Drive mechanism for a drug delivery device - Patent application

Abstract

The present disclosure provides a drive mechanism (11) for moving a stopper (24) of a pharmaceutical container (22), the stopper (24) being movably disposed within a longitudinally extending barrel (23) of the pharmaceutical container (22) and movable in a longitudinal direction (z) relative to the barrel (23), the drive mechanism (11) comprising: a receptacle (30) sized to receive the pharmaceutical container (22); an electromagnetic coil (42) and a core (34) extending through the electromagnetic coil (42); the first electromagnet (41) including a first electromagnet (41) and a second electromagnet (44), the first electromagnet (41) having a radial center (43) of the electromagnetic coil (42) located outside the receptacle (30); and a magnetic coupling member (80) mechanically engageable with the stopper (24) and configured for insertion into the barrel (23), the first electromagnet (41) being operable to generate a magnetic field that moves the magnetic coupling member (80) in a longitudinal direction (z).

Description

[Technical field]

[0001] The present disclosure relates to the field of drug delivery devices, in particular to the delivery of liquid medicaments, for example by infusion or injection. In one aspect, the present disclosure relates to a drive mechanism for moving a stopper of a cartridge filled with a liquid medicament. [Background technology]

[0002] Drug delivery devices for setting and dispensing single or multiple doses of liquid medicines are per se well known in the art. Generally, such devices have a purpose substantially similar to that of a conventional syringe.

[0003] Drug delivery devices such as pen injectors must meet many user-specific requirements. For example, in the case of patients suffering from chronic diseases such as diabetes, the patient may be physically debilitated and may also have poor eyesight. Therefore, a suitable drug delivery device, especially for home drug treatment, needs to be robust in construction and should be easy to use. Furthermore, the operation and general handling of the device and its components should be clear and easy to understand. Such an injection device should allow the setting and subsequent dispensing of drug doses of varying sizes. Moreover, the dose setting and dose dispensing procedures must be easy to perform and unambiguous.

[0004] Patients suffering from certain diseases may need to have certain amounts of medication infused through a syringe pen or through a pump.

[0005] In the case of a drug delivery or injection device, the liquid medicine is typically provided in a medicine container, such as a cartridge, syringe, or carpule. Such a medicine container is typically closed or sealed proximally by a stopper movably disposed in the barrel of such a medicine container. The liquid medicine can be expelled or dispensed from the medicine container by distally displacing, e.g., pressing, the stopper against the barrel of the container. The distal outlet of the medicine container can be in a fluid connected injection needle or infusion line.

[0006] To introduce or transmit a driving force into or onto the stopper, there is a mechanically implemented drive mechanism, e.g., comprising an elongated piston rod in longitudinal abutment with a proximal end face of the stopper. Previously known drive mechanisms are typically operable to advance the piston rod distally to apply a dispensing pressure on the stopper of the pharmaceutical container.

[0007] With increasing digitalization and availability of electrically implemented drive mechanisms, i.e. drive mechanisms, in which the force for moving the stopper in a distal direction is provided or generated by an electrical or electromechanical drive, there is an increasing demand for new solutions and approaches of how to provide a mechanical coupling between the drive or drive member of the drive mechanism and the stopper of the pharmaceutical container, e.g. the stopper of a cartridge. Furthermore, miniaturization of such drive mechanisms and drug delivery devices is also desired. The engagement or interface between the drive mechanism, particularly the components of the drive mechanism and the stopper of the pharmaceutical container moved by the drive mechanism, should be rather fail-safe, robust and efficient in terms of longitudinal force transmission. Summary of the Invention [Means for solving the problem]

[0008] In one aspect, the present disclosure relates to a drive mechanism for moving a stopper of a pharmaceutical container, e.g., a pharmaceutical cartridge. The stopper is movably disposed or positioned within a longitudinally extending barrel of the pharmaceutical container. The stopper is longitudinally movable relative to the barrel, e.g., to expel a dose of a liquid substance from the barrel. The drive mechanism includes a receptacle sized to receive the pharmaceutical container. The receptacle may be configured to hold the pharmaceutical container and / or secure the pharmaceutical container within the receptacle.

[0009] The drive mechanism further comprises a first electromagnet. The first electromagnet comprises an electromagnetic coil and a core extending through the electromagnetic coil. A radial center of the electromagnetic coil is located outside the receptacle. The drive mechanism further comprises a magnetic coupling member mechanically engagable with the stopper and configured for insertion into the barrel. The first electromagnet is further operable to generate a magnetic field, thereby moving the magnetic coupling member longitudinally.

[0010] Typically, the entire electromagnet is located outside or adjacent to the receptacle in the radial direction. Here, the radial direction extends perpendicular to the longitudinal direction. Generally, in the present context, the radial direction refers to the cylindrical shape of the barrel of the drug container and therefore may refer to the cylindrical shape of the receptacle. However, the present disclosure is not limited to tubular receptacles and / or drug containers. In this regard, the radial direction must generally be considered as the direction extending perpendicular to the longitudinal direction and pointing to the center of the cross section of the receptacle, in which the stopper is movable relative to the barrel of the cartridge. The respective considerations apply to the tangential or circumferential expressions, which extend perpendicular to the longitudinal and radial directions.

[0011] The generation of the magnetic field is caused by applying a current to a first electromagnet. For example, an electromagnetic coil comprising a solenoid is operable to generate a magnetic field that is amplified by a core extending through the hollow interior of the electromagnetic coil. In this way, by using an electromagnet comprising an electromagnetic coil and a core, the magnetic field generated by the electromagnetic coil can be amplified. In effect, a larger magnetic force can be applied to the magnetic coupling member. Furthermore, since the radial center of the electromagnetic coil is located outside the receptacle, the entire electromagnet can be located outside the receptacle. This provides a fairly compact and robust design of the drive mechanism.

[0012] By using a core that extends through the electromagnetic coil, the number of turns in the coil as well as the magnitude of the current applied to the coil can be substantially reduced without adversely affecting the strength of the magnetic field that interacts with the magnetic coupling member, and in this manner, the structural space of the drive mechanism can be reduced, allowing for further miniaturization of the drive mechanism and / or the drug delivery device equipped with such a drive mechanism.

[0013] By locating at least the center of the electromagnetic coil outside the receptacle, the first electromagnet does not necessarily have to contribute to the receptacle. Thus, the first electromagnet may be located radially next to the receptacle or radially adjacent and external to the receptacle. In this way, the first electromagnet does not necessarily have to be individually designed or formed to match a receptacle of a given size. This allows the first electromagnet to be universally usable for a wide variety of different shaped receptacles, where the receptacle may conform or be adapted and / or configured according to the geometry or shape of a pharmaceutical container intended to be inserted into the receptacle.

[0014] The core is typically implemented as an iron core. The core may comprise a ferromagnetic or ferromagnetic material. The core may be in single crystal form. The core may comprise a mild steel material. Thus, the iron material of the core has a low carbon content and is easily magnetized and demagnetized with small hysteresis losses.

[0015] According to a further example, the radial center of the electromagnetic coil is disposed radially offset from the radial center of the receptacle. Thus, when viewed radially, the electromagnetic coil may be located completely outside the receptacle. Furthermore, the radial distance between the radial center of the receptacle and the radial center of the electromagnetic coil may be greater than the sum of the radius of the electromagnetic coil and the radius of the receptacle.

[0016] In receptacles of non-circular cross section, this may be applied in relation to the distance from the side wall of the receptacle towards the lateral or radial centre of the receptacle as appropriate.

[0017] In this manner, the electromagnetic coil and optionally the entire electromagnet are located external to the receptacle. This allows for a fairly simple assembly of the first electromagnet to the receptacle. Furthermore, by locating the electromagnetic coil radially offset from the radial center of the receptacle and / or radially offset from the exterior of the receptacle, the electromagnetic coil can be accessible, for example, from the outside, thus providing a simple method of providing electrical contact to the electromagnetic coil.

[0018] Typically, and by way of further example, the electromagnetic coil is disposed parallel to the longitudinal direction of the receptacle or barrel of the pharmaceutical container, and a center line or line of symmetry extending longitudinally through the coil, thus forming the axis of symmetry of the coil, is typically disposed parallel to the longitudinal direction of the receptacle.

[0019] In a further example, the core includes a first leg, a base section, and a second leg. The base section extends through the electromagnetic coil. The first leg and the second leg extend radially toward the receptacle. Typically, the first leg and the second leg are interconnected by the base section. The base section includes a longitudinal extent that is equal to or only slightly longer than the longitudinal extent of the electromagnetic coil. The first leg and the second leg may extend along a longitudinal end surface of the coil. For a cylindrical shape of the electromagnetic coil, the first leg and the second leg extend radially from the base section of the core.

[0020] The base section extends longitudinally from the first leg to the second leg. Typically, the first leg and the second leg extend along the same radial direction from the base section. In this manner, the first leg and the second leg may extend parallel to each other. The first leg and the second leg may have equal extensions in the radial direction as well as in the tangential or circumferential direction with respect to the shape of the coil or receptacle.

[0021] In a further example, the first leg and the second leg are longitudinally separated and interconnected via the base section. Additionally, the first leg and the second leg and the base section may be integrally formed. Thus, the first leg, the base section, and the second leg may comprise a single part such that they are integrally formed.

[0022] In some examples, the core comprises a U-shaped profile. The first leg and the second leg comprise a substantially elongated straight shape. The first leg and the second leg are arranged parallel to each other in the same plane. The first and second legs each comprise a first longitudinal end representing a free longitudinal end. The opposite longitudinal ends of both legs are connected to the opposite longitudinal ends of the base section. By longitudinally separating the first and second legs, opposite or different magnetic poles can be provided along the length of the pharmaceutical container. Typically, the first electromagnet is located and arranged outside the receptacle such that the free ends of the first and second legs of the core face towards the receptacle to provide magnetic north and south poles that are separated along the length.

[0023] In some examples, the magnetic coupling member includes a magnet. The magnet includes opposing poles, i.e., a north pole and a south pole. The opposing poles are provided at opposite longitudinal ends of the magnetic coupling member. For example, one of the south pole and the north pole faces toward the distal direction and thus toward the outlet of the cartridge or receptacle, and the other of the south pole and the north pole faces in the opposite direction, i.e., toward the proximal longitudinal direction.

[0024] The magnetic coupling member may include a rod magnet or a ring magnet. The magnetic coupling member may be mechanically engaged with the stopper of the pharmaceutical container. The magnetic coupling member may face and proximally abut the end face of the stopper. The magnetic coupling member may be directly or indirectly connected or fixed to the stopper, or embedded or integrated within the stopper. In effect, the mechanical engagement between the magnetic coupling member and the stopper or bung allows the magnetic force applied by the first electromagnet on the magnetic coupling member to be invariantly transferred to the respective movement of the magnetic coupling member and thus the respective movement of the stopper relative to the barrel.

[0025] According to a further example, the core is located radially outside the receptacle. The free end of the first leg and the free end of the second leg face radially inward toward the receptacle. Here, the free ends of the first and second legs may be directly adjacent to the receptacle. In some examples, the first and second legs may form or contribute to a sidewall of the receptacle in which the drug container may be received. In this way, the first and second legs may even provide a mechanical guide, mechanical housing, and / or mechanical support for the drug container. The first and second legs may radially surround the drug container inside the receptacle.

[0026] According to a further example, at least one of the free ends of the first leg and the second leg includes a radially inwardly facing end surface having a concave shape when viewed tangentially, such that when the receptacle is tubular, the radially inwardly facing end surface of at least one of the free ends of the first leg and the second leg may precisely match or conform to the shape of the receptacle and / or the shape of the exterior surface of the tubular barrel.

[0027] In some examples, the tangential extent of the legs may be greater than the longitudinal extent of the legs, and more than 25°, more than 45°, or even more than 60° of the circumference of the drug container may be bounded by the radially inwardly facing end surfaces of each leg.

[0028] According to a further example, the drive mechanism comprises a second electromagnet longitudinally offset from the first electromagnet. The first and second electromagnets form a first longitudinally extending array of electromagnets. The array of electromagnets may not be limited to only the first and second electromagnets. The array or row of electromagnets may include more electromagnets. The array of electromagnets may include a plurality of electromagnets, where the longitudinal extent of the pharmaceutical container or receptacle is defined by being divided by the longitudinal extent of a single electromagnet.

[0029] Typically, the second electromagnet is conceptually identical to the first electromagnet. Also, the second electromagnet includes an electromagnetic coil and a core. Typically, the first and second electromagnets are substantially identical. In this manner, a plurality of individual identical electromagnets may be assembled in a longitudinal row to create an array of electromagnets. A longitudinal row or array of electromagnets typically extends parallel to the longitudinal direction of the barrel or the longitudinal direction of the receptacle.

[0030] The first electromagnet and the second electromagnet may be arranged longitudinally adjacent to each other. The second electromagnet may be longitudinally adjacent to the first electromagnet, where a second leg of the first electromagnet may be adjacent to a first leg of the second electromagnet. The first leg of the first electromagnet may face the second electromagnet. The second leg of the second electromagnet may face the first electromagnet. Apart from the first and second electromagnets, the array of electromagnets may include a number of further electromagnets, for example three, four, five, six or even more electromagnets.

[0031] By using a row or array of multiple electromagnets, the longitudinal range of the drive mechanism can be increased or extended. Typically, by having multiple electromagnets along the length, the magnetic coupling member can be moved from the proximal end towards the distal end of the barrel and vice versa.

[0032] According to a further example, the drive mechanism comprises a third electromagnet offset tangentially from the first electromagnet. Also, the third electromagnet may be implemented to be conceptually identical to the first electromagnet. The third electromagnet may be substantially identical to the first electromagnet. When viewed from the center of the longitudinal receptacle, the third electromagnet may be located at another circumferential portion of the receptacle. Thus, the third electromagnet may be offset tangentially from the first electromagnet. The third electromagnet may be located diametrically opposite the first electromagnet and may be radially adjacent to the receptacle. In this way, the receptacle may be located radially between the first electromagnet and the third electromagnet.

[0033] With first and third electromagnets located on opposite sides of the receptacle or at a circumferential or tangential offset with respect to the circumference of the receptacle, the net magnetic force applied to the magnetic coupling member and therefore the magnetic effect present on the magnetic coupling member may be increased. Furthermore, by having first and third electromagnets and increasing the magnetic field effective on or at the magnetic coupling member, the individual magnetic fields that must be provided by each individual first and third electromagnet may be reduced, thus allowing each electromagnet to be made even smaller.

[0034] According to a further example, the third electromagnet is longitudinally coplanar with the first electromagnet, such that the first and third electromagnets are disposed at a common longitudinal position relative to the receptacle, in this manner, the first and third electromagnets may provide somewhat symmetric or identical magnetic fields for driving the magnetic coupling members.

[0035] According to a further example, the third electromagnet is longitudinally offset from the first electromagnet. Thus, the first electromagnet and the third electromagnet may be longitudinally displaced. The longitudinal offset between the first and second electromagnets may be defined by the shape of the core. As an example, the first leg of the core of the third electromagnet may be located or arranged in a longitudinal position between the first and second legs of the core of the first electromagnet, and vice versa. In this way, for example, a longitudinally extending gap between the first and second legs of the first electromagnet may be effectively bridged by the leg of the core of the third electromagnet.

[0036] According to a further example, the third electromagnet is longitudinally shifted relative to the first electromagnet by approximately half the longitudinal extent of one of the first and third electromagnets. Typically, the longitudinal extent of the first electromagnet is the same as the longitudinal extent of the third electromagnet. Alternating magnetic poles can then be provided longitudinally shifted or offset along the circumference of the receptacle by longitudinally shifting the position of the third electromagnet by half the longitudinal extent of either the third or the first electromagnet.

[0037] Such a longitudinally offset arrangement allows the magnetic forces generated by the tangentially and / or circumferentially offset electromagnets to provide a fairly uniform mechanical force on the magnetic coupling member as the magnetic coupling member is moved, for example, longitudinally.

[0038] According to a further example, the drive mechanism includes a fourth electromagnet longitudinally offset from the third electromagnet, the third electromagnet and the fourth electromagnet forming a second longitudinally extending array of electromagnets.

[0039] Typically, with any of the electromagnet arrays or rows described herein, electrical current is sequentially applied to individual electromagnets in a row or array of electromagnets in a plurality of electromagnet arrays, such that the resulting magnetic field generated by the individual electromagnets in the electromagnet array moves and / or advances along a longitudinal direction.

[0040] The fourth electromagnet may provide the first and second arrays of multiple electromagnets, and wherein the second longitudinally extending array of electromagnets is not limited to only two electromagnets. It may comprise even more electromagnets, such as the first array of electromagnets described above. The total number of electromagnets in each array of electromagnets may be greater than 3, 4, 5, 6, or 8 electromagnets. The particular number of arrays or rows of electromagnets may be governed by the size of the individual electromagnets and by the extension of the receptacle or pharmaceutical container.

[0041] Typically, the second longitudinally extending array of electromagnets may be substantially identical to the first array of electromagnets. If the first and third electromagnets are arranged with a longitudinal offset as described above, this may apply equally to each array of electromagnets. Thus, the first array of electromagnets may be located longitudinally offset from the second array of electromagnets. Thus, the longitudinal shift or longitudinal offset of the second longitudinally extending array of electromagnets relative to the first longitudinally extending array of electromagnets may be within half the longitudinal extent of one of the electromagnets.

[0042] Typically, the first array of electromagnets extends parallel to the second array of electromagnets, and the first array of electromagnets and the second array of electromagnets are typically positioned at a circumferential or tangential offset relative to the circumference of the pharmaceutical container receptacle.

[0043] In this manner, by having first and second longitudinally extending arrays of electromagnets, the magnetic coupling between the individual electromagnets and the magnetic coupling members, and therefore the respective longitudinal force effects on the magnetic coupling members, can be uniformed.

[0044] According to a further example, the first array of electromagnets and the second array of electromagnets are disposed on radially opposite sides of the receptacle. In other words, the first array of electromagnets may be located diametrically opposite the second array of electromagnets when viewed from a cross-sectional view through the receptacle. In this manner, the magnetic forces provided by the individual electromagnets of the first and second electromagnets may be applied symmetrically to the magnetic coupling member, thereby allowing for a uniform force effect on the magnetic coupling member.

[0045] Of course, in the first and second arrays of electromagnets, those electromagnets located at common or overlapping longitudinal positions are rather provided with drive current simultaneously, and due to the longitudinal offset between the electromagnets of the first array of electromagnets and the electromagnets of the second array of electromagnets, there may be respective offsets for applying drive current to individual electromagnets.

[0046] The drive current may be provided as a constant drive current and thus represents a rectangular function over time. In other examples, the drive current may include or represent a ramp function, e.g., smoothly increasing and / or decreasing over time. In other examples, a drive current may be provided having a sinusoidal amplitude or intensity over time.

[0047] According to a further example, the drive mechanism comprises a third longitudinal array of electromagnets. The first array of electromagnets, the second array of electromagnets, and the third array of electromagnets are then equally spaced around the circumference of the receptacle. The first array, the second array, and the third array all extend substantially parallel to one another. They may also extend parallel to the longitudinal direction defined by the receptacle or by the pharmaceutical container. The equidistant spacing between the individual arrays is particularly beneficial for providing uniform magnetic coupling to the magnetic coupling member mechanically engaged with the stopper. For example, in three arrays of electromagnets, the angular distance between neighboring arrays of electromagnets may be about 120°.

[0048] In a further example, where the drive mechanism comprises an array of, for example, four electromagnets, the angular distance between adjacent arrays or rows of electromagnets is approximately 90°.

[0049] In another aspect, the present disclosure relates to a drug delivery device for dispensing a liquid drug. The drug delivery device comprises a housing configured to hold and / or receive a cartridge. Typically, the cartridge is filled with a liquid drug and sealed by a stopper. Typically, the stopper seals a proximal longitudinal end of the cartridge and is movable relative to the cartridge or to a tubular barrel of the cartridge. The drug delivery device further comprises a drive mechanism as described above. The drive mechanism may be integrated in the drug delivery device. The drive mechanism may be located and fixed inside the housing of the drug delivery device. For example, a receptacle of the drive mechanism, which may be surrounded by one or multiple electromagnets of the drive mechanism, may be incorporated in the housing of the drug delivery device. Thus, the receptacle of the drive mechanism may be equivalent or identical to a receptacle of the drug delivery device, which may be implemented as a cartridge, sized and configured to accommodate a drug container.

[0050] Once a pharmaceutical container, e.g., a cartridge, is properly assembled or positioned within the housing, a drive current can be suitably applied to at least a first electromagnet, thereby generating a magnetic field that magnetically interacts with a magnetic coupling member that is mechanically engaged with the stopper of the pharmaceutical container.

[0051] According to a further example, the medication delivery device further comprises a cartridge filled with a liquid medication and disposed within or secured to the housing of the medication delivery device.

[0052] In some examples, the drug delivery device comprises an injection device, such as a handheld injection device. In other examples, the drug delivery device comprises an infusion device, such as an infusion pump. In other examples, the drug delivery device may comprise an inhaler.

[0053] In general, magnetic coupling between at least one or multiple electromagnets disposed along and / or surrounding the longitudinal receptacle in the drive mechanisms described above can provide a rather constant and / or uniform force on the stopper that can be maintained over a relatively large distance as the stopper is moved along the extension of the pharmaceutical container. Furthermore, the longitudinal displacement and / or movement of the stopper can be precisely controlled by appropriately adjusting at least one of the strength, direction, and frequency of the drive current for each one of the electromagnets contributing to the array of electromagnets.

[0054] In this way, a fairly strong, variable and electronically adjustable force can be applied on the stopper.

[0055] The proposed implementation with at least the first and / or multiple electromagnets allows to achieve a relatively short overall longitudinal extension of the drive mechanism. Thus, an elongated piston rod extending into the proximal extension of the longitudinal cartridge is no longer required. In practice, the longitudinal size of the housing of the drive mechanism or the housing of the drug delivery device may be defined primarily by the longitudinal extent of the cartridge.

[0056] Furthermore, the implementation of at least a first electromagnet for moving the stopper of the cartridge is particularly used for a reusable drug delivery device, where repulsive and attractive forces can be provided in the longitudinal direction between the array of electromagnets and the magnetic coupling member, especially when the magnetic coupling member is implemented as a permanent magnet. In this way, bidirectional longitudinal force transmission can be enabled between the array of electromagnets and the magnetic coupling member, for example in the proximal direction as well as in the distal direction, from the outer coupling member to the inner coupling member.

[0057] In addition, maximum force can be provided in both opposing longitudinal directions. Furthermore, in addition, compared to preload force generation solutions, the magnetic coupling can be transitioned to a fairly force-free initial or stored configuration where there is substantially no magnetic interaction between the electromagnets and the magnetic coupling members. This can be easily achieved by deactivating the drive current of the electromagnets.

[0058] The magnets described herein may be implemented as permanent magnets. They may include or be composed of at least one of the following materials, including, for example, sintered neodymium-iron-boron (NdFeB), preferably with a medical grade coating, samarium-cobalt (SmCo) and aluminum-nickel-cobalt (AINiCo).

[0059] Generally, the scope of the present disclosure is defined by the content of the claims. The injection device is not limited to specific embodiments or examples, but includes any combination of elements of different embodiments or examples. To that extent, the present disclosure covers any combination of the claims and any technically feasible combination of features disclosed in relation to the different examples or embodiments.

[0060] In the present context, the term "distal" or "distal end" refers to the end of the injection device that points towards the injection site of a person or animal. The term "proximal" or "proximal end" refers to the opposite end of the injection device that is furthest from the injection site of a person or animal.

[0061] Pharmaceutically acceptable salts of any of the APIs described herein are also contemplated for use in the drug or pharmaceutical agent in the drug delivery device. Pharmaceutically acceptable salts include, for example, acid addition salts and base salts.

[0062] It will be understood by those skilled in the art that modifications (addition and / or deletions) may be made to the various components of the APIs, formulations, devices, methods, systems and embodiments described herein without departing from the full scope and spirit of the invention, and that the invention encompasses such modifications and all equivalents thereof.

[0063] Furthermore, it will be apparent to those skilled in the art that various modifications and changes can be made to the present disclosure without departing from the scope of the present disclosure. Furthermore, it should be noted that any reference signs used in the appended claims should not be construed as limiting the scope of the present disclosure.

[0064] In the following, a number of examples of injection devices as well as data logging devices for monitoring the use of the respective injection devices are described in more detail with reference to the drawings. [Brief description of the drawings]

[0065] [Figure 1] FIG. 1 shows an example of a drug delivery device having a drive mechanism according to a first example. [Diagram 2] FIG. 2 shows the drive mechanism of FIG. 1 without the housing. [Diagram 3] FIG. 2 shows a cross section through the drive mechanism in a first configuration. [Figure 4] FIG. 13 shows a cross-section of a further example of a drive mechanism. [Diagram 5] FIG. 13 illustrates a further example of a drive mechanism. [Figure 6] FIG. 13 is a diagram showing another example of a drive mechanism. [Figure 7] FIG. 13 shows a further example of a drive mechanism in the first configuration. [Figure 8]8 is a diagram showing another configuration of the drive mechanism of FIG. 7. [Figure 9] 13A-13C are exemplary diagrams illustrating multiple plots of magnetic force applied to a magnetic coupling member versus displacement along a pharmaceutical container. [Figure 10] FIG. 2 is a diagram showing a first configuration of a drive mechanism. [Figure 11] FIG. 13 is a diagram showing a second configuration of the drive mechanism. [Figure 12] FIG. 13 is a diagram showing a third configuration of the drive mechanism. [Figure 13] FIG. 2 shows a drive mechanism comprising first and second arrays of electromagnets. [Figure 14] FIG. 13 is a diagram showing an example using three electromagnets. [Figure 15] FIG. 1 shows an example of a drive mechanism comprising four separate arrays of multiple electromagnets. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] The drug delivery device 10 as shown in Figures 1-4 comprises a drive mechanism 11 and a housing 12. The drive mechanism 11 is integrated into or disposed within the housing 12. The housing 12 may comprise a receptacle 30 sized and configured to receive and / or hold, i.e., secure, a drug container 22, which in this case is implemented as a tubular cartridge. The cartridge may comprise a vitreous body. The cartridge comprises a tubular barrel 23, e.g., a vitreous material. The cartridge or container 22 is sealed proximally longitudinally by a stopper 24. The stopper 24, typically made of an elastomeric material, is longitudinally movable within the tubular barrel 23. The internal volume of the cartridge 22 is limited by the barrel 23, the stopper 24, and an outlet 27, provided at the distal end of the cartridge 22. The cartridge is fillable or filled with a liquid drug 21. The outlet 27 of the cartridge 22 is typically covered or sealed with a seal 28. The seal 28 may comprise a rubber disc pierceable by an injection needle 29 to expel a dose of the liquid medicament 21 from the interior of the cartridge 22 by displacing or forcing the stopper 24 towards the outlet 27 .

[0067] The outlet 27 of the cartridge 22 may be connected to an injection needle 29, which is shown only diagrammatically in Figure 3. In another example, the outlet 27 may comprise a standardized connector, such as a Luer-type connector way through which an infusion line may be connected in fluid transfer manner to the interior of the cartridge 22.

[0068] In the currently shown example, the cartridge 22 is fixed inside the housing 12. It may be removably fixed inside the housing. The housing may thus comprise some kind of removable fastener or movable closure by which access may be provided to the interior of the compartment 14 for replacing the cartridge 22 when empty.

[0069] The drive mechanism 11 includes at least a first electromagnet 41. The first electromagnet 41 includes an electromagnetic coil 42 and a core 44. The core 44 extends through the electromagnetic coil 42. A radial center 43 of the coil 42 is located outside the receptacle 30, which is sized and configured to house and / or receive the drug container 22. In the example of FIG. 1, the housing 12 includes a base portion 15 that forms a mount for a distal end of the drug container 22. The base portion 15 may be configured to secure the drug container 22. As shown in cross section in FIGS. 3-8, the base portion 15 of the housing 12 may be sized and configured to mechanically engage the neck of the drug container 22. Thus, the drug container 22 includes a shoulder at the distal end of the tubular portion. The shoulder merges into a radially narrowed neck that extends further into a radially widened head. To that extent, the neck defines or defines a circumferential groove configured to engage with a complementary shaped radial protrusion provided, for example, on or within the housing 12 .

[0070] The housing 12 may further comprise a closure 14, by which a proximal end of the receptacle 30 may be closed. The housing 12 may further comprise a sidewall 18. The sidewall may radially confine the receptacle 30. The closure may be connectable to the base portion 15 via the sidewall 18. As illustrated in FIG. 1 , the sidewall 18 includes at least an elongated rod or slat-like profile extending in a longitudinal direction (z) and along an extension of the receptacle 30.

[0071] In the illustration of FIG. 2, the housing 12 is not shown. FIG. 2 provides an unobstructed view of the multiple electromagnets 41, 61, 71, 141, 161, and 171. The electromagnets 41, 61, 71, 141, 161, and 171 may be attached and / or secured to the housing 12. They may be connected or attached to either of the opposing side walls 18. As shown in FIG. 1, the multiple electromagnets 41, 61, 71, 141, 161, and 171 are substantially identical. Each electromagnet includes an electromagnetic coil 42 having a core 44. The core 44 includes a U-shaped structure. The core 44 includes a first leg 45, a second leg 47, and a base section 46.

[0072] The first leg 45 and the second leg 47 are interconnected by a base section 46. The base section 46 extends through the center of the coil 42. It may protrude slightly from the opposite longitudinal end of the coil 42. The legs 45, 47 extend at an angle of about 90° from the extension of the base section 46. In the illustrated example, the first leg 45 and the second leg 47 extend in a radial direction. The legs 45, 47 extend in a radial direction (r) with respect to the, e.g., tubular, shape of the receptacle 30.

[0073] Both legs 45, 47 extend substantially parallel. They extend from the same radial side of the base section 46. The legs 45, 47 extend towards the receptacle 30. Each leg 45, 47 includes a free end 48, 49 facing away from the base section 46. Each leg 45, 47 further includes an end face 50 at the free end 48, 49. As shown in FIG. 2, the end faces 50 of the legs 45, 47 are concave. They are sized and shaped to accommodate the pharmaceutical container 22 or the barrel 23 of the cartridge. The tangential extent, and therefore the extension of the end face 50 in the tangential direction, is more than 30°, more than 45°, or more than 60° of the circumference of the receptacle 30 or the barrel 23.

[0074] 2, end faces 50 of free ends 48, 49 of legs 45, 47 of core 44 form or contribute to a sidewall or sidewall structure of receptacle 30. Thus, barrel 23 of drug container 22 may be in mechanical engagement or mechanical abutment with free ends 48, 49 of core 44.

[0075] The free ends 48, 49 of the core 44 form the opposing poles of the electromagnet 41 and form or constitute the iron circuit of the electromagnet 41. When a current is applied to the electromagnetic coil 42, the magnetic field induced by the current is magnified by the core 44 and the opposing type of magnetic poles, thus providing magnetic north and south poles at the free ends 48, 49 of the legs 45, 47. By changing the direction of the current in the electromagnetic coil 42, the direction of the magnetic field can be reversed.

[0076] The drive mechanism 11 further comprises a magnetic coupling member 80. The magnetic coupling member 80 comprises a magnet 81 implemented as a permanent magnet. In the illustrated example, the magnet 81 of the magnetic coupling member 80 comprises a rod magnet 82. Alternatively, it may comprise a ring magnet. In the example of Figures 4 and 5, the magnetic coupling member 80 further comprises two magnets 81, 83 arranged adjacent to each other in the longitudinal direction.

[0077] The magnetic coupling member 80 is in direct or indirect mechanical engagement with the stopper 24 of the pharmaceutical container 22. In the illustrated example, the magnetic coupling member 80 longitudinally abuts against an abutment surface of the proximally-facing end surface 26 of the stopper 24. In other examples (not shown), the magnetic coupling member 80 may be incorporated into the stopper 24. It may be embedded within the stopper 24. The magnetic coupling member 80 may be fixed to the stopper 24. In this manner, the magnetic coupling member 80 may provide distally and / or proximally directed forces on the stopper 24 to induce distal and / or proximal movement of the stopper 24 relative to the barrel 23.

[0078] In principle, the drive mechanism 11 only requires a single electromagnet 41. As the core 44 includes a U-shaped structure with first and second legs 45, 47 spaced apart in the longitudinal direction (z), a respective magnetic field may be established that extends in the longitudinal direction (z) and thus along or parallel to the extension of the receptacle 30. By applying a current to the coil 42, a respective magnetic field builds up between the free ends 48, 49 of the core 44 which magnetically interact with the magnetic coupling member 80, thereby forcing the magnetic coupling member 80 against the barrel 23 in the longitudinal direction (z).

[0079] In the currently illustrated example, a number of electromagnets 41, 61, 71, 141, 161, 171 are provided. For example, as shown in Figures 1 and 2, a first electromagnet 41 and a second electromagnet 61 are provided. The first and second electromagnets 41, 61 are arranged adjacent to each other in the longitudinal direction, where the second electromagnet 61 is located distally from the first electromagnet 41. The first electromagnet 41 and the second electromagnet 61 form or constitute a first array 60 of electromagnets 41, 61. As illustrated, the first array 60 includes four electromagnets 41, 61, 71 and one further electromagnet.

[0080] The electromagnets 41, 61, 71 are not twisted longitudinally, but rather arranged in a linear row. The first array 60 of electromagnets extends parallel to the longitudinal direction (z) and thus parallel to the elongation of the receptacle 30. The further electromagnets 61, 71 are substantially identical to the first electromagnet 41. A second array 160 of electromagnets is further provided. The second array 160 includes a third electromagnet 141 and a fourth electromagnet 161. Moreover, the second array 160 of electromagnets also includes all four electromagnets 141, 161, 171.

[0081] The first electromagnet 41 of the first array 60 of electromagnets and the third electromagnet 141 of the second array 160 are arranged at the same longitudinal position. They are provided on opposite radial sides of the receptacle 30, where the free ends 48, 49 of the core 44 of the first electromagnet 41 are diametrically opposite the free ends 48, 49 of the core 44 of the third electromagnet 141.

[0082] When applying identical currents on the first and third electromagnets 41, 141 at one time, a double and therefore rather radially symmetric magnetic field will be provided in the area between the first electromagnet 41 and the third electromagnet 141, thus improving the magnetic interaction with the magnetic coupling member 80. In this way, a fairly uniform and strong magnetic force can be applied on the magnetic coupling member 80.

[0083] When the magnetic coupling member 80 is displaced longitudinally, e.g., distally, i.e., towards the outlet 27, the second and fourth electromagnets 61, 161 can take over generating respective magnetic fields operable to apply respective distally directed forces on the magnetic coupling member 80 and thus the stopper 24. This situation is shown, for example, in FIG.

[0084] As the magnetic coupling member 80, and thus the stopper 24, is moved further distally, the functions of the second and fourth electromagnets 61, 161 of the first and second arrays 60, 160 of electromagnets may be replaced by further electromagnets 71, 171 of the respective arrays 60, 160 located adjacently in the longitudinal direction. Thus, to apply a rather constant and sufficient driving force on the stopper 24, the currents applied to the individual electromagnets 41, 61, 71, 141, 161, 171 may be individually controlled by a controller (not shown). The magnitude of the currents applied to the individual electromagnets 41, 61, 71, 141, 161, 171 may be adjusted according to the intended force effect to be applied on the magnetic coupling member 80. Also, by changing the direction of the current in the respective electromagnetic coils 42, the resultant magnetic forces provided by the multiple electromagnets 41, 61, 71, 141, 161, 171 may be reversed accordingly.

[0085] Typically, in order to provide a fairly smooth displacement of the magnetic coupling member 80, the electromagnets 41, 141 of the different arrays 60, 160 located at the same longitudinal position are intended to be synchronously activated by current. In the example of Fig. 4, the magnetic coupling member 80 comprises a first magnet 81 and a second magnet 83. Here, the two magnets 81, 83 are both implemented as rod magnets 82. They are arranged in an attractive configuration. Thus, the magnetic south pole of the magnet 81 faces the magnetic north pole of the magnet 83. Thus, the magnets 81, 83 attract each other.

[0086] With the two rod magnets 81, 83 arranged in a longitudinal row, the overall longitudinal extent of the magnetic coupling member 80 may be increased compared to the configuration of Figure 3. In this manner, the magnetic interaction between the individual electromagnets 41, 61, 71, 141, 161, 171 and the magnetic coupling member 80 may also be modified by changing the configuration, e.g., the mutual assembly or orientation of the rod magnets 81, 83 of the magnetic coupling member 80.

[0087] In the example of Figure 5, the magnetic coupling member 80 also includes two rod magnets 81, 83. However, here, in contrast to the configuration of Figure 4, the magnets 81, 83 are oriented in a repelling configuration, where the south pole of magnet 81 faces the south pole of magnet 83. Here, the magnetic coupling member 80 may comprise a mount 84 or base for mechanically interconnecting the two repelling magnets 81, 83.

[0088] The two magnets 81, 83 generate a fairly strong repulsive magnetic field, which can increase the magnetic coupling of the magnetic coupling member 18 with the electromagnets 41, 61, 71, 141, 161, 171. Here, the strength of the magnetic coupling can be increased compared to the configuration as shown in FIG.

[0089] In a further example in Fig. 6, the magnetic coupling member 80 is located at a longitudinal distance from the stopper 24. A rod is provided which abuts the proximal end face 26 of the stopper 24. The opposite end of the rod 16 supports the magnetic coupling member 80. The force effect acting on the magnetic coupling member 80 is transferred to the stopper 24 by the rod 16. Further, as shown in Fig. 6, the drive mechanism 11 comprises a first array 60 and a second array 160 of individual electromagnets 41, 61, 71, 141, 161, 171.

[0090] In contrast to the example of Figures 3-5, the arrays 60, 160 are longitudinally offset with respect to each other. Thus, the electromagnets 41, 61, 71 of the first array 60 are longitudinally offset from the electromagnets 141, 161, 171 of the second array 160. As shown, the second leg 47 of the core 44 of the third electromagnet 141 is longitudinally located between the first leg 45 and the second leg 47 of the core 44 of the first electromagnet 41. Of course, as previously mentioned, the legs 45, 47 of the core 44 of the electromagnets 41, 141 are located on opposite radial sides of the receptacle 30.

[0091] In this manner, a significantly staggered arrangement of alternating sequences of electromagnets on either side of the receptacle 30 can be provided, allowing for more spatially uniform magnetic coupling between the first array 60 and the second array 160 of electromagnets with the magnetic coupling member 80.

[0092] In a further example of Figures 7 and 8, the first and second arrays 60, 160 of electromagnets 41, 61, 71, 141, 161, 171 are longitudinally offset by half the longitudinal extent of an individual electromagnet 41 and / or by half the longitudinal extent of the core 44.

[0093] 7, when the stopper 24 is close to the proximal end of the barrel 23, the first electromagnet 41 of the first array 60 and the first electromagnet 141 of the second array 160 are activated. When the magnetic coupling member 80, and thus the stopper 24, is moved distally, i.e. towards the outlet 27, the longitudinally adjacent electromagnets 61, 161 will be activated at the expense of the first electromagnet 41 and the third electromagnet 141. Here, the third electromagnet 141, being the most proximally disposed electromagnet, may be switched off in favor of the fourth electromagnet 161, which will be activated.

[0094] Thereafter, as the magnetic coupling member 80 moves further in the distal direction, the first electromagnet 41 may be deactivated whilst the third electromagnet 61 is activated. In Figure 8 an end configuration is illustrated where the further electromagnets 71, 171 of the first and second arrays 60, 160 are finally activated until the stopper 24 reaches the distal end position.

[0095] 10-12, an example use sequence is illustrated for a first electromagnet 41 and a third electromagnet 141 located longitudinally offset on opposite sides of the barrel 23, where in an initial configuration as shown in FIG 10, both electromagnets 41, 141 are activated by a drive current flowing in the same direction. Thus, the north pole of electromagnet 41 and the north pole of electromagnet 141 face towards the proximal end. The south pole is provided at the distal end.

[0096] Now, because the magnetic coupling member 80 has been moved in a distal direction as shown in Figure 11, the direction of the current in the third electromagnet 141 may be reversed, thus reversing the magnetic field of the third electromagnet 141. The change in magnetization of the third electromagnet 141 further induces a driving force on the magnetic coupling member 80 toward the distal direction. When the configuration as shown in Figure 12 is achieved, the polarity, and therefore the magnetic field, of the first electromagnet 41 may also be reversed.

[0097] The resulting magnetic force applied to the magnetic coupling member 80 is further illustrated in diagram 100 of Fig. 9, where graph 102 shows the force applied on the magnetic coupling member 80 when the first and third electromagnets 41, 141 are in the configuration of Fig. 10. Graph 104 shows the magnetic force versus longitudinal displacement of the magnetic coupling member 80 when the first and third electromagnets 41, 141 are in the configuration according to Fig. 11, and graph 106 shows the magnetic force applied on the magnetic coupling member 80 when the first and third electromagnets 41, 141 are in the configuration of Fig. 12. Graph 108 represents the resulting force obtained by alternating the magnetization of the third and first electromagnets 141, 41 as the magnetic coupling member 80 undergoes a continuous longitudinal displacement towards the outlet 27.

[0098] In Figure 13, the drive mechanism 11 as shown in Figure 1 is shown in a top perspective view, where the closure 14 as well as the tangential extent of the core 44 are particularly shown.

[0099] In the example of Figure 14, three arrays 60, 160, 260 of multiple electromagnets are provided, where the third array 260 of electromagnets 241, 261, 271 may be substantially identical to either the first array 60 or the second array 160 of electromagnets. The individual electromagnets 241, 261, 271 are only shown in Figure 14. The single and individual electromagnets 241, 261, 271 are arranged in longitudinal rows and are not otherwise visible depending on the perspective of the figure.

[0100] 14, the electromagnet arrays 60, 160, 260 are spaced equidistant in the circumferential or tangential direction (t), such that adjacent electromagnet arrays 60, 160, 260 are separated by approximately 120°.

[0101] In a further example of Figure 15, a total of four rows or arrays 60, 160, 260, 360 of electromagnets are provided, where each array extends in the longitudinal direction (z) and comprises a number of electromagnets 41, 61, 71. The arrays 60, 160, 260, 360 are separated equidistantly in the circumferential or tangential direction, where the angular distance between neighbouring or adjacent arrays 60, 160, 260, 360 of electromagnets is approximately 90°.

[0102] In the example of three or four electromagnets 60,160,260,360, for example the electromagnets 41,61,71 of the first array 60 may be located at the same longitudinal position as the electromagnets 141,161,171 of the second array 160, for example.

[0103] In some examples, for example, the electromagnets 41, 61, 71 of the first array 160 may be positioned longitudinally offset from the electromagnets 141, 161, 171, 241, 261, 271 of any of the further arrays 160, 260, 360, where the longitudinal offset may be ⅓ or ¼ of the longitudinal extent of the individual electromagnets 41. In this manner, the individual electromagnets 41, 141, 241 of the arrays 60, 160, 260 of electromagnets may be activated sequentially according to the helical order of their spatial arrangement to apply a rather constant longitudinal force effect to the magnetic coupling member 80. [Explanation of symbols]

[0104] 10 Drug Delivery Devices 11 Drive mechanism 12. Housing 14 Closures 15 Base part 16 Rod 18 Side wall 21 Pharmaceuticals 22 Cartridge 23 Barrel 24 Stopper 25 External Surface 26 Proximal aspect 27 Exit 28 Seal 29 Syringe needle 30 Receptacle 33 Radial Center 41 Electromagnet 42 Electromagnetic Coil 43 Radial center 44 cores 45 Legs 46 Bass Section 47 Legs 48 Free end 49 Free end 50 End face 60 Array 61 Electromagnet 71 Electromagnet 80 Magnetic coupling member 81 Magnet 82 Rod Magnet 83 Magnet 84 Mount 141 Electromagnet 160 Array 161 Electromagnet 171 Electromagnet 241 Electromagnet 260 Array 261 Electromagnet 271 Electromagnet 360 Array

Claims

1. A drive mechanism (11) for moving a stopper (24) of a pharmaceutical container (22), the stopper (24) being movably disposed within a longitudinally extending barrel (23) of the pharmaceutical container (22) and movable in a longitudinal direction (z) relative to the barrel (23), the drive mechanism (11) comprising: - a receptacle (30) sized to receive said pharmaceutical container (22); a first electromagnet (41) including an electromagnetic coil (42) and a core (44) extending through said electromagnetic coil (42), the radial center (43) of said electromagnetic coil (42) being located outside said receptacle (30); a magnetic coupling member (80) mechanically engageable with said stopper (24) and adapted for insertion into said barrel (23); Equipped with - a drive mechanism (11), said first electromagnet (41) being operable to generate a magnetic field that causes said magnetic coupling member (80) to move in said longitudinal direction (z).

2. The drive mechanism (11) of claim 1, wherein the radial center (43) of the electromagnetic coil (42) is located radially offset from the radial center (33) of the receptacle (30).

3. 3. The drive mechanism (11) of claim 1 or 2, wherein the core (44) comprises a first leg (45), a base section (46) and a second leg (47), the base section (46) extending through the electromagnetic coil (42) and the first leg (45) and the second leg (47) extending in a radial direction (r) towards the receptacle (30).

4. 4. The drive mechanism (11) of claim 3, wherein the first leg (45) and the second leg (47) are separated in a longitudinal direction (z) and interconnected via the base section (46).

5. 5. The drive mechanism (11) according to claim 3 or 4, wherein the core (44) is located radially outside the receptacle (30), and a free end (48) of the first leg (45) and a free end (49) of the second leg (47) face radially inward towards the receptacle (30).

6. 6. The drive mechanism (11) according to claim 5, wherein at least one of the free ends (48, 49) of the first leg (45) and the second leg (47) includes a radially inwardly facing end surface (50) having a concave shape when viewed in the tangential direction (t).

7. The drive mechanism (11) according to any one of claims 1 to 6, further comprising a second electromagnet (61) longitudinally offset from the first electromagnet (41), the first electromagnet (41) and the second electromagnet (61) forming a first longitudinally extending array (60) of electromagnets (41, 61, 71).

8. The drive mechanism (11) according to any one of the preceding claims, further comprising a third electromagnet (141) tangentially offset from the first electromagnet (41).

9. 9. The drive mechanism (11) according to claim 8, wherein the third electromagnet (141) is longitudinally coplanar with the first electromagnet (41).

10. The drive mechanism (11) of claim 8, wherein the third electromagnet (141) is longitudinally offset from the first electromagnet (41).

11. 11. The drive mechanism (11) of claim 10, wherein the third electromagnet (141) is longitudinally shifted relative to the first electromagnet (41) by approximately half the longitudinal extent of one of the first electromagnet (41) and the third electromagnet (141).

12. The drive mechanism of any one of claims 8 to 11, further comprising a fourth electromagnet (161) longitudinally offset from the third electromagnet (141), the third electromagnet (141) and the fourth electromagnet (161) forming a second longitudinally extending array (160) of electromagnets (141, 161, 171).

13. 13. The drive mechanism of claim 12, wherein the first array (60) of electromagnets (41, 61, 71) and the second array (160) of electromagnets (141, 161, 171) are disposed on radially opposite sides of the receptacle (30).

14. 13. The drive mechanism of claim 12, further comprising a third longitudinally extending array (260) of electromagnets (241, 261, 271), wherein the first array (60) of electromagnets (41, 61, 71), the second array (160) of electromagnets (141, 161, 171), and the third array (260) of electromagnets (241, 261, 271) are equally spaced around a circumference of the receptacle (30).

15. 1. A drug delivery device for dispensing a liquid pharmaceutical product, comprising: a housing (12) adapted to hold and / or receive a cartridge (22) filled with said liquid medicinal product and sealed by a stopper (24); - a drive mechanism (11) according to any one of claims 1 to 14, A drug delivery device comprising:

16. 16. The medication delivery device (10) of claim 15, further comprising a cartridge (22) disposed within or secured to the housing (12).

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