Rotation sensing assembly for injection device

Abstract

The present disclosure relates to a rotation sensing assembly for an injection device (1), the rotation sensing assembly comprising: a first member (201) and a second member (202), wherein the first member (201) and the second member (202) are rotatable relative to each other about a rotation axis (203); at least one signal generator (210) arranged on the first member (201); at least one sensor (220; 320; 420) arranged on the second member (202), wherein the at least one sensor (220; 320; 420) comprises an interdigitated electrode structure (230; 330; 430) configured to generate an electrical signal in response to movement of the at least one signal generator (210) relative to the sensor (220; 320; 420); and a processor (240) connected to the at least one sensor (220; 320; 420) and operable to calculate a rotation angle of the first member (201) relative to the second member (202) based on the electrical signal.

Description

Technical Field

[0001] The present disclosure relates to the field of rotation sensors, and in particular to rotation sensors configured to detect and / or quantitatively measure the rotation of a component of an injection device. In one aspect, the present disclosure relates to a rotation sensing assembly implemented in an attachment configured to be attached to an injection device. In one aspect, the present disclosure relates to a rotation sensing assembly implemented in an injection device. In another aspect, the present disclosure relates to an injection device equipped with a rotation sensing assembly configured to detect and / or quantitatively measure the rotation of a component of an injection device. In another aspect, the present disclosure relates to a method of determining and / or quantitatively measuring the rotation of a component of an injection device. Background Art

[0002] Drug delivery devices for setting and dispensing single or multiple doses of liquid medicaments are well known in the art. Typically, such devices have substantially similar uses to ordinary syringes.

[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 weak and may also be visually impaired. Therefore, suitable drug delivery devices, especially those intended for home medication, need to be robust in construction and easy to use. In addition, the manipulation and general handling of the device and its components should be clear and easy to understand. Such injection devices should provide for the setting and subsequent distribution of medicament doses of variable size. In addition, the dose setting and dose distribution procedures must be easy to operate and must be clear.

[0004] Typically, such devices include a housing or a specific cartridge holder adapted to receive a cartridge at least partially filled with the medicament to be dispensed. The device further includes a drive mechanism, which typically has a displaceable piston rod to operably engage with the bung or piston of the cartridge. By means of the drive mechanism and its piston rod, the bung or piston of the cartridge can be displaced in the distal or dispensing direction and can thus expel a predefined amount of medicament via a piercing assembly (e.g., in the form of an injection needle) that is releasably coupled to a distal section of the housing of the drug delivery device.

[0005] The medicament to be dispensed by the drug delivery device can be provided and contained in a multi-dose cartridge. Such cartridges typically include a glass barrel that is sealed in the distal direction by means of a pierceable seal and further sealed in the proximal direction by a stopper. For reusable drug delivery devices, an empty cartridge can be replaced with a new one. In contrast, disposable drug delivery devices are disposed of when the medicament in the cartridge has been dispensed or used up.

[0006] For some drug delivery devices (such as pen-type injection devices), the user must set doses of equal or variable sizes by rotating the dose dial in a clockwise or dose-increasing direction relative to the body or housing of the injection device. In order to inject and expel a dose of liquid medicament, the user must depress a trigger or dose button in a distal direction and thus towards the body or housing of the injection device. Typically, the user applies distally directed pressure on the dose button (which is located at the proximal end of the dose dial and dose dial sleeve) with his thumb while holding the housing of the injection device with the remaining fingers of the same hand.

[0007] For mechanically implemented injection devices, it is desirable to be able to accurately, reliably and quasi-automatically monitor and / or collect injection-related data during use of the injection device. Mechanically operated injection devices can be equipped with electronically implemented attachments or data collection devices that are configured to monitor user-induced operation of the injection device. The data collection device for attachment to the injection device should be relatively compact in terms of its geometric size. For data collection devices configured for attachment to mechanically implemented injection devices, it is a challenge to detect and / or quantitatively measure manual operation of the device by the user of the device, for example when the user rotates a dial member of the injection device during dose setting or when a rotatable part of the injection device undergoes rotation during dose expulsion.

[0008] But also for electronically implemented injection devices (eg injection devices equipped with an electric drive), it is desirable to provide an accurate, reliable and fail-safe quantitative measurement of a rotatable component of the injection device.

[0009] Purpose of the Invention

[0010] Therefore, an object is to provide an improved rotation sensing assembly configured to detect and / or quantitatively measure the rotation of a rotatable component of an injection device. The rotation sensing assembly and sensor principles should be generally applicable to injection devices and additional devices configured for attachment to such injection devices.

[0011] The rotation sensing assembly should generally be applicable to a variety of rotatable components of an injection device or attachment. The rotation sensing assembly should be cost-effective to manufacture and have a relatively compact design and geometry. The rotation sensing assembly should be relatively robust. In some aspects, it should provide and enable non-contact sensing and / or quantitative measurement of rotation between at least a first component and a second component. The rotation sensing assembly should be easily implementable in an electronic device and should be easily integrable into a printed circuit board. Summary of the Invention

[0012] In one aspect, a rotation sensing assembly for an injection device is provided. The rotation sensing assembly includes a first member and a second member. The first member and the second member are rotatable relative to each other about a rotation axis. At least one of the first member and the second member is rotatable relative to the other of the first member and the second member. For example, the first member may be a stationary member or component of the injection device or an accessory, while the second member is rotatable relative to the first member. In other implementations, the second member is stationary, while the first member is rotatable relative to the second member and / or relative to a housing of the injection device or an accessory.

[0013] The rotation sensing assembly further includes at least one signal generator disposed on or attached to the first member. Typically, the at least one signal generator is located on a specific portion of the first member. Typically, the at least one signal generator is disposed off-axis, typically at a given radial distance from the axis of rotation.

[0014] The rotation sensing assembly further includes at least one sensor. The sensor is disposed on or attached to the second member. The at least one sensor includes an interdigitated electrode structure. The interdigitated electrode structure is configured to generate an electrical signal in response to movement of the at least one signal generator relative to the sensor.

[0015] The rotation sensing assembly further includes a processor connected to at least one sensor. The processor is operable or configured to calculate the rotation angle of the first member relative to the second member based on the electrical signal. The electrical signal processed by the processor is typically obtained from at least one sensor, particularly from an interdigitated electrode structure of the at least one sensor. In some examples, the interdigitated electrode structure is directly connected to the processor in a signal transmission manner. In this way, and once the interdigitated electrode structure generates a measurable signal, the measurable signal can be immediately processed by the processor to calculate or derive the degree of rotation of the first member relative to the second member.

[0016] Typically, and for some examples, the first member and the second member each include an axis of symmetry that substantially coincides with the axis of rotation. The first member and the second member may be arranged at an axial offset relative to each other. Here, the axial direction is parallel to or coincides with the axis of rotation. The first member may include an axial surface, for example, a proximal or distal surface facing a corresponding axial surface of the second member. Similarly, the second member may include an axial surface facing the first member. Typically, at least one signal generator is arranged on a surface or side of the first member facing the second member. Similarly, at least one sensor of the second member is typically located or arranged on a surface or side of the second member facing the first member.

[0017] For some examples, and when the first and second components are arranged at a predefined axial offset from each other, the radial and / or circumferential extension of the first component substantially overlaps with the corresponding radial and / or circumferential extension of the second component in the axial direction; and vice versa.

[0018] In other examples, the first and second components substantially overlap in the axial direction. Thus, with respect to the axial direction, the first and second components may lie in a common plane that is transverse to the axial direction, as defined by the axis of rotation. Here, the first and second components are radially and / or circumferentially offset relative to one another. For example, at least a portion of the first component may be radially inboard of a portion of the second component. Similarly, a portion of the second component may be radially inboard of the first component. Here, the signal generator is positioned at a radial distance from the at least one sensor.

[0019] For various examples, and while the first member undergoes rotation relative to the second member about the rotational axis, the at least one signal generator passes through the at least one sensor, thereby inducing a measurable electrical signal in the interdigitated electrode structure.

[0020] This electrical signal can be processed by a processor. Because the position of the at least one signal generator on the first component and the position of the at least one sensor on the second component are known, the electrical signal measurably generated by the interdigitated electrode structure indicates that the at least one signal generator has passed by the at least one sensor and / or its interdigitated electrode structure.

[0021] Each time the at least one signal generator passes by the at least one sensor, it generates a corresponding electrical signal. Each time the signal generator passes by the sensor corresponds to a predefined angular distance of rotation of the first member relative to the second member. By counting the number of electrical signals generated over time, the processor can derive a total angular displacement or rotation of the first member relative to the second member.

[0022] Providing at least one sensor with an interdigitated electrode structure allows for miniaturization of the rotation sensing assembly. The interdigitated electrode structure requires minimal construction space on the second component. Furthermore, the interdigitated electrode structure can be easily manufactured, for example, by printing or coating on the second component or a corresponding substrate, thereby enabling low-cost mass production of rotation sensing assemblies for injection devices.

[0023] This low-cost approach, coupled with the implementation of an interdigitated electrode structure as the sensing component of at least one sensor, enables the integration of an electronic rotation sensing assembly even into disposable injection devices. However, the currently proposed rotation sensing assembly is not limited to disposable injection devices. It can also be used in reusable injection devices and in attachment devices configured and intended to be mechanically coupled to an injection device.

[0024] According to another example, the rotation sensing assembly includes a planar substrate. The planar substrate is typically located on the second component. At least one sensor is arranged on the planar substrate. The entirety or only components of the at least one sensor can be arranged on the planar substrate. Planar substrates are particularly useful for cost-effective and therefore low-cost mass production of electronic components. Providing a planar substrate is particularly useful for implementing an interdigitated electrode structure. The interdigitated electrode structure can be relatively easily installed and / or arranged and / or fixed on such a planar substrate.

[0025] The planar substrate can be a separate substrate from the second component. In other examples, the planar substrate and the second component can be integrated. Thus, the second component can form, constitute, or provide the planar substrate. In particular, a side or axial surface of the second component can serve as the planar substrate, with the at least one sensor disposed directly thereon.

[0026] According to another example, the interdigital electrode structure is printed or coated on a planar substrate. For providing a low-cost rotation sensing component suitable for batch manufacturing processes, it is particularly useful to print or coat the conductive interdigital electrode structure on a planar substrate. From a manufacturing point of view, it is particularly useful to print or coat the interdigital electrode structure directly on a planar substrate. Therefore, the separate assembly step of attaching the interdigital electrodes to the substrate can be avoided. The corresponding costs and expenses for manual or mechanical assembly can be saved. In addition, by printing or coating the interdigital electrode structure directly on a planar substrate, a durable and quite stable connection between the interdigital electrodes and the planar substrate can be provided. This is particularly advantageous for the life, robustness and reliability of the rotation sensing component.

[0027] According to another example, the rotation sensing assembly includes a printed circuit board. The interdigitated electrode structure of at least one sensor is arranged on the printed circuit board. The processor of the rotation sensing assembly is also arranged on the printed circuit board. In addition, the planar substrate as described above can be integrated into or on the printed circuit board. Therefore, the planar substrate can be formed or constituted by a printed circuit board. In this way, the processor and / or other electronic components of the rotation sensing assembly and the interdigitated electrode structure can be arranged, mounted and / or fixed on the same printed circuit board. In addition, all conductive components of the rotation sensing assembly can be mounted, arranged, printed or coated on the same planar substrate, which can be implemented as a printed circuit board. In this way, and in order to manufacture the rotation sensing assembly, it can be sufficient to fully configure a single printed circuit board and arrange the printed circuit board on the second component.

[0028] The printed circuit board may further be provided with an electrical energy source, for example, in the form of a battery or solar cell. Typically, the processor and at least one sensor are located on the same side of the printed circuit board. The battery or power supply may be located on opposite sides of the printed circuit board. It may be located on the back side of the printed circuit board. The battery and / or electrical energy source may be attached and secured to opposite sides of the printed circuit board.

[0029] The processor and the at least one sensor are typically located on the same side of the printed circuit board.For some examples, the processor and the at least one sensor are located on opposite sides of the printed circuit board or planar substrate.

[0030] In this way, the overall geometry of the rotation sensing assembly can be varied and adapted depending on the available construction space inside the injection device and / or inside the attachment device.

[0031] According to another example, the interdigitated electrode structure is configured to generate an electric field. The at least one signal generator is configured to change the electric field. The interdigitated electrode structure can form an interdigitated capacitor having at least a first electrode and a second electrode. The first electrode and the second electrode are typically electrically insulated from each other.

[0032] In a quasi-stable configuration, the interdigitated electrode structure can be driven by a DC voltage. The interdigitated electrode structure can also be driven by an AC voltage. For each case, a corresponding electric field will be generated between the first electrode and the second electrode having different polarities. At least one signal generator is configured to change the electric field generated by the interdigitated electrode structure. By bringing at least one signal generator close to the interdigitated electrode structure (for example, when passing through the interdigitated electrode structure), at least one signal generator causes a measurable change in the electric field. The electric field change caused by this signal generator can be detected by a processor connected to at least one sensor and / or the interdigitated electrode structure. In this way, it is possible to detect and collect count pulses indicating that at least one generator passes through the interdigitated electrode structure or passes through at least one sensor.

[0033] According to another example, the interdigitated electrode structure includes a first electrode and a second electrode. The first electrode and the second electrode are arranged in an interdigitated geometric configuration. The first electrode and the second electrode may include a periodic microstrip electrode structure having an interdigitated pattern. The first electrode and the second electrode may each include a comb-like structure, wherein the free ends of the comb-like structures face each other and cross each other non-contactingly when arranged in a common plane on the substrate. The first electrode and the second electrode may also be arranged in a zigzag manner. In any conceivable interdigitated geometric configuration of the first electrode and the second electrode, the surface density of the electrode structure on the substrate can be increased or even maximized.

[0034] In another example of a rotation sensing assembly, an interdigitated electrode structure includes a first electrode and a second electrode, wherein the first electrode and the second electrode are electrically connected to each other via a meandering conductive structure. Here, the first electrode and the second electrode can be implemented as contact terminals of a single conductive structure, wherein the conductive structure is a meandering type or includes a meandering geometry.

[0035] The meandering conductive structure may include a plurality of elongated conductor segments extending parallel to one another. The plurality of elongated conductor segments are electrically connected in series. In the example of at least three elongated conductor segments, a first longitudinal end of a first conductor segment may constitute or be connected to a first electrode. An opposite second longitudinal end of the first conductor segment may be connected to a second longitudinal end of an adjacent second conductor segment.

[0036] The opposite end of the second conductor segment, and therefore the first end of the second conductor segment, can be connected to the first longitudinal end of another adjacent elongated conductor segment (i.e., the third elongated conductor segment). The opposite end of the third elongated conductor segment, and therefore the second end, can be connected to the second end of the fourth conductor segment, and so on. The free end segment of the final longitudinal conductor segment can be connected to the second electrode or can form the second electrode. For a meandering conductive structure comprising a total of three elongated, parallel-oriented conductor segments, the second end of the third elongated conductor segment can be connected to the second electrode or can form the second electrode.

[0037] According to another embodiment, the signal generator comprises a signal generating portion. At least the signal generating portion or the entire signal generator is composed of a relative dielectric constant ε r The signal generating portion of the signal generator includes polyamide, silicon dioxide, chloroprene rubber, natural or synthetic rubber, graphite, silicon, or a material with a relative dielectric constant ε. r Other materials greater than 3, or made thereof.

[0038] For some examples, the signal generator includes a signal generating portion that is coated, covered, or made of an elastomeric material (such as natural or synthetic rubber). Rubber includes a relatively large relative dielectric constant (greater than 5 or even greater than 6). Once the signal generating portion of the signal generator is in direct proximity to the interdigitated electrode structure, and once the signal generating portion penetrates or traverses the electric field provided and generated by the interdigitated electrode structure, a measurable signal is obtained at the processor, thereby indicating that at least one signal generator has passed by at least one sensor.

[0039] According to another example, the interdigitated electrode structure is configured to generate a magnetic field. Here, at least one signal generator is configured to change the magnetic field. Here, the interdigitated electrode structure includes at least a first or primary winding and at least one second or secondary winding. When properly driven by a driving voltage, the first or primary winding generates a spatially periodic magnetic field, and the second or secondary winding is implemented as an induction winding, for example, in the form of a single-turn wire. The second electrode or second winding is configured and operable to sense the magnetic field generated by the first electrode, the first winding or the primary winding. Any change in the magnetic field generated by the first electrode or winding can be detected and / or quantitatively measured by at least the second electrode or winding. Here, at least one signal generator includes a diamagnetic, paramagnetic or ferromagnetic material capable of changing the magnetic field generated or provided by the interdigitated electrode structure. For this example, at least one sensor can be implemented as a so-called meandering winding magnetometer (MWM).

[0040] In another example, at least one sensor is arranged at a predefined radial sensor distance D from the axis of rotation. Furthermore, at least one signal generator is arranged at a predefined radial signal generator distance d from the axis of rotation. Here, the difference (Dd) between the radial sensor distance and the radial signal generator distance is less than or equal to the difference between the radial extension of the at least one sensor and the radial extension of the at least one signal generator. In this manner, when the first component undergoes rotation relative to the second component about the axis of rotation, the at least one sensor and the at least one signal generator can overlap in both radial and axial directions.

[0041] According to another example, a plurality of sensors of at least one sensor are distributed on one side of the second member. Alternatively or additionally, a plurality of signal generators in at least one signal generator are distributed on the side of the first member facing the second member. In either way, a plurality of signal generators and / or a plurality of sensors are provided. The plurality of sensors and signal generators can be distributed equidistantly or equiangularly along the circumference of the first member and the second member, respectively. For example, if the first member is provided with four signal generators equidistantly arranged along the circumference of the first member, and if the second member includes only one sensor, the angular resolution of the rotation sensing assembly will be as small as 90°. By utilizing a plurality of sensors that are regularly or irregularly distributed along the circumference of the second member, the spatial resolution can be changed (e.g., increased) depending on the number of sensors and depending on the specific spacing between adjacent sensors.

[0042] For example, it is conceivable that a first number of sensors is provided on the second component, and a second number of signal generators is provided on the first component, wherein the first number and the second number are not equal. In this case, the plurality of regular or irregular spatial patterns representing sensors on the second component, combined with the regular or irregular pattern of the plurality of signal generators on the first component, can provide a clear rotary encoder between the first and second components, thereby allowing the sensing of rotation and the degree of rotation of the first component relative to the second component to be determined.

[0043] According to another example, at least one sensor and at least one signal generator are permanently disconnected from mechanical contact. Thus, the at least one sensor and at least one signal generator are arranged on the second component and the first component, respectively, in a collision-free manner. In particular, when the interdigitated electrode structure is implemented as an interdigitated capacitor or MWM, the passage of the at least one sensor past the at least one signal generator can be detected in a contactless manner. Contactless electrical and / or magnetic measurement is particularly advantageous for extending the overall life of the rotation sensing assembly because there is no friction between the first and second components. Furthermore, neither the at least one sensor nor the at least one signal generator is subject to wear or abrasion.

[0044] In another example, the planar substrate is a piezoelectric substrate. An interdigital electrode structure is arranged on the piezoelectric substrate, and the arrangement of the interdigital electrode structure on the piezoelectric substrate is operable to generate an electrical signal in response to surface acoustic waves on or through the planar substrate. In this way, and by implementing the planar substrate as a piezoelectric substrate, at least one sensor can be implemented as an interdigital transducer. The interdigital transducer includes a first electrode and a second electrode, typically having a comb-like shape. The first electrode and the second electrode, and thus the comb-like structure, can be arranged in the form of a zipper, i.e., wherein the free ends of the teeth of the comb-like structure face each other, and the free space between the teeth of one comb-like structure accommodates the teeth of another comb-like structure.

[0045] The interdigital transducer is operable to convert mechanical vibrations (e.g., surface acoustic waves on a planar substrate) into electrical signals via the piezoelectric effect. In this way, any surface acoustic waves present on the second member can be detected. Interdigital transducers are commercially available and can be easily implemented on or in a relatively miniaturized manner on the second member.

[0046] In another example, a rotation sensing assembly includes a strain gauge. Here, an interdigitated electrode structure is part of the strain gauge attached to a second member. The interdigitated electrode structure exhibits a measurable change in electrical conductivity in response to flexible deformation. Through a mechanical connection between the strain gauge and the second member, the interdigitated electrode structure exhibits a measurable change in electrical conductivity in response to the flexible deformation of the second member.

[0047] Typically, when subjected to rotation relative to the first member, the second member undergoes flexible deformation. To this end, the first member and the second member can be in at least temporary mechanical engagement. For example, the first member and the second member can be mechanically engaged by a ratchet assembly. When the first member rotates relative to the second member, the second member undergoes flexible deformation, for example, regular and repeated flexible deformation. Since the interdigitated electrode structure is attached (e.g., adhesively attached) to the second member, the deformation of the second member is equivalently transferred to a corresponding deformation of the interdigitated electrode structure. Therefore, when the second member undergoes elastic deformation, the resistance of the interdigitated electrode structure undergoes a measurable change.

[0048] The strain gauge may include an insulating flexible backing supporting a conductive (e.g., metal) interdigital pattern. The insulating flexible backing and / or the conductive interdigital pattern may be attached to the second member by a suitable adhesive (such as cyanoacrylate). The conductive interdigital pattern may include Constantan alloy.

[0049] The at least one sensor may include a first strain gauge and a second strain gauge, each of which includes an interdigitated electrode structure. The first strain gauge can serve as a reference resistor, while the second strain gauge can undergo elastic deformation and thus serve as a measuring resistor. The first and second strain gauges can be electrically connected to each other via a Wheatstone bridge circuit. Therefore, and to measure the mechanical strain or load present on the second component, it is generally sufficient to determine the change in the resistivity of the first strain gauge relative to the second strain gauge.

[0050] One of the first strain gauge and the second strain gauge may be integrated into the printed circuit board, while the other of the first strain gauge and the second strain gauge may be located remotely from the printed circuit board. Typically, the first strain gauge and, therefore, the reference resistor may be integrated into the printed circuit board, while the second strain gauge is adhesively attached to the elastically deformable portion of the second member.

[0051] When the second member rotates relative to the first member, the orientation of the interdigitated electrode structure of the strain gauge on the second member is typically aligned or parallel to the main direction of flexible deformation of the second member. In this way, the measurement sensitivity and thus the measurement accuracy can be enhanced.

[0052] According to another example, the rotation sensing assembly includes at least one ratchet assembly engaged with at least one of the first member and the second member. The ratchet assembly is configured to support the rotation of the first member relative to the second member in discrete rotational steps. Typically, the ratchet assembly includes a first ratchet member located on the first member and further includes a second ratchet member located on the second member. The first ratchet member faces the second ratchet member, and vice versa. The first ratchet member typically includes a first protrusion, for example in the form of teeth, facing the second ratchet member.

[0053] The second ratchet member typically includes a second protrusion facing toward the first ratchet member. The second ratchet member may also include teeth or a tooth-like structure. For some examples, the first ratchet member includes a toothed rim having a tooth-like structure on an outer surface or on an inner surface. The second ratchet member may include an elastically deformable ratchet member so as to regularly engage with the first ratchet member when the first ratchet member and the second ratchet member are subjected to rotation relative to each other about the rotation axis. In this way, the first member can rotate in discrete steps relative to the second member, for example, in a dose-increasing direction and / or in a dose-decreasing direction.

[0054] The size of these discrete steps is controlled by the periodicity of at least one of the first ratchet member and the second ratchet member. The elastically deformable or elastically biased ratchet member is elastically deformable in a radial direction (e.g., radially inwardly or radially outwardly). Alternatively, the corresponding ratchet member is elastically deformable in an axial direction. In any case, the ratchet engagement between the first member and the second member provides and generates surface acoustic waves in at least one of the first member and the second member. When the first member is rotated relative to the second member as discrete rotational steps defined and controlled by the ratchet engagement between the first member and the second member, an audible click can be produced, thereby indicating to the user that the first member has been rotated relative to the second member a discrete angular distance, which angular distance can correspond to a predefined dose size (e.g., one international unit).

[0055] Typically, the second ratchet member may be equipped or provided with at least one sensor comprising an electrical strain gauge which exhibits a measurable change in its electrical conductivity in response to flexible deformation of the second member.The electrical strain gauge comprises an interdigitated electrode structure.

[0056] For some examples, the first member and therefore the first ratchet member may be integrated into the housing of the injection device or into the housing of the attachment, while the second member of the rotation sensing assembly is rotatable relative to the housing. However, other examples are also conceivable in which the first member is rotatable relative to the housing and in which the second member of the rotation sensing assembly is integrated into the housing of the injection device or the attachment or is permanently and rigidly connected to the housing of the injection device or the attachment.

[0057] The implementation of a ratchet assembly is particularly advantageous for generating surface acoustic waves that can be detected by at least one sensor, ie when the sensor is implemented as an interdigital transducer.

[0058] According to another aspect, the present disclosure further relates to an injection device for setting and expelling a dose of a medicament. The injection device includes a housing and a trigger for initiating and / or controlling the expulsion of a dose. The injection device further includes a dial member that is rotatable relative to the housing for setting the dose. The injection device further includes at least one rotation sensing assembly as described above, wherein the first member and the second member are integrated into the injection device. Typically, the first member is rotationally locked or connected to one of the dial member and the housing, and the second member is rotationally locked to the other of the dial member and the housing. It is even conceivable that the first member is integrated into one of the dial member and the housing, and the second member is integrated into the other of the dial member and the housing.

[0059] Instead of a dial member or a housing, the first member may also be connected to or integrated into a rotatable component of the drive mechanism of the injection device, the rotatable component being rotationally locked to the dial member. Likewise, the other of the first and second members may be integrated into the housing, or may be rigidly fastened or attached to a component that is immovably connected to or fixed to the housing.

[0060] According to another aspect, the present disclosure also relates to an attachment configured for attachment to an injection device. The attachment includes a body configured to serve as a dial member for attachment to the injection device. The attachment further includes a housing configured to attach to the housing of the injection device. The attachment includes a rotation sensing assembly as described above, wherein the first member is rotationally locked to one of the attachment body and the housing, and wherein the second member is rotatable relative to the other of the attachment body and the housing.

[0061] In another aspect, the present disclosure also relates to a method for detecting and / or quantitatively measuring rotation of a first component of an injection device relative to a second component of the injection device as described above. The method comprises the steps of: introducing a torque to one of a first component and a second component of a rotation sensing assembly, typically during dose setting. The torque is introduced to one of the first component and the second component relative to the other of the first component and the second component, thereby causing at least one signal generator to move relative to at least one sensor of the rotation sensing assembly.

[0062] In a further step, an electrical signal of the interdigitated electrode structure of the at least one sensor is measured in response to movement of the at least one signal generator relative to the at least one sensor. In other words, the electrical signal of the interdigitated electrode structure is measured when the first member rotates relative to the second member.

[0063] In a further step, the electrical signal provided by the interdigitated electrode structure is processed by a processor, and the rotation angle of the first member relative to the second member is calculated based on the electrical signal.

[0064] Typically, the method can be performed by a rotation sensing assembly as described above, which can be implemented in an injection device, such as a handheld pen injector. Alternatively, the method can be performed by an attachment device, which is configured to be attached to such an injection device. The injection device can be implemented as a disposable injection device, which is intended to be discarded in its entirety once the medicament located therein has been used up or should no longer be used. The rotation sensing assembly can also be implemented in a reusable device configured for multiple and long-term use, wherein the medicament cartridge is intended to be replaced when it is empty or when the medicament located therein should no longer be used.

[0065] In the present context, the term "distal" or "distal end" relates to the end of the injection device facing towards the injection site of a person or animal. The term "proximal" or "proximal end" relates to the opposite end of the injection device, which is farthest from the injection site of a person or animal.

[0066] As used herein, the term "drug" or "medicament" refers to a pharmaceutical formulation containing at least one pharmaceutically active compound.

[0067] In one embodiment, the pharmaceutically active compound has a molecular weight of up to 1500 Da and / or is a peptide, protein, polysaccharide, vaccine, DNA, RNA, enzyme, antibody or antibody fragment, hormone or oligonucleotide, or a mixture of the above pharmaceutically active compounds,

[0068] Wherein in another embodiment, the pharmaceutically active compound can be used to treat and / or prevent diabetes or complications associated with diabetes (such as diabetic retinopathy), thromboembolic disease (such as deep vein or pulmonary thromboembolism), acute coronary syndrome (ACS), angina pectoris, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and / or rheumatoid arthritis,

[0069] Wherein in another embodiment, the pharmaceutically active compound comprises at least one peptide for the treatment and / or prevention of diabetes or complications associated with diabetes (such as diabetic retinopathy),

[0070] In other embodiments, the pharmaceutically active compound comprises at least one human insulin or a human insulin analog or derivative, glucagon-like peptide (GLP-1) or an analog or derivative thereof, or exendin-3 or exendin-4, or an analog or derivative of exendin-3 or exendin-4.

[0071] Insulin analogs are, for example, Gly(A21), Arg(B31), Arg(B32) human insulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin in which the proline at position B28 is replaced by Asp, Lys, Leu, Val or Ala, and in which position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

[0072] Insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoylLysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB2 9LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-γ-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-γ-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyheptadecanoyl) human insulin.

[0073] Exendin-4 refers, for example, to exendin-4(1-39), a peptide having the following sequence: H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

[0074] The exendin-4 derivative is, for example, selected from the following list of compounds:

[0075] H-(Lys)4-des Pro36,des Pro37 exendin-4(1-39)-NH2, H-(Lys)5-desPro36,des Pro37 exendin-4(1-39)-NH2, des Pro36 exendin-4(1-39),

[0076] des Pro36[Asp28] exendin-4(1-39),

[0077] des Pro36[IsoAsp28] exendin-4(1-39),

[0078] des Pro36[Met(O)14,Asp28]exendin-4(1-39), des Pro36[Met(O)14,IsoAsp28]exendin-4(1-39), des Pro36[Trp(O2)25,Asp28]exendin-4(1-39), des Pro36[Trp(O2)25,IsoAsp28]exendin-4(1-39), des Pro36[Met(O)14Trp(O2)25,Asp28]exendin-4(1-39), des Pro36[Met(O)14Trp(O2)25,IsoAsp28]exendin-4(1-39); or des Pro36[Asp28]exendin-4(1-39),

[0079] des Pro36[IsoAsp28] exendin-4(1-39),

[0080] des Pro36[Met(O)14,Asp28]exendin-4(1-39), des Pro36[Met(O)14,IsoAsp28]exendin-4(1-39), des Pro36[Trp(O2)25,Asp28]exendin-4(1-39), des Pro36[Trp(O2)25,IsoAsp28]exendin-4(1-39), des Pro36[Met(O)14Trp(O2)25,Asp28]exendin-4(1-39), des Pro36[Met(O)14Trp(O2)25,IsoAsp28]exendin-4(1-39), wherein the group -Lys6-NH2 can be bound to the C-terminus of the exendin-4 derivative;

[0081] or an exendin-4 derivative having the following sequence:

[0082] des Pro36 exendin-4(1-39)-Lys6-NH2(AVE0010), H-(Lys)6-des Pro36[Asp28] exendin-4(1-39)-Lys6-NH2, des Asp28 Pro36,Pro37,Pro38 exendin-4(1-39)-NH2, H-(Lys)6-des Pro36,Pro38[Asp28] exendin-4(1-39)-NH2, H-(Lys)6-des Pro36,Pro38[Asp28] exendin-4(1-39)-NH2, H-Asn-(Glu)5desPro36,Pro37,Pro38[Asp28] exendin-4(1-39)-NH2, des Pro36,Pro37,Pro38[Asp28] exendin-4(1-39)-(Lys)6-NH2, H-(Lys)6-des Pro36, Pro37, Pro38[Asp28] exendin-4(1-39)-(Lys)6-NH2, H-Asn-(Glu)5-des Pro36, Pro37, Pro38[Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0083] H-(Lys)6-des Pro36[Trp(O2)25,Asp28] exendin-4(1-39)-Lys6-NH2、H-desAsp28 Pro36,Pro37,Pro38[Trp(O2)25] exendin-4(1-39)-NH2、H-(Lys)6-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28] exendin-4(1-39)-NH2、

[0084] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28]exendin-4(1-39)-NH2,

[0085] des Pro36,Pro37,Pro38[Trp(O2)25,Asp28] exendin-4(1-39)-(Lys)6-NH2、H-(Lys)6-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28] exendin-4(1-39)-(Lys)6-NH2、

[0086] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Trp(O2)25,Asp28]exendin-4(1-39)-(Lys)6-NH2,

[0087] H-(Lys)6-des Pro36[Met(O)14,Asp28] Exendin-4(1-39)-Lys6-NH2, des Met(O)14Asp28 Pro36,Pro37,Pro38 Exendin-4(1-39)-NH2, H-(Lys)6-desPro36,Pro37,Pro38[Met(O)14,Asp28] Exendin-4(1-39)-NH2,

[0088] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-NH2,

[0089] des Pro36, Pro37, Pro38[Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH 2,

[0090] H-(Lys)6-des Pro36,Pro37,Pro38[Met(O)14,Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0091] H-Asn-(Glu)5des Pro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-(Lys)6-NH2,

[0092] H-Lys6-des Pro36[Met(O)14,Trp(O2)25,Asp28]exendin-4(1-39)-Lys6-NH2,

[0093] H-des Asp28 Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25]exendin-4(1-39)-NH2,

[0094] H-(Lys)6-des Pro36,Pro37,Pro38[Met(O)14,Asp28]exendin-4(1-39)-NH2,

[0095] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]exendin-4(1-39)-NH2,

[0096] des Pro36, Pro37, Pro38[Met(O)14, Trp(O2)25, Asp28] exendin-4(1-39)-(Lys)6-NH2,

[0097] H-(Lys)6-des Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28] Exendin-4(S1-39)-(Lys)6-NH2,

[0098] H-Asn-(Glu)5-des Pro36,Pro37,Pro38[Met(O)14,Trp(O2)25,Asp28]exendin-4(1-39)-(Lys)6-NH2;

[0099] or a pharmaceutically acceptable salt or solvate of any of the above exendin-4 derivatives.

[0100] Hormones are, for example, pituitary hormones or hypothalamic hormones or regulatory activity peptides as listed in Chapter 50 of the Rote Liste, 2008 edition, and their antagonists, such as gonadotropins (Follitropin, Luteinizing Hormone, Chorionic Gonadotropin, Gametogenic Hormone), somatropine (Somatropin), desmopressin, terlipressin, gonadorelin, triptorelin, leuprorelin, buserelin, nafarelin, goserelin.

[0101] The polysaccharide is, for example, a glycosaminoglycan, hyaluronic acid, heparin, low molecular weight heparin or ultra low molecular weight heparin or a derivative thereof, or a sulfated form (e.g., a polysulfated form) of the above polysaccharide, and / or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a polysulfated low molecular weight heparin is enoxaparin sodium.

[0102] Antibodies are globular plasma proteins (approximately 150 kDa), also known as immunoglobulins, that share a common basic structure. They are glycoproteins because sugar chains are attached to amino acid residues. The basic functional unit of each antibody is the immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimers with two Ig units (such as IgA), tetramers with four Ig units (such as bony fish IgM), or pentamers with five Ig units (such as mammalian IgM).

[0103] The Ig monomer is a "Y"-shaped molecule composed of four polypeptide chains; two identical heavy chains and two identical light chains are connected by disulfide bonds between cysteine residues. Each heavy chain is approximately 440 amino acids long; each light chain is approximately 220 amino acids long. The heavy and light chains each contain intrachain disulfide bonds that stabilize their folding. Each chain is composed of structural domains called Ig domains. These domains contain approximately 70-110 amino acids and are divided into different categories based on their size and function (such as variable regions, or V regions, and constant regions, or C regions). These domains have a characteristic immunoglobulin fold, in which two beta-sheets are arranged in a "sandwich" shape, held together by interactions between conserved cysteines and other charged amino acids.

[0104] There are five types of mammalian Ig heavy chains, designated α, δ, ε, γ, and μ. The type of heavy chain present defines the antibody's isotype; these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively.

[0105] The different heavy chains vary in size and composition; α and γ contain approximately 450 amino acids, δ contains approximately 500 amino acids, and μ and ε contain approximately 550 amino acids. Each heavy chain has a constant region (C H ) and variable regions (V H ) two regions. Within a species, the constant region is essentially the same in all antibodies of the same isotype, but differs in antibodies of different isotypes. Heavy chains γ, α, and δ have a constant region composed of three tandem Ig domains and a hinge region for increased flexibility; heavy chains μ and ε have a constant region composed of four immunoglobulin domains. The variable region of the heavy chain differs in antibodies produced by different B cells but is identical for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is approximately 110 amino acids long and consists of a single Ig domain.

[0106] In mammals, there are two types of immunoglobulin light chains, designated λ and κ. Light chains have two consecutive domains: a constant domain (CL) and a variable domain (VL). The approximate length of a light chain is 211 to 217 amino acids. Each antibody contains two always identical light chains; in mammals, only one type of light chain, κ or λ, is present per antibody.

[0107] Although the general structure of all antibodies is very similar, the unique properties of a given antibody are determined by the variable (V) region, as detailed above. More specifically, the variable loops (three per light chain (VL) and three on the heavy chain (VH)) are responsible for binding to the antigen, i.e., for its antigenic specificity. These loops are called complementarity determining regions (CDRs). Because the CDRs from the VH and VL domains constitute the antigen binding site, it is the combination of the heavy and light chains (rather than each individually) that determines the final antigenic specificity.

[0108] An "antibody fragment" contains at least one antigen-binding fragment as defined above and exhibits essentially the same function and specificity as the intact antibody from which it is derived. Limited proteolysis with papain cleaves the Ig prototype into three fragments. Two identical amino-terminal fragments are the antigen-binding fragment (Fab), each containing a complete L chain and approximately half of an H chain. The third fragment is the crystallizable fragment (Fc), which is similar in size but contains the carboxyl-terminal halves of the two heavy chains and their interchain disulfide bonds. Fc contains carbohydrates, complement binding sites, and FcR binding sites. Limited pepsin digestion produces a single F(ab')2 fragment containing both the Fab segment and the hinge region, including the HH interchain disulfide bond. F(ab')2 is divalent for antigen binding. The disulfide bonds of F(ab')2 can be cleaved to obtain Fab'. In addition, the variable regions of the heavy and light chains can be fused together to form a single-chain variable fragment (scFv).

[0109] Pharmaceutically acceptable salts include, for example, acid addition salts and basic salts. Acid addition salts include, for example, HCl salts or HBr salts. Basic salts include, for example, salts having a cation selected from: an alkali or alkaline cation, for example, Na+, K+, Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), wherein R1 to R4 independently represent: hydrogen, an optionally substituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenyl group, an optionally substituted C6-C10-aryl group, or an optionally substituted C6-C10-heteroaryl group. Further examples of pharmaceutically acceptable salts are described in the following literature: "Remington's Pharmaceutical Sciences," 17th edition, Alfonso R. Gennaro (ed.), Mark Publishing Company, Easton, Pa., USA, 1985, and Encyclopedia of Pharmaceutical Technology.

[0110] Pharmaceutically acceptable solvates are, for example, hydrates.

[0111] It is also clear to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the scope of the present disclosure. In addition, 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] In the following, a number of examples of containers and injection devices will be described in more detail with reference to the accompanying drawings, in which:

[0113] FIG1 shows an example of an injection device,

[0114] FIG2 shows the injection device of FIG1 in an exploded perspective view,

[0115] FIG3 shows a block diagram of a sensor assembly for a drug delivery device or an injection device, FIG4 is a schematic perspective illustration of the integration of a sensor assembly into a dosing assembly of an injection device,

[0116] FIG5 schematically shows an implementation of a sensor assembly in a top view.

[0117] FIG. 6 shows the example of FIG. 5 in a perspective side view,

[0118] Figure 7 schematically shows the interdigitated electrode structure of the sensor.

[0119] Figure 8 schematically shows a cross section of an interdigitated electrode structure.

[0120] FIG9 schematically shows another example of a sensor assembly.

[0121] Figure 10 shows another example of a sensor assembly.

[0122] FIG11 schematically shows an implementation of an interdigitated electrode structure forming a meander winding magnetometer.

[0123] Figure 12 shows a method for measuring rotation using a sensor assembly, and

[0124] FIG13 schematically illustrates an example of an interdigitated electrode structure implemented as a strain gauge. DETAILED DESCRIPTION

[0125] An example of an injection device 1 suitable for implementing a rotation sensing assembly is shown in Figures 1 and 2. The injection device 1 is a prefilled, disposable injection device comprising a housing 10 to which an injection needle 15 may be attached. The injection needle 15 is protected by an inner needle cap 16 and an outer needle cap 17 or protective cap 18, which is configured to surround and protect the distal section of the housing 10 of the injection device 1. The housing 10 may include and form a main housing portion configured to house a drive mechanism 8, as shown in Figure 2. The injection device 1 may further include a distal housing component, designated as a cartridge holder 14. The cartridge holder 14 may be permanently or releasably connected to the main housing 10. The cartridge holder 14 is typically configured to hold a cartridge 6 filled with a liquid medication. The cartridge 6 comprises a cylindrical or tubular barrel 25, which is sealed in the proximal direction 3 by a stopper 7 located inside the barrel 25. The stopper 7 can be displaced in the distal direction 2 relative to the barrel 25 of the cartridge 6 by means of the piston rod 20. The distal end of the cartridge 6 is sealed by a pierceable seal 26, which is configured as a septum and can be pierced by the proximally directed tip of the injection needle 15. The cartridge holder 14 comprises a threaded socket 28 at its distal end for threaded engagement with a corresponding threaded portion of the injection needle 15. By attaching the injection needle 15 to the distal end of the cartridge holder 14, the seal 26 of the cartridge 6 is penetrated, thereby establishing a fluid transfer path to the interior of the cartridge 6.

[0126] When the injection device 1 is configured to administer, for example, human insulin, the dose set by the dose dial 12 at the proximal end of the injection device 1 may be displayed in so-called international units (IU, where 1 IU is the biological equivalent of approximately 45.5 μg of pure crystalline insulin (1 / 22 mg)). The dose dial 12 may comprise or form a dose dial.

[0127] As further shown in Figures 1 and 2, the housing 10 includes a dose window 13, which may be in the form of an aperture in the housing 10. The dose window 13 allows the user to view a limited portion of a number sleeve 80, which is configured to move upon rotation of the dose dial 12 to provide a visual indication of the currently set dose. When rotated during dose setting and / or dispensing or expelling, the dose dial 12 rotates in a helical path relative to the housing 10.

[0128] The injection device 1 can be configured so that turning the dose knob 12 causes a mechanical click to provide acoustic feedback to the user. The number sleeve 80 mechanically interacts with the piston in the insulin cartridge 6. When the needle 15 is inserted into the patient's skin and the trigger 11 or injection button is pushed, the insulin dose displayed in the display window 13 is ejected from the injection device 1. If the needle 15 of the injection device 1 remains in the skin for a certain period of time after pushing the trigger 11, a higher percentage of the dose is actually injected into the patient. The ejection of the insulin dose may also cause a mechanical click, but this sound is different from the sound produced when using the dose dial 12.

[0129] In this embodiment, during insulin dose delivery, the dose dial 12 is rotated to its initial position in axial movement, ie no rotation, while the number sleeve 80 is rotated to return to its initial position, eg to display a dose of zero units.

[0130] The injection device 1 can be used for several injection procedures until the cartridge 6 is empty or the medicament in the injection device 1 reaches its expiry date (eg 28 days after first use).

[0131] Furthermore, before using the injection device 1 for the first time, it may be necessary to perform a so-called "priming shot" to remove air from the cartridge 6 and the needle 15, for example by selecting two units of medication and pressing the trigger 11 while holding the needle 15 of the injection device 1 pointing upwards. For ease of presentation, it will be assumed hereinafter that the ejected amount substantially corresponds to the injected dose, such that, for example, the amount of medication ejected from the injection device 1 is equal to the dose received by the user.

[0132] An example of the drive mechanism 8 is shown in more detail in FIG2 . It comprises a number of mechanically interacting components. A flange-shaped support member of the housing 10 includes a threaded axial through-opening that is threadedly engaged with a first or distal thread 22 of the piston rod 20. The distal end of the piston rod 20 includes a bearing 21 on which a pressure foot 23 is freely rotatable about the longitudinal axis of the piston rod 20. The pressure foot 23 is configured to axially abut a proximally-facing thrust-receiving surface of the bung 7 of the cartridge 6. During a dispensing action, the piston rod 20 rotates relative to the housing 10, thereby undergoing a distally directed thrust movement relative to the housing 10 and, therefore, relative to the barrel 25 of the cartridge 6. As a result, due to the threaded engagement of the piston rod 20 with the housing 10, the bung 7 of the cartridge 6 is displaced a well-defined distance in the distal direction 2.

[0133] The piston rod 20 is further provided at its proximal end with a second thread 24. The distal thread 22 and the proximal thread 24 have opposite rotation directions.

[0134] A drive sleeve 30 is further provided, having a hollow interior for receiving the piston rod 20. The drive sleeve 30 includes an internal thread that is threadedly engaged with the proximal thread 24 of the piston rod 20. Furthermore, the drive sleeve 30 includes an externally threaded section 31 at its distal end. The threaded section 31 is axially limited between a distal flange portion 32 and a further flange portion 33, which is located at a predefined axial distance from the distal flange portion 32. Between the two flange portions 32, 33, a last dose limiter 35 in the form of a semicircular nut is provided, which has an internal thread that cooperates with the threaded section 31 of the drive sleeve 30.

[0135] The last dose limiter 35 further includes radial recesses or protrusions on its outer circumference for engaging with complementary recesses or protrusions on the inner side of the sidewall of the housing 10. In this way, the last dose limiter 35 is connected to the housing 10 via a spline. During the continuous dose setting procedure, rotation of the drive sleeve 30 in the dose increment direction 4, or clockwise, results in cumulative axial displacement of the last dose limiter 35 relative to the drive sleeve 30. An annular spring 40 is further provided, which axially abuts the proximally facing surface of the flange portion 33. In addition, a tubular adapter 60 is provided. At a first end, the adapter 60 is provided with a series of circumferentially directed serrations. A radially inwardly directed flange is positioned toward the second, opposite end of the adapter 60.

[0136] Furthermore, a dose dial sleeve, also designated as a number sleeve 80, is provided. The number sleeve 80 is disposed outside the spring 40 and the adapter 60 and radially inwardly of the housing 10. A helical groove 81 is provided around the outer surface of the number sleeve 80. The housing 10 is provided with a dose window 13, through which a portion of the outer surface of the number sleeve 80 is visible. The housing 10 further includes a helical rib on the inner sidewall portion of the insert 62, which seats in the helical groove 81 of the number sleeve 80. The tubular insert 62 is inserted into the proximal end of the housing 10. The tubular insert is rotationally and axially fixed to the housing 10. First and second stops are provided on the housing 10 to limit a dose setting procedure during which the number sleeve 80 rotates in a helical motion relative to the housing 10. As will be explained in more detail below, at least one stop is provided by a preselector stop feature 71 provided on the preselector 70.

[0137] A dose dial 12 in the form of a dose dial handle is provided around the outer surface of the proximal end of the number sleeve 80. The outer diameter of the dose dial 12 typically corresponds to and matches the outer diameter of the housing 10. The dose dial 12 is fixed to the number sleeve 80 to prevent relative movement therebetween. The dose dial 12 is provided with a central opening.

[0138] The trigger 11 (also denoted as a dose button) is generally T-shaped. It is disposed at the proximal end of the injection device 10. The shank 64 of the trigger 11 extends through an opening in the dose dial 12, through the inner diameter of an extension of the drive sleeve 30, and into a receiving recess at the proximal end of the piston rod 20. The shank 64 is retained for limited axial movement within the drive sleeve 30 and prevented from rotating relative thereto. The head of the trigger 11 is generally circular. A trigger sidewall or skirt extends from the periphery of the head and is further adapted to seat in a proximally accessible annular recess in the dose dial 12.

[0139] To dial a dose, the user rotates the dose dial 12. With the spring 40 also acting as a clicker and the adapter 60 engaged, the drive sleeve 30, the spring or clicker 40, the adapter 60, and the number sleeve 80 rotate together with the dose dial 12. Audible and tactile feedback of the dialed dose is provided by the spring 40 and through the adapter 60. Torque is transmitted via the serrations between the spring 40 and the adapter 60. The helical groove 81 on the number sleeve 80 and the helical groove in the drive sleeve 30 have the same lead. This allows the number sleeve 80 to extend from the housing 10 and the drive sleeve 30 and climb up the piston rod 20 at the same rate. At the limit of travel, a radial stop on the number sleeve 80 engages with a first stop or a second stop provided on the housing 10 to prevent further movement in the first rotational direction (e.g., in the dose increment direction 4). Rotation of the piston rod 20 is prevented due to the opposing directions of the integral thread and the drive thread on the piston rod 20.

[0140] By rotation of the drive sleeve 30, the last dose limiter 35 keyed to the housing 10 is advanced along the threaded section 31. When the final dose dispensing position is reached, a radial stop formed on the surface of the last dose limiter 35 abuts a radial stop on the flange portion 33 of the drive sleeve 30, thereby preventing the last dose limiter 35 and the drive sleeve 30 from rotating further.

[0141] If the user inadvertently dials more than the desired dose, the injection device 1, configured as a pen-type injector, allows for dialing down the dose without dispensing medication from the cartridge 6. This is accomplished by simply rotating the dose dial 12 in the opposite direction. This causes the system to reverse. The flexible arm of the spring or clicker 40 then acts as a ratchet, preventing the spring 40 from rotating. The torque transmitted through the adapter 60 causes the saw teeth to overlap, producing a clicking sound corresponding to the decrease in the dialed dose. Typically, the saw teeth are arranged so that the circumferential extent of each tooth corresponds to a unit dose. In this case, the adapter can function as a ratchet mechanism.

[0142] Alternatively or additionally, the ratchet mechanism 90 may include at least one ratchet feature 91, such as a flexible arm on the sidewall of the tubular adapter 60. The at least one ratchet feature 91 may include, for example, a radially outwardly extending protrusion on the free end of the flexible arm. The protrusion is configured to engage with a correspondingly shaped, inverse ratchet structure on the inside of the number sleeve 80. The inside of the number sleeve 80 may include longitudinally shaped grooves or protrusions characterized by a sawtooth profile. During dialing or dose setting, the ratchet mechanism 90 permits and supports rotation of the number sleeve 80 relative to the adapter 60 in the second rotational direction 5, accompanied by a regular clicking sound of the flexible arm of the adapter 60. Angular momentum applied to the number sleeve 80 in the first rotational direction is transferred to the adapter 60 unchanged. Thus, the mutually corresponding ratchet features of the ratchet mechanism 90 provide torque transmission from the number sleeve 80 to the adapter 60.

[0143] Once the desired dose has been dialed, the user can simply dispense the set dose by depressing the trigger 11. This causes the adapter 60 to displace axially relative to the number sleeve 80, causing its teeth to disengage. However, the adapter 60 remains rotationally keyed to the drive sleeve 30. The number sleeve 80 and dose dial 12 can now rotate freely according to the helical groove 81.

[0144] The axial movement deforms the flexible arms of the spring 40 to ensure that the serrations are not overhauled during dispensing. This prevents the drive sleeve 30 from rotating relative to the housing 10, although it remains free to move axially relative to the housing. The deformation then serves to push the spring 40 and the adapter 60 back along the drive sleeve 30 to restore the connection between the adapter 60 and the number sleeve 80 when the distally directed dispensing pressure is removed from the trigger 11.

[0145] The longitudinal axial movement of the drive sleeve 30 causes the piston rod 20 to rotate through the through-opening of the support of the housing 10, thereby advancing the bung 7 in the cartridge 6. Once the dialed dose has been dispensed, the number sleeve 80 is prevented from further rotation by contact of at least one stop extending from the dose dial 12 with at least one corresponding stop of the housing 10. The zero dose position may be determined by abutment of one of the axially extending edges or stops of the number sleeve 80 with at least one or several corresponding stops of the housing 10.

[0146] The expelling mechanism or drive mechanism 8 as described above is only an embodiment of one of a plurality of different configurations of drive mechanisms that can be implemented in a disposable pen injector in general. The drive mechanism as described above is explained in more detail in, for example, WO 2004 / 078239A1, WO 2004 / 078240A1 or WO 2004 / 078241A1, the entire contents of which are incorporated herein by reference.

[0147] 2 , the dose setting mechanism 9 comprises at least a dose dial 12 and a number sleeve 80. When the dose dial 12 is rotated during and for dose setting, the number sleeve 80 begins to rotate relative to the housing along a helical path defined by the threaded engagement of the outer threads or helical grooves 81 of the number sleeve with correspondingly shaped thread sections at the inner surface of the housing.

[0148] During dose setting and when the drive mechanism 8 or dose setting mechanism 9 is in dose setting mode, the drive sleeve 30 rotates in unison with the dose dial 12 and the number sleeve 80. The drive sleeve 30 is threadedly engaged with the piston rod 20, which is stationary relative to the housing 10 during dose setting. Thus, the drive sleeve 30 undergoes a screwing or helical motion during dose setting. As the dose dial is rotated in a first rotational direction, or dose increasing direction 4 (e.g., in a clockwise direction), the drive sleeve 30 begins to travel in a proximal direction. To adjust or correct the size of the dose, the dose dial 12 can be rotated in an opposite second rotational direction, thus in the dose decreasing direction 5 (e.g., counterclockwise).

[0149] A number of examples of rotation sensing assemblies 200 for an injection device 1 or for an attachment 100 attachable to such an injection device 1 are illustrated in Figures 4 to 11. The rotation sensing assembly 200 is configured to detect and / or measure rotational movement of a first member 201 relative to a second member 202 of the injection device 1 or an attachment 100 configured for mechanical attachment to such an injection device 1, such as illustrated in Figures 1 or 2.

[0150] The rotation sensing assembly 200 shown in Figures 4 to 6 includes a first member 201 and a second member 202. The first member 201 can rotate relative to the second member 202 about a rotation axis 203. Typically, the first member 201 and the second member 202 are coaxially arranged about the rotation axis 203. For some examples, the first member 201 and the second member 202 are axially adjacently arranged about the rotation axis 203. The first member 201 and the second member 202 can be directly mechanically engaged. For other examples, the first member 201 and the second member 202 are mechanically disengaged from each other. Here, the first member 201 and the second member 202 can be separately arranged or rotationally supported in or at the housing 10 of the injection device 1, or in or at the corresponding housing of a separate additional device.

[0151] At least one of the first member 201 and the second member 202 is typically rotationally supported in or on the housing 10 of the injection device 1. For some examples, both the first member 201 and the second member 202 may be rotationally supported on or relative to the housing 10. Typically, and depending on the specific implementation or integration of the rotation sensing assembly 200 in the injection device 1, one of the first member 201 and the second member 202 is rotationally locked to the housing 10, while the other of the first member 201 and the second member 202 is rotationally movable relative to the housing 10. Typically, one of the first member 201 and the second member 202 is rotatable relative to the housing 10 about a rotation axis 203.

[0152] As shown in more detail in Figures 5 and 6, the first member 201 includes at least one signal generator 210. The second member 202 includes at least one sensor 220. For some examples, at least one of the first member 201 and the second member 202 includes a disk or disk-like shape having first and second axial planar surfaces. For example, and as shown in Figure 6, the first member 201 includes an upper (e.g., proximal) axial surface 205 and a lower (e.g., distal) axial surface 206. Similarly, the second member 202, which is coaxially aligned with the first member 201 but positioned and arranged at a predefined axial distance from the first member 201, includes an upper or proximal surface 207 and an oppositely positioned lower or distal surface 208.

[0153] 6 , the distal surface 206 of the first member 201 faces toward the second member 202. Thus, the proximal surface 207 of the second member 202 faces toward the first member 201. The distal surface 206 of the first member 201 faces toward the proximal surface 207 of the second member 202.

[0154] As shown in Figures 5 and 6, four individual sensors 220 are disposed on the second member 202. Each of these sensors 220 includes an interdigitated electrode structure 230 or an interdigitated electronic structure, as shown in more detail in Figures 7 and 8. Each of the sensors 220 is connected to a processor 240, as illustrated in Figures 3 and 4. The processor 240 is connected to each of the sensors 220 for signal transmission. Typically, as the first member 201 undergoes rotation relative to the second member 202, and when the signal generator 210 passes by one of the sensors 220, the corresponding sensor 220 is configured and operable to generate an electrical signal that can be processed or detected by the processor 240. For the example of Figures 5 and 6, when four equally spaced sensors 220 are arranged on the second member 202, and when only one signal generator 210 is disposed on the first member 201, a rotation of at least 90° of the first member 201 relative to the second member 202 can be detected and / or accurately measured.

[0155] The currently shown arrangement of multiple sensors 220 on the second member 202 and the arrangement of the signal generator 210 on the first member 201 is only one of many examples and is provided for illustrative purposes only. The planar spatial extension of the sensors 220 can be as small as a few millimeters in each direction. Therefore, for a typical implementation, multiple sensors 220 (e.g., up to 8 sensors, up to 12 sensors, up to 24 sensors, or even more than 36 sensors) can be arranged on the annular circumference of the second member 202. In this way, the angular or spatial resolution of the rotation sensing assembly 200 can be increased.

[0156] The rotation sensing assembly 200 typically includes a planar substrate 250. As shown in FIG4 , the planar substrate 250 may overlap with or be provided by a printed circuit board 260. The processor 240 may be disposed on the printed circuit board 260 together with the at least one sensor 220. Typically, the at least one sensor 220, and in particular the interdigitated electrode structure 230 of the corresponding sensor 220, may be directly printed or coated on the planar substrate 250 and / or the printed circuit board 260. As indicated in FIG4 , the printed circuit board 260 may further be provided with a power supply 120. The power supply 120 may be located on one side of the printed circuit board 260. The processor 240 and / or the at least one sensor 220 may be disposed on the same side or opposite sides of the printed circuit board 260.

[0157] The printed circuit board 260 can be fastened to the second member 202. The second member 202 can coincide with the dial member 12 of the injection device 1. Thus, the planar substrate 250 and / or the printed circuit board 260, which have the processor 240 and at least one sensor 220 arranged thereon, can be rigidly fastened to the dial member 12, and thus to the second member 202. The first member 201 can be implemented as a depressible trigger 11. The first member 201, and thus the trigger 11, can be rotationally locked to the housing 10 during and / or for dose setting, during which the dose dial 12, and thus the second member 202, undergoes rotation relative to the housing 10.

[0158] The implementation of the rotation sensing assembly 200 as indicated in FIG4 is only one of many possibilities. For other examples, the first member 201 may be rotatable during and / or for dose setting, while the second member 202 is rotationally locked to the housing during and / or for dose setting. For example, one of the first member 201 and the second member 202 may be connected to or integrated into the number sleeve 80, while the other of the first member 201 and the second member 202 is connected to or integrated into the adapter 60 of the injection device 1.

[0159] For the examples of Figures 4 to 6, both the first member 201 and the second member 202 are circular, annular, or disc-shaped. For the general working principle of the rotation sensing assembly 200, it is sufficient when only one or at least one of the first member 201 and the second member 202 includes a disc-shaped, circular, or annular structure, while the other of the first member 201 can be of any shape or structure. Typically, the components of the first member 201 and the second member 202 provided with multiple sensors 220 or multiple signal generators 210 include circular, annular, and / or disc-shaped structures to provide suitable rotational encoding configured to detect and measure the degree of rotation of the first member 201 relative to the second member 202.

[0160] In the example shown here, in which first component 201 and second component 202 are coaxially aligned about rotation axis 203 and are arranged at an axial distance from each other, it is particularly advantageous when at least one sensor 220 is arranged at a predefined radial sensor distance D from rotation axis 203. At least one signal generator 210 is arranged at a predefined radial signal generator distance d from the rotation axis. Here, radial sensor distance D and radial signal generator distance d are measured from the radial center points of at least one sensor 220 and at least one signal generator 210, respectively. For the example shown here, the difference between radial sensor distance D and radial signal generator distance d is less than or equal to the difference between the radial extension of the at least one sensor and the radial extension of the at least one signal generator. In this way, radial and / or axial overlap is provided and / or ensured between at least one signal generator 210 and at least one sensor 220 when first component 201 is subjected to rotation relative to second component 202.

[0161] Typically, the first member 201 and the second member 202 are arranged in a non-contact manner with respect to each other. Therefore, there is no direct mechanical engagement between the first member 201 and the second member 202. However, at least one of the first member 201 and the second member 202 may be mechanically engaged with other components of the injection device 1 or the attachment 100, typically with the housing 10 of the injection device 1.

[0162] For other examples, the first member 201 and the second member 202 can be arranged at the same axial position about the rotation axis. Here, the first member 201 and the second member 202 can be arranged in a nested or staggered configuration. For example, one of the first member 201 and the second member 202 includes a tubular or annular hollow structure, and the other of the first member 201 and the second member 202 is radially arranged therein. For example, the first member 201 is located radially inside the second member 202. Thus, at least one of the signal generator 210 and the at least one sensor 220 is located on the outer surface of the first member 201, while the other of the at least one signal generator 210 and the at least one sensor 220 is located on the inner surface of the second member 202.

[0163] An example of at least one sensor 220 is shown in Figures 7 and 8. Sensor 220 includes an interdigitated electrode structure 230 on a planar substrate 250. Interdigitated electrode structure 230 is coated or printed on the surface of planar substrate 250. Interdigitated electrode structure 230 includes a first electrode 231 and a second electrode 232. First electrode 231 is electrically insulated from second electrode 232. First electrode 231 includes an interdigitated or finger-shaped periodic pattern of parallel in-plane electrode portions 233, 234, 235. These electrode portions 233, 234, 235 extend parallel to each other. The longitudinal ends of electrode portions 233, 234, 235 are flush in a direction perpendicular to the direction of elongation of electrode portions 233, 234, 235.

[0164] The electrode portions 233, 234, and 235 are interconnected at one longitudinal end. The opposite longitudinal end of the electrode portions 233, 234, and 235 is a free end. The shape of the second electrode 232 can be symmetrical or identical to that of the first electrode 231. The second electrode 232 also includes an interdigitated or finger-shaped periodic pattern of parallel in-plane electrode portions 236, 237, and 238. The electrode portions 236, 237, and 238 are arranged in parallel. They can have equal lengths. The longitudinal free ends of the electrode portions 236, 237, and 238 are flush in a direction perpendicular to the direction of elongation of the electrode portions 236, 237, and 238. The opposite longitudinal ends of the electrode portions 236, 237, and 238 are electrically interconnected via a longitudinally extending connecting portion 242.

[0165] Similarly, the electrode portions 233, 234, 235 of the first electrode 231 are also interconnected by the connecting portion 241. The electrode portions 233, 234, 235 of the first electrode 231 are separated relative to each other along the elongated direction of the connecting portion 241. The longitudinal ends of the electrode portions 233, 234, 235 connected to or integrally formed with the connecting portion 241 face away from the second electrode and, in particular, away from the connecting portion 242 of the second electrode 232. The oppositely positioned free ends of the electrode portions 233, 234, 235 (i.e., the ends facing away from the connecting portion 241) face toward the second electrode 232 and, therefore, toward the connecting portion 242 of the second electrode 232.

[0166] Specifically, the electrode portions 233, 234, 235 of the first electrode 231 extend parallel to the electrode portions 236, 237, 238 of the second electrode 232. Furthermore, the electrode portions 233, 234, 235 are located in the intermediate free space between the electrode portions 236, 237, 238, and vice versa. Typically, the electrode portions 233, 234, 235 of the first electrode are equidistantly separated along the first connecting portion 241. Consequently, the electrode portions 236, 237, 238 of the second electrode 232 are also equidistantly separated along the second connecting portion 242.

[0167] In this way, a regular, periodic pattern of electrode portions 233, 236, 234, 237, 235, 238 is provided. This interdigitated electrode structure 230 comprises a plurality of microstrips or combs and / or forms a grid along the elongation direction of the connecting portions 241, 242 of the first electrode 231 and the second electrode 232, respectively.

[0168] As further illustrated in FIG7 , the first electrode 231 includes a first connector 243 that is connected to or integrally formed with the connecting portion 241 but faces away from the plurality of electrode portions 233, 234, and 235. Similarly, the second electrode 232 also includes a second connector 244 that is connected to or integrally formed with the connecting portion 242 and faces away from the plurality of electrode portions 236, 237, and 238. The connectors 243 and 244 are individually and separately connected to the processor 240 for signal generation, signal detection, and / or signal processing.

[0169] FIG8 shows a cross section through the periodic pattern of the interdigitated electrode structure 230. The cross section illustrates an electric field 270 generated by the interdigitated electrode structure 230. The cross section shows a cross section through the alternating pattern of electrode portions 233, 236, 234 of the first electrode 231 and the second electrode 232. When the first electrode 231 and the second electrode 232 are arranged on the electrically insulating substrate 250, the electric field 270 is formed, for example, in the form of a fringing electric field between the electrode portions 233, 236, 234 of the first electrode 231 and the second electrode 232, respectively.

[0170] Typically, the first electrode 231 and the second electrode 232 are driven with opposite polarities. They can be driven with a DC voltage or an AC voltage. The first electrode 231 and the second electrode 232 form a capacitance and thus form a planar capacitor. The first electrode 231 and the second electrode 232 can form or constitute a so-called interdigital capacitor. In this way, an interdigital dielectric measurement sensor is provided and supports direct measurement of the dielectric properties of insulating and semi-insulating materials from one side. The penetration depth and / or range of the edge quasi-static electric field 270 above the surface of the planar substrate 250 is proportional to the spacing between the center lines of the AC electrode portions 233, 236, and 234 of the first electrode 231 and the second electrode 232.

[0171] Now, if the signal generator 210 is moved through the electric field 270, the corresponding change in capacitance of the interdigitated electrode structure 230 can be detected and measured. To this end, the signal generator 210 does not have to be in mechanical contact with either the first electrode 231 or the second electrode 232. The interdigitated electrode structure 230 and the signal generator 210 are typically arranged in a contactless manner. In order to have a good signal-to-noise ratio, when the signal generator includes a relative permittivity ε greater than 3, greater than 4, greater than 5, greater than 6, greater than 7, greater than 10, greater than 12, or greater than 15. r For typical implementations, signal generator 210 comprises an elastomeric material, such as a natural or synthetic rubber exhibiting a relative dielectric constant greater than 5, greater than 6, or greater than or equal to 7.

[0172] Generally, the measurement principle of the at least one sensor 220 is not limited to an interdigitated capacitor. For other implementations of the interdigitated electrode structure 230, the at least one sensor 320 can be implemented as a magnetic sensor. It can be implemented as a meandering winding magnetometer, as shown in FIG11 . Here, the interdigitated electrode structure 330 includes a first electrode 331 implemented as a meandering wire or winding on a planar substrate 250. The first electrode 331 forms a primary electrode or primary winding for generating a spatially periodic magnetic field 280 when driven by an electric current.

[0173] A second electrode 332 is further provided, forming a secondary meander winding on the planar substrate 250. The second electrode 332 is typically implemented as an inductive winding that is configured or operable to detect changes in the magnetic field 280 generated by the primary winding 331. Typically, and when performing a measurement, a time-varying current is applied to the first electrode 331 or primary winding, which generates a time-varying magnetic field. When a conductive material (such as the signal generator 210) is brought into proximity with the interdigitated electrode structure 330, this has an effect on the magnetic field 280 induced in the second electrode 332 (i.e., in the secondary winding).

[0174] This changing magnetic field generates a measurable signal that can be detected by the processor 240 connected to the first electrode 331 and the second electrode 332, respectively. For some implementations, and as shown in more detail in Figure 11, two secondary electrodes 332, 333 can be provided. Here again, as a special case of the corresponding first electrode 331, the second electrode 332, and the third electrode 333, the interdigitated pattern is provided and / or formed by the insulating substrate 250 and the plurality of windings 331, 332, 333. When current passes through the primary winding 331, it induces eddy currents in the secondary windings 332, 333. The secondary winding voltage is given by the time rate at which the magnetic flux from the current in the primary winding 331 changes through the corresponding winding. At low frequencies, the induced voltage can become very small. To overcome such low-frequency limitations, the secondary winding can be replaced with a magnetoresistive sensor that can operate at very low frequencies down to DC.

[0175] When the sensor 320 is implemented as a magnetic sensor (eg a meander winding magnetometer), this is particularly advantageous when the signal generator 210 is operable to introduce a measurable change in the magnetic field generated by the first electrode 331 (and thus by the primary winding).

[0176] 9 and 10 illustrate two further implementations of a rotation sensing assembly 200. Here, a first member 201 and a second member 202 are mechanically engaged, for example, via a ratchet assembly 290. To this end, the first member 201 includes a first ratchet member 291 configured to mechanically engage a second ratchet member 292 of the second member 202. In this manner, and when the first member 201 undergoes rotation relative to the second member 202 about the rotation axis 203, surface acoustic waves are generated on at least one of the first member 201 and the second member 202. Here, the sensor 220 is configured to detect the presence or propagation of such surface acoustic waves.

[0177] To detect surface acoustic waves and, therefore, mechanical excitation of the second member 202, the second member 202, or at least a portion thereof, includes a piezoelectric substrate 250 in the region of at least one sensor 220. Here, the at least one sensor 220 is implemented as an interdigital transducer (IDT) operable to generate an electrical signal in response to surface acoustic waves propagating on the surface of the second member 202. In the example of FIG. 9 , the second member 202 is rotatable relative to the first member 201. The second member 202 includes a ratchet member 292 having a toothed structure on its outer or inner circumference. In the example of FIG. 9 , the sidewall or outer edge of the second member 202 includes a regular structure of radially outwardly projecting teeth, which are configured to engage with the first member 201, particularly with the protrusions of the first ratchet member 291. Here, the first member 201 is elastically deformable and can be biased radially inward to engage with the radially outer toothed surface of the second member 202. A plurality of first components 201 may be provided, which are arranged, for example, diametrically opposite one another with respect to the rotation axis 203 .

[0178] 9 , the second ratchet member 292 may also be implemented as an inwardly facing surface, and the first ratchet member 291 may be positioned radially inwardly from the second ratchet member 292. As the second member 202 rotates relative to the first member 201, the first ratchet member 291 is then biased radially outwardly so as to regularly engage with the tooth structure of the second ratchet member 292. With either implementation, one of the first member 201 and the second member 202 is typically engaged non-rotationally upwardly with the housing 10 of the injection device 1, while the other of the first member 201 and the second member 202 is rotationally supported relative to the housing.

[0179] In the example of FIG9 , at least one sensor 220 is located on the disc-shaped second member 202, while the first member 201 is flexibly deformable against an inherent restoring force. For example, the first member 201 includes an arc-shaped flexible structure. When the ratchet member 292 engages or disengages with the first ratchet member 291, surface acoustic waves travel on the second member 202. Typically, the ratchet assembly 290 produces an audible click each time the second member 202 rotates a discrete angular distance relative to the first member 201.

[0180] In another example shown in FIG10 , a similar ratchet engagement 290 is achieved between a first member 201 and a second member 202, but here, and in comparison to the example of FIG9 , the roles of the first and second members 201, 202 have been interchanged. The first member 201 comprises a disc-shaped circular or annular structure with a first ratchet member 291 on an outer or inner annular surface. The second member 202 comprises a radially protruding ratchet member 292 configured to regularly engage with the teeth of the first ratchet member 291 when the first member 201 undergoes rotation relative to the second member 202. Here, the second member 202 is elastically deformable. The second member 202 can be rotationally locked to the housing 10. Thus, it can be immobile relative to the housing 10. When the first member 201 rotates relative to the second member 202 about the rotation axis 203, the second member 202 undergoes elastic deformation that is accompanied by the generation of surface acoustic waves. Here, the at least one sensor 220 located on the elastically deformable second member 202 is configured or operable to detect surface acoustic waves via the provided interdigital transducer and thus the interdigital electrode structure 230 of the at least one sensor 220 .

[0181] The examples of Figures 9 and 10 can be easily implemented in existing injection devices 1, because such mechanically implemented injection devices typically include at least one ratchet engagement 290 as schematically illustrated in Figures 9 and 10. In the examples illustrated in Figures 9 and 10, one of the first member 201 and the second member 202 is elastically deformable in the radial direction.

[0182] It should be noted that the present disclosure is not limited to such radially deformable mechanical structures. Rather, the principle of rotational sensing can be implemented similarly with an axially elastically deformable first member 201 or second member 202. For the sensor 220 implemented as an interdigital transducer, it is generally sufficient when at least one of the first member 201 and the second member 202 is provided with only a single sensor 220. At least one sensor 220 arranged on or integrated in the second member 202 can be arranged on the rotating second member or on the second member 202 that is locked in rotation and therefore does not rotate. The implementation as an interdigital transducer provides the following benefits: when the first member 201 and the second member 202 are subjected to relative rotation accompanied by the mechanical engagement of the first ratchet member 291 and the second ratchet member 292, both the rotating member and the non-rotating member are subjected to surface acoustic waves equally.

[0183] FIG13 shows another example of a sensor 420. The sensor 420 also includes an interdigitated electrode structure 430. Here, the interdigitated electrode structure 430 is part of a strain gauge 422 attached to, for example, the second member 202 shown in FIG10 . Thus, the sensor 420 and / or the strain gauge 422 can replace the sensor 220 shown in FIG10 . The interdigitated electrode structure 430 exhibits a measurable change in conductivity in response to the flexible deformation of the second member 202.

[0184] Interdigitated electrode structure 430 includes a first electrode 431 and a second electrode 432 electrically connected to each other via a meandering conductive structure 433. Meandering conductive structure 433 includes a plurality of elongated conductor segments 434, 436 extending parallel to each other. The plurality of elongated conductor segments 434, 436 are electrically connected in series. When interdigitated electrode structure 430 undergoes a change in length, particularly along the direction of elongation of elongated conductor segments 434, 436, the resistance between first electrode 431 and second electrode 432 undergoes a measurable change. This measurable change can be detected and / or quantitatively measured by processor 240 connected to sensor 420.

[0185] Typically, the interdigitated electrode structure 430 is oriented and / or arranged on the second member 202 in such a manner that the elongated conductor segments 434, 436 extend substantially aligned with or substantially parallel to a primary direction of elastic deformation of the second member 202. In this manner, the sensitivity and / or measurement location of the sensor 420 can be maximized.

[0186] As a result, and when the first member 201 undergoes rotation relative to the second member 202, the second member 202 undergoes regular flexible deformation. This flexible deformation can be detected by the interdigitated electrode structure 430 of the strain gauge 422.

[0187] 12 schematically illustrates a method for detecting and / or quantitatively measuring a rotation of a first component 201 relative to a second component 202. In a first step 300, a torque is introduced into one of the first components 201 relative to the second component 202, thereby causing a corresponding rotation of the first component 201 relative to the second component 202 about the rotation axis 203. Consequently, and because the signal generator 210 is arranged or attached to the first component, and when the at least one sensor 220 is arranged or attached to the second component 202, the at least one signal generator 210 undergoes a movement relative to the at least one sensor 220.

[0188] In a further step 302, an electrical signal is generated and provided by the interdigitated electrode structure 230, 330 of the at least one sensor 220, 320 in response to the movement of the at least one signal generator 210 relative to the at least one sensor 220, 320. As a result, and in a further step 304, the electrical signal provided and generated by the processor 240, which is electrically connected to the at least one sensor 220 and, therefore, to the interdigitated electrode structure 230 of the at least one sensor 220, is processed. The processor 240 is configured and operable to calculate the rotation angle of the first member 201 relative to the second member 202 based on the electrical signal obtained from the at least one sensor 220, 320. Thus, in step 304, the occurrence and / or degree of rotational movement of the first member 201 relative to the second member 202 is detected and / or determined.

[0189] 3 is a block diagram of an implementation of a rotation sensing assembly 200 in the attachment 100. Here, the rotation sensing assembly 200 can be integrated into the attachment 100. At least some components of the attachment 100 are shared by the rotation sensing assembly 200 and the attachment 100. In a similar manner, the rotation sensing assembly 200 can also be integrated into the injection device 1.

[0190] The attachment 100 may include a data collection device. The attachment 100 includes one or more processors 240 (such as a microprocessor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), etc.) and memory 114. The memory 114 may include program memory and main memory, which can store software executed by the processor 240 and data generated during use of the attachment 100, such as count pulses, derived dose size, time stamps, etc. A switch 122 connects the power supply 120 to the electronic components of the device 100, including the rotation sensing assembly 200. The display 118 may or may not be present. The rotation sensing assembly 200 is coupled to the first member 201 and the second member 202 as described above. It includes at least one sensor 220 connected or attached to the second member 202, and further includes at least one signal generator 210 connected or attached to the first member 201.

[0191] For the present implementation of the rotation sensing assembly 200 in the attachment 100, one of the first member 201 and the second member 202 may be connected or fastened to the housing 101 of the attachment 100, and the other of the first member 201 and the second member 202 may be connected or fastened to the dial 12 of the injection device 1, for example.

[0192] The resolution of the sensing assembly 200 is determined by the design of the injection device 1. The appropriate angular resolution of the sensor assembly 200 can be determined by equation (1):

[0193]

[0194] For example, if one full rotation of the dose dial 12 corresponds to a 24 IU dose of medicament, a suitable resolution for the rotation sensing assembly 200 would be no more than 15°.

[0195] Typically, the rotation angle of the dose dial 12 or dial member measured by the rotation sensing assembly 200 is proportional to the amount of medication expelled. It is not necessary to determine the zero level or absolute amount of medication contained in the injection device 1. When the dose dial 12 is rotated relative to the housing 10 during dose setting or expelling of a dose of medication, the actual expelled dose can be accurately determined and monitored by the attachment 100.

[0196] The attachment 100 may include an interface 124 connected to the processor 240. The interface 124 may be a device for communicating with the processor 240 via a wireless network such as Wi-Fi or ) a wireless communication interface for communicating with another external device 65 (e.g., in the form of a portable electronic device); or an interface for a wired communication link, such as a receptacle for receiving a Universal Serial Bus (USB), mini-USB, or micro-USB connector. To this end, the interface 124 includes a transceiver 126 configured to transmit and receive data. FIG3 depicts an example of an injection system in which the attachment 100 is connected to an external electronic device 65 (such as a personal computer 65) via a data connection 66 for data transfer. The data connection 66 can be of a wired or wireless type.

[0197] For example, processor 240 may store the determined delivered dose and time stamp of an injection administered by the user and subsequently transmit the stored data to external electronic device 65. Computer 65 maintains a treatment log and / or forwards treatment history information to a remote location, such as for review by medical personnel.

[0198] The attachment 100 or data collection device can be configured to store data, such as the delivery dose and timestamp of up to multiple injection events (such as 35 or more injection events). According to the injection therapy once a day, this will be enough to store about a month's treatment history. Data storage is organized in a first-in, first-out manner, thereby ensuring that the latest injection event is always present in the memory of the data collection device 100. Once transmitted to the external electronic device 65, the injection event history in the attachment 100 will be deleted. Alternatively, the data is retained in the attachment 100, and once new data is stored, the oldest data is automatically deleted. In this way, the log in the data collection device is established over time during use and will always include the most recent injection event. Alternatively, other configurations can include the storage capacity of 70 times (twice a day), 100 times (three months) or any other suitable number of injection events, depending on the user's therapy needs and / or preferences.

[0199] In another embodiment, the interface 124 may be configured to transmit information using a wireless communication link and / or the processor 240 may be configured to periodically transmit such information to the external electronic device 65 .

[0200] The processor 240 may control the optional display 118 to show the determined medication dosage information and / or the time elapsed since the last medication dose was delivered. For example, the processor 240 may cause the display 118 to periodically switch between displaying the most recently determined medication dosage information and the elapsed time.

[0201] The power source 120 can be a battery. The power source 120 can be a button cell battery or multiple button cells arranged in series or parallel. A timer 115 can also be provided. In addition to or as an alternative to turning the attachment 100 on and off, the switch 122 can be arranged to trigger the timer 115 upon engagement and / or disengagement. For example, if the timer 115 is triggered upon engagement or disengagement of the first and second electrical contacts of the switch, or upon both operation and inactivity of the switch 122, the processor 240 can use the output from the timer 115 to determine the length of time the trigger 11 was depressed, for example, to determine the duration of the injection.

[0202] Alternatively or additionally, processor 240 may use timer 115 to monitor the length of time that has elapsed since the injection was completed, as indicated by the disengagement time of the corresponding switch component or the inactivity of switch 122. Optionally, the elapsed time may be displayed on display 118. Still further optionally, when switch 122 is subsequently operated, processor 240 may compare the elapsed time with a predetermined threshold to determine whether the user is attempting to administer another injection prematurely after the previous injection, and if so, generate an alert, such as an audible signal and / or warning message, on display 118 or via output 116. Output 160 may be configured to generate an audible sound or induce vibration, thereby generating a tactile signal, for example, to alert the user.

[0203] Reference Signs List

[0204] 1 Injection device

[0205] 2 Distal direction

[0206] 3 Proximal direction

[0207] 4 Dose escalation direction

[0208] 5 Dose reduction direction

[0209] 6 Cartridges

[0210] 7 plug

[0211] 8. Driving mechanism

[0212] 9 Dose setting mechanism

[0213] 10 Housing

[0214] 11 Triggers

[0215] 12-dose dial

[0216] 13 Dosage Window

[0217] 14 Cartridge Holder

[0218] 15 Injection needle

[0219] 16 Inner needle cap

[0220] 17 Outer needle cap

[0221] 18 protective cap

[0222] 19 Protrusion

[0223] 20 piston rod

[0224] 21 bearings

[0225] 22 First thread

[0226] 23 pressure foot

[0227] 24 Second thread

[0228] 25 cylinder

[0229] 26 seals

[0230] 28 threaded socket

[0231] 30 Drive sleeve

[0232] 31 thread segments

[0233] 32 flange

[0234] 33 flange

[0235] 35 Last dose limiter

[0236] 36 Shoulder

[0237] 40 Spring

[0238] 41 Depression

[0239] 50 Dose Tracker

[0240] 51 Tracking stop feature

[0241] 60 adapter

[0242] 62 Inserts

[0243] 64 handles

[0244] 65 External devices

[0245] 66 Data Connections

[0246] 80 number sleeve

[0247] 81 grooves

[0248] 90 ratchet mechanism

[0249] 91 Ratchet Features

[0250] 100 additional devices

[0251] 101 housing

[0252] 114 Memory

[0253] 115 Timer

[0254] 116 output

[0255] 118 Display

[0256] 120 Power Supply

[0257] 122 switch

[0258] 124 interfaces

[0259] 126 transceivers

[0260] 200 Rotation Sensing Assembly

[0261] 201 First Component

[0262] 202 Second Component

[0263] 203 rotation axis

[0264] 205 Surface

[0265] 206 Surface

[0266] 207 Surface

[0267] 208 Surface

[0268] 210 Signal Generator

[0269] 220 Sensor

[0270] 230 interdigitated electrode structure

[0271] 231 First Electrode

[0272] 232 second electrode

[0273] 233 Electrode part

[0274] 234 Electrode part

[0275] 235 electrode part

[0276] 236 Electrode part

[0277] 237 Electrode part

[0278] 238 Electrode part

[0279] 240 processors

[0280] 241 connection part

[0281] 242 connection part

[0282] 243 Connectors

[0283] 244 connectors

[0284] 250 flat substrate

[0285] 260 printed circuit boards

[0286] 270 Electric Field

[0287] 280 Magnetic Field

[0288] 290 ratchet assembly

[0289] 291 ratchet component

[0290] 292 ratchet component

[0291] 320 Sensor

[0292] 330 interdigitated electrode structure

[0293] 331 First Electrode

[0294] 332 second electrode

[0295] 333 Second Electrode

[0296] 420 Sensor

[0297] 422 strain gauge

[0298] 430 interdigitated electrode structure

[0299] 431 First Electrode

[0300] 432 second electrode

[0301] 433 Meandering Conductive Structure

[0302] 434 conductor segments

[0303] 436 conductor segments

Claims

1. A rotation sensing assembly for an injection device (1), the rotation sensing assembly comprising: - a first member (201) and a second member (202), wherein the first member (201) and the second member (202) are rotatable relative to each other about a rotation axis (203), - at least one signal generator (210) arranged on an axial surface (206) of the first member (201), - at least one sensor (220; 320; 420) arranged on an axial surface (207) of the second member (202), wherein the axial surface (207) of the second member (202) is coaxial with and faces the axial surface (206) of the first member (201), wherein the at least one sensor (220; 320; 420) comprises an interdigitated electrode structure (230; 330; 430) configured to generate an electrical signal in response to movement of the at least one signal generator (210) relative to the sensor (220; 320; 420), - a processor (240) connected to the at least one sensor (220; 320; 420) and operable to calculate the rotation angle of the first member (201) relative to the second member (202) based on the electrical signal, and wherein: i) the interdigitated electrode structure (230; 330) comprises a first electrode (231) and a second electrode (232), wherein the first electrode (231) and the second electrode (232) are arranged in a staggered geometric configuration, wherein the first electrode (231) and the second electrode (232) each comprise a comb-like structure, wherein the free ends of the comb-like structures face each other and cross each other without contact, or wherein ii) the first member (201) and the second member (202) are mechanically coupled by a ratchet assembly (290) such that when the first member (201) rotates relative to the second member (202), the second member (202) undergoes regular and repeated flexible deformation, wherein the interdigitated electrode structure (430) is part of a strain gauge (422) attached to the second member (202) and comprises a first electrode (431) and a second electrode (432), wherein the first electrode (431) and the second electrode (432) are electrically connected to each other via a meandering conductive structure (433).

2. The rotation sensing assembly according to claim 1, wherein the at least one signal generator (210) is arranged on or on a side of a surface (206) of the first member (201) facing the second member (202).

3. The rotation sensing assembly according to claim 1 or 2, wherein the at least one sensor (220; 320; 420) is located or arranged on or on a side of a surface (207) of the second member (202) facing the first member (201).

4. The rotation sensing assembly according to claim 1 or 2, further comprising a planar substrate (250), wherein the at least one sensor (220; 320; 420) is arranged on the planar substrate (250).

5. The rotation sensing assembly according to claim 4, wherein the interdigitated electrode structure (230; 330; 430) is printed or coated on the planar substrate (250).

6. The rotation sensing assembly of claim 1 or 2, further comprising a printed circuit board (260), and wherein the interdigitated electrode structure (230; 330; 430) of the at least one sensor (220; 320; 420) is arranged on the printed circuit board (260), and wherein the processor (240) is arranged on the printed circuit board (260).

7. The rotation sensing assembly of claim 6, wherein the processor (240) and the at least one sensor (220; 320; 420) are arranged on a same side of the printed circuit board (260).

8. The rotation sensing assembly according to claim 6, wherein the printed circuit board (260) is provided with an electrical energy source.

9. The rotation sensing assembly of claim 8, wherein the electrical energy source is disposed on a first side of the printed circuit board (260), and wherein the processor (240) and the at least one sensor (220; 320; 420) are located on a second side of the printed circuit board (260) opposite the first side of the printed circuit board (260).

10. The rotation sensing assembly of claim 1 or 2, wherein the interdigitated electrode structure (230) is configured to generate an electric field (270), and wherein the at least one signal generator (210) is configured to vary the electric field (270).

11. The rotation sensing assembly of claim 10, wherein changes in the electric field (270) caused by the signal generator (210) are detectable by the processor (240) connected to the at least one sensor (220; 320; 420).

12. The rotation sensing assembly according to claim 1 or 2, wherein the first electrode (231) and the second electrode (232) comprise a periodic microstrip electrode structure having an interdigitated pattern.

13. The rotation sensing assembly according to claim 1 or 2, wherein the signal generator (210) comprises a signal generating portion (212), the signal generating portion being made of a material having a relative dielectric constant greater than 3, greater than 4, greater than 5, greater than 6, greater than 7, greater than 10, greater than 12 or greater than 15.

14. The rotation sensing assembly of claim 1 or 2, wherein the interdigitated electrode structure (230; 330) is configured to generate a magnetic field (280), and wherein the at least one signal generator (210) is configured to vary the magnetic field (280).

15. A rotation sensing assembly according to claim 1 or 2, wherein the at least one sensor (220; 320; 420) is arranged at a predefined radial sensor distance (D) from the rotation axis (203), and wherein the at least one signal generator (210) is arranged at a predefined radial signal generator distance (d) from the rotation axis (203), and wherein the difference between the radial sensor distance (D) and the radial signal generator distance (d) is less than or equal to the difference between the radial extension of the at least one sensor (220; 320; 420) and the radial extension of the at least one signal generator (210).

16. The rotation sensing assembly according to claim 1 or 2, wherein a plurality of the at least one sensor (220; 320; 420) are distributed on one side of the second member (202) and / or wherein a plurality of the at least one signal generator (210) are distributed on a side of the first member (201) facing the second member (202).

17. The rotation sensing assembly of claim 16, wherein the plurality of sensors (220; 320; 420) are equidistantly or equiangularly distributed along the circumference of the second member (202).

18. The rotation sensing assembly according to claim 16, wherein the plurality of signal generators (210) are distributed equidistantly or equiangularly along the circumference of the first member (201).

19. The rotation sensing assembly of claim 1 or 2, wherein the at least one sensor (220; 320; 420) and the at least one signal generator (210) are permanently out of mechanical contact.

20. The rotation sensing assembly of claim 1 or 2, wherein the interdigitated electrode structure (430) exhibits a measurable change in electrical conductivity in response to flexible deformation of the second member (202).

21. The rotation sensing assembly of claim 1 or 2, wherein the ratchet assembly (290) is configured to support rotation of the first member (201) relative to the second member (202) in discrete rotational steps.

22. An injection device for setting and expelling a dose of a medicament, the injection device comprising: - housing (10), - a trigger (11) for initiating and / or controlling the expulsion of the dose, - a dial member (12) rotatable relative to the housing (10) for setting the dose, and - A rotational sensing assembly (200) according to any one of claims 1 to 21, wherein the first member (201) is rotationally locked to one of the dial member (12) and the housing (10), and wherein the second member (202) is rotationally locked to the other of the dial member (12) and the housing (10).

23. An attachment device (100) configured for attachment to an injection device (1), the attachment device comprising: - a body configured for attachment to a dial member (12) of the injection device (1), - a housing (101) configured for attachment to the housing (10) of the injection device (1), and - A rotation sensing assembly (200) according to any one of the preceding claims 1-21.

24. A method for detecting and / or quantitatively measuring a rotation of a first member (201) of an injection device (1) relative to a second member (202) of the injection device (1) as defined in claim 22, the method comprising the following steps: - introducing a torque into one of the first member (201) and the second member (202) relative to the other of the first member (201) and the second member (202), thereby moving the at least one signal generator (210) relative to the at least one sensor (220; 320; 420), - measuring an electrical signal of the interdigitated electrode structure (230; 330; 430) of the at least one sensor (220; 320; 420) in response to movement of the at least one signal generator (210) relative to the at least one sensor (220; 320; 420), and - processing the electrical signal by the processor (240) and calculating the rotation angle of the first member (201) relative to the second member (202) based on the electrical signal.

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