FR3142677A3 - DEVICE FOR SUBCUTANEOUS DRUG DELIVERY - Google Patents

Abstract

A device for subcutaneous drug administration includes a cartridge (20) including a container (22) containing the drug, an injection needle configured to inject the drug into a patient when the device is applied to the patient's skin and movable between a rest position in which the injection needle is entirely disposed inside the device and an injection position in which the injection needle protrudes at least partially from the device, a protective element movable between a first operating position in which the protective element projects from the device and covers the tip of the injection needle if the injection needle is in the position of injection, and a second operating position in which the protection element does not project from the device, an elastic element associated with the protection element and configured to exert on said protection element a pushing action which is adapted to maintaining the protective element in the first operating position both before application of the device to the patient's skin and when the device is removed from the patient's skin and to allow the protective element to reach the second operating position when the device is applied to the patient's skin. The protection element includes a locking element (70b) configured to cooperate with a stop element (74) to stop movement of the protection element and to lock the protection element in the first operating position when the device is removed from the patient's skin. Figure for abstract: 21

Description

DEVICE FOR SUBCUTANEOUS ADMINISTRATION OF A DRUG Technical field of the invention

The present invention relates to a device for subcutaneous administration of a drug.

In particular, the device of the present invention falls within the category of "infusion pumps" as defined by the FDA (US Food and Drug Administration) and relates, more particularly, to a device of the type that can be worn on oneself, that is to say configured to be applied to the body of a patient in order to allow the subcutaneous administration of a predetermined dose of medication. The application of the device to the patient's body is carried out by a user, for example a doctor or a nurse or the patient.

Technical background

Examples of delivery devices of the type discussed above are described in EP 3439715B1 and WO 2020/128821A1.

In all wearable delivery devices, the medication is initially contained in a cartridge housed inside the device and is transferred into the patient's body via a fluid pathway.

In the present application, the term "fluidic path" is used to designate any element or set of elements which is configured to be connected, at a first end thereof, to the cartridge housed inside the administration device and comprising, at an end thereof opposite the first end mentioned above, an injection needle intended to be inserted into the patient's body to allow the transfer of the drug from the cartridge to the patient's body.

Typically, the cartridge includes a cylindrical container, made of plastic or glass, a plunger that can slide inside the container to push the medication out of the container, and a pierceable septum that ensures the sterility of the container until therapy administration begins.

Typically, the fluid path includes a piercing needle configured to pierce the pierceable septum of the cartridge and a flexible tube that places the piercing needle in fluid communication with the injection needle.

In such devices, the cartridge container is kept closed by the pierceable septum until administration of the drug is required. When such administration is required, the piercing needle pierces the pierceable septum and opens the fluid path, allowing the drug to reach the patient first through the piercing needle, then through the flexible tube, and finally through the injection needle, due to the thrust exerted by the plunger on the drug within the container.

Obviously, the administration of the drug to the patient takes place after the injection needle is inserted into the patient's body.

Such insertion occurs upon activation of a displacement mechanism configured to move the injection needle between a rest position in which the injection needle is fully disposed within the device and an injection position in which the injection needle protrudes from the device and penetrates the patient's skin.

The displacement mechanism may also be configured to extract the injection needle from the patient's skin at the end of therapy delivery and return it to the interior of the device.

The use of protective elements configured to protect the patient from accidental contact with the injection needle at the end of therapy administration is known.

WO 2002/02165A2 describes various embodiments of protective elements which, through the action of a spring, are activated following removal of the device from the patient's skin.

In particular, the embodiment of figures 17 to 20 of document WO 2002/02165A2 provides for an automatic movement of extraction of a protective element 231 which is initially locked inside the device in a retracted position (figures 17 and 18) and which, only when the device is moved away from the patient's skin, comes out of the device due to the thrust exerted by a spring 232, thus covering the injection needle N ( ). Unlocking of the protective element 231 is operatively associated with moving the injection needle N from the inside to the outside of the device. This movement actually causes the fracture of bending elements which constrain the protective element 231 in the retracted position. It is intended that the protective element 231 remain locked in position once removed from the device.

Also in the device described in US 10881811B2, the shielding element is initially locked inside the device and is then unlocked to exit the device and cover the injection needle when the device is moved away from the patient's skin. Also in this device, the extraction of the shielding element takes place due to the pushing action exerted by a spring and, once extracted from the device, the shielding element remains locked in place. In this case, however, the extraction of the shielding element is functionally independent of the movement of the injection needle and requires a prior rotation of the shielding element. This rotation is only commanded at the end of the administration of the drug.

The Applicant observed that in devices where the extraction of the shield is functionally independent of the movement of the injection needle, the injection needle could accidentally exit the device before applying the device to the patient’s skin, for example due to a malfunction of the injection needle movement mechanism or due to intentional or accidental activation of the device by the user. The Applicant also considered the possibility that the device could be accidentally or intentionally removed from the patient’s skin before the end of therapy delivery. In both cases, the injection needle would be outside the device while the shield is still locked inside the device, with a consequent risk for the patient to prick themselves.

The technical problem solved by the present invention is to provide a device in which the extraction of the protective element is functionally independent of the movement of the injection needle and in which any possibility of voluntary or accidental contact of the patient with the tip of the injection needle is avoided both before applying the device to the patient's skin and after applying the device to the patient's skin.

The present invention therefore relates to a device for subcutaneous administration of a drug, comprising:
- a cartridge comprising a container containing the medicine;
- an injection needle configured to inject the medicament into a patient when the device is applied to the patient's skin, the injection needle being movable between a rest position in which the injection needle is fully disposed within the device and an injection position in which the injection needle protrudes at least partially from the device;
- a protective element movable between a first operating position in which the protective element projects from the device and covers the tip of the injection needle if the injection needle is in the injection position, and a second operating position in which the protective element does not project from the device;
- an elastic element associated with the protective element and configured to exert on said protective element a pushing action which is adapted to maintain the protective element in the first operating position both before the application of the device to the patient's skin and when the device is removed from the patient's skin and to allow the protective element to reach the second operating position when the device is applied to the patient's skin;
- a stop element configured to stop the movement of the protection element;
wherein said protective element comprises a locking element configured to cooperate with said stopping element and to lock the protective element in the first operating position when the device is removed from the patient's skin.

In the device of the invention, it is provided that the protective element is outside the device before applying the device to the patient's skin and covers the tip of the injection needle in the event that the latter for any reason is outside the device or comes out of the device, so as to prevent the patient from coming into contact with the tip of the injection needle. If, for example, due to accidental or intentional removal of the device from the patient's skin before the end of the administration of the therapy, the injection needle remains in the extracted position, the protective element immediately comes out of the device and remains locked in the extracted position, also preventing in this case the patient from coming into contact with the tip of the injection needle.

Preferred features of the device according to the invention are described below. Each of these features may be provided individually or in combination with the others.

Preferably, the device has a reversible initial configuration in which the stop member is in a distal position relative to the locking member and the locking member is integrally movable with the shield member from the first operating position to the second operating position, and vice versa. The shield member is then free to move between the first operating position and the second operating position prior to applying the device to the patient's skin.

Preferably, the device has an irreversible final configuration in which the stop element and the locking element are in mutual contact and the protection element is locked in the first operating position.

In preferred embodiments, when the device is in the initial reversible configuration, the injection needle is in the rest position. The injection needle displacement mechanism is therefore deactivated and a possible exit of the injection needle outside the device can only occur as a result of a malfunction of the injection needle displacement mechanism mentioned above or a voluntary or accidental activation of the device by the user. In these circumstances, however, the tip of the injection needle is covered by the protective element, which is in its extracted position.

In the preferred embodiments mentioned above, when the device is in the final irreversible configuration, the injection needle is in the rest position. If the injection needle is accidentally in the injection position and the device is not in contact with the patient's skin, for example because it was accidentally or intentionally removed from the patient's skin before the end of the administration of the therapy, the protective element immediately comes out and covers the tip of the injection needle.

Preferably, the stop element is movable from an initial position in which the stop element and the locking element are not superimposed on each other to a final position in which the stop element and the locking element are superimposed on each other. Until the stop element reaches the final position, the protective element remains free to move from the first operating position to the second operating position, and vice versa. When the stop element reaches the final position, the protective element extends out of the device and covers the tip of the injection needle if the injection needle is in the injection position.

Preferably, the stop element is movable from said initial position to said final position along a first direction.

Preferably, the locking element is movable integrally with the protective element between said first operating position and said second operating position along a second direction orthogonal to said first direction.

Preferably, when the device is in the initial reversible configuration, the stop element is movable along said first direction and the device passes from the initial reversible configuration to the final irreversible configuration when the stop element is in the final position and the locking element moves along said second direction from the second operating position to the first operating position passing beyond the stop element.

Preferably, one of the locking element and the stopping element is made of a rigid material and the other of the locking element and the stopping element is made of a deformable material.

Preferably, the movement of the locking element along said second direction causes an interference between the locking element and the stopping element and a deformation of the element made of a deformable material which is suitable to allow the passage of the element made of a rigid material.

In preferred embodiments, the locking member is made of a rigid material and the stopping member is made of a deformable material.

In this case, the stop member preferably comprises a first surface facing the locking member when the stop member is in the end position and the locking member is in the second operating position, and a second surface facing on the opposite side of the first surface and towards the locking member when the stop member is in the end position and the locking member is in the first operating position.

Preferably, said first surface allows the stop member to deform due to interference with the locking member and the locking member to move along said second direction from the second operating position to the first operating position.

More preferably, said first surface is inclined relative to a plane orthogonal to the second direction, thereby facilitating the passage of the locking element from one side to the other side of the stop element following deformation of the latter.

Preferably, said second surface defines a notch which prevents the locking element from moving from the first operating position when the device is in the final irreversible configuration.

More preferably, said second surface is orthogonal to the second direction.

Preferably, said protective element comprises a base provided with a through hole or a pierceable septum to allow the passage of the injection needle during movement of the injection needle between the rest position and the injection position when said protective element is in the second operating position.

Preferably, said base comprises a raised edge that defines in the shield member a recess configured to accommodate the tip of the injection needle both when the shield member is in the second operating position and the injection needle is in the rest position and when the shield member is in the first operating position and the injection needle is in the injection position. The raised edge surrounds the tip of the injection needle and prevents the user from coming into contact with the tip if the injection needle is outside the device and the device is not applied to the patient's skin.

In its preferred embodiments, the device comprises a fluid path opening system that can be activated to place the injection needle in fluid communication with the container. This system is activated shortly after the device is put into operation, which can be achieved for example by pressing a special button by the patient after applying the device to the patient's skin.

Preferably, the locking element is configured to lock the protective element in the first operating position upon activation of the fluid path opening system, and thus after the device has been removed from the patient's skin, possibly even before the end of therapy delivery.

Preferably, the fluid path opening system comprises a piercing needle configured to pierce a pierceable septum coupled to one end of said container, a drive member configured to drive movement of the piercing needle, and a motion transmission member configured to drive the drive member.

Preferably, the stop element is associated with said motion transmission member. In this way, both the fluid path opening system and the locking of the protection element are driven by a single motion transmission member, with a consequent structural simplification of the device.

In its preferred embodiments, the device comprises a position sensor configured to detect contact of the device with the patient's skin. Due to the above-mentioned sensor, it is ensured that the device cannot be put into service before being applied to the patient's body or, in other words, it is ensured that the device can only be put into service when it is actually in the condition to be able to administer the drug. This is particularly advantageous because the drugs used in these devices are typically very expensive and because to ensure patient safety, the device is considered to have been used immediately after being put into service, whether the drug is then actually administered to the patient or whether such administration is successful.

Preferably, the position sensor comprises a magnet integrally associated with the protective element and a Hall effect sensor arranged in the device in the vicinity of the magnet. In this way, the detection of the contact between the device and the patient's body takes place, after the magnet and the Hall effect sensor have been brought together, due to the movement of the protective element from the outside to the inside of the device as soon as the device is applied to the patient's body.

Preferably, the magnet is fully housed in a seat formed in the shielding element.

Preferably, said locking element is associated with said magnet.

Brief description of the figures

Other features and advantages of the present invention will become clearer upon reading the following detailed description of preferred embodiments thereof, made with reference to the accompanying drawings and given for information purposes only and without limitation. In these drawings:

- there is a perspective view of a device according to the present invention;

- there is an exploded perspective view of a first embodiment of a module of the device of the ;

- there is an exploded perspective view of another module of the device of the ;

- there is a perspective bottom view of the device of the equipped with a patch;

- there is a perspective bottom view of the device of the after removing a protective layer from the patch;

- there is a top sectional view of the module of the in an initial configuration of the device of the ;

- there is a perspective sectional view of the device of the before being applied to the patient's skin;

- there is a perspective sectional view of the device of the immediately after being applied to the patient's skin;

- there represents an enlargement of a detail of the module of the in an operating configuration of the device subsequent to that of the ;

- there is a sectional side view of part of the module of the in an initial configuration of the device of the ;

- there is a sectional side view of the portion of the in an operating configuration of the device subsequent to that of the and corresponding to that of the ;

- there is a sectional side view of another detail of the module of the in an initial configuration of the device of the ;

- there is a sectional side view of the detail of the in an operating configuration of the device subsequent to that of the and corresponding to that of figures 9 and 11;

- there is a perspective sectional view of some components of the module of the in an operating configuration of the device subsequent to that of the and corresponding to that of figures 9, 11 and 13;

And - Figures 15 and 16 are perspective views of certain components of a second embodiment of the device of the present invention in two subsequent operating configurations thereof;

- there is a perspective sectional view of some of the components of Figures 15 and 16 in an operating configuration of the device subsequent to that of the ;

, , And - Figures 18 to 21 show an enlargement of another part of the module of the in four subsequent operating configurations of the device of the ;

- there is a sectional side view of part of the device of the in an operating configuration of the device subsequent to that of the ;

-there is a sectional side view of the device of the in a possible operating configuration thereof in which said device is not applied to the patient's skin;

- there is a perspective view of a component of the device of the ;

- there is a perspective view of a portion of a third embodiment of the module of the when the device is not applied to the patient's skin;

- there is a perspective view of part of the immediately after applying the device to the patient's skin;

- there is a top view of the part of the in the operating configuration of the ;

- there is a perspective view of part of the in an operating configuration of the device subsequent to that of figures 26 and 27;

- there is a top view of the part of the in the operating configuration of the ;

, And - figures 30 to 32 are perspective views of the part of the in three operating configurations of the device subsequent to that of the ;

- there is a sectional side view of the portion of the in the operating configuration of the ;

- there is a sectional side view of the portion of the in the operating configuration of the ;

-there is a timing diagram relating to different operating steps implemented by the device of the present invention during its use.

Detailed description of the invention

The device 1 comprises an administration module 2, shown in the , and a control module 3, shown in the .

Device 1 is obtained by mutually coupling the administration module 2 and the control module 3. This coupling is reversible, that is to say that the two modules 2 and 3 can be decoupled after having been coupled.

One or more seals (not shown) are interposed between the administration module 2 and the control module 3 in order to ensure the sealing of the mutual coupling.

The administration module 2 is preferably disposable, while the control module 3 is preferably reusable. In other words, the administration module 2 is configured to be applied to the patient's body only once and for a certain period of time to administer the drug, completely or in part, in one or more successive injections, even spaced apart in time from each other. Conversely, the control module 3 can be used several times, by coupling it from time to time to a new administration module 2.

As shown in the , the control module 3 comprises a lower body 4 and an upper cover 5 associated with the lower body 4, preferably by ultrasonic welding. In this case, ultrasonic welding is preferable to laser welding because the latter requires the use of transparent materials that are not considered practical to use for the control module 3, since it can be customized with different colors and/or finishes.

A housing compartment 6 is defined between the lower body 4 and the upper cover 5. The housing compartment 6 contains a control unit 7, generally consisting of a printed circuit and configured to control the delivery of the drug from the delivery module 2, a power supply battery 8 configured to supply power to the control unit 7 and a motor 9 which rotates a magnetic drive rotor 9a.

A plurality of electronic components and a hardware unit that supplies power to said electronic components are provided in the control module 3.

The control module 3 further comprises a switch (not shown) configured to supply power to the control unit 7 and an activation button 3a. The patient actuates the device 1 by pressing the activation button 3a.

As shown in the , the administration module 2 comprises a main body 11 and an intermediate cover 15 associated with the main body 11 and interposed between the main body 11 and the lower body 4 of the control module 3. Preferably, the intermediate cover 15 is welded to the main body 11 by laser welding. In this case, the latter is preferable to ultrasonic welding, since the assembly of the administration module 2 takes place with all the members described below already mounted on the main body 11 and the use of ultrasonic welding would risk activating these members.

A housing compartment 10 is defined between the main body 11 and the intermediate cover 15.

As shown in the , the main body 11 comprises an application surface 12 configured to come into contact with the patient's body.

The application surface 12 is substantially flat and defines a plane P for resting on the patient's skin.

The application surface 12 comprises a through opening 12a ( ).

Referring again to the , the housing compartment 10 is configured to house a plurality of components, including a cartridge 20 and a fluid path 30.

The administration module 2 further comprises an ignition magnet 2a and an NFC tag 2b on which a plurality of information is stored.

The cartridge 20 is arranged on the main body 11 and comprises a substantially cylindrical container 22, made of a plastic or glass material and containing the medicament to be administered to a patient. A pierceable septum 24 which closes the container 22 and guarantees its sterility until the use of the device 1 is arranged at one end 23 of the container 22. A piston 26 (shown in the ) can slide into the container 22 to administer the medication.

As shown in the , the fluid path 30 is also arranged on the main body 11 and is configured to be traversed by the drug during subcutaneous administration of the drug, allowing the transfer of the drug from the cartridge 20 to the patient's body.

The fluid path 30 includes a piercing needle 32 configured to pierce the pierceable septum 24 (as illustrated for example in the ), an injection needle 34 configured to be inserted into the patient's body (as illustrated for example in the ), and a flexible tube 36 (illustrated for example in FIGS. 2 and 6) which places the needles 32 and 34 mentioned above in fluid communication.

In particular, as shown in Figures 2 and 6, the flexible tube 36 has an end portion 36a connected to a support member 42 which supports the piercing needle 32 and an opposite end portion 36b connected to a support member 62 which supports the injection needle 34.

In reference to the , the administration module 2 further comprises a fluid path opening system 40 configured to control the piercing of the pierceable septum 24 by the piercing needle 32 and thereby place the container 22 in fluid communication with the injection needle 34 through the piercing needle 32 and the flexible tube 36.

The support member 42 is slidably mounted on a slide guide 44 mounted on the main body 11 (FIGS. 9, 12 and 13). The support member 42 is movable between a first operating position in which the piercing needle 32 is spaced from the pierceable septum 24 (as illustrated for example in FIGS. 10 and 12) and the fluid path 30 is closed, and a second operating position in which the piercing needle 32 has pierced the pierceable septum 24 (as illustrated for example in FIGS. 11 and 13), thereby opening the fluid path 30.

Referring to Figures 10 and 11, the movement of the support member 42 is achieved by providing a motion transmission member 50 comprising a worm screw 54 engaged with a rack 51 at a coupling portion 53 of the rack 51. The latter is in turn coupled to a drive member 48 which can rotate about an axis of rotation X and which can be coupled to the support member 42.

In particular, the drive member 48 comprises a substantially circular base body 48a, a coupling portion 48b configured to couple to the support member 42 and a coupling portion 48c at which a coupling portion 52 of the rack 51 is engaged. The coupling portion 52 is arranged downstream of the coupling portion 53 along the direction A.

The coupling parts 48b and 48c extend from the base body 48a on axially opposite sides relative to the axis of rotation X.

The coupling portion 48b is defined by a peripheral wall 48d. The latter is provided with a through opening 48e and delimits in the coupling portion 48b a substantially cylindrical zone 48g (figures 11 and 14).

The coupling portion 48c comprises a toothing 48f engaging with the coupling portion 52 of the rack 51 and extending circumferentially over a predetermined angle less than 360°, more preferably less than 180°, for example equal to approximately 90°.

As shown in the , the rack 51 is driven to move, towards the support member 42 along a direction A orthogonal to the axis of rotation X and substantially parallel to the plane P, by the rotation of the worm screw 54 which in turn is driven in rotation by a magnetic rotor 56 (shown entirely on the ) mounted on the main body 11 and driven by the magnetic drive rotor 9a provided in the control module 3. Due to the coupling between the rack 51 and the toothing 48f, the movement of the rack 51 causes the rotation of the drive member 48 about the axis of rotation X.

As shown in the , the support member 42 is subjected to a pushing action along a direction B opposite to the direction A by an elastic element 46, in particular a torsion spring. This spring comprises a plurality of turns arranged around an axis orthogonal to the axis of rotation X and tends to push the support member 42 from the first operating position to the second operating position.

As shown in Figures 10, 11 and 14, the support member 42 includes a body 42a and a stop member 43 projecting from the body 42a and sized to pass through the through opening 48e. In particular, the stop member 43 is defined by a cylindrical pin 43a that extends cantilevered from the outer side surface of the body 42a.

Until the drive member 48 rotates about the axis of rotation X by an angle less than a predetermined value, the support member 42 remains in the first operating position due to the mutual abutment between the abutment element 43 and the outer surface of the peripheral wall 48d. This mutual abutment counteracts the thrust action exerted by the elastic element 46 on the support member 42 ( ).

As soon as the rotation angle of the drive member 48 reaches the predetermined value mentioned above, the support member 42 is free to move from the first operating position to the second operating position along the direction B due to the fact that the stop member 43 is located at the through opening 48e ( ) and can pass through it due to the pushing action exerted by the elastic element 46, so as to arrange itself in the zone 48g of the coupling part 48b ( ).

Figures 15 to 17 show a second embodiment of the fluid path opening system 40, which can also be used in the device 1 of the present invention as an alternative to that described above. Elements of this second embodiment that are identical or equivalent to those described above are designated by the same reference numeral.

In this second embodiment, the turns of the torsion spring which defines the elastic element 46 are arranged around an axis orthogonal to the axis of rotation X and positioned closer to the rack 51 relative to the axis of the torsion spring of the embodiment described above.

Furthermore, in the embodiment of Figures 15 to 17, the stop element 43 is defined by a rectilinear rib 43b arranged on the outer lateral surface of the body 42a.

On the , the drive member 48 is shown in a first angular position, while on the , the drive member 48 is shown in a second angular position. These angular positions are functionally similar to those of FIGS. 10 and 11 of the first embodiment described above.

On the , the drive member 48 is shown in another angular position posterior to that of the . When the drive member reaches the angular position of the , the rib 43b, which previously entered the area 48g of the coupling part 48b ( ), is located at an inner surface of the peripheral wall 48d and cannot move out of the area 48g. In this way, the drive member 48 hinders a possible tendency of the support member 42 to move from the second operating position to the first operating position.

As shown in the and Figures 18 to 23, the administration module 2 also comprises an injection needle moving mechanism 60, configured to move the injection needle 34, at the start of the administration of the therapy from a rest position, in which the injection needle 34 is entirely arranged inside the device 1 and does not protrude from the plane P of the device 1 (Figures 18 and 19), to an injection position in which the injection needle 34 protrudes at least partially from the plane P of the device 1 (Figures 20 and 22) through the through opening 12a, and at the end of the administration of the therapy from the injection position to the rest position ( ).

The support member 62 which supports the injection needle 34 is movable orthogonally to the plane P between a first operating position in which the injection needle 34 is in the rest position and a second operating position in which the injection needle 34 is in the injection position.

The support member 62 has a substantially cylindrical shape and has an outer side surface 62a to which the end portion 36b of the flexible tube 36 is connected.

As shown in the , the support member 62 is subjected to a pushing action exerted by a compression spring 64. This pushing action tends to push the support member 62 towards its first operating position, so as to maintain the injection needle 34 in the rest position before use of the device 1 ( ) and to return the injection needle 34 to the rest position after administration of the therapy ( ).

In particular, the compression spring 64 is arranged between the main body 11 and an inner surface 62b of the support member 62 facing the plane P.

The compression spring 64 extends along an axis C orthogonal to the plane P, while the injection needle 34 extends along a separate axis N parallel to the axis C. The axis N is arranged near the outer lateral surface 62a of the support member 62.

Referring to Figures 18 to 23, the injection needle moving mechanism 60 includes a push member 63 configured to move the support member 62 and, thus, the injection needle 34. The push member 63 is moveable from a first service position (Figures 18 and 19) in which the support member 62 is in the first operating position and the injection needle 34 is in the rest position to a second service position (Figures 20, 22 and 23) in which the support member 62 is in the second operating position and the injection needle 34 is in the injection position.

The thrust member 63 is subjected to a thrust action exerted by a compression spring 65 (Figures 22 and 23). This thrust action tends to push the thrust member 63 towards the second service position.

The compression spring 65 is arranged between the intermediate cover 15 and an inner surface 63a of the thrust member 63 facing away from the plane P.

The compression spring 65 extends along an axis D orthogonal to the plane P. The axis D is distinct from the axis C and the axis N, and parallel to them.

Compression spring 65 has a higher elastic constant than compression spring 64.

The injection needle moving mechanism 60 has two main operating configurations.

In a first operating configuration, illustrated in the , the pushing member 63 is coupled to the supporting member 62 and the force exerted by the compression spring 65 on the pushing member 63 moves it from the first operating position to the second operating position, moving the supporting member 62 from the first operating position to the second operating position. During the movement of the supporting member 62, the compression spring 64 is loaded.

In a second operating configuration, shown in the , the pushing member 63 is decoupled from the supporting member 62 and the force exerted by the compression spring 64 on the supporting member 62 moves it from the second operating position to the first operating position. When the injection needle moving mechanism 60 is in the second operating configuration, the pushing member 63, which is decoupled from the supporting member 62, remains in the second operating position due to the pushing action exerted by the compression spring 65.

The thrust member 63 has a substantially cylindrical shape and is movable in rotation around the axis D from a first angular position ( ) in which the injection needle moving mechanism 60 is in the first operating configuration at a second angular position ( ) in which the injection needle moving mechanism 60 is in the second operating configuration.

A 62c stop element (visible on the ) extends from the outer side surface 62a of the support member 62 toward the thrust member 63 and a thrust member 63c extends from an outer side surface 63b of the thrust member 63 toward the support member 62.

When the injection needle moving mechanism 60 is in the first operating configuration, the pushing member 63c is coupled to the stop member 62c and exerts a pushing action against the latter ( ), while when the injection needle moving mechanism 60 is in the second operating configuration, the thrust member 63c is decoupled from the stop member 62c ( ).

The rotation of the pushing member 63 from the first angular position to the second angular position, and consequently the transition of the injection needle moving mechanism 60 from the first operating configuration to the second operating configuration, is driven by an instruction member 61 arranged concentrically to and outside the pushing member 63.

The instruction member 61 has a substantially cylindrical shape and is driven to rotate about the axis D initially from an angular stop position ( ) in which the thrust member 63 is in the first angular position and the instruction member 61 is coupled to the thrust member 63 and maintains the latter in the first service position, towards a first angular release position ( ) in which the thrust member 63 is still in the first angular position and the instruction member 61 is decoupled from the thrust member 63 allowing the thrust member 63 to reach the second service position.

A protruding member 63d extends from the outer side surface 63b of the thrust member 63 on the opposite side relative to the thrust member 63c.

The instruction member 61 comprises a stop surface 61e which, when the instruction member 61 is in the angular stop position, abuts against the projecting element 63d (Figures 18 and 19).

The instruction member 61 further comprises a seat 61a which, when the instruction member 61 is in the first angular release position, houses the projecting element 63d ( ), and a through opening 61b ( ) through which the thrust member 63c passes to enable the thrust member 63 to couple to the support member 62.

When, following the rotation of the instruction member 61, the seat 61a is below the projecting element 63d, the thrust member 63 is free to move from the first operating position to the second operating position due to the thrust action exerted by the compression spring 65. Consequently, the support member 62 is moved from the first operating position to the second operating position due to the movement of the thrust member 63 from the first operating position to the second operating position and, consequently, to the thrust exerted by the thrust element 63c on the stop element 62c, this thrust no longer being hindered by the stop surface 61e of the instruction member 61. The injection needle 34 is thus extracted from the device 1.

The thrust member 63c passes through the through opening 61b of the instruction member 61 both when the thrust member 63 is in the first service position and when the thrust member 63 is in the second service position.

Then, the instruction member 61 is rotated about the axis D from the first angular release position ( ) to a second angular release position ( ) in which the thrust member 63 is in the second angular position. This rotation causes a similar rotation of the thrust member 63 because the projecting element 63d is housed in the seat 61a.

The housing of the projecting element 63d in the seat 61a therefore allows both the transition of the thrust member 63 from the first service position to the second service position due to the thrust exerted on the thrust member 63 by the compression spring 65, with the consequent extraction of the injection needle 34 from the device 1 ( ), and the transfer of the rotary motion of the instruction member 61 to the thrust member 63 when it is in the second service position ( ), with the consequent release of the support member 62 by the thrust member 63 and the consequent retraction of the injection needle 34 inside the device 1 due to the thrust exerted on the support member 62 by the compression spring 64.

The instruction member 61 comprises a coupling portion 61c engaged with the worm screw 54. The coupling portion 61c is a toothing extended circumferentially over a predetermined angle, preferably less than 180°.

As shown in the , a suitably shaped plate 630 is arranged above the pusher member 63 and the support member 62 in order to prevent rotation of the pusher member 63 about the axis D. This plate 630 also allows all components of the injection needle moving mechanism 60 to be aligned and retention of the compression springs 64 and 65 along the direction of the axis D to be ensured.

As shown in FIGS. 7, 8, 22 to 24, the delivery module 2 also includes a shielding element 70 disposed around the injection needle 34 and configured to cover the tip of the injection needle 34 if the latter is in the injection position, or moves therein, for example due to a malfunction or failure of the injection needle moving mechanism 60, before applying the device 1 to the patient's skin, or if the injection needle 34 accidentally remains in the injection position upon removal of the device 1 from the patient's skin, for example due to accidental or intentional removal by the patient before the end of the administration of the therapy ( ).

The protective element 70 is movable between a first operating position (Figures 7 and 23) in which it projects from the device 1 and covers the tip of the injection needle 34 if the injection needle 34 is in the injection position ( ), and a second operating position (figures 8 and 22) in which it does not protrude from the device 1.

The protective element 70 is shown in detail in the .

The protective element 70 is subjected to a pushing action exerted by an elastic element 72, in particular by a compression spring. This pushing action tends to maintain the protective element 72 in the first operating position both before applying the device 1 to the patient's skin and when the device 1 is removed from the patient's skin ( ) and to allow the protective element 70 to reach the second operating position when the device 1 is applied to the patient's skin (Figures 8 and 22).

In particular, the elastic element 72 is arranged between the intermediate cover 15 and an inner surface 70e which is inside the protective element 70 and which faces the intermediate cover 15 (Figures 22 and 23).

The elastic element 72 extends along an axis E orthogonal to the plane P. The axis E is distinct from the axes C, D and N, and parallel to them.

In reference to the , the administration module 2 comprises a stop mechanism 170 configured to stop the movement of the protection element 70.

In particular, the protective element 70 comprises a locking element 70b configured to lock the protective element 70 in the first operating position when the device 1 is removed from the patient's skin. The locking of the protective element 70 occurs when the locking element 70b interferes with a stop element 74 associated with the rack 51 at a coupling portion 55 of the rack 51 which is arranged upstream of the coupling portion 52 and downstream of the coupling portion 53 along the direction A, i.e. interposed between the coupling portion 53 and the coupling portion 52 (Figures 20 and 21).

The device 1 has a reversible initial configuration in which the protective element 70 is free to move between the first operating position and the second operating position and vice versa before the device 1 is applied to the patient's skin. In this configuration, the locking element 70b, integral with the protective element 70, is in a distal position relative to the stop element 74.

The device 1 has an irreversible final configuration in which the protection element 70 is locked in the first operating position. In this configuration, the locking element 70b is in contact with the stopping element 74.

Due to the movement of the rack 51 along the direction A, the stopping element 74 moves along this direction A from an initial position to an end position.

In the initial position, the stop element 74 and the locking element 70b are not superimposed on each other and the device 1 is in the initial reversible configuration (Figures 18 and 19), while in the final position, the stop element 74 and the locking element 70b are superimposed on each other and the device 1 is in the final irreversible configuration (Figures 20 and 21).

Preferably, the locking element 70b is made of a rigid material and the stopping element 74 is made of a deformable material.

The changeover from the reversible configuration to the irreversible configuration occurs when the stop element 74 is in the final position and the locking element 70b moves along a direction F ( ) orthogonal to direction A, passing beyond the stop element 74. This movement occurs when the device 1 is removed from the patient's skin due to the movement of the protection element 70 from the second operating position to the first operating position due to the pushing action exerted by the elastic element 72.

The movement of the locking member 70b along the direction F first causes the locking member 70b to interfere with the stopping member 74, and then the transition of the locking member 70b to the opposite side of the stopping member 74 due to the deformation of the latter.

In particular, the stop element 74 comprises a first surface facing away from the plane P and a second surface facing towards the plane P.

The first surface allows deformation of the stop member 74 as a result of interference with the locking member 70b and movement of the locking member 70b along the direction F from the second operating position to the first operating position.

The first surface is preferably inclined relative to a plane orthogonal to the direction F, thereby facilitating the transition of the locking element 70b from one side to the other side of the stop element 74 as a result of the deformation of the latter.

The second surface instead defines a notch which, when the device 1 is in the final irreversible configuration, prevents the locking element 70b from moving from the first operating position. The second surface is preferably orthogonal to the direction F.

As shown in the , the protective element 70 has a base 70a provided with a through hole 71 to allow the transition of the injection needle 34 during movement of the injection needle 34 between the rest position and the injection position when the protective element 70 is in the second operating position.

The base 70a includes a raised edge 70b defining in the base 70a a recess 70c which houses the tip of the injection needle 34 both when the protection element 70 is in its second operating position and the injection needle 34 is in the rest position ( ) and when the protective element 70 is in its first operating position and the injection needle 34 is in the injection position ( ).

As shown in Figures 33 and 34, the through hole 71 may be closed by a pierceable septum 271.

The device 1 comprises a position sensor 76 (figures 7 and 8) adapted to detect contact of the device 1 with the patient's skin.

The position sensor 76 comprises a magnet 77 integrally associated with the protection element 70 and a Hall effect sensor 78 arranged in the control module 3 in the vicinity of the magnet 77.

The magnet 77 is entirely housed in a seat 75 formed in the protective element 70 ( ).

The locking element 70b is associated with the seat 75 near the magnet 77.

As shown in Figures 2 and 5, the device 1 further comprises a flexible sleeve 80 associated in a watertight manner with the application surface 12 of the administration module 2 around the through opening 12a.

The flexible sleeve 80 is made of medical grade silicone material.

The flexible sleeve 80 surrounds the protective member 70 and includes a base surface 80a having an inner surface integrally associated with the outer surface of the base 70a of the protective member 70.

In the embodiment illustrated herein, the flexible sleeve 80 is defined by a bellows-type membrane having a frustoconical shape.

The flexible sleeve 80 is arranged entirely inside the administration module 2 when the protective element 70 is in its second operating position ( ).

The base surface 80a of the flexible sleeve 80 covers the through hole 71 of the protective member 70 and can be pierced by the injection needle 34 when the injection needle 34 moves from the rest position to the injection position.

The flexible sleeve 80 comprises an annular end portion 83 fixed to the application surface 12 of the administration module 2 by means of a compression ring 83a (FIGS. 23, 33 and 34). The latter is welded to the application surface 12 by ultrasonic welding.

The annular end portion 83 is thus interposed between the application surface 12 and the compression ring 83a and prevents water and powders from accessing the interior of the device 1 via the through opening 12a of the application surface 12.

As shown in Figures 4 and 5, a patch 90 is applied to the application surface 12 of the main body 11 of the administration module 2.

The patch 90 includes an adhesive layer 91 integrally attached to the application surface 12 and a protective layer 92 removably attached to the adhesive layer 91. Prior to administering the therapy, the protective layer 92 is removed ( ) and the device 1 is attached to the patient's skin through the adhesive layer 91.

The device 1 further comprises a cap 100 fixed in one piece to the protective layer 92. In particular, the cap 100 comprises a collar 101 fixed to the protective layer 92 by interposition of a double adhesive element 101a.

The cap 100 is made of a rigid material and is shaped to completely accommodate, with clearance, the protective element 70 and the flexible sleeve 80 which surrounds the protective element 70 when the latter is in its first operating position.

In the embodiment illustrated herein, the cap 100 has a frustoconical shape.

As already mentioned, the protective element 70 is initially in its extended configuration of the and the cover 100 covers the protective element 70, as shown in the .

Before applying the device 1 to the patient's skin, the patient removes the protective layer 92 from the patch 90, simultaneously removing with it also the cap 100 and thus exposing the protective element 70 and the adhesive layer 91 of the patch 90.

The patient can then proceed to apply the device 1 to his skin by securing it through the adhesive layer 91 of the patch 90. The patient's skin counteracts the pushing action exerted by the elastic element 72 and causes the protective element 70 to retract inside the administration module 2, bringing the magnet 77 closer to the Hall effect sensor 78 and thus allowing the control unit 7 to establish that the device 1 is in contact with the patient's skin and to activate the administration of the therapy.

The administration of the therapy comprises the controlled movement of the piston 26 within the container 22 towards the pierceable septum 24. For this purpose, the administration module 2 comprises a drug delivery mechanism 110 ( ) which is activated, driven by the control unit 7, by the same magnetic rotor 56 which drives the motion transmission member 50 and, consequently, the rotation of the worm screw 54. As already mentioned, the latter causes both the activation of the injection needle displacement mechanism 60 and the displacement of the rack 51 along the direction A, which in turn causes both the opening of the fluid path 30 and the locking of the protective element 70 in the first operating position after the removal of the device 1 from the patient's skin.

In particular, the control unit 7 drives the magnetic rotor 56 alternately in a first direction of rotation to activate the motion transmission member 50 and in a second direction of rotation opposite to the first direction of rotation to drive the delivery of the medicament from the container 22 upon activation of another motion transmission member 111 ( ) arranged in the main body 11 on the side opposite the motion transmission member 50 relative to the magnetic rotor 56 and the worm screw 54.

Figures 25 to 34 show another embodiment of a device which differs from the device 1 described above with respect to certain details relating to the injection needle displacement mechanism 60, the protective element 70 and the flexible sleeve 80. The elements and/or members of this embodiment which are identical or equivalent to those described above are indicated by the same reference numeral.

In this case, the flexible sleeve 80 does not have the base surface 80a and the protective element 70 has a base 70a having a diameter greater than that of the adjacent end portion of the flexible sleeve 80.

Also in this case, a support member 62 which supports the injection needle, a pushing member 63 and an instruction member 61 equivalent to those described above are provided.

There shows the operating configuration in which the injection needle 34 is in the rest position and the protective element 70 and the flexible sleeve 80 protrude from the device.

Figures 26 and 33 show the operating configuration in which the device is applied to the patient's skin. The injection needle 34 is still in the rest position and the protective element 70 and the flexible sleeve 80 are pushed inside the device. Only the base 70a of the protective element 70 remains protruding from the device.

There shows the operating configuration in which the device is applied to the patient's skin and the injection needle 34 is in the injection position to administer the therapy. The protective element 70 and the flexible sleeve 80 are still inside the device.

There shows the operating configuration in which the device is still applied to the patient's skin, but the injection needle 34 has been returned to the rest position.

There shows the operating configuration in which the device is removed from the patient's skin at the end of therapy delivery. The protective element 70 and the flexible sleeve 80 protrude from the device.

Figures 32 and 34 show the operating configuration in which the device is removed from the patient's skin before therapy delivery is complete and the injection needle 34 is still in the injection position. The shield member 70 and flexible sleeve 80 protrude from the device and the shield member 70 is locked in position outside the device.

In this embodiment, the instruction member 61 comprises two articulated arms 631 arranged on opposite sides with respect to the thrust element 63c ( ). As illustrated in the , each articulated arm 631 comprises a first lever 631a articulated on the outer lateral surface 61g of the instruction member 61 and a second lever 631b articulated on the first lever 631a. Each second lever 631b is slidably coupled to a respective guide 633 and comprises a respective stop member 174 whose shape and material are similar to those of the stop member 74 described above.

The protective element 70 comprises two locking elements 171 arranged on diametrically opposite sides with respect to the stop element 62c and configured to cooperate with the stop elements 174 ( ).

During rotation of the instruction member 61, the stop elements 174 approach the respective locking elements 171 until each of them is at the level of the respective locking element 171.

In the operating configuration of Figures 25 to 30, the two locking elements 171 are arranged on one side relative to the stopping elements 174, in particular close to the shaped plate 630. This is because the protective element 70 does not protrude from the device.

When the protective element 70 exits the device following removal of the device from the patient's skin, the locking elements 171 pass beyond the stopping elements 174 locking the protective element 70 in the position shown in the . In this operating configuration, the injection needle 34 has been previously returned inside the device.

If, after removal of the device from the patient's skin, the injection needle 34 remains outside the device, as in the operating configuration of the , the protective element 70 and the flexible sleeve 80 protect the patient from any contact with the injection needle 34.

Also referring to the , the sequence of operating steps implemented by the device 1 during its use is described in detail below.

During a first time interval preceding the instant t0 when the patient activates the device 1 by acting on the activation button 3a, the patient receives separately the administration module 2 and the control module 3 and couples them. In this time interval, the device 1 is in standby mode, that is to say that the energy supply battery 8 only powers some of the electronic components present in the control module 3 thanks to the provision of a hardware unit that cuts off the energy supply to all the electronic components except those associated with: the ignition magnet 2a, the switch that supplies energy to the control unit 7, the activation button 3a for activating the device 1 and the NFC tag 2b. The motor 9 is not supplied with energy.

After the mutual coupling, the administration module 2 and the control module 3 are temporarily coupled not only mechanically but also via a magnetic coupling established by the proximity between the magnetic drive rotor 9a provided in the control module 3 and the magnetic rotor 56 provided in the administration module 2. The control unit 7 is energized by a change in the magnetic field generated by the mutual approach between the ignition magnet 2a and the switch that supplies energy to the control unit 7 that are closer. This mutual approach triggers the above-mentioned switch, which energizes the control unit 7.

Once powered up, the control unit 7 performs a self-diagnosis.

In addition, after power-up, the control unit 7 interrogates the NFC tag 2b by reading the information stored therein. In particular, the control unit 7 performs any or all of the following actions: checking whether the administration module 2 has already been used, checking whether the administration module 2 is configured to administer a correct dosage of the drug, establishing the method of administering the drug, establishing the speed of administering the drug.

After power-up, the control unit 7 also reads the signal from the position sensor 76 to establish whether the device 1 is in contact with the patient's skin.

In particular, the patient removes the protective layer 92 from the patch 90, simultaneously removing the cap 100, and applies the device 1 to his skin.

In the time interval mentioned above preceding time t0 and before the application of device 1 to the patient's skin:
- the fluid path 30 is closed, that is to say that the piercing needle 32 is in a distal position relative to the pierceable septum 24 and the elastic element 46 is compressed;
- the protective element 70 is in its first operating position, that is to say it projects from the device 1 and the elastic element 72 is extended;
- due to the distance between the magnet 77 and the Hall sensor 78, the position sensor 76 signals to the control unit 7 that the device 1 has not yet been applied to the patient's body;
- the injection needle movement mechanism 60 is deactivated, that is to say the injection needle 34 is in the rest position, inside the device 1;
- the flexible sleeve 80 is extended.

In the time interval mentioned above preceding time t0, after application of device 1 to the patient's skin:
- the fluid path 30 remains closed;
- the protective element 70 is in its second operating position, that is to say it is arranged inside the device 1 and the elastic element 72 is compressed;
- due to the mutual approach between the magnet 77 and the Hall sensor 78, the position sensor 76 signals to the control unit 7 that the device has been applied to the patient's body and that the control unit 7 can be activated for therapy administration;
- the injection needle movement mechanism 60 remains deactivated;
- the flexible sleeve 80 is folded inside the device 1.

If the control unit 7 does not detect the signal from the position sensor 76 within a predetermined time, the control unit 7 turns off and the device 1 returns to standby mode.

At this point (i.e. at time t0), the device 1 is put into operation by the patient by pressing the activation button 3a. The motor 9 is activated and the control unit 7 orders a series of operations that do not require any action on the part of the patient.

In a time interval t1 following time t0 and lasting for example 10 to 15 seconds, the magnetic rotor 56 is rotated in the first direction of rotation by the motor 9 and activates the motion transmission member 50, which in turn simultaneously activates the fluid path opening system 40 (the piercing needle 32 pierces the pierceable septum 24 and the elastic element 46 extends) and the injection needle displacement mechanism 60 without however moving the injection needle 24, which remains in the rest position.

In particular, the rotation of the worm screw 54 causes the rack 51 to move along the direction A and the consequent rotation of the drive member 48 and the opening of the fluid path 30. This rotation also causes the rotation of the instruction member 61 which moves from the angular stop position of the to another angular stop position, shown in the . This rotation does not cause any rotation of the thrust member 63, which remains in the first service position because the projecting element 63d remains in abutment against the abutment surface 61e.

In a time interval t2 following the time interval t1 and lasting for example 8 to 12 seconds, the magnetic rotor 56 is rotated in the second direction of rotation by the motor 9 and activates the motion transmission member 111, causing the piston 26 to move inside the container 22. Such a movement causes the medication to exit through the piercing needle 32, but not the administration of the medication through the injection needle 34. The thrust exerted by the piston 26 on the medication causes the air contained in the fluid path 30 to exit (priming phase).

In a time interval t3 following the time interval t2 and lasting for example 8 to 12 seconds, the magnetic rotor 56 is rotated again in the first direction of rotation by the motor 9 and activates the motion transmission member 50 again, causing the reactivation of the injection needle movement mechanism 60.

In particular, the rotation of the worm screw 54 causes an additional rotation of the instruction member 61 which moves from the angular stop position of the at the first angular release position of the . This rotation causes the pushing member 63 to move from the first service position to the second service position and, consequently, the support member 62 (and therefore the injection needle 34) to move from the first operating position (injection needle 34 in the rest position) to the second operating position (injection needle 34 in the injection position). The injection needle 34 thus penetrates the patient's skin.

In a time interval t4 following the time interval t3 and lasting for example 2 to 5 seconds, the magnetic rotor 56 is rotated again in the second direction of rotation by the motor 9 and again activates the motion transmission member 111, causing the piston 26 to move inside the container 22 which this time causes the administration of the medication into the patient's body through the injection needle 34. In this phase, it may still happen that a very limited quantity of air, remaining inside the fluid path 30 after the priming phase, is expelled from the fluid path.

Following the time interval t4, the motor 9 again drives the magnetic rotor 56 in the first direction of rotation by reactivating the motion transmission member 50 and causing the reactivation of the injection needle movement mechanism 60.

In particular, the rotation of the worm screw 54 causes an additional rotation of the instruction member 61 which moves from the first angular release position of the at the second angular release position of the . This rotation causes a similar rotation of the thrust member 63 because the projecting element 63d is housed in the seat 61a and, consequently, the decoupling between the thrust member 63c and the stop member 62c. At this point, the force exerted by the compression spring 64 on the support member 62 moves it from the second operating position to the first operating position, leaving the thrust member 63 in the second service position. The injection needle 34 thus returns to the rest position, i.e. inside the device 1.

The control unit 7 emits an end of therapy signal n seconds after having caused the instruction member 61 to move from the first angular release position of the at the second angular release position of the , in order to ensure that the patient can remove the device from his skin when the injection needle 34 has returned to the rest position, i.e. it is inside the device 1.

The emission of the end of therapy signal by the control unit is communicated to the patient by visual and/or acoustic signals.

The patient can then remove device 1 from his skin.

The removal of the device 1 from the patient's body causes the protective element 70 (and consequently the flexible sleeve 80) to move from the second operating position (protective element 70 inside the device 1 and the flexible sleeve 80 folded inside the device 1) to the first operating position (protective element 70 outside the device 1 and the flexible sleeve 80 extended outside the device 1) due to the thrust exerted on the protective element 70 by the elastic element 72 and, consequently, the locking of the protective element 70 in the first operating position due to the movement of the at least one locking element 70b, 171 from one side to the other side of the at least one stop element 74, 174 and the stop between the at least one locking element 70b, 171 and the second surface of the stop element 74, 174 facing the plane P.

Claims (15)

Device (1) for subcutaneous administration of a drug, comprising:
- a cartridge (20) comprising a container (22) containing the medicament;
- an injection needle (34) configured to inject the medicament into a patient when the device (1) is applied to the patient's skin, the injection needle (34) being movable between a rest position in which the injection needle (34) is fully disposed within the device (1) and an injection position in which the injection needle (34) protrudes at least partially from the device (1);
- a protective element (70) movable between a first operating position in which the protective element (70) projects from the device (1) and covers the tip of the injection needle (34) if the injection needle (34) is in the injection position, and a second operating position in which the protective element (70) does not project from the device (1);
- an elastic element (72) associated with the protective element (70) and configured to exert on said protective element (70) a pushing action which is adapted to maintain the protective element (70) in the first operating position both before the application of the device (1) to the patient's skin and when the device (1) is removed from the patient's skin and to allow the protective element (70) to reach the second operating position when the device (1) is applied to the patient's skin;
- a stop element (74) configured to stop the movement of the protection element (70);
wherein said protective element (70) comprises a locking element (70b) configured to cooperate with said stopping element (74) and to lock the protective element (70) in the first operating position when the device (1) is removed from the patient's skin. Device (1) according to claim 1, wherein the device (1) has an initial reversible configuration in which the stop element (74) is in a distal position relative to the locking element (70b) and the locking element (70b) is movable integrally with the protection element (70) from the first operating position to the second operating position, and vice versa, and an irreversible final configuration in which the stop element (74) and the locking element (70b) are in mutual contact and the protection element (70) is locked in the first operating position. Device (1) according to claim 2, wherein, when the device (1) is in the initial reversible configuration, the injection needle (34) is in the rest position and when the device (1) is in the final irreversible configuration, the injection needle (34) is in the rest position or in the injection position. Device (1) according to claim 2 or 3, wherein the stop element (74) is movable from an initial position in which the stop element (74) and the locking element (70b) are not superimposed on each other to a final position in which the stop element (74) and the locking element (70b) are superimposed on each other. Device (1) according to claim 4, wherein the stop element (74) is movable from said initial position to said final position along a first direction (A) and the locking element (70b) is movable integrally with the protection element (70) between said first operating position and said second operating position along a second direction (F) orthogonal to said first direction (A). Device (1) according to claim 5, wherein when the device (1) is in the initial reversible configuration, the stop element (74) is movable along said first direction (A) and wherein the device (1) passes from the initial reversible configuration to the final irreversible configuration when the stop element (74) is in the final position and the locking element (70b) moves along said second direction (F) from the second operating position to the first operating position passing beyond the stop element (74). Device (1) according to claim 6, wherein one of the locking element (70b) and the stopping element (74) is made of a rigid material and the other of the locking element (70b) and the stopping element (74) is made of a deformable material, and wherein the movement of the locking element (70b) along said second direction (F) causes an interference between the locking element (70b) and the stopping element (74) and a deformation of the element made of a deformable material which is suitable to allow the passage of the element made of a rigid material. Device (1) according to claim 7, wherein the locking element (70b) is made of a rigid material and the stop element (74) is made of a deformable material and comprises a first surface facing the locking element (70b) when the stop element (74) is in the final position and the locking element (70b) is in the second operating position, and a second surface facing on the opposite side of the first surface and towards the locking element (70b) when the stop element (74) is in the final position and the locking element (70b) is in the first operating position, wherein said first surface allows the stop element (74) to deform due to interference with the locking element (70b) and the locking element (70b) to move along said second direction (F) from the second operating position to the first operating position and wherein said second surface surface defines a notch which prevents the locking element (70b) from moving from the first operating position when the device (1) is in the final irreversible configuration. Device (1) according to any one of the preceding claims, wherein said protective element (70) comprises a base (70a) provided with a through hole (71) or a pierceable septum (171) to allow the passage of the injection needle (34) during movement of the injection needle (34) between the rest position and the injection position when said protective element (70) is in the second operating position, wherein said base (70a) comprises a raised edge (70b) which defines in the protective element (70) a recess (70c) configured to accommodate the tip of the injection needle (34) both when the protective element (70) is in the second operating position and the injection needle (34) is in the rest position and when the protective element (70) is in the first operating position and the injection needle (34) is in the injection. Device (1) according to any one of the preceding claims, comprising a fluid path opening system (40) which can be activated to place the injection needle (34) in fluid communication with the container (22) and wherein the locking element (70b) is configured to lock the protection element (70) in the first operating position upon activation of the fluid path opening system (40). Device (1) according to claim 10, wherein the fluid path opening system (40) comprises a piercing needle (32) configured to pierce a pierceable septum (24) coupled to one end (23) of said container (22), a drive member (48) configured to drive the movement of the piercing needle (32) and a motion transmission member (50) configured to drive the drive member (48), wherein the stop element (74) is associated with said motion transmission member (50). Device (1) according to any one of the preceding claims, comprising a position sensor (76) configured to detect contact of the device (1) with the skin of the patient. Device (1) according to claim 12, wherein said position sensor (76) comprises a magnet (77) integrally associated with the protection element (70) and a Hall effect sensor (78) arranged in the device (1) in proximity to said magnet (77). Device (1) according to claim 13, in which the magnet (77) is entirely housed in a seat (75) formed in the protective element (70). Device (1) according to claim 13 or 14, wherein said locking element (70b) is associated with said magnet (77).