubber band 280, a distal end with a cylindrical projection 220 onto which the piston ring 290 is mounted, a proximal end 230 with two feet 231 , 232 adapted to engage the guiding grooves 122, 132, and an upper flexible locking finger 240 with a free end adapted to engage the central bore 158. The two feet also serve as a stop against the proximal end of the cylinder portion.

The piston stop member 300 comprises a body portion 310 adapted to be slidingly received in a groove 160 between the cylinder portion and the wall 131 of the second cavity, a proximal portion 330 comprising two feet 331 , 332 adapted to engage the guiding grooves 122, 132, and a notch 335 adapted to receive and lock a middle portion of the rubber band 280. The distal-facing surface of the foot 331 also serves to engage the proximal-facing surfaces of the piston feet. The body portion comprises an upper toothed rack 311 and a lower groove 312 adapted to receive a portion of the rubber band 280. The groove is provided with a distal notch 161 adapted to lock a proximal portion of the rubber band 280.

The dose setting member 400 has a general disc form with an upper and lower surface and a central bore. The upper surface has a stepped configuration with a thinner peripheral portion 410 and a raised central portion 420 adapted to be received in an upper opening 610 of the drug unit housing 600. The central portion has an upwardly protruding central tubular portion 430 adapted to receive the button 490, as well as four gripping flanges 431 allowing a user to set a dose by turning the dose setting member. Between the peripheral and central portion a detent 421 is provided serving as both a pointer for the set dose and a stop for rotation relative to the housing. The lower surface comprises a downwardly protruding central tubular portion 440 with a bore 447 adapted to receive the axle 157 in rotational engagement. The lower outer surface of the tubular portion is in the form of a pinion 441 adapted to engage the rack 31 1 , rotation of the dose setting member thereby moving the piston stop member 300 linearly. Around the upper outer surface of the tubular portion four locking detents 442 are arranged for engagement with the central bore 510 of the coupling member 500. The periph- eral portion of the lower surface is provided with a circular band 450 of teeth having ramp shaped surfaces, the distance between the teeth corresponding to one increment of dose as also indicated by indices on the housing, see below. Radially across the lower surface a linear guiding groove 460 for the EOC indicator 590 is arranged.

The coupling member 500 is in the form of a generally circular disc with an upper and lower surface and a central bore 510 adapted to be mounted around the downwardly protruding central tubular portion 440 of the dose setting member and held axially in place by the locking detents 442. The peripheral portion of the upper surface is provided with a number of teeth 530 having ramp shaped surfaces and adapted to engage the circular band 450 of teeth on the dose setting member. Between the bore and the periphery the upper surface is provided with a spiral groove 560 in which a guide projection 591 of the EOC indicator is slid- ingly arranged. The peripheral portion of the lower surface is provided with a circular band of teeth 540, the spaces 541 between the teeth being adapted to engage the detent 156 of the flexible locking finger.

The lock between the dose setting member and the coupling member, as well as the flexibility of the latter, is designed to slightly force the members against each other. By this arrangement a bi-directional coupling is provided between the dose setting member and the coupling member, the engaging peripheral portions being forced against each other with the ramp shaped surfaces of the teeth on one surface abutting the ramp shaped surfaces of the teeth on the other surface. When the dose setting member is rotated in either direction, i.e. setting or adjusting a dose size, the teeth on the coupling parts will slide with their ramp shaped parts over each other, whereby essentially the coupling member is axially displaced against the force of the spring provided by the central part of the coupling member and will jump back each time a top of the teeth is reached. Each jump back may be heard and/or sensed by the operator, and the pitch of the teeth may be chosen so that a jump back takes place each time the dose setting is increased by say one unit. The two coupling surfaces could be provided by any suitable combination of materials and surface configurations providing the desired functionality. To prevent a user to set and infuse a too large dose the dose setting mechanism may be provided with a settable stop allowing a maximum dose to be set, e.g. 20 units of insulin.

In its initial position as supplied to the user the EOC indicator 590 is arranged at the inner end of the linear guiding groove 460. As the EOC indicator is guided by both the linear guiding groove and the spiral groove 560 rotational movement between the dose setting member and the coupling member will result in the EOC indicator being moved outwardly or inwardly when the dose setting member is dialled up respectively dialled down. In this way the EOC indicator will serve to summarize the relative movement of the two members in the "dial up" direction, i.e. corresponding to the doses set and later expelled by the user, whereby the indicator will positioned in its outer-most position when the reservoir is empty. When the EOC indicator reaches the outer end of the spiral groove the dose setting member cannot be rotated further relative to the coupling member, this indicating EOC to the user. Indeed, in order to allow a user to observe the position of the EOC indicator the dose setting member or a portion thereof has to be made from a transparent material.

The priming button 490 is arranged axially moveable relative to the dose member by means of two locking legs 491 engaging the bore 447, this allowing the button to move between an initial upper and an actuated lower position. A spring (not shown) is arranged between the two parts biasing the button towards its initial position. The priming button further comprises a central projection 492 adapted to engage the flexible locking finger 240 via the central bore 158.

To drive the expelling mechanism, i.e. the piston 200 and the piston stop member 300, a single elastic rubber band member 280 is used, the rubber band comprising a distal connector portion 281 adapted to engage the piston body 210, an intermediate connector portion 282 adapted to engage the notch 335 of the piston stop member, a proximal connector portion 283 adapted to engage the notch, as well as distal and proximal drive portions 284, 285. The proximal extension 286 is for manufacturing purposes only and is cut off later. Fig. 6 shows the rubber band in its mounted position corresponding to the state in which a dose has been set but before priming (see below). Fig. 6 does not show the inspection window 124. The above-described components of the drug delivery unit is enclosed in a cavity formed between the ring-formed drug unit housing 600 and the base plate portion 110, thereby enclosing and holding together the different components of the drug delivery unit. The housing comprises an upper opening 610 with an inner edge and is as described above adapted to receive the central portion of the dose setting member 420, the inner edge comprises an inwardly protruding portion 61 1 having first and second stop surfaces 612, 613 adapted to engage the pointer detent 421 and thereby serve as rotational stops. Arranged on the upper surface 620 are indices (not shown) serving as a dose setting guide for the user like on an egg timer. In the shown embodiment the pointer can be moved 300 degrees between its two stops which may correspond to a maximum of 50 units of drug which can be set and subsequently expelled. The drug unit housing further comprises a cut-out portion 630 allowing structures of the dose setting and expelling mechanism to engage with the needle storage unit 20. As can be seen in fig. 1 the opening allows access to the free end of the flexible locking finger 155 as well as the valve member 190 arranged distally in the dose cylinder. The upper outer wall of the housing is provided with a number of projections 631 adapted to re- leasably engage the needle storage unit. Facing away in fig. 1 , the outer wall of the housing is provided with an opening allowing inspection of the reservoir through window 124.

With reference to figs. 8 and 9 the structure and functionality of the needle storage unit 20 will be described. More specifically, the needle storage unit comprises a generally ring- formed housing 700 in which a needle insertion and release button 790 as well as a needle- forwarding member 780 are arranged and guided, a ring-formed magazine member 800 rota- tionally arranged in the housing, and a plurality of needle units 900 arranged in the needle magazine, each needle unit comprising a body member 910 and a U-formed needle 920 hav- ing downwardly facing pointed distal and proximal ends 921 , 922. A ring-formed paper membrane (not shown) is attached to the lower planar surface of the magazine member.

Turning to the individual components, the housing 700 comprises a ring-formed cavity formed between a full outer wall 710 and a partial inner wall, the latter comprising three flexi- ble portions 711 serving as locking members to hold the magazine in place, yet allows it to rotate. Between the upper surface 715 of the housing and the inner wall a number of cut-out portions 712 are arranged and adapted to releasably engage the projections 631 on the drug unit housing. The housing further comprises a "nose-formed" extension 720 and an associated cut-out 721 in the upper surface adapted to receive an inner radial extension of the but- ton 790, as well as on oppositely arranged and outwardly protruding housing portion 730 with an upper slit-formed opening 731 adapted to receive the member 780. The nose portion is provided with a cross-formed guide opening 722 adapted to receive a corresponding cross- formed guide member 792 on the needle insertion and release button. The inner side of the outer cavity wall is corresponding to the nose portion provided with a pair of horizontally arranged flexible arms 718 with distal hook portions 719 adapted to engage corresponding locking grooves 819 in the outer wall 810 of needle magazine. The hooks and grooves are designed to allow uni-directional rotation of the needle magazine only.

The needle insertion and release button 790 comprises the above-described cross-formed guide member 792, a pair of opposed locking hooks 793 engaging corresponding edges 723 on the on the housing, this allowing the button to move between an initial upper and an actuated lower position. A spring (not shown) is arranged between the two parts biasing the button towards its initial position. The button further comprises a user actuatable portion 799 allowing a finger of a user to fully actuate the button, as well as an inner radial extension 791 adapted to be received in the housing cut-out 721 and having on its lower surface a pair of guide members 797, 798 adapted to receive a guide portion of a needle unit. By providing an inwardly directed extension to actuate both a needle unit and release the dosing mechanism, the button per se can be arranged peripherally in relation to the circular needle magazine, this providing a pocket-friendly flat design.

The needle magazine 800 comprises a ring-formed body portion 810 having a plurality of vertical bores 81 1 with upper and lower openings, and an outer wall 810 with a corresponding number of locking grooves 819. Between each bore a vertical tower 815 is arranged, each pair of towers (i.e. two towers arranged on each side of a bore) comprising a pair of guide flanges 816 for engaging and vertically guiding a needle unit.

Each needle unit 900 comprises a body member 910 having an upper generally flat guide portion 915 with a pair of opposed vertical guide grooves 916 adapted to engage a pair of guide flanges 816. The flat guide portion has inner and outer edges 918, 919 adapted to be received in the guide members 797, 798 of the button extension 791. From the lower surface of the guide portion an outer long 91 1 and an inner short 912 tubular portion extend. Each tubular portion comprises a bore which is connected to each other by an open groove 917 in the upper surface of the guide portion. A U-formed needle 920 is mounted in the body member with a leg projecting from each tubular portion with the connecting needle portion arranged in the groove 918. The needle and its method of manufacture are described in greater detail in applicants co-pending application EP 08168817.8. In an initial position (see fig. 10) the outer tubular portion 912 is positioned in sealing and sliding engagement with a circumferential sealing lip in the proximal end 812 of a bore 811 , the distal opening 813 of the bore being closed and sealed by a membrane 814 (see fig. 10), e.g. made from Tyvek ® paper allowing a sterilizing gas to penetrate, thereby creating a sterile chamber 818 for the distal needle end between the tubular portion and the membrane. To fully enclose the U-formed needle in a sterile state a collapsible closed membrane 817, e.g. made from silicone rubber, is arranged around the proximal end of the needle. When all the needle units are mounted in the needle magazine the guide portions create an upper circular surface adapted to slide through the guide members 797, 798 of the button 790. As appears from figs. 8 and 9, one needle unit is "missing", however, this allows the needle storage unit 20 to be assembled as otherwise the release button could not be "threaded" onto the circular row of needle unit guide portions. When supplied to the user the needle magazine may be positioned corresponding to the empty position which would necessitate the user to "prime" the needle magazine by forwarding a first new needle to the actuatable position. Further, the needle magazine may advantageously be provided with a stop preventing more than one full rotation and thus unintended re-use of needles.

The needle-forwarding member 780 comprises a body portion with a horizontally arranged flexible arm 781 with a distal hook portion 782 adapted to engage the corresponding locking grooves 811 in the needle magazine, as well as a button part 785 projecting through opening 731. The member 780 can be moved back and forth with the hook and grooves serving as a uni-directional coupling allowing the hook 782 to slide backwards on the wall 810 (with the needle magazine being held in place by the oppositely arranged hooks 719), whereas full forwards movement of the needle-forwarding member will result in the hook 782 pushing the needle magazine an increment corresponding to the distance between to needle units. With the needle insertion and release button in its upper position, this will result in an "old" needle being moved out of engagement with guide members 797, 798 of the radial extension 791 , and a "new" needle being moved into engagement with the guide members. In this "active" position up- and downwards movement of the needle insertion and release button will result in the active needle unit being moved up and down and thereby the distal needle end in and out of the needle magazine. The needle magazine may advantageously be designed to allow only one rotation of the needle magazine in order to prevent re-using a previously used needle.

Next a situation of use of the above-described drug infusion device 1 will be explained. The device will only work when the two units are assembled, however, they can be exchanged independently of each other, e.g. when either the reservoir or the number of needles is exhausted.

To set (or "dial") a dose the user will rotate the dose setting member clockwise until the pointer 421 points at the desired amount of drug as indicated be indices on the upper housing surface 620, e.g. 20 units of insulin. As the coupling member 500 initially is locked to the base member 100 via locking finger 155 the dose setting member can be rotated bi- directionally relative to the remaining device, with the coupling 450, 530 between the dose setting member and the coupling member preventing the dose setting member to be rotated backwards by the spring (see below) and at the same time providing a clicking sound with each click corresponding to one increment of dose. As the pinion 441 engages the rack 311 the rotation of the dose setting member moves the piston stop member 300 linearly back and forth corresponding to the set dose. As the piston 200 initially is locked in place by the locking finger 240 engaging the central bore 158, backwards movement of the piston stop mem- ber will result in stretching of both the distal and proximal drive portions 284, 285 of the rubber band, this as shown in fig. 6. Indeed, the same couplings preventing rotation of the dose setting member during dose setting will also prevent movement of the piston stop member. In addition to the piston stop member also the EOC indicator is moved radially outwards in its guide groove 460 corresponding to the set dose.

When the user has positioned the pointer 421 at the desired dose (and thereby the piston stop member in a corresponding position), the user pushes down the priming button 490 which via the central projection 492 pushes the flexible locking finger 240 out of engagement with the central bore 158, this allowing the piston to be pulled backwards into engagement with the piston stop member by the distal rubber band drive portion 284, whereby fluid drug will be sucked from the reservoir, through the channel and past the valve member into the dose chamber, this as shown in fig. 7.

Next the user positions the "nose portion" of the lower surface 1 12 on a skin surface corre- sponding to the desired location of injection and pushes the needle insertion and release button 790 down until in its fully actuated position, this providing that a needle is inserted subcu- taneously and the set dose infused.

More specifically and as illustrated in figs. 9 and 10, initial movement of the button 790 moves the distal end 921 of the "active" needle out of its sterile compartment and into subcu- tis of the user as well as the proximal end 922 of the needle towards the valve member 190. Before the needle penetrates the valve member the radial button extension 791 moves the free end of the flexible locking finger 155 downwards and thereby out of engagement with the teeth 540 of the coupling member, this allowing the coupling member, and the thereto coupled dose setting member 400, to rotate relative to the base member 100. As the pinion 441 is part of the dose setting member, the piston stop member is no longer locked in its set position via the rack 31 1 and can thus move distally pulled by the proximal drive portion 284 of the rubber band, this resulting in the piston 200 being forced distally by the piston stop member. At this point in time the dose chamber is closed such that the force acting on the piston via the piston stop member merely will pressurize the fluid in the dose chamber. However, shortly after the dose chamber has been pressurized the proximal end 922 of the needle will penetrate the valve member 190 and thus establish a flow communication between the dose chamber and the distal subcutaneously arranged end of the needle, this resulting in subcutaneous infusion of the fluid drug contained in the dose chamber. Before the proximal end of the needle is inserted into the valve member it will penetrate the collapsing flexible enclosure 817 arranged around the needle to ensure sterility. By pressurizing the dose chamber before connection is established with the needle, it is prevented that body fluids at a slightly elevated pressure can flow into and contaminate the dose chamber. At the same time the piston stop member is pulled forwards by the rubber band the dose setting member 400 is via the rack and pinion rotated anti-clockwise into its initial position, i.e. with the pointer 421 in abut- ment with the stop 612. Finally the user removes pressure from the needle insertion and release button 790 whereby the active needle unit 900 will be returned to its initial position, this providing that the distal needle end is retracted into the device and the proximal needle end is withdrawn from the valve member. By actuating the forwarding member 780 a new needle unit is rotated into place and the device is ready for a new dose to be set and infused.

In the above description of the device the valve member has been described during its normal use, i.e. serving as a flap valve controlling flow from the reservoir as well as a needle penetratable septum for the proximal needle end. However, the valve member also serves to control diffusion prior to and during use. During storage it is essential that components of the drug, e.g. insulin preservatives such as cresol, will not diffuse out of the reservoir. To prevent this, the reservoir is made from materials having diffusion properties preventing loss of e.g. preservatives, however, the preservatives may also diffuse from the reservoir through the channel 128 for which reason the valve member during storage should prevent diffusion. For this purpose a material as e.g. brome-butyl rubber could be used, this material also being used to seal conventional insulin cartridges. However, as a needle has to be inserted into the dose chamber during emptying thereof, it follows that a small amount of drug will be standing in the dose chamber after a set dose has been expelled. As the drug in the dose chamber is in contact with different surfaces (e.g. the cylinder bore, the piston end, and the piston ring), preservatives may be absorbed by these surfaces and would thus change the properties of the drug remaining in the dose chamber. If the next set dose is small this may result in a drug being infused having undesired properties. To compensate for this absorption it would be desirable to replenish preservatives from the much larger reservoir by allowing diffusion through the channel 128 and the valve member. Correspondingly, a composite valve member is provided having a distal portion preventing diffusion and a proximal skirt portion allowing diffusion, whereby the distal portion will cover the channel during storage and the proximal por- tion will cover the channel during the period of use. A corresponding valve member may be configured as shown in fig. 10 with a proximal skirt portion 195 made of e.g. silicone rubber having a high permeability for insulin preservatives such as cresol, and a ring-formed distal portion 196 made of e.g. brome-butyl rubber having a low permeability for insulin preservatives such as cresol. During storage the valve member will be positioned in a proximal posi- tion with the ring-formed distal portion covering the reservoir channel. Indeed, this position will result in the piston and thus the piston stop member being displaced proximally with the proximal portion 285 of the rubber band slightly stretched. Correspondingly, when supplied to the user the dose setting member is not positioned in its "zero" position but with the pointer at e.g. five units of insulin. Although the rubber band will tend to rotate the dose setting member via the rack and pinion, this is prevented by the coupling to the coupling member which is firmly locked in place. Thus, before using the device, the user will rotate the dose setting member to its zero position which will move the piston and thus the valve member to its forward-most position in which the reservoir channel is covered by the proximal skirt portion. By this design it is also assured that the valve function is improved as e.g. silicone rubber is a better material for this function than brome-butyl rubber.

As described above, the reservoir comprises a cavity 125 formed integrally with the relatively rigid base member 100 and has an upper opening closed by a flexible foil 127 (see fig. 12A). The foil is configured to be collapsible into the rigid cavity (e.g. formed by attaching a planar foil to the upper edge of the rigid reservoir wall, thermoforming the foil into the cavity, and then fill and expand the reservoir), this providing a variable volume reservoir. Alternatively, the reservoir may also be formed entirely from flexible foils. To ensure that visual inspection of the drug is possible the rigid part of the semi-flexible reservoir is made from a transparent material having desired optical properties (e.g. as part of a base member made entirely in a transparent material). For this design a non-transparent foil can be used allowing for use of many more grades of foil (i.e. non-transparent foils), hence allowing for a more optimal de- sign. The non-transparent sheet can be marked or coloured on the side facing the drug hereby allowing for a better drug inspection.

In the above-described embodiment a window is provided on the side surface of the drug unit 10, this allowing the window to be covered by the needle magazine 20. In this way a user can inspect the drug in the reservoir when a new drug unit is taken use, whereas the window will be covered by the needle magazine during normal use. As the needle magazine easily disconnects from the drug unit the user can inspect the reservoir when desired. In case the base member is made fully from a transparent material it would also be possible to inspect the reservoir through the lower surface of the reservoir cavity, however, this may result in undesired exposure of the drug to light for a much longer time, e.g. if the device was left on a table with the lower surface upwards. Correspondingly, a lower transparent surface would be covered by a non-transparent foil, e.g. a sticker with data relating to the contents of the drug reservoir. Alternatively, the bottom surface of the device may be provided with a window as well as means protecting the drug against decomposition, e.g. a material that absorbs UV light to protect the drug, or a door that may be opened (e.g. by sliding) to allow the drug reservoir and its contents to be inspected.

In the above-described embodiment the needle magazine has a ring-formed configuration in the form of a general circular configuration, however, alternatively the ring could have other configurations such as square (e.g. as a boxing ring) or other closed configurations. To provide for non-circular needle magazine forms the needles (or needle units) could be arranged in a flexible conveyer belt adapted to be moved "around corners" or just along a non-circular path.

In the above-described embodiment the needle magazine is forwarded fully manually by the user, however, alternatively the needle magazine may be configured so it has to be forwarded before the needle insertion and release button 790 can be actuated again, this ensuring that the user can use a given needle only once. Such a mechanism could essentially comprise two basic components: (i) a blocking element associated with the button mechanism which has to be in an "activated" position to allow button actuation, and (ii) an element associated with the needle magazine and configured to activate the blocking element. Depending on the market it may be desirable to offer devices in which the needle can be used only once as well as devices in which a given needle can be used a number of times by the user. By designing the blocking element in such a way that a small change of form in a single component would turn on an off the blocking functionality, it would be possible in a simple way to provide both alternatives which then may be offered on relevant markets.

In the above-described embodiment the needle magazine is forwarded manually by the user, however, alternatively the needle magazine may be forwarded automatically, e.g. energy stored during actuation of the needle insertion and release button 790 may be used to forward the needle magazine when the button is returned to its new position, this ensuring that a new and sterile needle is used for each injection. Such a mechanism would essentially comprise two basic components: (i) an element associated with the button mechanism and "pushing" the needle magazine forwards, and (ii) an element associated with the needle magazine and being pushed by the actuator element. Depending on the market it may also here be desirable to offer devices in which the needle can be used only once by setting the "automatic forward" option to "on" as well as devices in which a given needle can be used a number of times by the user by setting the "automatic forward" option to "off".

In the above-described embodiment an EOC mechanism is provided ensuring that a user cannot set a dose larger than the "calculated" remaining amount of drug, i.e. if full movement of the EOC indicator to its stop will allow setting and expelling doses of e.g. 300 IU of insulin, then a position of the EOC indicator corresponding to 280 expelled IU would allow setting a dose of 20 IU before reaching the stop. However, flexible reservoirs for injection devices have to be overfilled to ensure there is drug until the pre-specified amount has been injected and the device is blocked. To make sure there is enough drug the reservoir needs to be filled with the pre-specified amount plus an amount for all the tolerances in the delivery system and filling system. This often adds up to an overfilling at 10-20 % which is left in the device when it locks and are therefore waste for the costumer as well as the manufacturer. Thus, instead of using a blocking EOC mechanism it would be desirable to allow a user to fully utilize the amount of drug in a flexible reservoir, yet preventing that a too large dose is set. As described above, drug is drawn from the flexible reservoir into a piston-based variable volume dosing chamber. When there is no more drug in the reservoir further withdrawal of the piston will result in the creation of a relative vacuum in the dosing chamber. Thus, if a dose higher than what is left in the reservoir is chosen, the piston will be forced to the corresponding position but when the user let go of the setting button, the vacuum created in front of the piston will then serve to return the piston to the position that corresponds to the amount of drug drawn into the dosing chamber. Indeed, to allow such a mechanism to work properly it should be ensured that the "vacuum forces" created will be sufficiently high to overcome friction in the dosing mechanism and thus be able to turn back the dose setting member. In the above-described embodiment a valve member is described comprising a distal flexible skirt portion 192 serving as a uni-directional flap valve for controlling a flow of fluid through channel 128 into the metering chamber. By using such a flap valve it is not possible to adjust a given dose setting after an amount of fluid has been drawn into the metering chamber, this requiring a two-step arrangement as described above, i.e. finalizing the dose setting before drawing fluid into the metering chamber.

Thus, alternatively, an open fluid communication can be provided between the reservoir and the metering chamber, this allowing a flow of fluid between the reservoir and the metering chamber during setting of a dose, i.e. allowing dialling up and down with fluid in the metering chamber, but at the same time requiring the fluid communication to be closed when the dose is to be expelled from the metering chamber. Turning to figs. 13A and 13B a valve arrangement will be described which is actuated between an open and a closed position when a hol- low needle is brought into fluid communication with the metering chamber.

More specifically, fig. 13A shows a pump assembly 950 comprising a piston-cylinder fluid metering chamber 951 with an inlet 952, a fluid inlet 961 adapted to be arranged in fluid communication with a fluid reservoir, e.g. a collapsible, flexible reservoir, and a fluid communica- tion structure 960 between the fluid inlet and the drug metering chamber. As seen in fig. 13B the fluid communication structure comprises a flexible membrane 962 providing flow control means operatable between an open state in which fluid is allowed to flow in a conduit 963 between the fluid inlet and the drug metering chamber, and a closed state in which fluid is not allowed to flow between the drug metering chamber and the fluid inlet. The flexible mem- brane 962 further provides a needle-penetratable outlet portion 964. The assembly further comprises outlet control means in the form of a hollow needle (which could be a U-formed needle as disclosed above) having an inlet portion 971 and an outlet, the inlet portion being adapted to penetrate the needle-penetratable outlet portion, and actuation means in the form of a circumferentially mounted actuation member 972 adapted to operate the flow control means between the open and closed state. The outlet control means is thus operatable between an initial state in which the flow control means is in the open state, and there is no fluid communication between the fluid communication structure and the needle, and an actuated state in which the actuation means has operated the flow control means to the closed state, i.e. the flexible outlet portion 964 has been forced by the actuation member 972 into sealing contact with a corresponding valve seat thereby blocking the conduit 963, and in which the needle has penetrated the needle-penetratable outlet portion thereby providing fluid commu- nication between the needle and the fluid metering chamber via the fluid communication structure. As appears, by this arrangement a simple means of providing a fluid outlet via a needle and actuation of a valve is provided. In alternative embodiments the valve and the needle-penetratable outlet portion may be separate, the valve being operated by a separate actuation member not mounted on the needle.

In the above description of the preferred embodiment, the different structures and means providing the described functionality for the different components have been described to a degree to which the concept of the present invention will be apparent to the skilled reader. The detailed construction and specification for the different components are considered the object of a normal design procedure performed by the skilled person along the lines set out in the present specification.

LISTNING OF EXAMPLES In the following different examples embodying the invention in accordance with the second aspect will be listed.

1. A drug delivery assembly (10) comprising: a drug reservoir (126) containing a fluid drug comprising a given component, a drug metering chamber (129), a fluid communication (128) between the drug reservoir and the drug metering chamber, a drug outlet (191), drug expelling means (200) for expelling an amount of drug from the metering chamber through the drug outlet, first valve means (191 , 196) having an initial position in which the fluid communication is sealed by the first valve means, and an actuated position in which the fluid communication is not sealed by the first valve means, and second valve means (192, 195) having an initial position in which the fluid communication is not sealed by the second valve means, and an actuated position in which the fluid communication is sealed by the second valve means, wherein the permeability of the second valve means to the given component is higher than the permeability of the first valve means to the given component, whereby a high barrier for diffusion of the given component from the reservoir is provided when the fluid communication is closed by the first valve means, whereas the higher permeability for the given component when the fluid communication is closed by the second valve means assures that an intended amount of diffusion will take place between drug in the drug metering chamber and drug in the reservoir. 2. A drug delivery device as in example 1 , wherein the first and second valve means are coupled to each other and moveable between an initial position in which the fluid communication is sealed by the first valve means, and an actuated position in which the fluid communication is sealed by the second valve means.

3. A drug delivery device as in example 1 , wherein the second valve means in its actuated position can be controlled to allow a flow of fluid from the reservoir to the metering chamber, yet prevents a flow of fluid from the metering chamber to the reservoir.

4. A drug delivery device as in example 3, wherein the second valve means will allow a flow of fluid from the reservoir to the metering chamber when a pressure gradient is established across the second valve means.

5. A drug delivery device as in example 1 , wherein the first valve means in both its ini- tial and actuated position provides an outlet seal (191 ) for the drug outlet.

6. A drug delivery device as in example 5, wherein the outlet seal can be controlled to allow a flow of fluid from the metering chamber.

7. A drug delivery device as in example 6, wherein the outlet seal is a needle- penetratable self-sealing membrane (191).

8. A drug delivery device as in example 2, comprising a valve member (190) having a first portion (191) providing the first valve means and a second portion (192) providing the second valve means.

9. A drug delivery device as in example 8, wherein the metering chamber comprises a cylindrical portion (154) in which the valve member (190) is slidingly arranged.

10. A drug delivery device as in example 9, wherein the valve member has a general tubular configuration comprising a distal closed end portion (191) forming the first valve means and a proximal open portion (192) forming the second valve means.

11. A drug delivery device as in example 10, wherein the distal and proximal portions are formed at least partially from first and second polymers (196, 195) providing the defined permeabilities. 12. A drug delivery device as in any of the previous examples, wherein the fluid drug is an insulin formulation comprising preservatives in the form of phenol and/or meta-cresol, and wherein the permeability of the second valve means to phenol and/or meta-cresol is higher than the permeability of the first valve means to phenol and/or meta-cresol.

13. A method of controlling the permeability between two chambers, comprising the steps of (a) providing first and second chambers, the first chamber comprising a fluid having a given component, the second chamber being initially empty, a first seal being arranged be- tween the two chambers, (b) arranging a second seal between the two chambers replacing the first seal, the permeability of the second seal to the given component being higher than the permeability of the first seal to the given component, (c) transferring an amount of fluid from the first to the second chamber, and (d) allowing diffusion of the given component between two chambers through the second seal.

In the following different examples embodying the invention in accordance with the third aspect will be listed.

1. A reservoir comprising (a) a generally rigid reservoir member in which a first gener- ally concave cavity is formed, and (b) a flexible foil member forming a second oppositely and generally concave cavity, wherein the first and second cavities are sealed to each other at the peripheries thereof thereby forming a closed reservoir, the portion of the flexible foil member forming the second concave cavity being collapsible into the first concave cavity thereby providing a variable volume reservoir, wherein the foil material is essentially non- transparent, and at least a portion of the first concave portion is transparent allowing visual inspection of a fluid contained in the reservoir.

2. A reservoir as in example 1 wherein the reservoir member is made from a transparent polymeric material.

3. A method of manufacturing a reservoir as in example 1 , comprising the steps of (a) providing a generally rigid reservoir member in which a first generally concave cavity is formed, (b) providing a generally planar flexible foil member, (c) sealing the rigid reservoir member and the flexible foil member to each other thereby forming a closed reservoir, and (d) moving the flexible foil member into contact with the concave cavity to thereby form a generally concave cavity in the flexible foil member. 4. A method as in example 3, wherein the flexible form is either cold- or warm-formed into its concave shape.

5. A method as in example 3 or 4, comprising the further step of introducing a fluid into the reservoir to thereby force the flexible form into an opposed concave shape relative to the shape of the concave cavity of the reservoir member.

In the following different examples embodying the invention in accordance with the fourth as- pect will be listed.

1. A method for operating a drug delivery device, comprising the steps of (a) providing a drug chamber having a closed outlet, (b) pressurizing an amount of drug contained in the drug chamber, (c) moving a drug delivery needle from a retracted to an intermediately ex- tended position, and (d) moving the drug delivery needle to a further extended position in which fluid communication is established with the drug chamber via the drug outlet.

2. A drug delivery device comprising (a) a housing having a contact portion adapted to be arranged in contact with a skin surface of a patient, (b) a drug delivery assembly compris- ing: a drug chamber, an initially closed drug outlet, and drug expelling means for pressurizing an amount of drug contained in the drug chamber, (c) a drug delivery needle having a distal end arranged in an initially retracted position relative to the contact portion, and (d) actuation means for moving the drug delivery needle from its retracted to an intermediate position in which the distal end extends relative to the contact portion, and to a further extended position in which fluid communication is established with the drug chamber via the drug outlet.

In the following different examples embodying the invention in accordance with the fifth aspect will be listed.

1. An actuator system, comprising (a) a housing (100), (b) a setting member (300) selectively adjustable to a set position, (c) an actuation member (200) moveable between an initial position and a set position determined by the set position of the setting member, (d) first spring means (284) for moving the actuation member from its initial position to its set position, and (e) second spring means (285) for moving the actuation member from the set po- sition back to its initial position, wherein the first and second spring means are actuated from an initial condition to an actuated condition when the setting member is adjusted to a set po- sition, (f) first release means (490) for releasing the first spring means, and (g) second release means (155) for releasing the second spring means, the second release means being independently operatable relative to the first release means,

wherein: the first spring means acts between the setting member and the actuation member, the second spring means acts between the housing and the setting member, and the setting member acts on the actuation member when the setting member and the actuation member are arranged in their respective set positions, whereby the actuation member can be moved back to its initial position by the second spring means.

2. An actuator system as in example 1 , wherein the first and second spring means are in the form of a common elastic member (280) having first and second portions (281 , 283) attached to the actuation member and housing respectively, and an intermediate portion (282) engaging the setting member, whereby the portion between the first and intermediate portion provides the first spring means, and the portion between the intermediate portion and the second portion provides the first spring means.

3. An actuator system as in example 2, wherein the intermediate portion is attached to the setting member.

4. An actuator system as in example 2 or 3, wherein the common elastic member is in the form of a rubber band (280) having first and second end portions providing the first and second portions respectively.

5. A drug delivery device (10) in combination with an actuator system as in any of the previous examples, the drug delivery system further comprising: a drug reservoir (126), a drug metering chamber (129), a fluid communication (128) between the drug reservoir and the drug metering chamber, valve means (192) controlling a flow of fluid through the fluid communication, and an initially closed drug outlet (191),

wherein the actuation member is arranged to: draw an amount of fluid contained in the drug reservoir from the drug reservoir to the metering chamber via the fluid communication when the actuation member is moved from its initial position to its set position, and expel an amount of fluid from the metering chamber through the drug outlet when the actuation mem- ber is moved from its set position back to its initial position. 6. A drug delivery device as in example 5, wherein: the actuation member comprises a piston (200), and the metering chamber comprises a cylindrical portion (154) in which the piston is slidingly arranged.

7. A drug delivery device as in example 6, further comprising: a portion adapted to be arranged in contact with a skin surface of a user, a drug delivery needle (920) having a distal end (921) arranged in an initially retracted position relative to the contact portion (112), and actuation means (790) for releasing the second release means (155) to thereby pressurize the drug contained in the metering chamber, and for moving the drug delivery needle from its retracted to an intermediate position in which the distal end extends from the drug delivery device, and to a further extended position in which fluid communication is established between the drug delivery needle and the pressurized metering chamber via the drug outlet.

In the following different examples embodying the invention in accordance with the sixth as- pect will be listed.

1. A needle assembly (800, 900), comprising (a) a housing (800) having a first initially sealed opening (813, 814) and a second opening (812) defined by a cylindrical tube portion, (b) a drug delivery needle (920) having a distal end (921) and a proximal end (922), (c) a guide member (910, 911 ) mounted on the needle between the distal and proximal ends, the guide member comprising a cylindrical portion being mounted in and in sealing engagement with the cylindrical tube portion, this providing a sealed interior space (818) in which the distal end of the needle is arranged in an initial position, wherein the cylindrical portion of the guide member can be axially and slidingly dis- placed in the cylindrical tube portion from the initial position to an extended position in which the distal end of the needle protrudes through the first opening.

2. A needle assembly as in example 1 , wherein the guide member has a general cylindrical form (911) corresponding to the cylindrical tube portion.

3. A needle assembly as in example 1 , wherein the first opening initially is covered by a needle-penetratable membrane (814).

4. A needle assembly as in any of the previous examples, wherein the needle (920) has a general U-shape. 5. A needle assembly as in any of the previous examples, wherein the proximal end of the needle is arranged in an initially sealed enclosure.

6. A needle assembly as in example 5, wherein the sealed enclosure comprises a col- lapsible member (817) adapted to collapse axially around the proximal end of the needle.

7. A needle magazine (20) comprising a plurality of needle assemblies as in any of examples 1-6.

8. A needle magazine as in example 7, wherein the needle assemblies are individually formed and arranged in a common carrier.

9. A needle magazine as in example 8, wherein the needle assemblies are arranged in a ring-formed configuration.

10. A needle magazine as in example 9, wherein the needle assemblies are arranged in a non-circular configuration.

11. A needle magazine as in example 7, comprising a magazine member (800) in which a plurality of housings are formed.

In the following different examples embodying the invention in accordance with the seventh aspect will be listed.

1. A drug delivery device, comprising (a) a drug delivery assembly (10) comprising: a drug reservoir (126), a drug outlet (191 ), and drug expelling means (200) for expelling an amount of drug from the reservoir through the drug outlet, (b)a needle assembly (20) having a ring-shaped configuration defining a central space, comprising: a housing, a plurality of drug delivery needles (920) arranged in a ring-shaped configuration relative to the central space, whereby the needles consecutively can be moved into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted position and an extended position in which a pointed end (921) of the needle projects from the device and fluid communication is established between the needle and the drug outlet, and (c) needle actuation means (790, 791) for moving a needle positioned in its ac- tuatable position from its retracted to its extended position, wherein: the drug delivery assembly is arranged generally in the central space and thereby being surrounded by the plurality of drug delivery needles, and the needle actuation means comprises a user actuatable needle inserter button (790) arranged generally peripherally relative to the needle assembly housing.

2. A drug delivery device as in example 1 , wherein the needles have a general U- formed configuration comprising a first distal leg portion adapted to be connected to the drug outlet, a second distal leg portion comprising the pointed end, and a proximal portion connecting the two legs.

3. A drug delivery device as in example 2, wherein the user actuatable needle inserter button comprises an actuation surface moveable between an initial upper position and an actuated lower position corresponding to the needle being moved to its extended position, and wherein the actuation surface in the actuated lower position is arranged distally relative to the proximal portions of the needles in their retracted position.

4. A drug delivery device as in any of examples 1-3, wherein the needle assembly comprises a peripheral nose-like extension (720) adapted to receive the user actuatable needle inserter button.

5. A drug delivery device as in any of examples 1-4, wherein the needle assembly has a generally circular configuration allowing the needles to be rotated relative to the central space.

6. A drug delivery device as in any of examples 1-5, wherein the needle assembly comprises a plurality of needle units each comprising a needle carrier and a needle.

7. A drug delivery device as in any of examples 1-4, wherein the needle assembly comprises a conveyer belt in which the plurality of drug delivery needles is arranged.

8. A drug delivery device as in example 7, wherein the needle assembly has a non- circular configuration, the conveyer belt allowing the needles to move non-circularly relative to the central space. 9. A drug delivery device as in any of examples 1-8, wherein the needle assembly and the drug delivery assembly are separate units comprising corresponding coupling means allowing the two units to be coupled to each other.

In the following different examples embodying the invention in accordance with the eighth aspect will be listed.

1. A drug delivery device (1 ), comprising (a) a drug delivery assembly (10) comprising: a drug reservoir (126), a drug outlet (191), and drug expelling means (200) for expelling an amount of drug from the reservoir through the drug outlet, (b) a needle assembly (20) comprising a plurality of drug delivery needles (920) arranged in such a way that the needles consecutively can be moved into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted position and an extended position in which a distal end of the needle projects from the device and fluid communication is estab- lished between the needle and the drug outlet, (c) needle actuation means (790, 791 ) for moving a needle positioned in its actuatable position from its retracted to its extended position, and (d) control means for controlling movement of the needle assembly relative to the drug delivery assembly, wherein the control means can be configured in either a first state or a second state, the first state allowing a given needle to be moved from its retracted to its extended position only once when positioned in its actuatable position for the first time, the second state allowing a given needle to be moved from its retracted to its extended position more than once when positioned in its actuatable position for the first time.

2. A drug delivery device as in example 1 , wherein the control means in the first state is configured to move a second needle into an actuatable position after a first needle has been moved from its retracted to its extended position.

3. A drug delivery device as in example 1 , wherein the control means comprises a con- trol portion that can be configured to determine whether the control means will be configured in either the first state or the second state.

4. A drug delivery device as in example 3, wherein the control portion is arranged on either the drug delivery assembly or the needle assembly. 5. A drug delivery device comprising (a) a drug delivery assembly having a drug outlet,

(b) a needle assembly comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, (c) needle actuation means for moving a needle positioned in its actuatable position from a retracted to an ex- tended position in which fluid communication is established with the drug outlet, wherein the drug delivery device can be configured in either a first state or a second state, the first state allowing a given needle to be moved from its retracted to its extended position only once when positioned in its actuatable position for the first time, the second state allowing a given needle to be moved from its retracted to its extended position more than once when positioned in its actuatable position for the first time.

6. A drug delivery system comprising (a) a drug delivery assembly having a drug outlet, (b) a first needle assembly mountable on the drug delivery assembly and comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, the first needle assembly being configured to allow given needle to be moved from its retracted to its extended position only once when positioned in its actuatable position for the first time, (c) a second needle assembly mountable on the drug delivery assembly and comprising a plurality of drug delivery needles arranged in such a way that the needles consecutively can be moved into an actuatable position, the second needle assembly being configured to allow a given needle to be moved from its retracted to its extended position more than once when positioned in its actuatable position for the first time, and (d) needle actuation means, associated with either the drug delivery assembly or a needle assembly, for moving a needle positioned in its actuatable position from a retracted to an extended position in which fluid communication is established with the drug outlet.

In the following different examples embodying the invention in accordance with the ninth aspect will be listed.

1. A pump assembly (950) comprising: a fluid metering chamber (951), a fluid inlet

(961 ), and a fluid communication structure (960) between the fluid inlet and the drug metering chamber, the fluid communication structure comprising:

(a) flow control means (964) operatable between (i) an open state in which fluid is allowed to flow between the fluid inlet and the drug metering chamber, and (ii) a closed state in which fluid is not allowed to flow between the drug metering chamber and the fluid inlet,

(b) a needle-penetratable outlet portion (964), and outlet control means comprising: (c) a hollow needle (970) having an inlet portion (971) and an outlet, the inlet portion being adapted to penetrate the needle-penetratable outlet portion, and

(d) actuation means (972) adapted to operate the flow control means between the open and closed state, wherein the outlet control means is operatable between: (i) an initial state in which the flow control means is in the open state and there is no fluid communication between the fluid communication structure and the needle, and (ii) an actuated state in which the actuation means has operated the flow control means to the closed state, and in which the needle has penetrated the needle-penetratable outlet portion thereby providing fluid communication be- tween the needle and the fluid metering chamber via the fluid communication structure.

2. A pump assembly as in example 1 , wherein the hollow needle and the actuation means are provided as an actuatable unit.

3. A pump assembly as in example 1 or 2, wherein the actuation means is arranged circumferentially relative to the hollow needle, the hollow needle having an inlet opening arranged distally of the actuation means.

4. A pump assembly as in any of examples 1-3, wherein the flow control means com- prises a flexible control portion operatable between an open and an actuated closed state, this providing the open and closed state of the flow control means, the needle-penetratable outlet portion being formed integrally with the flexible control portion, whereby operation of the outlet control means between the initial and actuated state moves the needle through the needle-penetratable outlet portion and thereby into fluid communication with the fluid meter- ing chamber, and moves the actuation means into actuating engagement with the flexible control portion to thereby prevent a flow of fluid between the drug metering chamber and the fluid inlet.

5. A pump assembly as in any of examples 1-3, wherein the flow control means com- prises a flexible control portion operatable between an open and an actuated closed state, this providing the open and closed state of the flow control means.

6. A pump assembly as in example 5, wherein the needle-penetratable outlet portion is formed integrally with the flexible control portion. 7. A pump assembly as in any of examples 4-6, wherein the flow control means comprises a valve formed between a valve seat and the flexible control portion, the flow control means being in (i) the open state when the flexible control portion does not fully engage the valve seat, and in (ii) the closed state when the flexible control portion fully engages the valve seat when actuated by the actuation means.

8. A pump assembly as in example 7, wherein the valve seat circumferentially surrounds an opening in fluid communication with the fluid inlet, the flexible control portion engaging the valve seat comprising the needle-penetratable outlet portion, the opening being adapted to receive the needle inlet portion to thereby establish the fluid communication between the needle and the fluid metering chamber.

Claims

1. A drug delivery device (1 ), comprising:

(a) a drug delivery assembly (10) comprising: a drug reservoir (126) comprising a window (124) allowing inspection of the interior thereof, a drug outlet (191), and drug expelling means (200) for expelling an amount of drug from the reservoir through the drug outlet,

(b) a needle assembly (20) comprising a plurality of drug delivery needles (920) ar- ranged in a ring-formed configuration, whereby the needles consecutively can be moved into an actuatable position, wherein a needle when positioned in its actuatable position can be moved between a retracted sealed position and an extended position in which a distal end of the needle projects from the device and fluid communication is established between the needle and the drug outlet, and

(c) needle actuation means (790, 791 ) for moving a needle positioned in its actuatable position from its retracted to its extended position,

wherein the ring-formed arrangement of the needles defines a central space in which the drug delivery assembly generally is arranged in a situation of use, and wherein the needle assembly and the drug delivery assembly comprise releasable mating coupling means (631 , 712) allowing the needle assembly to be secured to the drug delivery assembly in the situation of use, the needle assembly thereby covering the window.

2. A drug delivery device as in claim 1 , wherein the coupling means is adapted to be arranged in an intermediate position where the needle assembly is secured to the drug delivery assembly with the window visible for inspection.

3. A drug delivery device as in claim 1 , wherein the needle actuation means comprises a user actuatable element (790), and wherein the user actuatable element is arranged peripherally relative to a needle in its actuatable position.

4. A drug delivery device as in any of the previous examples, wherein the needles (920) have a general U-shape.

5. A drug delivery device as in any of claims 1-4, wherein the needle assembly has a generally circular configuration allowing the needles to be rotated relative to the central space.

6. A drug delivery device as in any of claims 1-5, wherein the needle assembly comprises a plurality of needle units each comprising a needle carrier and a needle.

7. A drug delivery device as in any of claims 1-4, wherein the needle assembly comprises a conveyer belt in which the plurality of drug delivery needles is arranged.

8. A drug delivery device as in claim 7, wherein the needle assembly has a non- circular configuration, the conveyer belt allowing the needles to move non-circularly relative to the central space.

9. A drug delivery device comprising:

(a) a generally cylindrical central portion (10) comprising a drug delivery assembly with a drug reservoir having a window (124) allowing inspection of the interior thereof, and

(b) a generally ring-formed needle assembly (20) adapted to be arranged around the central portion and comprising a plurality of drug delivery needles, - wherein the needle assembly and the drug delivery assembly comprise releasable mating coupling means (631 , 712) allowing the needle assembly to be secured to the drug delivery assembly in a situation of use, the needle assembly thereby covering the window.