Reservoir unit for injection device

Abstract

The present invention relates to a disposable reservoir unit (2) configured for releasable attachment to a reusable drive unit (3) of an infusion device. The reservoir unit (3) comprises a reservoir holder (12) for holding a reservoir (15); two radially extending and oppositely arranged projections (33) for releasably attaching the reservoir unit (2) to the drive unit (3); and a needle cover sleeve (20) guided by the guide means and movable relative to the reservoir holder (12) along the longitudinal axis between a covering position and a retracted position. In a plane perpendicular to the longitudinal axis, the needle cover sleeve (20) has a first outer dimension along a first axis and a second outer dimension along a second axis perpendicular to the first axis, and wherein the first outer dimension is greater than the second outer dimension, and wherein the projection (33) is arranged on the first axis.

Description

TECHNICAL FIELD

[0001] The present invention relates to a drug delivery device or medicament delivery device for injecting, delivering, administering, infusing or dispensing a substance and / or a liquid, such as insulin, a hormone preparation or a vaccine. It starts from a disposable reservoir unit for an injection device for dispensing a liquid medicament through an injection needle, which reservoir unit is configured for releasable attachment to a reusable drive unit of the injection device. BACKGROUND

[0002] There are a number of diseases that require regular treatment by subcutaneous medicament administration, and a number of drug delivery devices have been developed to support the patient in delivering an amount of drug accurately and controllably during self-administration. Delivery devices include injection devices that are removed from the injection site after each drug event or drug delivery process, as well as infusion devices that have a cannula or needle that remains in the patient's skin for an extended period of time.

[0003] By way of example, diabetes can be treated by self-administration of insulin or a derivative thereof with the help of a multi-dose insulin injection pen. The injection pen device generally has an elongated device body defining a longitudinal main device axis. Automatic injection devices have a motor or a drive spring for biasing a plunger rod and displacing a piston in a container cartridge, wherein the drive spring can have to be manually loaded or tensioned before dose injection. Manually powered delivery drives require the user to manually provide energy to move the piston, for example by applying a distal force component to the injection device.

[0004] The medicament dose to be injected can typically be manually selected by turning a dose knob and observing the actually dialled dose from a dose window or display of the insulin pen. The dose is dispensed by inserting the needle into a suitable portion of the human skin and by manually moving the piston or by pressing a release button of the automatic injection device. Automatic injection devices can comprise an electronic dose dialling mechanism to automatically set the dose.

[0005] It is also known to use automatic injectors with syringes. Automatic injectors generally comprise a body for housing a syringe and a drive mechanism to move a plunger of the syringe upon actuation of the automatic injector. The drive mechanism typically comprises a drive source, such as a motor or a strong spring, for moving a transmission element, for example a rod acting on the plunger of the syringe.

[0006] For safety and hygiene reasons, it is desirable that the needle does not protrude from the housing of the automatic injector except for the time of use of the needle for injecting the medicament. Therefore, either the automatic injector moves the needle out of the housing for injection and back into the housing after injection, or the housing provides a needle guard that is movable to remove a cover for the needle for injection and that is movable back to a position covering the needle after injection.

[0007] Most auto-injectors are configured as single-use devices that combine both the syringe and the drive mechanism in the same housing. For hygienic reasons, such devices are usually disposable.

[0008] Disposable auto-injectors that include an electrically powered actuator or electronic control means require an energy source, usually in the form of a battery. In this case, however, the auto-injector should not be disposed of as normal waste, but must be subjected to special disposal or recycling, which is an additional burden on the patient. Furthermore, disposal of the battery, motor and / or electronics after a single use is a waste of resources and increases the cost of the auto-injector.

[0009] To take into account the need to handle and dispose of auto-injector components differently, semi-reusable auto-injectors have been developed. Such auto-injectors typically comprise a reusable drive unit and a disposable syringe unit that can be releasably coupled to the drive unit. The drive unit usually comprises a drive mechanism and electronics, while the syringe unit comprises a needle-equipped syringe and a needle cover sleeve. Thus, the user can discard the syringe unit when or after it is empty and can load the drive unit with a new syringe unit for an upcoming injection.

[0010] WO21254744A1 discloses a reusable auto-injector having a syringe unit that is releasably attachable to a drive unit. The syringe unit comprises two oppositely arranged cams in the form of protrusions in a proximal end portion of the syringe unit. When the syringe unit is inserted into the drive unit, the protrusions travel in corresponding grooves of the drive unit. Then, when the syringe unit is rotated relative to the drive unit about a longitudinal axis in order to attach the syringe unit to the base unit, the protrusions engage with the corresponding cam profiles.

[0011] WO23275254A1 discloses a reusable auto-injector, wherein a syringe unit fixing tab at the proximal end snaps behind a corresponding fixing opening in the drive unit housing when the syringe unit is loaded into the drive unit to couple the syringe unit to the drive unit.

[0012] EP4108277A1 discloses a disposable syringe unit attachable to a reusable drive unit of a reusable auto-injector. The syringe comprises two oppositely arranged protrusions in a proximal end portion to attach the syringe unit to the drive unit. Furthermore, the syringe unit comprises an opening for a locking arm of the drive unit to lock the syringe unit to the drive unit. SUMMARY

[0013] It is an object of the present invention to provide a secure and reliable attachment of the reservoir unit to the drive unit while providing a compact design.

[0014] This object is achieved by a disposable reservoir unit or injection device according to the independent claims. Preferred embodiments are evident from the dependent claims.

[0015] The present invention relates to a disposable reservoir unit for an injection device for dispensing a liquid medicament through an injection needle, in particular for a reusable automatic injection. The reservoir unit is configured for releasable attachment to a reusable drive unit of the injection device. The reservoir unit comprises • a reservoir holder for holding the reservoir in place relative to the drive unit and adapted for releasable connection to the drive unit and comprising guiding means, and wherein the reservoir holder extends along a longitudinal axis; • two radially extending and oppositely arranged protrusions for releasable attachment of the reservoir unit to the drive unit; • a needle cover sleeve guided by the guiding means and movable relative to the reservoir holder along the longitudinal axis between a covering position in which the injection needle is covered and a retracted position in which the injection needle is exposed and protrudes from the needle cover sleeve. The needle cover sleeve further comprises two oppositely arranged lateral locking openings adapted to accommodate actuating arms of the drive unit to lock the reservoir unit to the drive unit.

[0016] Further, in a plane perpendicular to the longitudinal axis, the needle cover sleeve has a first outer dimension (or outer diameter) along a first axis and a second outer dimension (or outer diameter) along a second axis perpendicular to the first axis, and wherein the first outer dimension is larger than the second outer dimension. The first and second outer dimensions are measured on an outer surface of the needle cover sleeve without guiding elements, cams or balls protruding from the outer surface of the needle cover sleeve. The protrusions are arranged on and / or aligned with the first axis.

[0017] The needle cover sleeve further comprises two pairs of oppositely arranged guiding elements protruding, preferably radially, from an outer surface of the needle cover sleeve and adapted to engage counter guiding elements in the reservoir unit to prevent rotation of the reservoir unit relative to the drive unit. Each pair of guiding elements is arranged next to or near the first axis. That is, in a plane perpendicular to the longitudinal axis, a first guiding element of each pair is arranged on a first side (or left side) of the first axis and a second guiding element of each pair is arranged on a second side (or right side) of the first axis.

[0018] The second outer dimension of the needle cover sleeve is between 2 and 3.6 times a dimension between the first and second guiding elements of each pair. The distance between the first and second guiding elements is measured in a plane perpendicular to the longitudinal axis from a center of the first guiding element to a center of the second guiding element of each pair.

[0019] the second dimension is a maximum of 3.6 times, preferably a maximum of 3.2 times larger or longer than (also referred to as a maximum of 3.6 times, preferably a maximum of 3.2 times of) the distance between the first guide element and the second guide element in each pair, measured in a plane perpendicular to the longitudinal axis.

[0020] That means that the reservoir unit has a compact design in a plane perpendicular to the longitudinal axis (cross-section) and the relationship between the guide element distance and the second dimension is optimal. Thus, the cross-section is as small as possible and the distance between the guide elements provides a safe and reliable guidance during attachment of the reservoir unit to the drive unit. Furthermore, the claimed spaced apart guide elements allow a reliable guidance of the needle cover sleeve movement along the longitudinal axis while maintaining a compact design.

[0021] Furthermore, the reservoir unit having a protrusion on the first axis with a larger outer dimension allows for an easy and quick attachment to the reservoir unit, as the protrusion is located on the outermost part of the reservoir unit shape. The locking opening provides access to a locking arm of the drive unit, such that after attaching the reservoir unit to the drive unit, the locking arm can enter the locking opening to hold and lock the reservoir unit to the drive unit, such that the reservoir unit cannot be moved in a distal direction relative to the drive unit. Thus, the reservoir unit is held by a form fit and cannot be removed from the drive unit unless the locking arm is released and retracted.

[0022] The protrusion is adapted to engage and cooperate with a corresponding engagement element in the drive unit, like a clip, a hook or a recess, to releasably couple the reservoir unit to the drive unit. Upon insertion of the reservoir unit into the opening of the drive unit housing, the engagement element can be deformable or deflectable to engage the protrusion. Preferably, the protrusion is adapted to attach to the drive unit engagement element to form a releasable snap fit connection. The protrusion can be formed integrally with the reservoir holder, or alternatively, the protrusion can be formed by a separate member of the reservoir unit, such as a holding structure or a connection part.

[0023] The reservoir unit has an extension in a plane perpendicular to the longitudinal axis which is larger along the first axis than along the second axis, which is perpendicular to the first axis. That means that the reservoir unit has a non-circular cross-section. The outer form or shape of the reservoir unit in a plane or cross-section perpendicular to the longitudinal axis can for example be oval, rectangular or any free form. Due to the larger dimension along the first axis than along the second axis, the opening in the drive unit can have a corresponding non-circular shape, so that the outer form can support the user in aligning the reservoir unit relative to the drive unit before attachment. Furthermore, the non-circular cross-section can prevent the reservoir unit from rolling away if not connected to the drive unit.

[0024] The guiding elements provide a safe and reliable procedure for the attachment of the reservoir unit to the drive unit, as the guiding elements ensure that the reservoir unit is kept in the correct rotational orientation and alignment relative to the drive unit during attachment. The correct rotational orientation of the reservoir unit relative to the drive unit is crucial, as the locking arms of the drive unit have to be positioned correctly into the locking openings to be able to insert the openings to lock the reservoir unit to the drive unit. Thus, the guiding elements provide the user with a help to rotate the reservoir unit into the correct orientation to the drive unit during attachment.

[0025] The distance between the first guiding element and the second guiding element is preferably between 6.5 and 9 mm, and more preferably between 6.9 and 8.3 mm. The dimension or diameter of the needle cover sleeve along the first axis is preferably between 16 and 23.5 mm (more preferably between 18 mm and 23 mm), and the dimension or diameter along the second axis is preferably between 15 and 21 mm (more preferably between 17 mm and 20.5 mm).

[0026] The drive unit is preferably sleeve-shaped to provide an opening to accommodate at least the proximal portion of the reservoir unit for attachment. In this case, the counter guiding elements can be arranged within the opening. The guiding elements of the reservoir unit can guide the reservoir unit during the insertion process so that the reservoir unit is kept in the correct rotational orientation during insertion and in the correct orientation in the final attachment position.

[0027] In a preferred embodiment, the guiding elements have a thickness or width (in a plane parallel to the longitudinal axis) which is thinner than the thickness of the outer sleeve wall of the needle cover sleeve. That means that the guiding elements are made of a minimum amount of material. Unlike known approaches with guiding cams having a thick and heavy design, the two pairs of thin-walled guiding elements contribute to a reduction of material of the disposable reservoir unit and thus to a reduction of waste.

[0028] For example, the guiding elements can have a thickness of less than 1.5 mm, and preferably less than 1 mm. In a preferred embodiment, the thickness of each guiding element is between 0.6 mm and 1.2 mm, more preferably between 0.8 mm and 1 mm.

[0029] By way of example, the guiding elements can be protrusions, knobs, cams, rails or ribs extending along a longitudinal axis. The counter elements in the drive unit can be, for example, grooves, nuts or rails which are adapted to guide the guiding elements of the reservoir unit along the longitudinal axis during the attachment process.

[0030] The disposable reservoir unit is part of a semi-disposable (also referred to as semi-reusable) injection device. Thus, the reservoir unit cannot be operated without the reusable drive unit of the injection device. In order to prime the injection device for an injection, the user has to attach or connect the reservoir unit to the drive unit. The drive unit can comprise drive means which are adapted to dispense the liquid medicament from the reservoir held within the reservoir unit once the reservoir unit is attached to the drive unit.

[0031] The injection device can be a manual or an automatic injection device. An automatic device or automatic injector typically comprises automatic drive means, such as an elastic element (e.g. a pre-tensioned spring) or an electric motor, to drive the dispensing member to dispense the liquid medicament from the reservoir. A manual injection device comprises manual drive means, such as a dispensing button, which the user has to press to move the dispensing member in the dispensing direction.

[0032] The reservoir unit comprises two oppositely arranged protrusions. By "oppositely arranged" it is meant that the two protrusions are spaced 180° from each other in the circumferential direction. Correspondingly, the two locking openings are spaced 180° from each other, and the two pairs of guiding elements are spaced 180° from each other.

[0033] The needle cover sleeve is movable along the longitudinal axis and guided by the reservoir holder. The needle cover sleeve is adapted to cover or enclose the needle within the reservoir (pre-filled syringe or cartridge with releasably attachable needle) mounted within the reservoir holder. The movement of the needle cover allows switching between a safe state in which the needle is covered and the needle does not protrude from the device housing, and an injection device in which the needle is exposed and protrudes or protrudes from the housing.

[0034] The reservoir holder is adapted to hold the reservoir in place relative to the reservoir holder and preferably relative to the drive unit housing. The reservoir holder can have clamping means or stop elements or abutment surfaces to fix and hold the reservoir by form fit and / or by force fit.

[0035] In the present context, the terms "substance", "drug", "medicament" and "medicinal product" are to be understood as including any flowable medicinal preparation which is suitable for controlled administration by means of a device such as, for example, a cannula or hollow needle, and includes a liquid, a solution, a gel or a fine suspension containing one or more medically active ingredients. The medicament can be a composition comprising a single active ingredient, or a pre-mixed or co-formulated composition with more than one active ingredient present in a single container. The medicinal product includes drugs such as peptides (e.g. insulin, insulin-containing drugs, GLP-1 or derivatized or analogous preparations containing), proteins and hormones, active ingredients derived from or harvested by biological sources, hormone- or gene-based active ingredients, nutritional preparations, enzymes and other substances in both solid (suspended) or liquid form, as well as polysaccharides, vaccines, DNA, RNA, oligonucleotides, antibodies or parts of antibodies, and appropriate base, auxiliary and carrier substances.

[0036] The term "distal" means referring to the direction or end of the drug delivery device carrying the injection needle or the injection cannula, while the term "proximal" means referring to the opposite direction or end pointing away from the needle or cannula.

[0037] The term "infusion system" or "infuser" refers to a device which is removed from the injection site after each medicinal product event or drug delivery process, while the term "infusion system" refers to a device with a cannula or needle remaining in the patient's skin for an extended period of time (e.g. several hours).

[0038] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. For example, "a arm" does not exclude two arms, which are functionally or structurally identical. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

[0039] The guiding element preferably protrudes from the outer surface of the needle cover sleeve. In a plane perpendicular to the longitudinal axis, the guiding element protrudes along an axis which is angled with an angle between 0° and 45°, preferably between 0° and 30°, to the first axis. The guiding element protruding in the above-mentioned angle range allows a reliable guiding of the reservoir unit relative to the drive unit.

[0040] Preferably, the first outer dimension of the reservoir unit is between 1.05 and 1.5 times the second outer dimension. This ratio between the first (height) dimension and the second (width) dimension provides a compact design of the reservoir unit.

[0041] The dimension along the first axis is preferably between 16 and 23.5 mm (more preferably between 18 mm and 23 mm), and the dimension along the second axis is preferably between 15 and 21 mm (more preferably between 17 mm and 20.5 mm).

[0042] In a preferred embodiment, the needle cover sleeve is the outermost part of the reservoir unit, and the reservoir holder is arranged concentrically within the needle cover sleeve. This means that the needle cover sleeve is the outermost part except for the cap or rear opening element, if any. That means that the reservoir unit does not comprise any housing or casing, but only the movable needle cover sleeve. This provides a simple design.

[0043] Preferably, in a plane perpendicular to the longitudinal axis, the outer form or shape of the reservoir unit is a regular oval form, which extends in longitudinal direction along the length of the reservoir unit. Preferably, the oval form extends along the entire length of the reservoir unit except for the device cap, if any. That means that the reservoir (without cap) has only a single cross section, which is an oval form.

[0044] The term "regular" means that the oval form is not interrupted, for example, by flattened portions or by straight line sections. The term "oval" form excludes circular or rectangular cross sections, but the term "oval" includes shapes such as elliptical or egg-shaped forms.

[0045] The oval form prevents the reservoir unit from rolling away if separated from the drive unit. Furthermore, the regular oval form allows for a simple and cost-effective way of applying labels or markings to the outer surface of the reservoir unit.

[0046] Preferably, each protrusion is arranged adjacent to the respective locking opening with respect to the longitudinal direction. That means that the reservoir unit is brought close together by the holding of the protrusions and the locking of the reservoir unit (preventing the reservoir unit from being accidentally released from the drive unit) to allow for a compact design of the reservoir unit.

[0047] In a preferred embodiment, the locking opening is arranged on the distal side of the protrusion or on the distal portion of the protrusion. This means that the protrusion can be located in a proximal portion of the reservoir unit or at the proximal end and thus can reliably hold the reservoir unit in place with respect to the drive unit. The actuation arm of the drive unit can be inserted into the locking opening to lock the reservoir. Since the opening is located distal of the protrusion and thus in a more distal portion of the reservoir unit, the latter can be held stably in place.

[0048] Preferably, the locking opening extends along the longitudinal axis, such that the needle cover sleeve is not obstructed when the actuation arm is positioned within the locking opening and can be moved relative to the protrusion between the covering position and the retracted position. That means that the longitudinally extending opening provides enough space for the actuation arm to engage and be positioned in the opening, while the needle cover sleeve can be moved between its covering position and its retracted position. Thus, when the actuation arm is inserted, it does not block or hinder the needle cover sleeve from moving.

[0049] The protrusion preferably has a rectangular cross-section in a plane parallel to the longitudinal axis. Correspondingly, the counter element of the drive unit, e.g. a clamp, a recess, adapted to engage the protrusion to couple and attach the reservoir unit to the drive unit, preferably also has a rectangular cross-section to accommodate or surround the protrusion in the attached state.

[0050] The needle cover sleeve preferably further comprises two oppositely arranged second openings accommodating the protrusion, and wherein the protrusion is accessible through the second openings. That means that the protrusion is positioned within the openings and the outermost end of the protrusion (radially outer free end) can be flush with the outer surface of the needle cover sleeve, or alternatively, the free end of the protrusion can protrude from the outer surface of the needle cover sleeve. Since the protrusion is positioned on the first axis, the second openings are accordingly also aligned with the first axis.

[0051] The second openings preferably extend along the longitudinal axis, such that the needle cover sleeve can be moved relative to the protrusion between the covering position and the retracted position without covering the protrusion. That means that the protrusion can be engaged with the counter element in the drive unit and the needle cover sleeve does not touch or rest against the protrusion or the counter element and thus the needle cover sleeve can be moved between its covering position and its retracted position without being blocked or hindered by the protrusion.

[0052] In a preferred embodiment, the reservoir unit further comprises a locking element movable relative to the needle cover sleeve, and wherein the locking element can be in a locked position in which the locking element engages the needle cover sleeve and prevents the needle cover sleeve from moving out of the covering position. Further, the locking element can be in an unlocked position in which the locking element does not engage the needle cover sleeve such that the needle cover sleeve is not prevented from moving out of the covering position.

[0053] The locking element is a further safety measure to prevent accidental access to the needle and thus can prevent injuries caused by the injection needle. Since the locking element can lock the needle cover sleeve in the covering position, the injection needle is covered and the user cannot (accidentally) retract the needle cover sleeve. The locking element can be controlled by the drive unit by means of the actuation arm or by another movable member of the drive unit and switched between the locked position and the unlocked position.

[0054] Preferably, the locking element is a radially protruding flexible arm with a free end portion, and wherein the needle cover sleeve comprises a stop surface, and wherein the free end portion is adapted to engage the stop surface when the flexible arm is in its locked position to hold the needle cover sleeve in the covering position. That means that the flexible arm is in its locked position when it abuts or touches the stop surface, and that the flexible arm is in its unlocked position when it is released from the stop surface and when it does not prevent the needle cover sleeve from moving out of the covering position.

[0055] Preferably, the end portion engages the stop surface in the undeflected position of the arm, and the end portion is disengaged from the stop surface in the deflected state of the arm, allowing the needle cover sleeve to move out of the covering position.

[0056] The deflection allows for a quick and reliable switching between the locked position and the unlocked position. That means that the arm can quickly switch to engage the stop surface and thus block the needle cover sleeve, and be deflected to move away from the stop surface and thus release the needle cover sleeve.

[0057] In a preferred embodiment, the flexible arm is integrally formed in the reservoir holder and monolithic with the reservoir holder. The flexible arm and the reservoir holder are preferably manufactured by injection molding from plastic. That allows for a simplified manufacturing.

[0058] Preferably, the reservoir holder comprises a clamping element adapted to press on an outer surface of the reservoir, and the reservoir holder further comprises a bearing surface within the reservoir holder adapted to abut against a distal shoulder of the reservoir, such that the reservoir is immovable relative to the reservoir holder. The clamping element and the bearing surface fix and immovably hold the reservoir within the reservoir holder. That means that the reservoir is not moved before, during and after the injection process.

[0059] The reservoir unit without the reservoir preferably does not contain metal parts. That means that the reservoir unit comprises only plastic parts, and more preferably only injection molded thermoplastic parts (except for the reservoir and its reservoir elements), besides the reservoir with its reservoir elements (piston, needle, rigid needle shield directly mounted on the needle in the transport state). That means that the reservoir unit does not contain any metal parts, such as springs, clamps, etc. This facilitates production and contributes to a cost-efficient design.

[0060] The needle cover sleeve preferably comprises a machine readable code attached on a surface of the needle cover sleeve. The code comprises identification information specific to the reservoir unit.

[0061] The code comprises identification information specific to the reservoir unit. An external code reader can read the information from the code and based on the read identification information can identify the reservoir unit and preferably the drug within the reservoir. The identification information can comprise data about the reservoir, the drug, the volume and the expiry date or injection instructions for the drug contained in the reservoir.

[0062] The external code reader can be an external device, or it can be in the drive unit and adapted to read the code as soon as the reservoir unit is attached to the drive unit.

[0063] The machine readable code can be implemented in the form of an optical code or an electromagnetic field based readable code. Examples for optical codes are object identifier codes (OID), QR codes, bar codes, color codes and optical patterns. Examples for electromagnetic field based codes are radio frequency identification (RFID) tags or near field communication (NFC) tags.

[0064] The code can be attached on the outside surface of the cover member, e.g. by means of a label or sticker comprising the code. Alternatively, the code can be located on the inside surface or integrally formed in the wall of the cover member as an electromagnetic tag or chip.

[0065] Preferably, the reservoir unit further comprises a reservoir in the form of a syringe comprising a cylindrical barrel made of glass and an injection needle made of steel non-detachably connected to the barrel. Alternatively, the reservoir of the reservoir unit is a cartridge comprising a needle mounting portion on its distal end adapted to be releasably connected to a needle prior to injection.

[0066] The present invention further relates to an injection device comprising a disposable reservoir unit as described above and a reusable drive unit. The latter comprises a plunger rod and a drive member for moving the plunger rod in a dispensing direction to dispense the drug from the reservoir. The reservoir unit is releasably attachable to the drive unit.

[0067] As mentioned above, the injection device can be a manual injection device requiring user force to drive the plunger rod to dispense the drug, or alternatively, the injection device can be an automatic injection device comprising an automatic drive member, e.g. in the form of a biased spring element or an electric motor.

[0068] The drive unit can further comprise a flexible retaining arm engaging a radially extending protrusion of the reservoir unit if the reservoir unit is attached to the drive unit. The flexible retaining arm allows the reservoir unit to be releasably attached to the drive unit.

[0069] In a preferred embodiment, the cover member is lockable to the reservoir holder in the covering position, and the cover member is unlockable by relative movement between the reservoir unit and the drive unit. The reservoir unit can be moved manually by the user, or automatically by an automatic drive of the drive unit.

[0070] Preferably, the injection device is a semi-reusable (or semi-disposable) auto-injector. The automatic drive can comprise an electric motor adapted to drive the plunger rod to dispense the medicament from the reservoir. BRIEF DESCRIPTION OF DRAWINGS

[0071] Figure 1 A perspective view of an auto-injector according to the present application is depicted; Figure 2 A perspective view of a syringe unit of an auto-injector is depicted; Figure 3 An exploded view of a syringe unit is depicted; Figure 4 A second embodiment of a syringe unit is depicted; Figure 5 A cross-sectional view of a drive unit of an auto-injector is depicted; Figure 6a A cross-sectional view of an auto-injector is depicted, wherein the syringe unit is attached to the drive unit; Figure 6b A cross-sectional view of an auto-injector is depicted, Figure 6a wherein the plane of the cross-sectional view is offset from and parallel to the plane of the center of the longitudinal axis; Figure 6c A cross-sectional view of an auto-injector is depicted, Figure 6a wherein the plane is offset from and parallel to the plane of the center of the longitudinal axis; Figure 7 An auto-injector before injection is depicted, wherein the syringe unit is locked to the drive unit, and there is no cap, and the cover sleeve is released; Figure 8 An auto-injector after dispensing of a dose is depicted; Figure 9a A drive unit without the housing part is depicted, Figure 9b ,9c An upper housing part and a lower housing part of a drive unit are depicted.

[0072] In this specification, the term "distal" refers to the side where the injection needle is located. This is on the left-hand side in the figures. The term "proximal" refers to the opposite side or rear end of the device, and is on the right-hand side in the figures. DETAILED DESCRIPTION

[0073] Figure 1A perspective view of an injection device of a first embodiment of the present application is shown in the form of a semi-reusable auto-injector 1. The auto-injector 1 comprises a disposable reservoir unit in the form of a syringe unit 2 and a reusable drive unit 3. As Figure 1 The drive unit 3 has an elongated housing defining a longitudinal axis and comprises a push button 4 at its proximal end, as shown in

[0074] In the following, the structural features of the syringe unit 2 and the drive unit 3 will be described in detail. Subsequently, the functionality of the semi-reusable auto-injector 1 will be explained.

[0075] Syringe unit Figure 2 A perspective view of the syringe unit 2 without the drive unit is depicted. The syringe unit 2 has an oval form in cross-section. The oval form extends along the entire length of the syringe unit in the longitudinal axis. On the distal end, a cap 10 is mounted in an initial state or shipping state. The proximal end comprises a holding structure as described below to releasably attach the syringe unit 2 to the drive unit 3.

[0076] Figure 3 An exploded view of the syringe unit 2 is depicted. As shown in Figure 3 The syringe unit 2 comprises a syringe holder 30 (reservoir holder), a needle cover sleeve 20 arranged coaxially around the syringe holder 30 and movable relative thereto along the longitudinal axis, a label 25 wrapped around the needle cover sleeve 20, a cap 10 with RNS remover, and a reservoir in the form of a pre-filled syringe 15 Figure 6a ) comprising a liquid drug and a rigid needle sheath 17 (RNS) initially mounted on the injection needle. The syringe holder 30, the cover sleeve 20 and the cap 10 are individually injection molded plastic parts, all made of the same material, preferably polypropylene.

[0077] The pre-filled syringe 15 with a barrel made of glass is rotationally and axially fixed within the sleeve-shaped syringe holder 30. For this purpose, the syringe holder 30 comprises a clamping element (not shown) pressing against the outer surface of the syringe barrel. The syringe holder 30 provides a bearing surface 19 (see Figure 6a ) on its inner upper side, which is adapted to abut against the shoulder of the syringe barrel. The syringe holder 30 further has a longitudinal guide rail (not shown) on its outer side for the needle cover sleeve 20, so that the needle cover sleeve 20 is displaceable relative to the syringe holder 30 only in the longitudinal direction.

[0078] As Figure 3 andFigure 6a As shown, the syringe holder 30 includes two opposing rocker arms 38 or seesaw-like members extending in the longitudinal direction. Each rocker arm 38 is pivotable about a center 35 formed by a flexible or resilient connector that secures the rocker arm 38 to the outer surface of the syringe holder 30. The center 35 divides the rocker arm 38 into a distal portion 38.1 or distal arm and a proximal portion 38.2 or proximal arm. The distal portion 38.1 is adapted to engage and deflect the cap retaining tongue 11. For this purpose, the distal portion 38.1 includes a nose 36 (see...). Figure 6a The nose 36 is adapted to engage the protrusion of the cap retaining tongue 11 so that the snap-fit ​​connection between the tongue 11 and the needle cap sleeve 20 or the retainer 30 is disengaged.

[0079] like Figure 6a As best shown, the proximal portion of the rocker arm 38 includes an actuating surface 34 adapted to be contacted by the free end of a locking element in the form of a release arm 32. The rocker arm 38 is adapted to tilt or pivot about a center 35 between a first or initial tilt position (where the distal portion 38.1 is in a radially inward position) and a second tilt position (where the distal portion 38.1 is in a radially outward position).

[0080] Two radially deflectable locking elements or release arms 32 (see...) Figure 3 or Figure 6a Arranged on opposite sides of the syringe holder 30, each includes a distally pointing free end with an end protrusion 31, and a connecting end for connecting the release arm 32 to the syringe holder 30. At the free end, and laterally to the protrusion 31, are two side support surfaces 37 on both sides of the protrusion 31, guiding the release arm 32 as described below. The rocker arm 38 and the release arm 32 are integrally formed as a single component in the syringe holder 30. Figure 3 As shown in the best example, this means that the syringe holder 30 with rocker arm and release arm is injection molded as a single part.

[0081] In the initial state, the release arm 32 is in an undeflected and locked position, preventing the cap sleeve 20 from moving proximally relative to the syringe holder 30. Therefore, the cap sleeve 20 covers or shields the injection needle of the syringe 15 in the covered position. For this purpose, the free end of the locking arm 32 abuts against a stop surface (not shown) within the cap sleeve 20. As will be described below, once the locking arm 32 is radially deflected inward and in the unlocked position, the cap sleeve 20 can be pushed proximally.

[0082] The syringe retainer 30 further includes two opposing and radially projecting end shoulders or protrusions 33 at the proximal end of the syringe retainer 30 for use with the clamping arm 61 within the drive unit 3.Figure 6a ) engage. The protrusions 33 have a rectangular cross section in a plane parallel to the longitudinal axis and the clamping arms of the drive unit have corresponding openings with a rectangular cross section on their free ends to accommodate and engage the protrusions 33.

[0083] As shown in Figure 3 , the needle cover sleeve 20 has a non-circular cross section and in particular an oval form in a cross section or plane perpendicular to the longitudinal axis. In a plane perpendicular to the longitudinal axis, the outer dimension of the needle cover sleeve along the first axis (height) is between 18 and 23 mm and the outer dimension along the second axis perpendicular to the first axis (width) is between 17 and 20.5 mm. In the cross section, the height is between 1.05 and 1.5 times the width of the needle cover sleeve.

[0084] On the outer surface of the needle cover sleeve 20 and in the proximal portion, two pairs of guide elements 91.1, 91.2 are arranged opposite. The guide elements 91.1, 91.2 protrude from the needle cover sleeve surface. The guide elements protrude along an axis which in a plane perpendicular to the longitudinal axis forms an angle of between 20° and 40° with the first axis (height). The dimension from the center of the first guide element 91.1 to the center of the second guide element 91.2 in each pair in a plane perpendicular to the longitudinal axis is between 1.9 and 3.6 times shorter or smaller than (also referred to as between 1 / 3.6 and 1 / 1.9 of) the width or diameter of the needle cover sleeve 20 along the second axis. That is, the distance between the first and second guide elements is between 6.9 mm and 8.3 mm and the thickness of each guide element 91.1, 91.2 is between 0.8 and 1 mm.

[0085] As shown in Figure 2 and Figure 3 , the guide elements 91.1, 91.2 are realized in the form of small ribs extending along the longitudinal axis. The drive unit comprises corresponding guide grooves on the inner side of the openings which guide the guide elements 91.1, 91.2 along the longitudinal axis. During attachment, when the proximal portion of the syringe unit is inserted into the drive unit, the guide elements thus guide the syringe unit and prevent rotation relative to the drive unit. Furthermore, the guide elements 91.1, 91.2 guide the needle cover sleeve during retraction and distal movement of the needle cover sleeve 20 relative to the drive unit.

[0086] The needle cover sleeve comprises a medicament window 24 to allow the user to see the fill level of the syringe inside the syringe unit. The needle cover sleeve further comprises two oppositely arranged lateral openings 21 for the nose 36 of the rocker arm 38 to access the cap holding tongues 11. The cover sleeve 20 further has two oppositely arranged locking openings 22 for access to the release arm 32. The locking openings 22 are distal to two oppositely arranged openings 23 for access to the protrusions 33 from the outside. The locking openings 22 and the openings 23 are best shown in Figure 2 Fig. 6c. Both the locking openings 22 and the openings 23 for the protrusions extend along the longitudinal axis and have a rectangular shape, so that the needle cover sleeve 20 can be moved between its covering position and its retracted position without being hindered by the protrusions 33 and / or by the actuation arm 66 inserted into the locking openings 22.

[0087] A label 25 is wrapped around the outer surface of the syringe unit. The label comprises an RFID code 26 integrated in the label and positioned in the proximal part of the label 25. The code 26 comprises information about the syringe unit for identification and can comprise further information about the drug, the volume, the expiration date and dispensing parameters such as injection speed and hold time in the syringe. The code 26 can have further country specific information such as the user language for adjusting the user interface language.

[0088] The cap 10 is releasably attached at the distal end of the needle cover sleeve 20 by a snap fit connection. The cap 10 comprises on both sides two deflectable holding members in the form of holding tongues 11 on each side. The tongues 11 comprise on the free end a notch or recess 13 which is adapted to snap to protrusions 28 arranged on the outer surface of the cover sleeve 20 (also shown in 6c). Each tongue further comprises a protrusion which protrudes in the opening 21 of the needle cover sleeve if the cap is installed. The release of the snap fit will be described below with reference to the removal of the cap from the syringe unit 2. The cap 10 comprises in its interior a sleeve shaped holder 12 (RNS remover) which can be connected to the rigid needle shield (RNS) 17 of the syringe 15 so that the RNS 17 is removed together with the cap 10 if the cap 10 is released from the needle cover sleeve 20. The holder 12 is made of an elastomer and is shrunk onto the RNS during assembly of the syringe unit. Since the outer cap housing is made of plastic, the holder 12 and the outer cap housing are made of a two-component injection molded part. The cap 10 with holder is described in detail in patent application EP 23165348.6 (Ypsomed) which is incorporated herein by reference. In this embodiment the syringe unit without syringe does not contain any metal parts.

[0089] As an alternative, the retainer can be made of metal and arranged coaxially with the outer cap housing, as described above for retainer 12. In this case, the metal retainer engages RNS 17, and if the cap is released from the needle cap, the RNS is removed together with the cap 10.

[0090] The syringe 15 includes a syringe barrel and a movable piston 16 within the barrel. Figure 6a Injection needle 18 ( Figure 6a The injection needle 18 is non-releasably attached to the distal end of the syringe barrel. In the non-use state, the injection needle 18 is covered by RNS17, see [link / reference]. Figure 6a Once the syringe 15 is installed into the syringe holder 30, the RNS is then fixedly connected to the cap 10 axially and radially via the holder 12 as described above.

[0091] Figure 4 An alternative syringe unit 102 is depicted. (Referencing) Figure 2 and Figure 3 Compared to the syringe unit described in [the text], Figure 4 The syringe unit 102 shown includes a cap 110 that is mounted to the cap sleeve 120 via a bayonet-like connection.

[0092] Instead of the tongue, the cap 110 includes two opposing and radially inwardly projecting cams or protrusions (not shown) adapted to project into corresponding recesses 114 in the distal cap sleeve portion.

[0093] The groove 114 is U-shaped. Each groove 114 includes a straight groove portion 115 perpendicular to the longitudinal axis, and end groove portions 116 at both ends of the straight groove at an angle to the longitudinal axis.

[0094] By combining axial movement and rotational displacement, the cap 110 can be installed onto and released from the cap sleeve 120. Therefore, compared to the embodiment described above with a rocker arm, Figure 4 The cap 110 shown can be manually removed from the cap sleeve by the user at any time without the release mechanism with rocker arm as described above.

[0095] If the user grasps the cap 110 and rotates it, the cam will engage the angled recessed portion 116, and due to the angled recessed portion 116, the cap 110 will additionally move axially upwards away from the cap sleeve end in a distal direction. The user can then completely remove the cap 110 from the cap sleeve 120. All other features and functions of the syringe unit are consistent with reference to [reference needed]. Figure 3 The first embodiment shown is the same as that described.

[0096] Drive unit Figure 5A cross-sectional view of the drive unit 3 without the syringe unit is depicted. The cross-sectional view is taken along the longitudinal axis of the drive unit. The drive unit 3 comprises a support structure 80 comprising an outer housing cover or casing 87.1, 87.2 and, within the cover, a mechanical sleeve 83 is fixedly connected to the support structure 80. Further, the drive unit 3 comprises an opening on its distal side which is adapted to accommodate the proximal portion of the syringe unit 2.

[0097] The support structure 80 guides the clamping sleeve 60 which is arranged immovably. The trigger sleeve 50 is arranged coaxially to the clamping sleeve 60 and inside the clamping sleeve, the trigger sleeve being movable relative to the support structure 80 along the longitudinal axis. Again, the movable cover sleeve connector 45 is located within the trigger sleeve 50 and is biased in the distal direction by the cover sleeve spring 46. The spring abuts on its distal end against the cover sleeve connector 45 and on its proximal end against a radial wall of the mechanical sleeve 83. The movable sleeve-shaped syringe connector 47 is coaxially arranged within the cover sleeve connector 45 and is biased distally by the syringe connector spring 48 which is coaxially within the cover sleeve spring 46 and proximally supported by the mechanical sleeve 83. The spring 46 ensures that the syringe connector 45 pushes the syringe 15 of the inserted syringe unit 2 in the distal direction.

[0098] In the proximal portion, the support structure 80 supports and guides the sleeve-shaped trigger sleeve connector 51 which is movable along the longitudinal axis, the drive assembly of the electrically charged motor (not shown) and the transmission mechanism (not shown) connecting the motor with the threaded rod 41, the battery 94, the threaded rod 41 and the plunger rod 40 which is threadedly connected with the threaded rod 41. The support structure 80 further accommodates an electronic module 92 with a controller configured to control the electronic motor and to provide information to the user via a display or LED 95 or a communication module (not shown). The trigger sleeve connector 51 is fixedly and immovably connected to the trigger sleeve 50 and is pressed by the trigger sleeve spring 53 distally onto the proximal end of the plunger rod 40. The plunger rod 40 is non-rotatably guided by the mechanical sleeve 83 and comprises on its distal end a flange 49 which is adapted to engage the piston 16 (see Figure 6a ) during dispensing.

[0099] As shown in Figure 6b , within the proximal portion of the support structure 80, a detection pin 97 is axially movable through the cover sleeve connector 45. The detection pin 97 comprises a cam 98 which is engageable with two mechanical switches 96.1, 96.2 arranged along the longitudinal axis Figure 6bThe position sensor implemented interacts with the detection pin 97. Thus, the presence of the syringe unit 2 within the drive unit 3 can be detected via the detection pin 97 and a first switch 96.1 which provides a corresponding signal to the controller of the electronics module. Furthermore, the retraction of the cover sleeve 20 can be detected by a second switch 96.2 when the cover sleeve 20 retracts further moving the pin 97 and its cam 98 in proximal direction.

[0100] Additionally, in the distal end portion, a mechanical switch (not shown) held by the support structure 80 senses the presence or absence of the cap 10 of the attached syringe unit 2.

[0101] The gripper sleeve 60 comprises two axially extending and deflectable clamping arms 61 which have a clamp 62 at their distal free end which is adapted to accommodate the syringe holder shoulder 33. The clamping arms 61 are deflectable radially outward to allow the clamp 62 to snap onto or release the shoulder 33. Furthermore, each clamping arm 61 provides support for an axially aligned gripper sleeve spring 64 which biases the clamping arm 61 in the holding position.

[0102] Each clamping arm 61 comprises a mechanical sensor with an actuation lever to detect when the syringe holder shoulder 33 is inserted into the clamp 62. Alternatively, a strain gauge or a piezoelectric strain gauge can be arranged on the radially outer surface of the clamping arm 61 and electrically connected to the controller in the electronics module. Based on the strain gauge signal or the piezoelectric sensor signal, the deflection of the clamping arm 61 can be detected. This allows to determine whether the clamping arm 61 is pivoted by the shoulder 33 during insertion of the syringe unit 2 into the drive unit 3. This in turn allows to infer whether the syringe unit is fully inserted and attached to the drive unit.

[0103] As a further alternative, an optical guide (fiber) can be used to detect the clamping arm deflection. This means that the optical guide is arranged from the PCB to each clamping arm 61 such that the deflection of the clamping arm 61 interrupts the optical guide. The corresponding signal allows to determine that the clamping arm is deflected by the shoulder 33 of the inserted syringe unit 2.

[0104] The gripper sleeve 60 further comprises two oppositely arranged and radially inward deflectable actuation arms 66. The actuation arms 66 extend essentially on the longitudinal axis and comprise on their distal free end 67 a guiding surface 65 or a tilted contact surface. When in contact with the counterpart guiding surface 55 or the counterpart tilted contact surface of the trigger sleeve 50, the actuation arms 66 can be deflected radially inward. As further described below, the free ends 67 of the actuation arms 66 further each comprise a radially inwardly oriented contact surface to abut against the end protrusion 31 of the release arm 32 of the syringe unit 2.

[0105] The trigger sleeve 50 is axially guided by the support structure 80 and displaceable relative thereto. For this purpose, the trigger sleeve 50 comprises longitudinal rails (not shown) which engage longitudinal grooves (not shown) in the support structure. As Figure 5 and Figure 6a can be seen, the trigger sleeve 50 comprises oppositely arranged contact elements with mating guiding surfaces 55 or mating inclined contact surfaces. As mentioned above, the trigger sleeve 50 is further immovably connected to a trigger sleeve connector 51. Since the trigger sleeve connector 51 is biased by a trigger sleeve spring 53, the trigger sleeve 50 is also biased in the distal direction. The trigger sleeve connector 51 is in turn connected to the plunger rod via a shoulder 52 which engages a proximal shoulder of the plunger rod 40, so that axial movement of the plunger rod 40 in the proximal direction also moves the trigger sleeve 50 proximally.

[0106] In the state shown in Figure 5 , the drive unit 3 is ready to be loaded with the syringe unit 2. The controller displays the current state to the user by means of a steady green light.

[0107] The support structure 80 supports and holds the entire drive mechanism, including the above mentioned trigger sleeve 50 and the gripper sleeve 60, as well as the motor and electronics module in the proximal part. The drive unit 3 further comprises an outermost housing which comprises two housing parts 87.1, 87.2 which are connected to each other by a snap-fit connection so that the parts are fixed tightly to each other. Figure 9a The support structure with the drive mechanism is depicted in Figure 9b , and the upper housing part 87.1 is shown in Figure 9c , and the lower housing part 87.2 is shown in .

[0108] The housing parts do not support any internal parts, but are fixedly connected to the support structure 80 and function as a grip for the user. The housing parts 87.1, 87.2 can be adapted in color, form, size and appearance for specific use cases.

[0109] Function To prepare the auto-injector 1 for an injection, the user attaches the syringe unit 2 to the drive unit 3. When the syringe unit is detected by the switch 96.1 Figure 6b of the position sensor, the electronics in the drive unit 3 switches from an inactive state or sleep mode to an active mode. Alternatively, the user can press the button 4 to activate the electronics.

[0110] Figure 6a Figs. 6a, 6b and 6c depict cross-sectional views of the drive unit 3 with the inserted syringe unit 2. InFigure 6a In particular, the cut for the sectional view is made in the center plane along the longitudinal axis. The plane for the sectional view of Figure 6b and 6c is parallel to the central longitudinal axis, but is in radial distance to the central longitudinal axis and thus deviates from and is parallel to the central plane.

[0111] In the state shown in Figs. 6b and 6c, the syringe unit 2 is inserted with its proximal end portion into the distal opening of the drive unit 3. In the state shown in Figs. 6b and 6c, the proximal shoulder or protrusion 33 of the syringe holder 30 snaps into the clamp 62 of the gripper sleeve clamping arm 61. Thus, the syringe unit 2 is held in the drive unit 3 by the clamping arm 61. However, in the state shown in Figs. 6b and 6c, the syringe unit 2 is still removable from the drive unit 3 by overcoming the holding force. Thus, if the user pulls the syringe unit 2 in distal direction, the clamping arm 61 is deflected radially. Thus, the protrusion 33 of the syringe holder 30 is released from the clamp 62 and the syringe unit 2 is removable from the drive unit 3. Figure 6a Figure 6a In the state shown in Figs. 6b and 6c, the proximal shoulder or protrusion 33 of the syringe holder 30 snaps into the clamp 62 of the gripper sleeve clamping arm 61. Thus, the syringe unit 2 is held in the drive unit 3 by the clamping arm 61. However, in the state shown in Figs. 6b and 6c, the syringe unit 2 is still removable from the drive unit 3 by overcoming the holding force. Thus, if the user pulls the syringe unit 2 in distal direction, the clamping arm 61 is deflected radially. Thus, the protrusion 33 of the syringe holder 30 is released from the clamp 62 and the syringe unit 2 is removable from the drive unit 3. Figure 6a The presence of the protrusion 33 in the clamp is detected by the controller as the shoulder abuts against a cam of a mechanical switch within the clamp 62. The controller thus receives a signal indicating that the syringe unit is correctly and completely inserted into the drive unit. Alternatively, if the detection is provided by strain gauges on the clamping arm 61 or by a light guide interrupted by the deflected clamping arm 61, the engagement movement of the clamping arm is detected and thus the controller can determine the attachment of the syringe unit 2 based on the strain gauge or light guide signal.

[0112] This means that in this state the syringe unit 2 is held within the drive unit 3, but is not yet locked within the drive unit 3. A mechanical switch in the distal end portion of the support structure 80 is actuated by the cap 10 of the inserted syringe unit. Thus, the controller can determine that the cap 10 is mounted on the inserted syringe unit 2.

[0113] In the initial state or transport state, the cover sleeve 20 is locked in the covering position. This is shown in Fig. 6a, wherein the plane for the sectional view is deviating from the central axis. As can be seen in Fig. 6b, the distally oriented end of the release arm 32 abuts against or engages the proximally oriented stop surface 29 of the cover sleeve 20. The release arm 32 is in its locked position. Thus, a force acting on the cover sleeve 20 in proximal direction is absorbed by the release arm 32 and thus the cover sleeve cannot be moved out of the covering position towards the retracted position.

[0114] Figure 6c In the state shown in Figs. 6b and 6c, the proximal shoulder or protrusion 33 of the syringe holder 30 snaps into the clamp 62 of the gripper sleeve clamping arm 61. Thus, the syringe unit 2 is held in the drive unit 3 by the clamping arm 61. However, in the state shown in Figs. 6b and 6c, the syringe unit 2 is still removable from the drive unit 3 by overcoming the holding force. Thus, if the user pulls the syringe unit 2 in distal direction, the clamping arm 61 is deflected radially. Thus, the protrusion 33 of the syringe holder 30 is released from the clamp 62 and the syringe unit 2 is removable from the drive unit 3. Figure 6a In the state shown in Figs. 6b and 6c, the proximal shoulder or protrusion 33 of the syringe holder 30 snaps into the clamp 62 of the gripper sleeve clamping arm 61. Thus, the syringe unit 2 is held in the drive unit 3 by the clamping arm 61. However, in the state shown in Figs. 6b and 6c, the syringe unit 2 is still removable from the drive unit 3 by overcoming the holding force. Thus, if the user pulls the syringe unit 2 in distal direction, the clamping arm 61 is deflected radially. Thus, the protrusion 33 of the syringe holder 30 is released from the clamp 62 and the syringe unit 2 is removable from the drive unit 3.

[0115] ​​Furthermore, in the initial state or transport state of the syringe unit, the syringe barrel does not abut against the bearing surface 19 and thus there is a gap between the distal end of the syringe barrel and the bearing surface 19 of the syringe holder 30. The gap can be several millimeters, in particular 2 to 5 mm.

[0116] The reason for the gap is that the device cap 10 must be movable over a small distance if the user grabs the cap 10 to remove the (unused) syringe unit or to position the syringe unit. The cap travel is due to play provided between the components for taking into account manufacturing or assembly tolerances. During this cap movement, the RNS 17 is not intended to be removed and thus the sterile barrier is not intended to be removed.

[0117] Due to the initial gap between the syringe barrel and the bearing surface 19, the RNS (with needle) can travel over a small distance without affecting the sterile barrier. This means that the gap between the syringe barrel and the syringe holder bearing surface 19 is preferably greater than the maximum play of the cap (cap travel relative to the syringe holder).

[0118] Figure 7 An auto-injector 1 in the locked state without cap is depicted. When the syringe unit 2 is inserted as described above, the proximal end of the syringe unit 2 moves the detection pin 97 proximally and thus the switch 96.1 of the position sensor automatically sends a signal to the controller in the electronics module, which detects the presence of the syringe unit 2 within the drive unit 3. The controller wakes up the electronics and sets the device in the active state. A code reader (not shown) in the form of an NFC reader within the drive unit 3 reads the RFID code 26 of the syringe unit 2. Optionally, a temperature sensor is additionally integrated in the syringe unit RFID code, which is configured to sense the current syringe unit temperature. Subsequently, the controller of the drive unit sends the read drug information and possibly the temperature information from the read code 26 to an external device to verify the drug or medicament (and possibly the temperature information) with predetermined values or tables. Alternatively, the controller compares the read information from the code 26 with predetermined information stored in a memory within the drive unit 2.

[0119] In case of successful medicament and possibly temperature verification, the controller receives an enable signal (either from the external device or from the internal comparison). The controller then controls the electric motor to rotate the threaded rod 41 to move the trigger sleeve 50 over a small distance of several millimeters in the proximal direction. This trigger sleeve 50 movement is achieved by a kinematic chain as described below.

[0120] The motor rotates the pinion gear and a transmission mechanism transfers the rotation to the threaded rod 41 which in turn moves the non-rotating plunger rod 40 in proximal direction, preferably by an axial stroke of about 5 mm. Since the trigger sleeve connector 51 is connected via its shoulder 52 to the proximal shoulder of the plunger rod 40, the latter causes the trigger sleeve connector 51 to move and thus also the trigger sleeve 50 to be displaced in proximal direction. Furthermore, during the proximal movement, the trigger sleeve spring 53 is compressed.

[0121] The proximal movement of the trigger sleeve 50 brings the counter inclined guiding surface 55 of the trigger sleeve 50 into contact with the inclined guiding surface 65 of the actuation arm. When both inclined surfaces 65, 55 slide along each other, the actuation arm 66 is forced to deflect radially inwards and when the trigger sleeve 50 moves further in proximal direction, the free end 67 of the actuation arm is pressed radially underneath the trigger sleeve portion with the guiding surface 65. The radially inwards oriented contact surface deflecting the free end 67 of the actuation arm 66 in turn meets the end protrusion 31 of the release arm 32, deflecting the release arm 32 also radially inwards. Subsequently, the inwards moving release arm 32 abuts against the rocker actuation surface 34 and tilts the rocker 38 from the first inclined position towards the second inclined position, such that the proximal portion 38.2 of the rocker with the actuation surface 34 is pivoted radially inwards. Figure 7

[0122] Thus, the distal portion 38.1 of the rocker moves radially outwards and thus deflects the retaining tongue 11 of the cap 10 radially outwards. That in turn means that the snap connection holding the cap 10 to the distal end of the cover sleeve 20 is released, because the recess 13 of the deflected retaining tongue 11 no longer engages the protrusion 28 on the cover sleeve 20. The user can thus pull the cap 10 off the auto-injector.

[0123] When the cap 10 is removed, the cam of the mechanical switch is no longer actuated and the controller thus derives from the corresponding switch signal that the cap 10 has been removed. Alternatively, if the sensor is implemented with a light guide, the removal of the cap 10 interrupts the light guide, or alternatively, allows an uninterrupted light guide, and thus the corresponding signal indicates that the cap is no longer present. Additionally, in case of a light guide, if the cap is made of a translucent or transparent plastic, the cap can be illuminated by the light guide. That means that the controller can activate a light which illuminates the cap in a certain color, flashing or continuously bright, signaling to the user that the cap is released and can be removed. If the cap is removed, the light guide is interrupted and a cap removal signal is generated to the controller.

[0124] ​If the cap 10 is mounted, the syringe 15 inside the syringe holder 30 is held in place via the holder 12 and the RNS 17 by the cap 10, and thus the syringe connector 47, which is biased distally, cannot move the syringe 15 relative to the syringe holder 30. However, when the cap 10 is removed, the syringe 15 is no longer held and due to the syringe connector spring 48, the syringe connector 47 moves the syringe 15 distally relative to the syringe holder 30, and thus the gap between the distal end of the syringe barrel and the bearing surface 19 disappears. That means, when the cap is removed, the syringe connector forces the syringe 15 against the bearing surface 19, so that the syringe 15 is firmly held between the biased syringe connector 47 and the bearing surface 19.

[0125] The radially inwardly deflected release arms 32 further have the effect that they no longer engage the stop surface 29 of the cap sleeve 20 ( Figure 6c ), and thus allow the cap sleeve 20 to move out of the covering position and in the support structure 80 relative to the syringe holder 30 in the proximal direction.

[0126] At the same time, the radially inwardly deflected urging arms 66, i.e. the proximally oriented surface of the free end 67 of the urging arms 66, abut against the ribs 27 of the cap sleeve 20. The ribs 27 are located between the opening 22 and the opening 23 in the cap sleeve shown in the cross-sectional view in Figure 3 and Figure 6c That means in this locked state, the syringe unit 2 cannot be pulled out, because the free end 67 abuts against the ribs 27 of the cap sleeve, and thus the syringe unit 2 is locked in the drive unit.

[0127] The cap 10 of the auto-injector 1 has now been removed, and the auto-injector is ready for an injection. The controller displays a corresponding notification on the display, the LED 95 is continuously lit up.

[0128] As a next step, the user places the distal end of the cap sleeve 20 onto the injection site and pushes the auto-injector 1 towards the injection site. This causes the cap sleeve 20 to move proximally from the distal covering position into the support structure 80 (pushing on the skin) and to compress the cap sleeve spring 46, which biases the cap sleeve 20 in the distal direction via the cap sleeve connector 45. Due to the end shoulder 31 of the release arms 32 being held radially inwardly by the deflected urging arms 66 ( Figure 7 ), the retraction of the cap sleeve 20 is possible. During its proximal movement, the cap sleeve 20 is guided by the guide elements 91.1, 91.2, which travel within the guide grooves in the drive unit. As shown in Figure 8 , when the cap sleeve 20 is in its retracted position, the injection needle 18 protrudes from the cap sleeve.

[0129] When the cap sleeve is pushed on the skin, the cap sleeve connector 45 moves proximally and thus the detection pin 97 moves further proximally. The further movement brings the cam 98 in contact with the second switch 96.2 Figure 6b ), which triggers the controller in the electronics module to start the injection. That means the controller drives the motor in dispensing direction and thus rotates the threaded rod 41 and thereby moves the plunger rod 40 in distal direction.

[0130] The controller drives the plunger rod distally with low torque. When the plunger rod flange 49 comes in contact with the piston 16 inside the syringe barrel, the motor current increases due to the motor control. This is a signal to the controller that the plunger rod 40 is in place correctly. Subsequently, the motor drives the plunger rod to dispense the predefined dose.

[0131] During dispensing, the distal flange 49 of the plunger rod 40 moves the piston 16 inside the syringe 15 in distal direction and thus dispenses the liquid drug through the injection needle out of the syringe 15. If the piston 16 hits the distal end inside the syringe barrel, the motor control increases the current and the controller stops driving the plunger rod distally. Figure 8 The end of this injection state is shown in Fig. 8. As can be seen, the plunger rod 40 and thus the piston 16 inside the syringe barrel are in the distal end position.

[0132] The distal movement of the plunger rod 40 moves the trigger sleeve 50 via the trigger sleeve connector 51 in distal direction into its initial position. That means the urging arm 66 can move radially outwards back into its undetured position. However, since the cap sleeve 20 is in the retracted proximal position, the release arm 32 is blocked from moving back into the initial undetured position by the side support surface 37 abutting the inner surface of the retracted cap sleeve. That means the release arm 32 remains deflected as long as the cap sleeve 20 is in its retracted position.

[0133] The user can interrupt the dispensing movement by pressing the button 4. The controller stops the motor and thus the plunger rod movement. When pressing the button 4 again, the dispensing can be continued.

[0134] The controller displays a holding time, which indicates the time period the user has to hold the auto-injector 1 to the injection site after the injection to ensure complete administration and absorption of the drug. The controller can display a countdown counter to inform the user about the remaining holding time. The counter is realized by a progress bar provided by the display visible from the outside. Furthermore, the controller can drive the motor at idle without moving the piston rod to generate a motor sound, which shall prevent the user from removing the auto-injector from the injection site too early.

[0135] Once the holding time has elapsed, a notification in the form of a sound is emitted, prompting the user that the automatic injector can be removed from the injection site. Alternatively, the end of the holding time can be indicated by the LED only.

[0136] When the user removes the automatic injector 1 from the injection site, the compressed cap sleeve spring 46 can release and thus it can move the cap sleeve 20 distally back into the needle covering position.

[0137] When the cap sleeve 20 moves into its covering position, the side support surface 37 disengages from contact with the inner surface of the cap sleeve 20 and the release arm 32 can pivot radially outward back into its locking position, in which the free end of the release arm 32 abuts against a contact surface inside the cap sleeve 20, thereby locking the cap sleeve 20 in its covering position. Thus, after the injection process, the cap sleeve 20 can no longer be moved into the retracted position.

[0138] Upon completion of the injection, the controller sends the recorded injection data together with a time stamp to an external receiver, for example a cloud server.

[0139] Furthermore, since the actuation arm 66 is no longer deflected and thus does not contact the distal stop surface of the syringe holder 30, the entire syringe unit 2 can be pulled out by the user from the drive unit. The user can now discard the syringe unit 2 and the drive unit 3 is ready for loading with a new syringe unit.

[0140] Additionally or alternatively, the automatic injector can indicate misuse by the user. For example, misuse can be that the user removes the automatic injector 1 from the skin prematurely or before the entire dose has been released or delivered.

[0141] The automatic injector can have a sensor that detects contact with and / or removal from the skin. The automatic injector 1 can have an additional sensor for this purpose, or the built-in sensor can perform this function. For example, a skin sensor (not shown) can be provided on the needle cap sleeve 20 of the syringe unit 2.

[0142] If the user removes the automatic injector 1 from the skin before the end of the dispensing or delivery process, the cap sleeve 20 can be moved distally back into the needle covering position by the compressed cap sleeve spring 46. As described above, the needle cap sleeve 20 is locked in the needle covering position.

[0143] The skin sensor (not shown) detects that the user has removed the automatic injector 1 from the skin and provides a corresponding signal to the controller of the electronic module 92. The controller stops driving the plunger rod 40 distally. In addition, the motor control does not detect an increase in motor current.

[0144] Thus, the controller can provide information to the user via the display or via a communication module (not shown) that the user can continue the dispensing or delivery process as the user has only performed a partial dispensing or partial delivery of the medicament. Information is displayed on the display or on the communication module (not shown) about how the dispensing or delivery process can be continued.

[0145] A partial dispensing or partial delivery of the medicament means that the user or patient receives too little medicament, which endangers their health, and that the syringe unit with the partially filled syringe has to be thrown away, which leads to more waste and consumption of medicaments or higher healthcare costs.

[0146] The display or the communication module displays how the locking element 32 of the cover sleeve 20 can be released. For example, a code can be entered on the display or the communication module (not shown), a button can be activated or pressed, or a doctor or healthcare professional can unlock the locking element 32 via an external receiver, such as a cloud.

[0147] Thus, the locking element 32 can be moved into an unlocked position, in which it does not engage the needle cover sleeve 20, so that the needle cover sleeve 20 can be moved out of the covering position. The controller continues to drive the plunger rod 40 distally. Thus, the remaining dose in the syringe is administered.

[0148] Upon completion of the injection, the controller sends information to the user or to an external receiver, such as a cloud server, via the display or the communication module that the dispensing has been completed.

[0149] Although the present application has been described in detail in the drawings and foregoing description, the description should be considered as illustrative or exemplary and not restrictive; variations of the disclosed embodiments can be understood and implemented by those skilled in the art from a study of the drawings, disclosure, and appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. In particular, any further meaningful combination of the measures recited in the attached claims should be considered disclosed.

[0150] List of reference signs 1 automatic injector 2 syringe unit 3 drive unit 4 button 10 cap 11 retaining tongue 12 holder 13 recess 15 pre-filled syringe 16 piston 17 rigid needle shield RNS 18 injection needle 19 support surface 20 needle cover sleeve 21 opening 22 locking opening 23 159 opening 24 medicament window 25 label 26 RFID tag 27 rib 28 protrusion 29 stop surface 30 syringe holder 31 end protrusion 32 release arm 33 protrusion / end shoulder 34 actuation surface 35 center 36 nose 37 side support surface 38.1 distal portion 38 rocker 38.2 proximal portion 40 plunger rod 41 threaded rod 45 cap sleeve connector 46 cap sleeve spring 47 syringe connector 48 syringe connector spring 49 flange 50 trigger sleeve 51 trigger sleeve connector 52 shoulder 53 trigger sleeve spring 55 counter inclined guide surface 60 clamp sleeve 61 clamping arm 62 clamp 64 clamp sleeve spring 65 inclined guide surface 66 actuation arm 67 free end 80 support structure 83 mechanical sleeve 87.1 first housing 87.2 second housing 88 support 91.1 first guide element 91.2 second guide element 92 electronic device 94 battery 95 LED 96.1 first switch 96.2 second switch 97 pin 98 cam 102 syringe unit 110 cap 114 recess 115 straight portion 116 angled portion 120 cover sleeve

Claims

1. A disposable reservoir unit (2) for an injection device (1) for dispensing liquid medication via an injection needle (18), the reservoir unit (2) being configured for releasably attaching to a reusable drive unit (3) of the injection device, the reservoir unit (3) comprising: - A reservoir holder (12) for holding the reservoir (15) in place and includes a guide and defines a longitudinal axis; - Two radially extending and oppositely arranged protrusions (33) for releasably attaching the reservoir unit (2) to the drive unit (3); - A needle cap sleeve (20), guided by the guiding device, and movable relative to the reservoir holder (12) along the longitudinal axis between a covered position and a retracted position, in which the injection needle (18) is covered, and in the retracted position, the injection needle (18) protrudes from the needle cap sleeve (20), and The needle cap sleeve (20) further includes two opposing lateral locking openings (22) adapted to receive the actuator arm (66) of the drive unit (3) to lock the reservoir unit (2) to the drive unit (3), and In a plane perpendicular to the longitudinal axis, the needle cap sleeve (20) has a first outer dimension along a first axis and a second outer dimension along a second axis perpendicular to the first axis, wherein the first outer dimension is larger than the second outer dimension, and wherein the protrusion (33) is arranged on the first axis. The needle cap sleeve (20) is characterized in that it includes two pairs of guide elements (91.1, 91.2) arranged opposite to each other, the guide elements protruding from the outer surface of the needle cap sleeve (20) and adapted to engage the mating guide elements in the drive unit (3) to prevent the reservoir unit (2) from rotating relative to the drive unit (3). In a plane perpendicular to the longitudinal axis, the first guide element (91.1) of each pair is arranged on a first side of the first axis, and the second guide element (91.2) of each pair is arranged on a second side of the first axis, wherein the second outer dimension is between 2 and 3.6 times the distance from the center of the first guide element (91.1) to the center of the second guide element (91.2) in the plane perpendicular to the longitudinal axis.

2. The disposable storage unit (2) according to claim 1, wherein, In a plane perpendicular to the longitudinal axis, the guide elements (91.1, 91.2) protrude along an axis that forms an angle between 0° and 45° with the first axis.

3. The disposable storage unit (2) according to any one of claims 1 to 2, wherein, The first outer dimension is between 1.05 and 1.5 times the second outer dimension.

4. The disposable storage unit (2) according to claim 1 or 3, wherein, The needle cap sleeve (20) is the outermost part of the reservoir unit (2), and the reservoir holder (12) is concentrically arranged inside the needle cap sleeve (20).

5. The disposable storage unit (2) according to claim 1 or 4, wherein, In a plane perpendicular to the longitudinal axis, the external form of the reservoir unit (2) is a regular oval shape, which extends along the length of the reservoir unit in the longitudinal direction.

6. The disposable storage unit (2) according to any one of claims 1 to 5, wherein, Each protrusion (33) is arranged to be adjacent to the corresponding locking opening (22) with respect to the longitudinal direction.

7. The disposable storage unit (2) according to any one of claims 1 to 6, wherein, The locking opening (22) is located on the far side of the protrusion (33).

8. The disposable storage unit (2) according to any one of claims 1 to 7, wherein, The locking opening (22) extends along the longitudinal axis such that when the actuating arm (66) is positioned within the locking opening (22), the needle cap sleeve (20) is unobstructed and can move relative to the protrusion between the covered position and the retracted position.

9. The disposable storage unit (2) according to any one of claims 1 to 8, wherein, The protrusion (33) has a rectangular cross-section in a plane parallel to the longitudinal axis.

10. The disposable storage unit (2) according to any one of claims 1 to 9, wherein, The needle cap sleeve (20) further includes two opposing second openings (23) for receiving the protrusion (33), wherein the protrusion is accessible through the second openings, and wherein the second openings extend along the longitudinal axis such that the needle cap sleeve (20) is movable relative to the protrusion (33) between the covered position and the retracted position without covering the protrusion.

11. The disposable reservoir unit (2) according to any one of claims 1 to 10, further comprising a locking element (32) movable relative to the needle cap sleeve (20), wherein the locking element (32) is capable of being in a locked position in which the locking element engages the needle cap sleeve and prevents the needle cap sleeve (20) from moving out of the covered position, and wherein the locking element (32) is capable of being in an unlocked position in which the locking element does not engage the needle cap sleeve (20) such that it does not prevent the needle cap sleeve from moving out of the covered position.

12. The disposable storage unit (2) according to claim 11, wherein, The locking element (32) is a radially projecting flexible arm having a free end portion (31), and wherein the needle cap sleeve includes a stop surface (29), and wherein when the locking element is in its locked position, the free end portion (31) is adapted to engage the stop surface (29) to hold the needle cap sleeve (20) in the covered position.

13. The disposable storage unit (2) according to claim 12, wherein, The end portion (31) engages the stop surface (29) in the undeflected position of the arm (32), and the end portion disengages from the stop surface (29) in the deflected state of the arm, thereby allowing the needle cap sleeve (20) to move out of the covered position.

14. The disposable storage unit (2) according to any one of claims 1 to 13, wherein, The storage unit (2) without the storage device (15) does not contain any metal parts.

15. An injection device (1) comprising a disposable reservoir unit (2) according to any one of claims 1 to 14 and a reusable drive unit (3), the reusable drive unit comprising a plunger rod (40) and a drive for moving the plunger rod in a dispensing direction to dispense the drug from the reservoir unit (15), wherein the reservoir unit (2) is releasably attachable to the drive unit (3).

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