WO2025157892A1

WO2025157892A1 - Electronic add-on module comprising a sensor arrangement

Info

Publication number: WO2025157892A1
Application number: PCT/EP2025/051611
Authority: WO
Inventors: Paul Richard Draper; Hugh John DAY-SMITH
Original assignee: Sanofi SA
Current assignee: Sanofi SA
Priority date: 2024-01-24
Filing date: 2025-01-23
Publication date: 2025-07-31
Anticipated expiration: 2026-07-24

Abstract

The present disclosure is generally directed to an electronic system, e.g. an electronic add-on module(100), which is configured to be attached to a drug delivery device (1). The module comprises a first portion (101) configured to be attached to a dose dial grip (12) of the drug delivery device, such that the first portion follows axial and rotational movements of the dose dial grip when attached to the drug delivery device. Further, the module comprises a second portion (102) coupled to the first portion, wherein the second portion is axially moveable relative to the first portion but rotationally constrained to the first portion, wherein the second portion is configured to apply pressure onto a dose button (11) of the drug delivery device when axially moved relative to the first portion. Still further, the module comprises a third portion (103) coupled to the second portion on a proximal side of the second portion, wherein the third portion is free to rotate relative to the second portion. A sensor arrangement is provided configured to detect rotational movement between the second portion (102) of the electronic add-on module (100) and the proximal end face (19) of the dose button (11) of the drug delivery device (1). The sensor arrangement comprises at least one optical flow sensor (112) facing towards the proximal end face (19) of the dose button (11).

Description

ELECTRONIC ADD-ON MODULE COMPRISING A SENSOR ARRANGEMENT

The present disclosure is generally directed to an electronic system, e.g. an electronic add-on module, which is configured to be attached to a drug delivery device.

Electronic add-on modules for releasable attachment to drug delivery devices are generally known and often used to measure relevant data with respect to dose setting and/or dose dispensing.

An exemplary data collection device for attachment to an injection device is shown in WO 2016/198516 A1. Further injection monitoring modules are known from WO 2021/140352 A1 , WO 2020/217094 A1 and WO 2021/214275 A1. The modules typically comprise two portions, wherein one portion is attached and rotationally constrained to a dose dial grip of an injection device to measure for example rotational relative movement between components of the modules and/or the injection devices.

WO 2016/198516 A1 , for example, discloses the use of a sensing arrangement inside the data collection device comprising optical, magnetic, capacitive or mechanical sensors configured to detect rotational movement between a first portion and a second portion of the data collection device. The first portion is configured for attaching to a dosage knob of the injection device and the second portion is coupled to the first portion and axially movable relative thereto. During dose dispensing of a medicament, for example, the first portion rotates with the dosage knob of the injection device, wherein the angle of rotation measured by the sensing arrangement allows to determine the amount of medicament expelled.

An electronic module with an electrical power source, a sensor arrangement and a processor is disclosed in WO 2021/214275 A1. The sensor arrangement is used to detect rotation of the number sleeve. WO 2020/217094 A1 discloses an injection monitoring module comprising a magnetic field sensor which allows the determination of a translational position of a reference point along a central longitudinal axis in order to determine an administered amount of injectable substance. Although there are different sensor arrangements for electronic modules known in the art, the use of these sensor arrangements requires modifications to component parts of the drug delivery device in order to detect movements of components that are usually difficult to access.

Based on the aforementioned problem, it is therefore an object of the present disclosure to provide an electronic add-on module which may be used on a standard drug delivery device without modifications to component parts of the drug delivery device.

This object is solved by an electronic add-on module according to claim 1. Further, the object is solved by an assembly according to claim 11.

The electronic add-on module for, e.g. releasable, attachment to a drug delivery device comprises a first portion, a second portion, a third portion, a circuit board assembly which may form or comprise a processor, an electrical power source and a sensor arrangement. The sensor arrangement of the electronic add-on module is arranged inside the electronic add-on module, e.g. encased in one or more of the portions, and is configured to detect rotational movement between a portion of the electronic add-on module and a component of a drug delivery device.

More specifically, the electronic add-on module may be suitable to be used with and attached to a drug delivery device comprising at least the dose button, the dose dial grip and a dose delivery unit comprising a component part which does not rotate during dose dispensing and a plunger which moves at least axially during dose dispensing. Although not required in the context of the present disclosure, the drug delivery device may optionally comprise further components such as a number sleeve, a clutch, a drive sleeve, a cap, a needle, a spring, a lead screw or the like, interacting with the dose button, the dose dial grip, the plunger and/or the housing, for example as disclosed in WO 2004/078239 A1. However, the present disclosure is not limited to the drug delivery device of WO 2004/078239 A1. Other suitable drug delivery devices to be used are described e.g. in EP 1 570 876 B1 , EP 2 814 547 B1 , EP 2 890 434 B1 , WO 2005/018721 A1 , WO 2009/132777 A1 , WO 2014/033195 A1 , US 5,693,027 A, US 6,663,602 B2, US 7,241 ,278 B2 or US 9,937,294 B2.

If the drug delivery device has a similar working principle as in the example of WO 2004/078239 A1 , during dose setting components of the drug delivery device may perform the following movements. A housing may be stationary and may be used as a reference system for the further movements of other components. A plunger may be stationary and may be guided in a housing thread. A drive sleeve may perform a helical movement, i.e. a combined axial and rotational movement, and may be in threaded engagement with the plunger. A dose dial grip may perform a rotational movement, e.g. a helical movement. A dose button may be free to rotate but axially constrained to the drive sleeve. For example, the dose button may be axially retained to the drive sleeve by a clutch. An optional clutch may perform a helical movement and may couple a number sleeve to the drive sleeve. An optional clutch spring may perform an axial movement and may be guided in housing splines and may click over clutch teeth. An optional number sleeve may be permanently fixed on the dose dial grip and may perform a helical movement and may be guided in a housing thread. An optional last dose nut may perform a helical movement on a drive sleeve track of the drive sleeve and may be rotationally constrained to the housing. Hence, the last dose nut may perform axial movement relative to the housing and a helical movement with respect to the drive sleeve.

During dose dispensing components of the drug delivery device may perform the following movements. The housing may remain stationary as a reference system for the further movements of other components. The plunger may perform a helical movement and may be guided in the housing thread. The drive sleeve may perform a pure axial movement and may be in threaded engagement with the plunger. The dose dial grip may perform a rotational movement, e.g. a helical movement and may be permanently fixed on the number sleeve. The dose button may perform an axial movement. The optional clutch may perform pure axial movement and may de-couple the number sleeve from the drive sleeve. The optional clutch spring may perform pure axial movement and may be rotationally constrained to the clutch due to a pressure applied to the dose button. The optional number sleeve may perform a helical movement and may be guided in the housing thread. The optional last dose nut may maintain its axial position on the drive sleeve track and may be rotationally constrained to the housing.

The first portion of the electronic add-on module may define an auxiliary dose dial grip. Further, the first portion is configured to be permanently or releasably attached to the dose dial grip of the drug delivery device, such that the first portion follows axial and rotational movement, for example helical movement, of the dose dial grip when attached to the drug delivery device. In this regard, the first portion may comprise protrusions, ribs, recesses, grooves, elastically deformable portions, clips or the like respective coupling elements configured for attachment to the dose dial grip. Hence, when the auxiliary dose dial grip is attached to the dose dial grip and is for example rotated during dose setting, the dose dial grip of the drug delivery device is entrained and rotates.

Furthermore, the first portion has a first longitudinal axis. The electronic add-on module or first portion extends along the first longitudinal axis from a proximal region to a distal region. A distally facing cavity may be provided in the first portion adapted to receive a portion of a drug delivery device. When the electronic add-on module is attached to a drug delivery device, the proximal region is generally closer to the second portion and the distal region is closer to the drug delivery device. The drug delivery device may also comprise a second longitudinal axis. The drug delivery device may extend from a distal region, provided for example with a needle, to a proximal region, provided for example with the dose button. If the electronic add-on module is attached to the drug delivery device, the first and second longitudinal axes may be concentrically in line.

The second portion of the electronic add-on module is coupled to the first portion. The second portion is axially moveable relative to the first portion and parallel to the first longitudinal axis but is rotationally constrained to the first portion. This relative axial movement may be limited such that the first portion and the second portion remain engaged and do not detach from each other. An axial movement parallel to the first longitudinal axis may comprise a parallel movement along the first longitudinal axis. Thus, relative rotational movement between said second portion and said first portion about the first longitudinal axis is prevented, such that the second portion follows rotational movement of said first portion. In other words, the first portion and the second portion are mutually rotated together. Therefore, when the electronic add-on module is for example releasably attached to the dose dial grip of the drug delivery device, rotation of the dose dial grip also rotates the first portion and the second portion together with the dose dial grip. In addition, axial movement of the dose dial grip axially moves the first portion and this movement may entrain the second portion or may result in a relative axial movement between the first portion and the second portion. For example, when the dose dial grip is helically moved during dose setting or dose dispensing, for example axially moved along the first and/or second longitudinal axis and rotationally moved about the first and/or longitudinal axis, the first portion and the second portion may follow the movement of the dose dial grip together. Therefore, rotating the first portion may rotate the dose dial grip and thus may set a dose.

The second portion may be encased and/or retained in the first portion, for example by clips or splines that engage in grooves. In addition, the second portion is configured to apply a force onto a dose button of the drug delivery device when axially moved along the first longitudinal axis relative to said first portion. Consequently, axial movement of the second portion relative to the first portion may cause or trigger dose dispensing.

The third portion, which is coupled to said second portion on a proximal side of the second portion, i.e. substantially opposite to said first portion, such that the second portion is arranged at least partially between said first portion and said third portion, is free to rotate relative to the second portion about the first longitudinal axis. The third portion may protrude from the first portion and may be partially encased in the first portion. Since the second portion is rotationally constrained to the first portion, the third portion is also free to rotate relative to the first portion. However, applying pressure to the third portion, for example to a proximal end surface of the third portion, may axially move the second portion in a distal direction relative to the first portion. The third portion, which is coupled to the second portion, may axially move together with the second portion. Therefore, the third portion may define an auxiliary dose button operated by a user which may exert via the second portion a force to the dose button of the drug delivery device when attached to the drug delivery device and axially moved.

Further, the electronic add-on module comprises the electrical power source, such as an, e.g. rechargeable or non-rechargeable, battery, arranged inside the electronic add-on module. In one aspect, the electrical power source is arranged inside the second portion of the electronic add-on module. The electrical power source is electrically connected to the circuit board assembly of the electronic add-on module. The circuit board assembly, which is arranged inside the electronic add-on module, may be arranged inside the second portion of the electronic add-on module. The electrical power source may be configured to power electrical components electrically connected to or provided on said circuit board assembly. Electronic components may be chips, processors, conductors, wireless modules or the like. The circuit board assembly may comprise a printed circuit board assembly. The circuit board assembly may comprise a substrate equipped with electronic components. The electronic components may be electrically connected to the circuit board assembly and may therefore also be supplied by power of the electrical power source.

Further, the electronic add-on module comprises a sensor arrangement arranged in or on the second portion of said electronic add-on module. The sensor arrangement is electrically connected to the circuit board assembly. The sensor arrangement is powered by the electrical power source. The sensor arrangement is configured to detect rotational movement between the second portion, rotationally constrained to the first portion, and the dose button of the drug delivery device. According to one aspect of the present disclosure, the sensor arrangement comprises at least one optical flow sensor facing towards the proximal end face of the dose button. The optical flow sensor may be configured to detect, when the module is attached to the drug delivery device, rotational movement between the second portion of said electronic add-on module and the proximal end face of the dose button of said drug delivery device. An optical flow sensor according to the present disclosure typically works by sensing the changing in pattern of brightness across the field of view to sense the movement of surface texture across the sensor. It uses that to calculate, based on the radius of the target area from the second longitudinal axis of the rug delivery device, the amount of rotation and therefore dose size. This type of sensing technology is commonly used in optical mouse controllers for computers, which are able to sense the relative motion of a mouse in relation to a mat or table surface. An optical tracking miniature chip suitable for use in a module according to the present disclosure is e.g. PAT9125EL of PixArt Imaging Inc., however other commercially available optical flow sensors are also suitable.

A principal benefit of the electronic add-on module is that known drug delivery devices, e.g. the drug delivery device as disclosed in WO 2004/078239 A1 , do not require any modification to be used with the module. Rather, the sensor is able to measure the rotation of the dose button without special features.

A requirement for drug delivery devices to be used with the module without any modifications is that the dose button does not rotate relative to the pen housing such that the module may rotate relative to the stationary dose button during dose dispensing, as in in WO 2004/078239 A1. The module may include an arrangement of interface features to support this. For example, the thrust bearing protrusion of the electronic add-on module may have a diameter being less than 10%, e.g. less than 8%, for example between 5% and 1%, of the outer diameter of the first portion. Thus, any friction between the thrust bearing protrusion of the electronic add-on module which rotates together with the dial grip of the drug delivery device relative to the stationary dose button during dose dispensing occurs on a quite small surface such that the resulting torque is relatively small.

In addition or as an alternative, the thrust bearing protrusion may have a distally facing rounded tip configured to form a friction type bearing with the proximal end face of the dose button. The design of the thrust bearing protrusion with a rounded tip allows minimizing the effective contact surface between the thrust bearing protrusion of the electronic add-on module which rotates together with the dial grip of the drug delivery device relative to the stationary dose button during dose dispensing such that the resulting torque becomes small.

Irrespective of the minimization of the contact surface between the thrust bearing protrusion and the proximal end face of the dose button, the torque resulting from the relative rotation may be kept small if the thrust bearing protrusion has a tip arranged concentrically with respect to the first longitudinal axis of the module. The electronic add-on module is able to monitor the dose delivery of the drug delivery device via the optical sensor positioned within the module, e.g positioned in or on the second portion, that is able to sense the relative rotary motion of the proximal end face of the dose button during dose delivery. More specifically, the at least one optical flow sensor may be provided on the distal side of the circuit board assembly which is in turn retained in the second portion.

Further, when the second portion is applying pressure onto the dose button in order to axially move the dose button in the distal direction, the sensor arrangement is moved together with the dose button. Therefore, there is no relative axial movement between the dose button of the drug delivery device and the sensor arrangement when the dose button is moved axially in the distal direction, for example for dose delivery.

The second portion may comprises a distal wall, i.e. a wall facing towards the dose button of the drug delivery device, having an aperture, a transparent window, a lens and/or a light pipe configured to provide a pathway from the at least one optical flow sensor to the proximal end face of the dose button such that the sensor is able to detect movement of the dose button during dose dispensing. For example, the sensor may be axially facing an aperture in the second portion, e.g. in the plastic of the housing of the inner component or sub-assembly which forms the second portion. The aperture provides a direct pathway to the proximal end face of the dose button such that light generated by the sensor may be reflected back from the proximal end face of the dose button. During operation of the device this arrangement is able to sense the rotational motion of the module in relation to the stationary dose button, and this may be used to count the doses delivered.

According to a further independent aspect of the present disclosure, the module essentially consists of three functional components, namely the first portion which may be an outer component/sub-assembly, the second portion which may be an inner component/sub- assembly configured within the outer component/sub-assembly (first portion), and the third portion which may be a rotating disc axially retained but free to rotate on the inner component/sub-assembly (second portion). The first portion may comprise coupling elements configured for releasable or permanent attachment to the dose dial grip.

The first portion may comprises a first coupling element, for example a first spline, arranged on an inner lateral surface of the first portion, the second portion may comprise a second coupling element, for example a groove, arranged on an outer lateral surface of the second portion, and, when the first coupling element and the second coupling element are engaged, limited relative axial movement between the second portion and the first portion is permitted but relative rotation is prevented by means of the first coupling element and the second coupling element. For example, recess features on the inner component/subassembly (second portion) may interact with rib features on the outer component/sub-assembly (first portion) allowing limited relative axial motion but preventing relative rotation.

The first and second coupling elements may form counterparts which interact in order to allow relative axial movement but at the same time limit axial translation between the first portion and the second portion. In an unloaded state, in which no pressure is applied to a proximal end surface of the third portion, a spring may push the first portion and the second portion apart, so that both portions may have a maximum axial displacement, i.e. the second portion is in its most proximal position relative to the first portion. When the electronic add-on module is loaded, i.e. when pressure is applied to the proximal end surface, the second portion is axially moved relative to the first portion. When the second portion is distally moved in the axial direction relative to the first portion, a switch may be actuated before the second portion starts to apply a pressure onto the dose button of the drug delivery device. Limiting the relative axial movement between the first portion and the second portion may prevent damaging of components of the electronic add-on module and/or the drug delivery device due to excessive axial movement.

The sensor arrangement may be arranged in the second portion of the electronic add-on module which is not rotated with respect to the first portion which has the function of releasably attaching to the dose dial grip of the electronic add-on module of the drug delivery device. Further, the sensor arrangement is arranged in the second portion of the electronic add-on module which is applying pressure onto the dose button of the drug delivery device. Therefore, when the first portion is releasably attached to the dose dial grip, the sensor arrangement rotates only if the dose dial grip rotates.

In one aspect, the third portion may be coupled to a spigot of the second portion. The spigot may be a kind of pin which forms a second thrust bearing. The third portion may be free to rotate about the spigot. The spigot may run in line with the first longitudinal axis. The spigot may allow releasable attachment of the third portion to the second portion. When a user applies a pressure onto the third portion in order to axially move the second portion, wherein the axial movement may apply pressure onto the dose button, the dose dial grip may start rotating, wherein the first portion and the second portion may rotate together with the dose dial grip. Thus, for example, the rotation of the dose dial grip, the first portion and the second portion may not be blocked by the thumb of the user resting on the third portion, as the third portion is free to rotate about the spigot.

According to one aspect, the second portion may comprise a backup friction surface arranged around said spigot. In other words, the backup friction surface may surround the spigot and may therefore be arranged on a proximal facing surface of the second portion. The third portion may comprise a support structure directed towards the second portion. For example, towards the proximal facing surface of the second portion. Further, the support structure may be configured to contact the backup friction surface when the third portion is loaded off axis with respect to the first longitudinal axis. The support structure may be a projection or any other structure comprising a flat surface configured to contact the backup friction surface when the third portion is loaded off axis. In this regard, off axis means off axis with respect to the first longitudinal axis, i.e. with respect to the axis of rotation of the third portion. In other words, if the third portion is not loaded centered so that the third portion may tilt slightly, the support structure of the third portion may contact the backup friction surface. The support structure may be ring shaped and arranged around a socket for the spigot. Therefore, the support structure and the backup friction surface may be in abutment in case of excessive off axis load. The abutment between the support structure and the backup friction surface may form an interface. The material of the support structure and the backup friction surface, i.e. the interface, may be selected in order to provide low friction, thus not blocking relative rotation between the second portion and the third portion. In one aspect, the support structure may be arranged close to the socket of the third portion. In other words, the support structure and the backup friction surface may be arranged in an area of the respective portion to minimize the unwanted load caused by off-axis loading.

In one aspect, a material pairing for the interface between the support structure and the backup friction surface and/or for the interface between the dose button and the second portion of the module, e.g. the interface formed by the thrust bearing protrusion and the proximal end face of the dose button, may comprise one or more of the following materials: polytetrafluoroethylene, polyoxymethylene, silicone lubricated polyoxymethylene, polytetrafluoroethylene lubricated polyoxymethylene, etc. The materials may be applied as a coating or may form the support structure and/or backup friction surface.

In one aspect, the third portion may be configured to be snapped onto the spigot. Additionally or alternatively, the spigot may comprise a greater diameter in an area closer to the second portion than in an area further away from the second portion. The third portion may be clipped over the area comprising a greater diameter. The structure of the spigot may provide sufficient stability and at the same time reduces possible friction of the second thrust bearing. The snap- on also allows the third portion to be replaced or removed during cleaning.

The electronic add-on module may be an electronic dose recording system for determining, storing and/or transmitting data indicative of at least a condition of the drug delivery device or its use. For example, the system may detect if the drug delivery device is switched between a dose setting mode and a dose dispensing mode and vice versa. In addition or as an alternative, the system may detect if a dose is set and/or if a dose is dispensed. Still further, the system may detect the amount of dose selected and/or the amount of dose dispensed. Preferably, the electronic add-on module is configured such that it may be switched from a first state having lower energy consumption into a second state having higher energy consumption. This may be achieved by operation of the electronic add-on module, especially by providing the electrical connection between the electrically conductive elements. The first state may be a sleeping mode and the second mode may be a detection and/or communication mode. As an alternative, an electronic control unit may issue a command, e.g. a signal, to another unit of the electronic dose recording system such that this unit is switched on or rendered operational.

The electronic add-on module may further comprise a communication unit for communicating with another device, e.g. a wireless communications interface for communicating with another device via a wireless network such as Wi-Fi or Bluetooth, or even an interface for a wired communications link, such as a socket for receiving a Universal Series Bus (USB), mini-USB or micro-USB connector. Preferably, the electronic add-on module comprises an RF, Wi-Fi and/or Bluetooth unit as the communication unit. The communication unit may be provided as a communication interface between the electronic add-on module and the exterior, such as other electronic devices, e.g. mobile phones, personal computers, laptops and so on. For example, dose data may be transmitted by the communication unit to the external device. The dose data may be used for a dose log or dose history established in the external device.

According to one aspect, the object may also be solved by an assembly comprising a drug delivery device and an electronic add-on module as mentioned above. The electronic add-on module is configured for attachment, preferably for releasable attachment, to the drug delivery device. Further, the drug delivery device comprises at least a housing with a container configured to receive a drug or a cartridge filled with a drug. Further, the drug delivery device comprises a dose setting unit and a dose delivery unit.

The dose setting unit comprises a dose dial grip which is, at least rotationally, e.g. helically, moveable with respect to the housing during dose setting and a dose button with a proximal end face at least axially moveable with respect to the housing for causing dose dispensing. The dose button may have a T-shape with the proximal end surface being a circular disc that serves as a pressure surface and a central shaft that extends distally. The dose delivery unit comprises a plunger at least axially, e.g. helically, moveable with respect to the housing during dose dispensing and at least one further component part rotationally constrained to the housing during dose dispensing.

According to an aspect of the present disclosure, the dose button comprises at least one friction type bearing interface with the dose delivery unit configured to prevent rotation of the dose button during dose dispensing. In other words, the drug delivery device may be configured such that although relative rotation of the dose button with respect to the housing is not blocked during dose delivery (dose dispensing) by a clutch, a blocking member or the like, it would be required to overcome a friction torque in order to rotate the dose button. If this friction torque is sufficiently high and the torque exerted on the dose button during dose delivery is sufficiently low, then the dose button will remain stationary during dose delivery, i.e. the dose button does not rotate during dose dispensing. In this case, the optical flow sensor which rotates together with the module and the dial grip during dose dispensing is able to detect the amount of relative movement (rotation) between the module and the dial grip on the one hand and the dose button on the other hand. This magnitude of this relative rotation is indicative of the amount of dose dispensed.

More specifically, the dose delivery unit and the dose button may form a first friction type bearing interface, the dose dial grip and the dose button may form a second friction type bearing interface, and, when the electronic add-on module is attached to the drug delivery device, the thrust bearing protrusion of the electronic add-on module and the proximal end face of the dose button form a third friction type bearing interface. During dose dispensing the frictional torque of the first friction type bearing interface is preferably larger than the sum of the frictional torques of the second friction type bearing interface and third friction type bearing interface such that the dose button does not rotate during dose dispensing.

For example, when using the electronic add-on module as described above with a drug delivery device as described in WO 2004/078239 A1 , the frictional torque at the third friction type bearing interface between the inner sub-assembly (second portion) of the module and the dose button, plus the frictional torque of the second friction type bearing interface between the dose button and the dial grip is always less than the frictional torque at the first friction type bearing interface between the dose button and a component of the dose delivery unit, e.g. a clutch. As mentioned above, this is all governed by friction without requiring geometric features on the interface between the dose button and a component of the dose delivery unit to prevent rotation.

The first friction type bearing interface may located radially outside of the third friction type bearing interface. Thus, as the radius is a factor for the torque, this allows minimizing the friction torque at the third friction type bearing interface. The second friction type bearing interface may be located radially outside of the first friction type bearing interface. If the forces or any non-frictional drag acting via the second friction type bearing interface are small, this outweighs the fact that the thrust radius between the dose button and the dial grip is larger than that between the dose button and e.g. the clutch of the dose delivery unit.

In the assembly according to the present disclosure, the axial force applied by the thrust bearing protrusion onto the dose button via the via the third friction type bearing interface during dose dispensing may be reacted within the drug delivery device by a primary load path reaction force via the first friction type bearing interface and by a secondary load path reaction force via the second friction type bearing interface. In this case, the primary load path reaction force may be preferably larger than the secondary load path reaction force. For example, in the drug delivery device as described in WO 2004/078239 A1 , the primary load path reaction force acting via the first friction type bearing interface is considerably larger than the secondary load path reaction force acting via the second friction type bearing interface. Thus, the electronic add-on module may be used in conjunction with the drug delivery device as described in WO 2004/078239 A1 without requiring any adaptions to the drug delivery device.

The third friction type bearing interface may comprise a central recess in the proximal end face of the dose button forming a counter bearing surface for the thrust bearing protrusion. This central recess may contribute in providing a predefined small contact surface between the dose button and the module.

The terms “drug” or “medicament” are used synonymously herein and describe a pharmaceutical formulation containing one or more active pharmaceutical ingredients or pharmaceutically acceptable salts or solvates thereof, and optionally a pharmaceutically acceptable carrier. An active pharmaceutical ingredient (“API”), in the broadest terms, is a chemical structure that has a biological effect on humans or animals. In pharmacology, a drug or medicament is used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being. A drug or medicament may be used for a limited duration, or on a regular basis for chronic disorders. As described below, a drug or medicament can include at least one API, or combinations thereof, in various types of formulations, for the treatment of one or more diseases. Examples of API may include small molecules having a molecular weight of 500 Da or less; polypeptides, peptides and proteins (e.g., hormones, growth factors, antibodies, antibody fragments, and enzymes); carbohydrates and polysaccharides; and nucleic acids, double or single stranded DNA (including naked and cDNA), RNA, antisense nucleic acids such as antisense DNA and RNA, small interfering RNA (siRNA), ribozymes, genes, and oligonucleotides. Nucleic acids may be incorporated into molecular delivery systems such as vectors, plasmids, or liposomes. Mixtures of one or more drugs are also contemplated.

The drug or medicament may be contained in a primary package or “drug container” adapted for use with a drug delivery device. The drug container may be, e.g., a cartridge, syringe, reservoir, or other solid or flexible vessel configured to provide a suitable chamber for storage (e.g., short- or long-term storage) of one or more drugs. For example, in some instances, the chamber may be designed to store a drug for at least one day (e.g., 1 to at least 30 days). In some instances, the chamber may be designed to store a drug for about 1 month to about 2 years. Storage may occur at room temperature (e.g., about 20°C), or refrigerated temperatures (e.g., from about - 4°C to about 4°C). In some instances, the drug container may be or may include a dual-chamber cartridge configured to store two or more components of the pharmaceutical formulation to-be-administered (e.g., an API and a diluent, or two different drugs) separately, one in each chamber. In such instances, the two chambers of the dualchamber cartridge may be configured to allow mixing between the two or more components prior to and/or during dispensing into the human or animal body. For example, the two chambers may be configured such that they are in fluid communication with each other (e.g., by way of a conduit between the two chambers) and allow mixing of the two components when desired by a user prior to dispensing. Alternatively or in addition, the two chambers may be configured to allow mixing as the components are being dispensed into the human or animal body.

The drugs or medicaments contained in the drug delivery devices as described herein can be used for the treatment and/or prophylaxis of many different types of medical disorders. Examples of disorders include, e.g., diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism disorders such as deep vein or pulmonary thromboembolism. Further examples of disorders are acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis. Examples of APIs and drugs are those as described in handbooks such as Rote Liste 2014, for example, without limitation, main groups 12 (anti-diabetic drugs) or 86 (oncology drugs), and Merck Index, 15th edition.

Examples of APIs for the treatment and/or prophylaxis of type 1 or type 2 diabetes mellitus or complications associated with type 1 or type 2 diabetes mellitus include an insulin, e.g., human insulin, or a human insulin analogue or derivative, a glucagon-like peptide (GLP-1), GLP-1 analogues or GLP-1 receptor agonists, or an analogue or derivative thereof, a dipeptidyl peptidase-4 (DPP4) inhibitor, or a pharmaceutically acceptable salt or solvate thereof, or any mixture thereof. As used herein, the terms “analogue” and “derivative” refers to a polypeptide which has a molecular structure which formally can be derived from the structure of a naturally occurring peptide, for example that of human insulin, by deleting and/or exchanging at least one amino acid residue occurring in the naturally occurring peptide and/or by adding at least one amino acid residue. The added and/or exchanged amino acid residue can either be codable amino acid residues or other naturally occurring residues or purely synthetic amino acid residues. Insulin analogues are also referred to as "insulin receptor ligands". In particular, the term ..derivative” refers to a polypeptide which has a molecular structure which formally can be derived from the structure of a naturally occurring peptide, for example that of human insulin, in which one or more organic substituent (e.g. a fatty acid) is bound to one or more of the amino acids. Optionally, one or more amino acids occurring in the naturally occurring peptide may have been deleted and/or replaced by other amino acids, including non-codeable amino acids, or amino acids, including non-codeable, have been added to the naturally occurring peptide.

Examples of insulin analogues are Gly(A21), Arg(B31), Arg(B32) human insulin (insulin glargine); Lys(B3), Glu(B29) human insulin (insulin glulisine); Lys(B28), Pro(B29) human insulin (insulin lispro); Asp(B28) human insulin (insulin aspart); human insulin, wherein proline in position B28 is replaced by Asp, Lys, Leu, Vai or Ala and wherein in 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.

Examples of insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin, Lys(B29) (N- tetradecanoyl)-des(B30) human insulin (insulin detemir, Levemir®); B29-N- palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl- ThrB29LysB30 human insulin; B29-N-(N-palmitoyl-gamma-glutamyl)-des(B30) human insulin, B29-N-omega-carboxypentadecanoyl-gamma-L-glutamyl-des(B30) human insulin (insulin degludec, Tresiba®); B29-N-(N-lithocholyl-gamma-glutamyl)-des(B30) human insulin; B29-N- (w-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(w-carboxyheptadecanoyl) human insulin.

Examples of GLP-1 , GLP-1 analogues and GLP-1 receptor agonists are, for example, Lixisenatide (Lyxumia®), Exenatide (Exendin-4, Byetta®, Bydureon®, a 39 amino acid peptide which is produced by the salivary glands of the Gila monster), Liraglutide (Victoza®), Semaglutide, Taspoglutide, Albiglutide (Syncria®), Dulaglutide (Trulicity®), rExendin-4, CJC- 1134-PC, PB-1023, TTP-054, Langlenatide / HM-11260C (Efpeglenatide), HM-15211 , CM-3, GLP-1 Eligen, GRMD-0901 , NN-9423, NN-9709, NN-9924, NN-9926, NN-9927, Nodexen, Viador-GLP-1, CVX-096, ZYOG-1 , ZYD-1 , GSK-2374697, DA-3091 , MAR-701 , MAR709, ZP- 2929, ZP-3022, ZP-DI-70, TT-401 (Pegapamodtide), BHM-034. MOD-6030, CAM-2036, DA- 15864, ARI-2651 , ARI-2255, Tirzepatide (LY3298176), Bamadutide (SAR425899), Exenatide- XTEN and Glucagon-Xten.

An example of an oligonucleotide is, for example: mipomersen sodium (Kynamro®), a cholesterol-reducing antisense therapeutic for the treatment of familial hypercholesterolemia or RG012 for the treatment of Alport syndrom.

Examples of DPP4 inhibitors are Linagliptin, Vildagliptin, Sitagliptin, Denagliptin, Saxagliptin, Berberine.

Examples of hormones include hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, and Goserelin.

Examples of polysaccharides include a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra-low molecular weight heparin or a derivative thereof, or a sulphated polysaccharide, e.g. a poly-sulphated form of the above-mentioned polysaccharides, and/or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium. An example of a hyaluronic acid derivative is Hylan G-F 20 (Synvisc®), a sodium hyaluronate.

The term “antibody”, as used herein, refers to an immunoglobulin molecule or an antigenbinding portion thereof. Examples of antigen-binding portions of immunoglobulin molecules include F(ab) and F(ab')2 fragments, which retain the ability to bind antigen. The antibody can be polyclonal, monoclonal, recombinant, chimeric, de-immunized or humanized, fully human, non-human, (e.g., murine), or single chain antibody. In some embodiments, the antibody has effector function and can fix complement. In some embodiments, the antibody has reduced or no ability to bind an Fc receptor. For example, the antibody can be an isotype or subtype, an antibody fragment or mutant, which does not support binding to an Fc receptor, e.g., it has a mutagenized or deleted Fc receptor binding region. The term antibody also includes an antigen-binding molecule based on tetravalent bispecific tandem immunoglobulins (TBTI) and/or a dual variable region antibody-like binding protein having cross-over binding region orientation (CODV).

The terms “fragment” or “antibody fragment” refer to a polypeptide derived from an antibody polypeptide molecule (e.g., an antibody heavy and/or light chain polypeptide) that does not comprise a full-length antibody polypeptide, but that still comprises at least a portion of a full- length antibody polypeptide that is capable of binding to an antigen. Antibody fragments can comprise a cleaved portion of a full length antibody polypeptide, although the term is not limited to such cleaved fragments. Antibody fragments that are useful in the present invention include, for example, Fab fragments, F(ab')2 fragments, scFv (single-chain Fv) fragments, linear antibodies, monospecific or multispecific antibody fragments such as bispecific, trispecific, tetraspecific and multispecific antibodies (e.g., diabodies, triabodies, tetrabodies), monovalent or multivalent antibody fragments such as bivalent, trivalent, tetravalent and multivalent antibodies, minibodies, chelating recombinant antibodies, tribodies or bibodies, intrabodies, small modular immunopharmaceuticals (SMIP), binding-domain immunoglobulin fusion proteins, camelized antibodies, and immunoglobulin single variable domains. Additional examples of antigen-binding antibody fragments are known in the art.

The term “immunoglobulin single variable domain” (ISV), interchangeably used with “single variable domain”, defines immunoglobulin molecules wherein the antigen binding site is present on, and formed by, a single immunoglobulin domain. As such, immunoglobulin single variable domains are capable of specifically binding to an epitope of the antigen without pairing with an additional immunoglobulin variable domain. The binding site of an immunoglobulin single variable domain is formed by a single heavy chain variable domain (VH domain or VHH domain) or a single light chain variable domain (VL domain). Hence, the antigen binding site of an immunoglobulin single variable domain is formed by no more than three CDRs.

An immunoglobulin single variable domain (ISV) can be a heavy chain ISV, such as a VH (derived from a conventional four-chain antibody), or VHH (derived from a heavy-chain antibody), including a camelized VH or humanized VHH. For example, the immunoglobulin single variable domain may be a (single) domain antibody, a "dAb" or dAb or a Nanobody® ISV (such as a VHH, including a humanized VHH or camelized VH) or a suitable fragment thereof. [Note: Nanobody® is a registered trademark of Ablynx N.V.]; other single variable domains, or any suitable fragment of any one thereof.

“VHH domains”, also known as VHHs, VHH antibody fragments, and VHH antibodies, have originally been described as the antigen binding immunoglobulin variable domain of “heavy chain antibodies” (i.e., of “antibodies devoid of light chains”; Hamers-Casterman et al. 1993 (Nature 363: 446-448). The term “VHH domain” has been chosen in order to distinguish these variable domains from the heavy chain variable domains that are present in conventional 4- chain antibodies (which are referred to herein as “VH domains”) and from the light chain variable domains that are present in conventional 4-chain antibodies (which are referred to herein as “VL domains”). For a further description of VHH’s, reference is made to the review article by Muyldermans 2001 (Reviews in Molecular Biotechnology 74: 277-302).

For the term “dAb’s” and “domain antibody”, reference is for example made to Ward et al. 1989 (Nature 341 : 544), to Holt et al. 2003 (Trends Biotechnol. 21 : 484); as well as to WO 2004/068820, WO 2006/030220, WO 2006/003388. It should also be noted that, although less preferred in the context of the present invention because they are not of mammalian origin, single variable domains can be derived from certain species of shark (for example, the so- called “IgNAR domains”, see for example WO 2005/18629).

The terms “Complementarity-determining region” or “CDR” refer to short polypeptide sequences within the variable region of both heavy and light chain polypeptides that are primarily responsible for mediating specific antigen recognition. The term “framework region” refers to amino acid sequences within the variable region of both heavy and light chain polypeptides that are not CDR sequences, and are primarily responsible for maintaining correct positioning of the CDR sequences to permit antigen binding. Although the framework regions themselves typically do not directly participate in antigen binding, as is known in the art, certain residues within the framework regions of certain antibodies can directly participate in antigen binding or can affect the ability of one or more amino acids in CDRs to interact with antigen.

Examples of antibodies are anti PCSK-9 mAb (e.g., Alirocumab), anti IL-6 mAb (e.g., Sarilumab), and anti IL-4 mAb (e.g., Dupilumab). Pharmaceutically acceptable salts of any API described herein are also contemplated for use in a drug or medicament in a drug delivery device. Pharmaceutically acceptable salts are for example acid addition salts and basic salts.

Those of skill in the art will understand that modifications (additions and/or removals) of various components of the APIs, formulations, apparatuses, methods, systems and embodiments described herein may be made without departing from the full scope and spirit of the present invention, which encompass such modifications and any and all equivalents thereof.

An example drug delivery device may involve a needle-based injection system as described in Table 1 of section 5.2 of ISO 11608-1 :2014(E). As described in ISO 11608-1 :2014(E), needlebased injection systems may be broadly distinguished into multi-dose container systems and single-dose (with partial or full evacuation) container systems. The container may be a replaceable container or an integrated non-replaceable container.

As further described in ISO 11608-1 :2014(E), a multi-dose container system may involve a needle-based injection device with a replaceable container. In such a system, each container holds multiple doses, the size of which may be fixed or variable (pre-set by the user). Another multi-dose container system may involve a needle-based injection device with an integrated non-replaceable container. In such a system, each container holds multiple doses, the size of which may be fixed or variable (pre-set by the user).

As further described in ISO 11608-1 :2014(E), a single-dose container system may involve a needle-based injection device with a replaceable container. In one example for such a system, each container holds a single dose, whereby the entire deliverable volume is expelled (full evacuation). In a further example, each container holds a single dose, whereby a portion of the deliverable volume is expelled (partial evacuation). As also described in ISO 11608- 1 :2014(E), a single-dose container system may involve a needle-based injection device with an integrated non-replaceable container. In one example for such a system, each container holds a single dose, whereby the entire deliverable volume is expelled (full evacuation). In a further example, each container holds a single dose, whereby a portion of the deliverable volume is expelled (partial evacuation).

The terms “axial”, “radial”, or “circumferential” as used herein may be used with respect to a first longitudinal axis of the electronic add-on module, the first portion, the second portion, the drug delivery device, the cartridge, the housing, the cartridge holder or the assembly of the drug delivery device and the electronic add-on module, e.g. the axis which extends through the proximal and distal ends of the cartridge.

"Distal" is used herein to specify directions, ends or surfaces which are arranged or are to be arranged to face or point towards dispensing end of the drug delivery device or, regarding the electronic add-on module, arranged to face or point towards the drug delivery device. On the other hand, “proximal” is used to specify directions, ends or surfaces which are arranged or are to be arranged to face away from or point away from the dispensing end and/or from the distal end of the electronic add-on module or the drug delivery device or components thereof. The dispensing end may be the needle end where a needle unit is or is to be mounted to the device, for example. Furthermore, when the electronic add-on module is considered alone, the term "distal" may be used with regard to the more distal end of the electronic add-on module, which is located closer to the dispensing end of the drug delivery device when attached to the drug delivery device, and the term "proximal" may be used with regard to the proximal end of the electronic add-on module, which is located further away from the dispensing end of the drug delivery device when attached to the drug delivery device.

In the following, non-limiting, examples of the electronic add-on module, the drug delivery device and the assembly of the drug delivery device and the electronic add-on module are described in more detail by making reference to the drawings, in which:

Figure 1 shows a drug delivery device;

Figure 2 shows the proximal end of a drug delivery device suitable for use with an electronic add-on module according to the present disclosure;

Figure 3 shows an exploded view of an electronic add-on module according to a first example;

Figure 4 shows a sectional view of an electronic add-on module according to the first example, which is attached to a drug delivery device;

Figure 5 shows a sectional view of an electronic add-on module, which is attached to a drug delivery device, in an unloaded state;

Figure 6 shows a sectional view of the electronic add-on module of Figure 5 at a switch point; and Figure 7 shows a sectional view of the electronic add-on module of Figure 5 during dose dispensing.

In the Figures, identical elements and components as well as identical elements and components in different examples or embodiments, i.e. elements and components acting identical or provided for the same purposes but belong to different examples, are provided with the same reference signs.

Figure 1 shows an exploded view of an exemplary medicament or drug delivery device 1. The drug delivery device 1 is a pen-type injector comprising a housing 10 in which a drive mechanism for dose setting and dose dispensing is arranged. The drug delivery device 1 extends from a distal point to a proximal direction P or from a proximal point to a distal direction D along a second longitudinal axis Y of the drug delivery device 1. In order to set a dose for delivery a user may rotate or dial a dose dial grip 12 with respect to the housing 10, wherein the dose dial grip 12 is arranged at a distal end of the housing 10. During dose setting the dose dial grip 12 may perform a helical movement, i.e. a combined axial and rotational movement, or may perform pure rotational movement.

The drive mechanism of the drug delivery device 1 may comprise a plunger, a number sleeve 13, a clutch, a clutch spring, a number sleeve, a last dose nut and so on, which may move during dose setting and/or dose dispensing. Although not all of these components are shown in detail, for example, the drive mechanisms disclosed in EP 1 570 876, EP 2 814 547, US 9,937,294 B2 or WO 2004/078239 A1 represent suitable drive mechanisms for the present disclosure.

Once the dose is set by means of the dose dial grip 12, the user may press a dose button 11 arranged at the proximal end of the drug delivery device 1 in the distal direction D in order to dispense the dose. When pressing the dose button 11 , the user applies a force directed towards the proximal end of the drug delivery device 1 , wherein the force moves the dose button 11 in the distal direction of the pen and parallel to the second longitudinal axis Y. This axial movement of the dose button 11 releases the drive mechanism for example by decoupling a number sleeve from the drive sleeve, wherein irrespective of which component of the drug delivery device 1 performs a rotational movement during dose delivery, the dose dial grip 12 is coupled to a respective component in order to perform a rotational movement during dose delivery. This rotational movement of the dose dial grip 12 during dose delivery may be used to determine, for example, the actual dose delivered by means of an electronic add-on module 100 as shown in Figures 3 to 7 and described here below.

The exemplary drug delivery device 1 shown in Figure 1 comprises in addition to the dose dial grip 12 and the dose button 11 an optional dosage window through which the number sleeve 13 is partially visible, a container 14, and a needle 15. The set dose may be displayed via the dosage window. The container 14 may be filled directly with a drug, for example, insulin or may be configured to receive a cartridge and thus act as a cartridge holder. The needle 15 may be affixed to the container or the receptacle. During dose dispensing the drug is dispensed through the needle 15. The needle 15 may be protected by an inner needle cap 16. In addition, the needle 15 may be protected by either an outer needle cap 17 or another cap 18 which also encloses the container 14.

In order for an electronic add-on module 100 to be functionally attached to a drug delivery device 1 , i.e. attached and usable, either the drug delivery device 1 can be adapted to the electronic add-on module 100 or, conversely, the electronic add-on module 100 can be adapted to the drug delivery device 1. Regardless of this, the drug delivery device 1 as well as the electronic add-on module 100 may have different examples, wherein the further description with respect to the drug delivery device 1 essentially deals with the dose button 11 , the dose dial grip 12 and the number sleeve 13.

Figures 2 and 4 to 7 show the proximal end of a drug delivery device 1 operating as described e.g. in WO 2004/078239 A1 . The dose button 11 has an essentially T-shaped configuration with a proximal end face 19 in the form of a circular disc having a central recess 20. A stem 21 extends distally from the proximal end face 19. A first distally facing bearing surface 22 is formed by a stepped portion of the stem and a second distally facing bearing surface 23 is formed in the transition of the proximal end face 19 and the stem 21. The diameter of the central recess 20 is significantly smaller than the diameter of the first bearing surface 22 which in turn is smaller than the diameter of the second bearing surface 23.

Figures 4 to 7 further show a proximal portion of a clutch sleeve 24 of the drug delivery device 1 , wherein the clutch sleeve 24 comprises two spring arms at the proximal end thereof. Each of the spring arms has a proximally facing bearing surface abutting the first bearing surface 22 of the dose button 11. The proximally facing bearing surface of the arms of the clutch sleeve 24 and the first bearing surface 22 of the dose button 11 form a first friction type bearing B1. This means that relative rotation between the clutch sleeve 24 and the dose button 11 is generally possible at this first friction type bearing B1 if a torque is applied which exceeds the frictional torque of this interface.

In operation of the drug delivery device 1 , the clutch sleeve 24 rotates together with the dial grip 12 during dose setting, is axially displaced together with the dose button 11 when the dose button 11 is pressed distally, and is rotationally constrained to but axially displaceable relative to the housing 10 during dose delivery (dose dispensing) as described in more detail in WO 2004/078239 A1. During dose dispensing, the axial force required for moving a bung in the container 14 in order to expel medicament via the needle 15, is transmitted via the clutch sleeve 24 and the first friction type bearing B1.

The dial grip 12 comprises a proximally facing bearing ring which abuts the second bearing surface 23 of the dose button 11 , thus forming a second friction type bearing B2. Again, relative rotation between the dial grip 12 and the dose button 11 is generally possible at this second friction type bearing B2 if a torque is applied which exceeds the frictional torque of this interface.

The number sleeve 13 (omitted in Figures 4 to 7) is axially and rotationally constrained to the dial grip 12. The number sleeve 13 rotates along a helical path defined by a threaded interface with the housing 10 together with the dial grip 12 during dose setting and during dose dispensing as described in more detail in WO 2004/078239 A1. During dose dispensing, only a relatively small torque is required to overhaul the number sleeve 13 down its threaded interface with the housing 10 and, optionally, a non-frictional drag may be exerted by a clicker arm (not shown). Thus, the axial forces acting at the second friction type bearing B2 during dose dispensing are considerably lower than the axial forces transmitted via the clutch sleeve 24 and the first friction type bearing B1.

A third friction type bearing B3 is formed between the dial grip 11 , more specifically the recess 20 of the proximal end face 19, and a corresponding bearing portion of the electronic add-on module 100 as will be described below in more detail.

A first example of the electronic add-on module 100 is shown in Figure 3. The electronic addon module 100 comprises a first portion 101 , a second portion 102 and a third portion 103 arranged along a first longitudinal axis X. The second portion 102 comprises a proximal facing surface 104 facing towards the third portion 103. The third portion 103 comprises a proximal end surface 105 onto which a pressure may be applied, for example, by a user's thumb during dose dispensing. The first portion 101 comprises coupling elements for, e.g. releasable, attachment to the dial grip 12 of the drug delivery device 1. When the electronic add-on module 100 is coupled to the drug delivery device 1 , the first longitudinal axis X and the second longitudinal axis Y may be in line.

When the electronic add-on module 100 is attached to a drug delivery device 1 , a user may rotate the first portion 101 in order to set a dose for delivery. The first portion 101 may provide an auxiliary dose dial grip allowing for a controlled rotational movement of the first portion 101. Further, pressure may be applied to the proximal end surface 105, for example by a thumb of a user, in order to axially move the second portion 102 with respect to the first portion 101 along the first longitudinal axis X. Here, the third portion 103 of the electronic add-on module 100 is coupled by a spigot 106 to the second portion 102. The third portion 103 is free to rotate about said spigot 106.

If the proximal end surface 105 is not loaded centered, i.e., when the user presses eccentrically onto the proximal end surface 105, the third portion 103 may tilt relative to the first longitudinal axis X, so that a support structure 107 of the third portion 103 comes into contact with a backup friction surface 108 on the proximal facing surface 104 of the second portion 102. The material pairing of the support structure 107 and the backup friction surface 108 may be selected in such a way that only low friction occurs between the two components. In other words, the friction of the interface between the support structure 107 and the backup friction surface 108 may still allow relative rotation between the third portion 103 and the second portion 102 while the second portion 102 is axially moved due to a load applied to the proximal end surface 105.

An electrical power source as shown in Figures 4 to 7, here a battery 109, may be arranged in the second portion 102. In addition, the second portion 102 comprises a circuit board assembly with a substrate 110. The electrical power source may be electrically connected to said circuit board assembly. Various electronic components 111 are arranged on the substrate 110. In addition, a sensor arrangement, for example an optical flow sensor 112, is electrically connected to the circuit board assembly. As shown in Figure 4, the optical flow sensor 112 is arranged on the distal side of the circuit board assembly facing towards the proximal end face 19 of the dose button 11.

The components of the second portion 102 are arranged inside a housing of the second portion 102, wherein the housing is formed, inter alia, by a distal wall 113 forming an abutment surface which is arranged to apply pressure to the dose button 11 of the drug delivery device 1 in order to move the dose button 11 axially to cause dose dispensing. The wall 113 comprises a thrust bearing protrusion 114 configured to contact the recess 20 of the proximal end face 19 of the dose button 11 , thereby defining the third friction type bearing B3. The wall 113 may be at least partially transparent so that the optical flow sensor 112 may, for example, detect a movement of the dose button 11 of the drug delivery device 1. As an alternative to such a transparent area, Figure 4 shows an aperture 115 in the wall 113 providing a direct pathway to the proximal end face 19 of the dose button 11.

When a user applies presses onto the proximal end surface 105 of the third portion 103 of the electronic add-on module 100, the second portion 102 is axially moved in the distal direction D with respect to the first portion 101 along the first longitudinal axis X. When the electronic add-on module 100 is attached to the drug delivery device 1 and the second portion 102 is sufficiently axially moved with respect to the first portion 101 , the thrust bearing protrusion 114 applies pressure onto the dose button 11 , more precisely onto the proximal end face 19 of the dose button 11. When the module 100 is attached to the drug delivery device 1 , the thrust bearing protrusion 114 may be permanently in contact with the dose button 11.

The second portion 102 may be coupled to the first portion 101. The first portion 101 comprises first coupling elements, e.g. splines 117, arranged on an inner lateral surface 118, which engage with second coupling elements, e.g. recesses or grooves 119, arranged on an outer lateral surface 120 of the second portion 102 as shown in Figure 3. The splines 117 may comprise a lower part 117A that may slide into grooves 119. The grooves 119 may comprise an axial stop 119A which may limit the relative axial movement between the second portion 102 and the first portion 101 , when the lower part 117A abuts against the axial stop 119A.

When a pressure is applied onto the proximal end face 19 of the dose button 11 , this pressure may actuate a clutch mechanism comprising the clutch sleeve 24. Actuating the clutch mechanism may rotationally decouple a drive sleeve (not shown) from the dose dial grip 12 and may rotationally constrain the clutch sleeve 24 to the housing 10. The electronic add-on module 100, more precisely the first portion 101 , rotates together with the dose dial grip 12 during dose dispensing. The second portion 102, which is rotationally constrained to the first portion 101 , rotates together with the first portion 101. Consequently, the optical flow sensor 112 is rotated relative to the dose button 11 such that the optical flow sensor 112 is able to detect the relative rotation.

The working principle of the module 100 is based on the fact that a relative rotation occurs between the dose button 11 and the module 100 during dose dispensing, i.e. the dose button 11 does not rotate relative to the pen housing 10. This may be achieved without modifying the drug delivery device 1 using the different frictional torques existing at the above described interfaces of the first friction type bearing B1 , the second friction type bearing B2 and the third friction type bearing B3. More specifically, the frictional torque between thrust bearing protrusion 114 and recess 20 of the dose button 11 at the third friction type bearing B3 plus the frictional torque between the dose button 11 and the dial grip 12 at the second friction type bearing B2 is always less than the frictional torque between the dose button 11 and the clutch sleeve 24 at the first friction type bearing B1. This is required in order for relative rotation to occur at the interfaces of the third friction type bearing B3 and the second friction type bearing B2 whilst no relative rotation occurs at the interface of the first friction type bearing B1 which is all governed by friction without requiring geometric features on interface of the first friction type bearing B1 to prevent rotation.

The axial force between the dose button 11 and clutch sleeve 24 is always higher than the axial force between the dose button 11 and the dial grip 12 which is inherent in the pen mechanism as the load path through the dose button 11 and clutch sleeve 24 is ultimately directly through the plunger to the container 14, whereas the load path through the dose button 11 and the dial grip 12 is a secondary path to overhaul the number sleeve 13 down its thread whereby the only non-frictional drag is an optional clicker arm which is small compared to the container 14 dispense force. This outweighs the fact that the thrust radius between the dose button 11 and the dial grip 12 is larger than that between the dose button 11 and the clutch sleeve 24. Further, the thrust radius between the thrust bearing protrusion 114 and recess 20 of the dose button 11 is controlled to be small enough to mitigate the fact the axial force between the thrust bearing protrusion 114 and recess 20 of the dose button 11 is the sum of the axial forces between the dose button 11 and the dial grip 12 and the dose button 11 and the clutch sleeve 24.

In other words, if the frictional torque T1 at bearing B1 is T1 = F1 * p1 * r1 and the frictional torque T2 at bearing B2 is T2 = F2 * p2 * r2 and the frictional torque T3 at bearing B is T3 = (F1 + F2) * p3 * r3, with p being the friction coefficient at the respective bearing, r being the radius at the respective bearing and F1 being the axial force in the load path through the dose button 11 and clutch sleeve 24 and F2 being the axial force in the secondary path through the bearing B2, the mechanism has to meet the equation T1 > T2 + T3.

With the sensor 112 axially facing the aperture 115 in the wall 113 the direct pathway to the proximal end face 19 on the dose button 11 , light which is generated by the sensor 112 is reflected back from the proximal end face 19 on the dose button 11. During operation of the drug delivery device 1 , this arrangement is able to sense the rotational motion of the module

100 in relation to the stationary dose button 11 , and this may be used to count the doses delivered. The optical flow sensor 112 works by sensing the changing in pattern of brightness across the field of view to sense the movement of surface texture across the sensor. It uses that to calculate, based on the radius of the target area from the pen axis Y, the amount of rotation and therefore dose size. This has the benefit that the electronic add-on module 100 may be used with a standard available pen type drug delivery device without requiring modifications and that the sensor is able to reliably measure the rotation of the dose button 11 without any special features.

The electronic add-on module 100 may further comprise a switch 121 as shown in Figures 5 to 7. The sectional view of Figures 5 to 7 shows the components from a different angle than Figure 4. The switch 121 shown here is a mechanical switch comprising a lever 116 which is deflected due to relative axial movement between the second portion 102 and the first portion

101 of the electronic add-on module 100. In the depicted example, the lever 116 is pivotably attached to the circuit board assembly 110 and/or the second portion 102 and its free end abuts a web projecting inwards from the first portion 101 such that upon relative axial movement of the first portion 101 and the second portion 102, the lever 116 is deflected which in turn actuates the switch 121.

The switch 121 may be used to ensure that electronic components 111 of the electronic addon module 100 are only activated or actuated or only woken up when they are needed in order to save energy of the electrical power source 109. For example, the sensor arrangement with the optical flow sensor 112 may only be actuated if sufficient load is exerted on the proximal end surface 105 of the third portion 103 to move the second portion 102 axially relative to the first portion 101 in order to dispense a dose. This axial movement may then deflect the lever of the switch 121 which may then activate the sensor 112.

Figure 5 shows an unloaded or idle state in which no pressure is applied to the proximal end surface 105 of the third portion 103. In this position, a small gap is present between thrust bearing protrusion 114 and recess 20 of the dose button 11. Further, a small gap is present between the dose button 11 and the dial grip 12 at the second friction type bearing B2. As the dose button 11 and the clutch sleeve 24 are in a proximal position, the drug delivery device 1 is in its dose setting mode. The switch 121 is not actuated because the free end of the lever 116 is in its most distal position. Figure 6 shows a switch point, i.e. a state in which the lever 116 is deflected to a degree actuating the switch 121 such that the electronic components are actuated or woken up. In this position, the gap between thrust bearing protrusion 114 and recess 20 of the dose button 11 is closed but the gap between the dose button 11 and the dial grip 12 at the second friction type bearing B2 is present indicating that the dose button 11 has not been pressed distally yet such that the drug delivery device 1 is still in its dose setting mode.

Figure 7 shows the state in which the third portion 103 has been pressed in further such that dose dispensing begins. In this state the lever 116 of the switch 121 is fully deflected. Comparing Figures 6 and 7 shows that the gap between the dose button 11 and the dial grip 12 at the second friction type bearing B2 is now closed indicating that the dose button 11 and the clutch sleeve 24 have been pressed distally such that the drug delivery device 1 is now in its dose delivery mode. Thus, the switch 121 is activated prior to switching the drug delivery device 1 is now in its dose delivery mode.

Again comparing Figures 6 and 7 shows that because the gap between thrust bearing protrusion 114 and recess 20 of the dose button 11 is already closed in the position of Figure 6, the axial distance between the optical flow sensor 112 and the proximal end face 19 of the dose button 11 remains unchanged in Figures 6 and 7 such that the optical flow sensor 112 is constantly in the same measuring distance to the proximal end face 19 of the dose button 11 as soon as the switch 121 is actuated.

However, other switches allowing similar purposes may be used. For example, switches may be used that actuate components, such as a sensor arrangement, by creating an electrical connection due to the axial relative movement of the first portion 101 and the second portion 102.

Reference Numerals

I drug delivery device 109 battery

10 housing 110 substrate (circuit board assembly)

I I dose button 111 electronic components

12 dose dial grip 112 optical flow sensor

13 number sleeve 113 distal wall

14 container 114 thrust bearing protrusion

15 needle 115 aperture

16 inner needle cap 116 lever

17 outer needle cap 117 spline

18 cap 117A lower part

19 proximal end face 118 inner lateral surface

20 recess 119 groove

21 stem 119A axial stop

22 first bearing surface 120 outer lateral surface

23 second bearing surface 121 switch

24 clutch sleeve

B1 first friction type bearing

100 electronic add-on module B2 second friction type bearing

101 first portion B3 third friction type bearing

102 second portion

103 third portion D distal direction

104 proximal facing surface P proximal direction

105 proximal end surface X first longitudinal axis (first portion)

106 spigot Y second longitudinal axis (drug

107 support structure delivery device)

108 backup friction surface

Claims

1. An electronic add-on module (100) for attachment to a drug delivery device (1), which drug delivery device (1) comprises a dose dial grip (12) and a dose button (11) with a proximal end face (19), the electronic add-on module (100) comprising:

• a first portion (101) configured to be attached to the dose dial grip (12) of the drug delivery device, such that the first portion (101) follows axial and rotational movements of the dose dial grip (12) when attached to the drug delivery device, wherein the first portion (101) has a first longitudinal axis (X) extending from a proximal side to a distal side,

• a second portion (102) coupled to the first portion (101), wherein the second portion (102) is axially moveable relative to the first portion (101) and parallel to the first longitudinal axis (X) but rotationally constrained to the first portion (101), wherein the second portion (102) comprises a thrust bearing protrusion (114) configured to apply a force onto the dose button (11) of the drug delivery device when axially moved along the first longitudinal axis (X) relative to the first portion (101),

• a third portion (103) coupled to the second portion (102) on a proximal side of the second portion, wherein the third portion (103) is free to rotate relative to the second portion (102) about the first longitudinal axis (X),

• a circuit board assembly and an electrical power source arranged within the first portion (101) and/or the second portion (102), and

• a sensor arrangement arranged in or on the second portion (102), wherein the sensor arrangement is electrically connected to the circuit board assembly and powered by the electrical power source, characterized in that the sensor arrangement comprises at least one optical flow sensor (112) facing towards the proximal end face (19) of the dose button (11), wherein the optical flow sensor (112) is configured to detect rotational movement between the second portion (102) of the electronic add-on module (100) and the proximal end face (19) of the dose button (11) of the drug delivery device (1).

2. The electronic add-on module (100) according to claim 1 , wherein the thrust bearing protrusion (114) has a diameter being less than 10% of the outer diameter of the first portion (101).

3. The electronic add-on module (100) according to claim 1 or 2, wherein the thrust bearing protrusion (114) has a distally facing rounded tip configured to form a friction type bearing (B3) with the proximal end face (19) of the dose button (11).

4. The electronic add-on module (100) according to any one of the preceding claims, wherein the thrust bearing protrusion (114) has a tip arranged concentrically with respect to the first longitudinal axis (X).

5. The electronic add-on module (100) according to any one of the preceding claims, wherein the at least one optical flow sensor (112) is provided on the distal side of the circuit board assembly.

6. The electronic add-on module (100) according to any one of the preceding claims, wherein the second portion (102) comprises a distal wall (113) having an aperture (115), a transparent window, a lens and/or a light pipe configured to provide a pathway from the at least one optical flow sensor to the proximal end face (19) of the dose button (11).

7. The electronic add-on module (100) according to any one of the preceding claims, wherein the first portion (101) comprises a first coupling element, for example a first spline (117), arranged on an inner lateral surface (118) of the first portion, wherein the second portion (102) comprises a second coupling element, for example a groove (119), arranged on an outer lateral surface (120) of the second portion, and wherein when the first coupling element and the second coupling element are engaged, relative axial movement between the second portion and the first portion is limited.

8. The electronic add-on module (100) according to any one of the preceding claims, wherein the third portion (103) is coupled to a spigot (106) of the second portion (102), wherein the spigot forms a second thrust bearing, and wherein the third portion is free to rotate about the spigot (106).

9. The electronic add-on module (100) according to claim 8, wherein the second portion (102) comprises a backup friction surface (108) arranged around the spigot (106), wherein the third portion (103) comprises a support structure (107) directed towards the second portion, and wherein the support structure is configured to contact the backup friction surface when the third portion is loaded off axis with respect to the first longitudinal axis (X), thereby forming an interface.

10. The electronic add-on module (100) according to any one of the preceding claims, wherein the first portion (101) comprises coupling elements (122) configured for releasable attachment to the dose dial grip (12).

11. An assembly comprising a drug delivery device (1) and an electronic add-on module (100) according to any one of the preceding claims configured for attachment to the drug delivery device (1), wherein the drug delivery device comprises:

• a housing (10) with a container (15) configured to receive a drug or a cartridge filled with a drug,

• a dose setting unit comprising a dose dial grip (12) at least rotationally moveable with respect to the housing (10) during dose setting and a dose button (11) with a proximal end face (19) at least axially moveable with respect to the housing (10) for causing dose dispensing, and

• a dose delivery unit comprising a plunger axially moveable with respect to the housing (10) during dose dispensing and at least one component part (24) rotationally constrained to the housing (10) during dose dispensing, characterized in that the dose button (11) comprises at least one friction type bearing interface with the dose delivery unit configured to prevent rotation of the dose button (11) during dose dispensing.

12. The assembly according to claim 11 , wherein the dose delivery unit and the dose button (11) form a first friction type bearing interface (B1), wherein the dose dial grip (12) and the dose button (11) form a second friction type bearing interface (B2), wherein, when the electronic add-on module (100) is attached to the drug delivery device (1), the thrust bearing protrusion (114) of the electronic add-on module (100) and the proximal end face (19) of the dose button (11) form a third friction type bearing interface (B3), and wherein during dose dispensing the frictional torque of the first friction type bearing interface (B1) is larger than the sum of the frictional torques of the second friction type bearing interface (B2) and third friction type bearing interface (B3).

13. The assembly according to claim 12, wherein the first friction type bearing interface (B1) is located radially outside of the third friction type bearing interface (B3) and the second friction type bearing interface (B2) is located radially outside of the first friction type bearing interface (B1).

14. The assembly according to any one of claims 12 or 13, wherein the force applied by the thrust bearing protrusion (114) onto the dose button (11) via the via the third friction type bearing interface (B3) during dose dispensing is reacted within the drug delivery device (1) by a primary load path reaction force via the first friction type bearing interface (B1) and by a secondary load path reaction force via the second friction type bearing interface (B2), and wherein the primary load path reaction force is larger than the secondary load path reaction force.

15. The assembly according to any one of claims 1 to 14, wherein the third friction type bearing interface (B3) comprises a central recess (20) in the proximal end face (19) of the dose button (11) forming a counter bearing surface for the thrust bearing protrusion (114).