Portable electronic injection device for injecting liquid medication

Technical Field The present invention relates to a drug delivery device, such as a manual, electronically controlled injection device for injecting liquid drugs, especially of the type for performing subcutaneous injections in a fully automatic manner.

BACKGROUND OF THE INVENTION [0002] As is well known, some types of diseases such as diabetes require injection of drugs such as insulin several times a day, with the dose of the drug being injected being different for different patients, and even for the same patient, within day and on different days.

[0003] In the last few years, electronically controlled injection devices have therefore been developed that are widely used to allow self-injection of drugs at appropriate dosages.

[0004] Patent application US-A-2002/0133113 describes one such injection device, essentially comprising a hand grip housing that houses a cartridge containing a liquid drug for injection, and also designates, on the surface in contact with the patient's skin, a through hole with which a disposable needle is attached to the tip of the cartridge. This injection device also includes an electromechanical actuator that is selectively actuated to move the plunger through the piston rod hermetically within the cartridge body for delivering liquid drug through the needle to the patient's skin.

[0005] Operation of the infectious device is controlled by a programmable microprocessor that receives signals from various switches and buttons - e.g. one or more drug dose select buttons as well as an injection start button - and generates signals by which the unit is controlled starting, according to the program stored in the microprocessor.

[0006] This described injection device thus allows selection of each dose of drug to be injected, as well as delivery of the dose automatically.

[0007] One drawback of the known drug delivery devices is that if the user attempts to remove the cartridge while the piston rod is still in the cartridge, i.e. typically between two injections, it may cause damage.

[0008] DE 29 50 140 A1 discloses a drug delivery device according to the initial part of claim 1, i.e. a fully mechanical ampoule syringe comprising a cylindrical housing having flaps that in the open position allow insertion of the ampoule into the housing. These flaps are subjected to springs that keep them open. The flaps have protrusions that are pushed by the ampoule during insertion, which closes the flaps. When the ampoule is in the housing, the axially displaceable portion is displaced by the action of a spring towards the front of the syringe to push the ampoule and lock the tabs in the closed position. The flaps can be unlocked by retracting the piston rod in such a way that the enlarged end of the piston rod rests against the surface of this movable part and withdraws the latter out of the housing. When the flaps are in the open position, one of the flaps stops this moving part with its protrusion.

ΕΡ 2,298,391 Β1 [0009] In this way, with such a syringe, the user cannot prevent the ampoule from being removed while the piston rod is still in the ampoule. Such a syringe, however, has the disadvantage that its flaps remain open and the movable part continuously acts on the protrusion of one of the flaps when no ampoule is inserted into the syringe.

Disclosure of the Invention [0010] The object of the present invention is to provide a drug delivery device in which the abovementioned drawbacks are prevented.

[0011] To this end, as well as as defined in claim 1, the present invention relates to a drug delivery device, comprising a housing, a door, which in the open position allow insertion / removal of a drug container into / out of the housing, door opening mechanism / closing the door, as well as a pushing member that can be moved axially from the retracted position, located outside of the medicine container, to insert the drug container and push the liquid drug contained inside the drug container outside the drug container to deliver it to the patient and then return to its retracted position, characterized in that it includes a locking mechanism, for locking the door opening button, the opening mechanism door to prevent the door from opening when the pushing member is inside the medicine container, and also for unlocking the door opening button when the pushing member is in its retracted position.

Brief Description of the Drawing [0012] A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a front view of a first exemplary injection device;

Figures 2 and 3 show, with some parts removed for the sake of clarity of communication, enlarged perspective views, from opposite sides, of the internal components of the injection device according to Figure 1;

Figures 4, 5, 6, 7 and 8 show a part of the injection device according to Figure 1, illustrating the assembly of the disposable needle;

Figures 9, 10 and 11 are similar to Figs. 4-8 and also illustrate removal of the needle from the injection device of Fig. 1;

Fig. 12 is a block diagram illustrating the operation of the control unit for controlling the injection device of Fig. 1;

Figures 13 and 14 are front views of a second exemplary injection device with the front wall removed to show the interior of the device;

Figs. 15 and 16 are cross-sectional views of the interior of a second exemplary injection device, showing different positions of the pushing member in the device;

Figs. 17 and 18 are cross-sectional views showing the needle and end of the cartridge inserted into the second exemplary injection device in dismantled and assembled condition, respectively;

Figures 19 to 22 are cross-sectional views showing the process of connecting the needle to the cartridge;

Figures 23 to 22 are cross-sectional views showing the process of disconnecting the needle from the cartridge;

Figures 26 to 29 show the inner portion of a second exemplary injection device, including sensor elements for detecting the connection of the needle and the cartridge;

ΕΡ 2 298 391 Β1

Figures 30 and 31 show alternative sensor means for detecting the connection of the needle and the cartridge;

Figs. 32 to 34 are, respectively, a front view, a side view, and a partially cut away side view, with some parts removed for the sake of clarity of communication, parts of a second exemplary injection device comprising a door opening mechanism and a door locking mechanism according to this invention in first configuration;

Figs. 35 to 37 are, respectively, a front view, a side view, and a partially cut away view, with some parts removed due to the clarity of the message, of parts of a second example injection device comprising a door opening mechanism and a door locking mechanism according to the present invention in a second configuration ;

Figures 38 to 40 are, respectively, a front view, a side view, and a partially cut away view, with some parts removed for the sake of clarity of communication, of parts of a second example injection device comprising a door opening mechanism and a door locking mechanism according to the present invention in a third configuration ; and

Fig. 41 is a block diagram illustrating the operation of the control unit for controlling a second exemplary infection device.

Best Mode for Carrying Out the Invention [0013] The reference number 1 in Fig. 1 indicates as a whole a hand-held, electronically controlled injection device for injecting liquid drugs, and especially for performing subcutaneous injections in a fully automatic manner.

[0014] The infectious device 1 generally comprises a hand-gripped housing 2 defining a seat 3 for receiving a cartridge 4 containing a liquid drug; an injection drive unit 5 (Figs. 2 and 3) located inside the housing 2 and selectively actuated in such a way as to cooperate with the cartridge 4 and inject a certain pre-set dose of drug into the patient; and electronic control unit 6 (Fig. 12) - in the example shown here, a microprocessor - also suitable for housing inside enclosure 2, to control the operation of the infectious drive unit 5.

[0015] More specifically, the housing 2, in the example shown here, has the shape of a narrow prism, and also includes a front wall 7 provided with a liquid crystal display (LCD) 8 and setting buttons 9 (their operation is described in detail below); back wall 10; two sides 11, 12; a bottom wall 15 defining a contact surface 16 for contacting the skin of the patient; and an upper wall 17 equipped with an injection start button 18, as explained in detail below.

[0016] As shown in Fig. 1, one of the two sides (11) of the housing 2 has a door 19 hinged about an axis perpendicular to the front wall 7 and rear wall 10, as well as opening outwards to allow insertion 4 inside the socket 3.

[0017] In the example shown here, the seat 3 for receiving the insert 4 has an axis A perpendicular to the bottom wall 15 and the top wall 17, and is formed near the side 11.

[0018] Near the opposite side 12, the housing 2 also defines a socket 20 (Figures 1 to 3) having an axis parallel to the axis A, and intended to receive one or more batteries 21 for electrically supplying the injection device 1, inserted through successive doors 22 formed in an attached wall 15.

ΕΡ 2 298 391 Β1 [0019] As shown in Fig. 1 to 11, the cartridge 4 is defined by a hollow cylindrical body 23 containing a predetermined quantity of liquid drug and having a closed transverse end 24 having a small cross-section through which a commercially available disposable needle 25 can be inserted in a known manner. and an open opposite end 26 connected in a fluid sealing manner via a disk-shaped movable member or mandrel 27, which is actuated by the driving injection unit S to move the inner body 23 and deliver the drug through the needle 25.

[0020] The insert 4 is inserted into the inner housing 2 with the needle end 24 facing the bottom wall 15 and thus the contact surface 16 to come into contact with the skin of the patient; while the bottom wall 15 has a through hole 30, with an A axis, with which the needle 25 can be attached and removed to / from the cartridge 4, and through which the needle 25 is fired to pierce the skin.

[0021] The insert 4 has known external markings (not illustrated), e.g. barcodes, notches, conductive or reflective material arranged in a specific pattern, etc., by which the presence of the insert 4 inside the housing 2 is determined, as well as for obtaining information regarding the drug, such as composition, concentration, expiry date, etc. Another possibility to identify the cartridge 4 is the use of a radio frequency identification system.

[0022] As clearly shown in Figs. 4 to 6, the needle 25 is provided in a protective housing 31 to prevent injury to the user, and also defines, together with the needle housing 31, the needle assembly 32.

[0023] More specifically, the needle 25 is attached to and protrudes from the plastic needle support 33, which is attached to the end 24 of the body 23 of the cartridge 4.

[0024] As is known, the needle 25 includes a front portion 34 (bottom in Figs. 2 to 11) for forging a patient's skin and protruding from the needle support 33; and the rear end 35 (on top in Figs. 4 to 11) enclosed in the needle support 33 and passed through the end 24 of the cartridge body 23 4. More specifically, the needle support 33 includes a plurality of flexible flanges 36 surrounding the rear end 35 of the needle 25, and engaging end 24 of body 23 of cartridge 4 as described in detail below.

[0025] As an alternative concept not shown here, an inverted coupling arrangement between the needle support and the cartridge is also possible; in the latter case, the end of the cartridge may be provided with flexible flanges engaging the needle support. This further embodiment has the advantage that the needle support need not be specifically designed with flexible flanges, but instead a standard commercially available needle assembly (even a screw thread assembly which is a commercially available version) can be used.

[0026] The needle housing 31 is defined by a cylindrical cup-shaped front portion 34 of the needle body housing 25, as well as an open end that is attached to the needle housing 33. In the example shown here, the needle assembly 32 also includes an inner needle housing 37 covering the front portion 34 of the needle 25.

[0027] Referring to Figs. 2 and 3, the drive injection unit 5 includes an electromechanical actuation assembly 40 that is selectively actuated to act on the plunger 27 of the cartridge 4 and to slide it, within the body 23 of the cartridge 4, towards the end 24 to delivering liquid medicine through a needle 25.

EP 2 298 391 Β1 [0028] The drive injection unit 5 comprises a further electromechanical actuation unit 41 for moving the cartridge 4 inside the housing 2 and along the axis A, to and from the contact surface 16 for automatic attachment and removal of the needle 25 to / from the cartridge 4 and to introduce the needle into the patient's skin at a predetermined speed.

[0029] More specifically, the insert 4 is attached to the support sleeve 42, which slides axially inside the seat 3 in the housing 2.

[0030] As shown in Figs. 2 and 3, the support sleeve 42 is open, not only at the opposite axial ends, but also on the side facing the door 19 to allow insertion 4.

[0031] More specifically, the support sleeve 42 comprises a lower cross-section, a lower cross-section 38, for receiving 24 of the cartridge 4, which, when the needle 25 is attached to the cartridge 4, is engaged by the flexible fingers 36 of the needle support 33. The end portion 38 also defines an annular projection 39 with the rest of the support sleeve 42.

[0032] The actuation assembly 40 comprises an electric gear motor 43; a pushing member 44 that acts on the plunger 27 of the cartridge 4 to move it within the body 23 of the cartridge 4 towards the end 24; and a gear 45 for converting the rotation of the pushing member 44 caused by the gear motor 43 into a translational displacement.

[0033] More specifically (Fig. 2), the transmission 45 generally includes a pinion 46, attached to the output member of the transmission motor 43; a screw assembly 47 connected to the push member 44; and an intermediate gear 48 having external teeth meshing with the pinion 46, and internal teeth engaging the lead screw 49 of the screw assembly 47.

[0034] More specifically, the lead screw 49 is attached to the housing 2 to rotate, but not translational, axially; wherein the screw assembly 47 also includes a screw nut 50 attached to the lead screw 49 integral with the push member 44 attached to the housing 2 for translational displacement longitudinally but not rotating relative to the lead screw 49.

[0035] The push member 44 is preferably defined by the core of a known hose 51 in the form of a Bowden cable whose sheath 52 has a portion attached to the housing 2, e.g. to the upper wall 17. [0036] The actuation assembly 41 comprises an electric gear motor 53; a slide 54 integral with the support sleeve 42 of the insert 4 and movable parallel to axis A; and a gear 55 for converting the rotation caused by the gear motor 53 to the translational movement of the slider 54.

[0037] More specifically (Fig. 3), the slide 54 is defined by a screw nut extending laterally from the support sleeve 42 and attached to the housing 2 for translational displacement longitudinally but not rotating about an axis parallel to the axis A. The gear 55 includes a gear shaft 56 attached to the output member of the gear motor 53; a lead screw 57 connected to the slider 54 and attached to the housing 2 to rotate around but not translational displacement longitudinally about its own axis; and an intermediate gear 58 having external teeth meshing with the pinion 56, as well as internal teeth engaging the lead screw 57.

[0038] With reference to Figs. 4 to 11, the injection device 1 also includes two or more retaining elements 60 extending around the seat 3 to hold the needle assembly 32 attached.

292 298 391 Β1 to the housing 2 in a predetermined position (Fig. 5), in which the needle assembly 32 extends along the axis A from the bottom wall 15 of the housing 2, while the portion having the needle bracket 33 engages the hole 30 in the wall 15.

[0039] More specifically, the retaining elements 60 are defined by levers running parallel to the A axis and having upper ends 61 hinged to the structural portion of the housing 2, as well as free lower ends having locking flanges 62. More specifically, locking flanges 62 are located at hole 30 and also run perpendicular to axis A and inside hole 30.

[0040] The retaining elements 60 are flexibly loaded inside the seat 3 to adopt the locked configuration (Figs. 5, 6, 10 and 11), and are also separated to obtain the released configuration (Figs. 4, 7, 8 and 9) by respective cam profiles 63 cooperating with the profiled annular projection 64 on the support sleeve 42 when the support sleeve 42 travels along axis A.

[0041] More specifically, the support sleeve 42, and with it the cartridge 4 together, can be moved together by the actuation assembly 41 in opposite directions along the axis A to take three different positions, namely:

- the upper limit position (Figs. 4 and 7), in which the cartridge 4 is loaded and all automatic operation of the injection device 1 begins and ends (in this case, assembling and removing the needle 25, as well as injecting the patient with the drug);

- the lower limit position (Figures 10 and 11) in which the needle 25 is removed from the cartridge 4; and

- the operating position (Fig. 6), near the lower limit position, in which liquid drug is delivered through the skin of the patient, while the needle 25 is connected to the cartridge 4.

[0042] As shown in Fig. 4 up to 11, the cam profile 63 of each stopping element 60 and the projection 64 on the support sleeve 42 are in the form of complementary thresholds and are designed to cooperate together to separate the stopping elements 60 and close to the upper limit position of the support sleeve 42, and to disconnecting them from each other, leaving the retaining elements 60 subjected solely to the action of the elastic return force towards the A axis, in other positions assumed by the support sleeve 42 during its movement.

[0043] As shown in Fig. 5 and 6, in a locked configuration, the locking flanges 62 of the retaining elements 60 cooperate with an outer rib 65 formed at the open end of the needle housing 31 to hold the needle assembly 32 inside the hole 30 in the bottom wall 15 when the support sleeve 42 moves to the operating position, as a result, the end portion 38 of the support sleeve 42 fits inside the flexible flanges of the needle support 33, while the rear end 35 of the needle 25 is inserted inside the end 24 of the cartridge 4.

[0044] When the support sleeve 42 then moves from the operating position to the upper limit position, the locking collars 62 of the retaining elements 60, still in the locked configuration, press the needle housing 31 to prevent it from moving along with the movement of the needle 25, bracket 33 the needle and the inner housing 37 of the needle moving together with the support sleeve 42, so that the needle 25 and the needle support 33 can be connected to the cartridge 4 and removed from the needle housing 31 automatically.

ΕΡ 2 298 391 Β1 [0045] It can be seen that the retaining elements 60, when they press the needle housing 31, also block the needle housing 31 relative to the user. In this way, the premature removal of the needle housing 31 by the user is prevented, e.g. when the needle 25 is connected to the cartridge 4.

[0046] In the lower limit position of the support sleeve 42 (Figs. 10 and 11), the locking collars 62 of the retaining elements 60 engage the gap between the projection 39 of the support sleeve 42 and the rear end of the needle support 33 to stop the needle support 33 when the support sleeve 42 moves then to the upper limit position, whereby the needle 25 and needle holder 33 are automatically removed from the cartridge 4 after use.

[0047] Referring to Fig. 12, the control unit 6 receives a plurality of signals from various detection elements and buttons on the injection device 1, and also sends control signals to gear motors 43, 53 and display 8, according to the program stored in the control unit itself. 6.

[0048] More specifically, the control unit 6 receives the following signals:

- S1 signals from sensors 66 (e.g. optical, electrical, radio frequencies, infrared, etc.), facing towards the socket 3 and intended to detect the markings on the insert 4;

- a signal S2 from a proximity sensor 67, e.g. a contact switch, located at the opening 30 in the bottom wall 15, intended to determine the engagement of the opening by an external object of a certain diameter, e.g. a needle housing 31;

- a signal S3 from a skin sensor 68, e.g. a mechanical or capacitive sensor, located on the bottom wall of the housing 2 and intended to detect contact with the patient's skin;

- signals S4 from the setting buttons 9, by means of which, for example, the dose to be injected is selected, the speed at which the needle 25 pierces the patient's skin, the speed of drug delivery, etc .; and

- S5 signal from the injection start button 18.

[0049] Based on the incoming signals, the control unit 6 sends signals C1 and C2 for controlling the respective gear motors 43, 53 in both directions of rotation, as well as the signal C3 for controlling the display 8.

[0050] The control unit 6 has its own memory 70 (externally presented for simplicity), which stores the program of the control unit 6 and the doses and time of injections to inform the patient and / or doctor about them and about the number of doses remaining in the cartridge 4. The doctor can therefore check the patient's compliance.

[0051] The injection device 1 is also provided with an interface (known per se and not illustrated here), e.g. a USB port, Bluetooth communication, infrared port etc. which allows the exchange of information with a computer for data analysis.

[0052] Programming of the injection device 1 may also be possible (for example by loading data from a computer), which may be useful for clinical trials (for example, allowing injection of only specific amounts and at specific times / intervals).

[0053] The operation of the injection device 1 will be described starting from the configuration according to Fig. 4, in which the support sleeve 42 has no needle 25 and is positioned in the upper limit position, while the insert 4 has been inserted through the door 19 into the seat 3 of the housing 2 and connected to support sleeve 42.

[0054] The assembly of the needle 25 to the cartridge 4 is controlled completely automatically by the control unit

6, and is also actuated simply by inserting the needle assembly 32 through the open end of the housing 31 7

292 298 391 Β1 needles, inside the hole 30 in the attached wall 15 of the housing 2. The insertion of the needle assembly is immediately detected by the proximity sensor 67, so that the control unit 6 starts the gear motor 53 in the direction provided by the gear 55 and slide 54 to move the sleeve support 42 to the working position.

[0055] As a result of the above-described movement of the support sleeve 42, the projection 64 is detached from the cam profiles 63, whereby the retaining elements 60 move inwardly into the opening 30, while the locking collars 62 close on the needle housing 31 to lock it in the partially position engaging the bore 30 (Fig. 5).

[0056] The needle assembly 32 can be inserted into the opening 30 either manually or using the connector indicated as a whole with the reference number 71 in Figs. 4 to 10.

[0057] More specifically, the connector 71 has the shape of a double hemisphere and comprises opposing parts 72, 73 of different diameters, defining respective cavities open on opposite sides and intended to contain respectively the needle housing 31 and the inner needle housing 37. The portion 72 having a larger cross-section also houses a cylindrical slide sleeve 76 defining a proper seat for the needle housing 31, the function of which is explained further, and the portion having a smaller cross-section 73 is internally provided, near the open end, with an internal rib 74, which pushes the inner housing 37 of the needle to remove it from the assembly defined by the needle 25 and the needle support 33.

[0058] When the support sleeve 42 reaches its operating position (Fig. 6), the end portion 38 is inserted between the elastic flanges 36 and connected to the needle support 33, and the rear end 35 of the needle 25 is inserted inside the end 24 of the cartridge 4.

[0059] At this point, the direction of rotation of the gear motor 53 is inverted and the support sleeve 42 moves from the operating position to the upper limit position. When this happens, the needle support 33, the needle 25, and with it the inner needle housing 37 are retracted axially from the housing 31 locked with partial engagement of the hole 30 by the retaining elements 60.

[0060] Near the upper limit position, the projection 64 on the support sleeve 42 cooperates with cam profiles 63 of the retaining elements 60 to separate the retaining elements 60 in such a way that the locking flanges 62 move outside the opening 30 to release the needle housing 31 (Fig. 7).

[0061] When the support sleeve 42 reaches the upper limit position, the connector 71 can be inserted through the opening 30 into the seat 3 through the part 73, the cavity of which is thus engaged by the inner needle housing 37. Given its smaller diameter, insertion of part 73 is not detected by the proximity sensor 67. When the connector 71 is removed from the hole 30, the inner needle housing 37 is removed from the needle 25 (Fig. 8).

[0062] Permission to initiate the correct injection is given by the surface 16 coming into contact with the patient's skin, which triggers the skin sensor 68.

[0063] When the start button 18 is pressed, the gear motor 53 is first started, which moves via the gear 55, the support sleeve 42 back to the operating position, whereby the needle 25 pierces the patient's skin. Then the gear motor 43 is started and through the gear 45 pushes the push member 44, acting on the plunger 27 of the cartridge 4 to move it towards the end 24 and deliver a predetermined dose of liquid drug.

ΕΡ 2 298 391 Β1 [0064] Before the injection is made, the set dose 9 can be selected and displayed on the display 8 by the set buttons 9 for injection, the speed at which the needle 25 pierces the patient's skin, the speed with which the liquid drug is delivered, as well as the depth of injection.

[0065] When the injection is done, the support sleeve 42 moves back to the upper limit position.

[0066] The needle 25 can be removed from the cartridge 4 completely automatically, using the connector 71 (Figures 9 and 10), or directly using the needle frame 75 (Fig. 11), e.g. of the type known under the trade name "SHARPS" ".

[0067] More specifically, when using the frame 71 used to remove the needle housing 31 and the inner needle housing 37 (Figures 9 and 10), the slide sleeve 76 must first be removed from the part 72 to axially rest on the rib 65 of the needle housing 31 .

[0068] At this moment, the housing 31 and the removed sleeve sleeve 76 are inserted through the opening 30 in the housing 2 to actuate the proximity sensor 67, whereby the control unit 6 starts the gear motor 53 to move the support sleeve 42 from the upper limit position to the lower limit position.

[0069] When the cam profiles 63 become detached from the projection 64 on the support sleeve 42, the retaining elements 60 cannot move to the locked configuration by the locking flanges 62 resting on the slide sleeve 76 of the connector 71 (Fig. 9).

[0070] However, when the support sleeve 42 reaches the lower limit position (Fig. 10), the locking flanges 62 of the retaining elements 60 are latched inside the gap between the projection 39 on the support sleeve 42 and the upper axial end of the needle support 33.

[0071] At this point, the direction of rotation of the gear motor 53 is reversed, and the support sleeve 42 moves to the upper limit position. When this happens, the needle support 33 and the needle 25 remain in their place where they are retained by the locking flanges 62 and are thus axially discharged from the support sleeve 42 and the cartridge 4.

[0072] When the support sleeve 42 reaches the upper limit position, the retaining elements 60 are separated again and the injection device 1 is ready to attach another needle 25 for the next injection.

[0073] When using the needle frame 75 (Fig. 11), it is simply inserted through the outlet end inside the opening 30 to actuate the proximity sensor 67 and automatically remove the needle 25 from the cartridge 4 in exactly the same way as described with respect to to connector 71.

[0074] The benefits of the injection device 1 become apparent from the description below.

[0075] In detail, by allowing the movement of the cartridge 4 to and from the contact surface 16 to be controlled, the injection device 1 provides fully automatic attachment and removal of the needle 25 to / from the cartridge 4, as well as controlling the speed at which the needle 25 pierces the patient's skin.

[0076] In other words, when the correct injection is done, it is possible to set not only the dose of the drug and the speed at which the dose is delivered, but also the speed at which the needle 25 is pushed out of the housing 2, and thus the skin penetration rate.

[0077] It is understood that changes can be made to the injection device 1 as described and illustrated in this document.

292 298 391 Β1 [0078] More specifically, the displacement of the cartridge 4 and the delivery of the drug contained in the cartridge 4 can be controlled using a single gear motor which can, for example via a gear similar to those already described, control the axial displacement of the core Bowden cables, acting on the plunger 27 of the cartridge 4; and the releasable locking elements can be used to selectively integrate together the plunger 27 and the body 23 of the insert 4, whereby when the locking elements are actuated, the insert 4 is moved to and from the contact surface 16 and when the locking elements released, the plunger 27 slides inside the body 23 of the cartridge 4 to deliver the drug.

[0079] Furthermore, the device 1 can be used in the same manner as disclosed with other types of drug containers, such as a syringe.

[0080] Figs. 13-16 show a further manual, electronically controlled injection device 80. Like the injection device 1, the injection device 80 shown in Figs. 13-16 includes, inside the housing 81 (only shown in Fig. 13, 14), cartridge holder 82, for receiving a liquid drug-containing cartridge 83, a push member 84 designed to act on the plunger 85 of the cartridge 83, a first electromechanical actuator 86 for driving the pushing member 84 and a second electromechanical actuator 87 for axial movement, in particular insert holders 82. The door 88 used on the side wall of the housing 81, and actuated by the slide button 89 applied on the same side wall, can be opened by rotating about the axis of rotation 90 to insert or remove the cartridge 83 into / from the injection device. The cartridge holder 82 can move axially with respect to door 88, but can rotate with the door 88 about the pivot axis 90 when it is in the axial retracted position.

[0081] The push member 84 comprises an axially and laterally incompressible flexible tube 91, having the form of a spring, deflected by 180 ° by a leading rigid semicircular housing 92 at the top of the device, and a piston 93 attached to the end of the tube 91, protruding from the housing 92 along the axis B of the cartridge holder 82, as well as the cartridge 83. The piston 93 is designed to mate with the plunger 85 of the cartridge 83 (see Fig. 16) and the movable recessed portion 94 (see Fig. 15), whose function will be explained later.

[0082] After the control unit 95 shown in Fig. 41 is inspected, the first actuation assembly 86 can move the push member 84 axially from the retracted position in which the piston 93 is outside the cartridge 83 and inside the recessed portion 94 (Fig. 15), towards the disposable needle 96 connected to the cartridge 83, whereby the piston 93 comes into contact with the plunger 85 inside the cartridge 83 and pushes the plunger 85 to deliver the drug through the needle 96 (Fig. 16). The push member 84 can then be moved back to its retracted position, leaving the spindle 85 in the position to which it has been pushed.

[0083] The second actuation assembly 87 can be controlled by the control unit 95 to move the structure comprising the first actuation assembly 86, the pushing member 84, the pushing member housing 92 and the cartridge holder 82 along the B axis, i.e. to and from the bottom wall 97 of the device housing 81 until it comes into contact with the patient's skin to automatically attach and remove the needle 96 to / from the cartridge 83 and to insert and remove the needle 96 into / from the patient's skin. More specifically, structure 82, 84, 86, 92 can be moved between the upper retracted position, 10

ΕΡ 2 298 391 Β1 in which the needle 96 connected to the cartridge 83 is located inside the housing 81 of the device and one or more lower positions in which the needle 96 protrudes through the hole 98 made in the bottom wall 97.

[0084] Referring to Figs. 17, 18, the needle 96 is attached to and extends from the plastic needle holder 99, which fits into the lower end 100 of the cartridge holder 82 in such a way that the corresponding lower end 83a of the cartridge 83, surrounded by the lower end 100, is pierced through the rear end 101 of the needle 96. The attachment of the needle bracket 99 to the cartridge holder 82 is achieved through an intermediate metal member 102 attached to the lower end 100 of the cartridge holder 82 and having a plurality of flexible flanges 103 that can be squeezed between the outer circumferential wall of the lower end 83a of the cartridge 83 and the inner circumferential wall of the bracket 99 needles, in grooves 82a made in the wall of the cartridge holder.

[0085] Before the needle 96 is connected to the cartridge 83, the needle support 99, together with the needle 96, is secured in the protective housing or needle cap 104 and forms with the latter a needle assembly 105 (see Fig. 1920).

[0086] Referring to Figs. 19-20, the injection device 80 further includes releasable retention means for holding the needle assembly 105 in a predetermined position within the opening 98 in the bottom wall 97. These releasable retention members include two or more releasable tongues or retention fingers 106 that are actuated by the needle assembly 105 after it has been inserted into the opening 98, as well as an axial abutment surface 107 that limits the insertion of the needle assembly 105 into the opening 98. These releasable retaining tabs 106 are disposed around the periphery of the opening 98 and are subjected to a flexible load facing the B axis. By using a thrust surface 107, the releasable retaining tabs 106 define gaps that are engaged by the annular upper flange 108 of the needle housing 104 to lock the needle assembly 105 in the hole 98. Electromechanical sensor (electric switch) 109 (Fig. 41), coupled to the releasable stop tabs 106, detects the activation of the tabs 106 through the needle housing 104 and sends an electrical signal to the control unit 95.

[0087] The automatic connection of the needle 96 to the cartridge 83 is actuated by inserting the needle assembly 105 between the tabs 106. This insertion, immediately detected by the sensor 109, causes the control unit 95 to actuate the second actuation assembly 87 to move the structure 82, 84 downwards , 86, 92 inside the device housing 81, from its retracted position. The retaining force with which the retaining tabs 106 act on the needle housing 104 is sufficient for the needle housing 104 to remain closed in its position shown in Fig. 20, while the lower end 100 of the cartridge holder 82, equipped with an intermediate retaining member 102, engages the bracket 99 needles (Fig. 21). When the movable structure 82, 84, 86, 92 has reached a predetermined lower position in which the lower end 100 of the cartridge holder 82 fully engages the needle support 99, thereby connecting the needle 96 to the cartridge 83, the second actuation unit 87 moves the structure 82, 84 , 86, 92 back to its upper retracted position, with the needle support 99 and the needle 96 connected to the cartridge 83, while the needle housing 104 is retained by the abutment surface 107 (Fig. 22).

[0088] Unlike the retaining elements 60 in the injection device 1, the retaining tabs 106 do not prevent the user from removing the needle housing 104 when the needle 96 and the cartridge 83 are present. However, any removal of the needle housing 104 during the process

The connection is detected by the sensor 109. If such removal has occurred, the control unit 95 immediately stops the process of making the connection and controls the restoration of the movable structure 82, 84, 86, 92 to its upper connection. Then, the user is suggested via the display screen 110 (Fig. 41) used on the injection device to start the process of making the connection again.

[0089] To disconnect the needle 96 from the cartridge 83, the user inserts the empty needle housing 104 into the opening 98 until the retaining members 106, 107 engage the needle housing 104. The actuation of the tabs 106 is detected by the sensor 109. This causes the control unit 95 to actuate the second actuator 87 to move the structure 82, 84, 86, 92 down to the lower position, where the needle support 99 is secured in the needle housing 104 (Fig 23, 24). The user may then actuate the needle release button 111 provided on the housing of the device 81 and connected to the control unit 95 to move the square stop member 112 transversely to the B axis to a position in which the leg 113 of the stop member 112 inserted into the gap between the abutment surface 107 and the upper annular flange 108 of the needle housing 104 will be above the upper end of the needle support 99 (Fig. 24). Then, the structure 82, 84, 86, 92 is moved in the opposite direction, while the needle carrier 99, and with it the needle 96, are stopped by the stopping member 112, and thus the needle carrier 99 and the needle 96 detach from the holder 82 of the cartridge and from the cartridge 83 (Fig. 25). The user can then unhook the needle assembly 105 from the retaining tabs 106 and remove it from the injection device. [0090] The sensor elements are used in the injection device to detect the connection of the needle 96 to the cartridge 83. These sensor elements, seen in Fig. 26 - 29, include an optical transmitter 114, such as a light emitting diode, as well as first and second optical receivers 115, 116, such as photodiodes, attached to the inner surface of the front or rear wall of the device housing 81, and a reflector 117, such as a mirror, attached to the opposite of the rear or front wall of the device housing 81. The optical transmitter 114 is aligned with the first and second optical receivers 115, 116 in a direction parallel to the B axis and is disposed between them. When the cartridge holder 82, and more specifically the movable structure 82, 84, 86, 92, is in the retracted position and no needle is connected to the cartridge 83 (Fig. 26), is the first optical beam 118, forming part of the beam emitted by the transmitter 114, runs for the first time near the lower end 100 of the cartridge holder 82, is reflected by the mirror 117 and passes for the second time near the lower end 100, and then reaches the first receiver 115, while the second optical beam 119 emitted by the transmitter 114 passes for the first time near the lower end 100, is reflected by the mirror 117 and passes a second time near the lower end 100 and then reaches the second receiver 116. As is clearly seen in Fig. 27, the cross section of the upper part of the lower end 100 of the cartridge holder 82 is only partially circular, i.e. the lower end 100 has a bevelled flat side portion 120 to allow the first optical beam 118 to pass through. When the needle support 99, together with the needle 96, is properly connected to the lower end 100 of the cartridge holder 82, the optical beams 118, 119 are interrupted by the needle support 99 (Fig. 29). Receivers 115, 116 no longer receive optical beams 118, 119. This is interpreted by the control unit 95 as an indication that the needle 96 is correctly connected to the cartridge 83. Fig. 28 shows an intermediate configuration in which the needle bracket 99 and the needle 96 are only partially connected to the cartridge holder 82 and the cartridge 83. In this configuration, the second optical beam 119 is interrupted by the bracket 99

ΕΡ 2 298 391 Β1 needles, but the first beam 118 still reaches the first receiver 115. This is interpreted by the control unit 95 as an indication that the needle 96 is only partially connected to the cartridge 83.

Thus, after completing the needle connection process described above, if the control unit 95 determines that no needle is connected to the cartridge 83 or that the needle is only partially connected to the cartridge 83, the user cannot start the injection and proposes he has to redo the needle connection process. The safety of using this injection device is thus increased. [0092] In Fig. thirty and 31 show alternative sensor elements for detecting the connection of the needle 96 to the cartridge 83. In this variation, one of the flexible flanges 103a of the intermediate fastening member 102 is longer than the others. When the cartridge holder 82 is in the retracted position and the needle 96 is properly connected to the cartridge 83, the longest elastic collar 103a, compressed between the needle support 99 and the lower end 83a of the cartridge 83, has an end portion that projects outside the needle support 99 and defines some first angle a1 with axis B. In this configuration, the optical beam emitted by the optical transmitter 121 is reflected by the protruding end portion of the collar 103a towards the optical receiver 122. The receiving of the signal by the optical receiver 122 is interpreted by the control unit 95 as an indication that the needle 96 is correctly connected to the cartridge 83. If, on the other hand, the needle 96 is not properly connected to the cartridge 83, as shown in Fig. 31 , then the protruding end portion of the flange 103a defines a second angle a2, different from the first angle a1, with axis B. In this case, the optical ray reflected by the protruding end portion of the flange 103a is not received by the receiver 122. This is interpreted by the control unit 95 as an indication that no needle is connected to the cartridge 83 or that the needle is incorrectly connected to the cartridge 83.

[0093] Returning to Figs. 15 and 16, drug delivery via needle 96 is, as explained above, passed through the piston 93 of the pushing member 84, which pushes the plunger 85 of the cartridge 83. During this process, the piston 93 and the tube portion 91 are located inside the cartridge 83. Piston 93 and tube 91 remain inside the cartridge 83 as long as the drug doses remain therein. When all doses of the drug contained in the cartridge 83 have been injected into the patient, then the push member 84 is withdrawn from the outside of the cartridge 83 to allow the latter to be replaced (Fig. 15). There is, however, the risk that between two injections, the user will open the door 88 to remove the cartridge 83 from the injection device while the push member 84 is still inside the cartridge 83. Such action could seriously damage the push member 84.

[0094] To eliminate this risk, the present invention preferably relates to a locking mechanism that locks / unlocks the door opening mechanism 88 when the pushing member 84 is inside / outside the cartridge 83.

[0095] Referring to Figs. 32-40, the door opening mechanism 88 includes an opening button 89 that can slide slidably in a direction parallel to the B axis, a locking portion 123 attached to the opening button 89 inside the housing 81 of the device and comprising a collar 124 , a lever 125 actuated by the locking portion 123 and a locking member 126 actuated by the lever 125. The lever 125 is mounted on an axial shaft which is fixed relative to the housing 81 of the device. The locking member 126 is mounted on the movable structure 82, 84, 86, 92 in a position on the opposite side of the B axis from the opening button 89 and in such a way that it can slide sliding relative to the movable structure 82, 84, 86, 92 in the direction parallel to axis 13

ΕΡ2 298 391 Β1

Β, and also has a recess with a flange 127 designed to mate with the corresponding flange 128 of the cartridge holder 82.

[0096] This locking mechanism includes a movable recessed portion 94 and a lever 129 actuated by the recessed portion 94 and having at one end thereof, a flange 130 designed to mate with the flange 124 of the locking portion 123. Lever 129 is mounted on an axis that is relative to the housing 81 of the device. The recessed part 94 can move relative to the B axis and is fixedly attached to one end of the spring 131 (visible in Fig. 13 - 16), the other end of which is permanently attached to the movable structure 82, 84, 86, 92.

[0097] The operation of the opening and blocking mechanisms is as follows: when injecting a dose of drug (Figs. 32-34), the movable structure 82, 84, 86, 92 is in the down position, the piston 93 of the pushing member 84 is inside the cartridge 83, while the recessed portion 94 is in the resting position, except for contact with the lever 129. In this configuration, the flange 130 of the second lever 129 engages the flange 124 of the locking portion 123 (Fig. 33, 34) in such a way that this locking portion 123, and with it the opening button 89, are locked, i.e. they cannot be moved, thus preventing the opening of the door 88. Between two injections using the same cartridge 83, the movable structure 82, 84, 86, 92 is in its retracted position, the piston 93 of the pushing member 84 is inside the cartridge 83, while the depressed portion 94 is in the resting position, out of contact with lever 129 (Figs 35-37). In this configuration, the flange 130 of the second lever 129 still engages the flange 124 of the lock portion 123 (Fig. 37) in such a way that this locking portion 123, and with it the opening button 89, remain locked, thus preventing the door 88 from being opened. When doses of the drug contained in the cartridge 83 have already been injected, then the movable structure 82, 84, 86 , 92 and piston 93 of pushing member 84 are retracted. When retracting the pushing member 84, the piston 93 enters the recess in the recessed portion 94 and pushes the recessed portion 94 upward against the direction of spring 131, whereby the recessed portion 94 comes into contact with the end of the second lever 129 opposite the end having the collar 124 to rotate the lever 129 and thereby disengage it from the locking portion 123 (Fig. 40). The door opening button 89 can then be moved upwards as shown in Fig. 38. The upward movement of the opening button 89 causes the first lever 125 to rotate to move the locking member 126 downwards and thereby disengage the holder 128 insert from the collar 127 of the locking member 126. Under the action of the spring, the door 88, and together with it the cartridge holder 82, are then rotated about the pivot axis 90 to allow the cartridge 83 to be removed from the cartridge holder 82 (Fig. 38). The door opening button 89, the lever 125, the locking member and the lever 129 are subjected to the action of suitable springs which cause them to be held in their resting position, shown in Figs. 32 to 34 or 35 to 37.