WO2019001919A1

WO2019001919A1 - Accessory device with pairing feature

Info

Publication number: WO2019001919A1
Application number: PCT/EP2018/064915
Authority: WO
Inventors: Kalle Holck MADSEN
Original assignee: Novo Nordisk A/S
Priority date: 2017-06-27
Filing date: 2018-06-06
Publication date: 2019-01-03

Abstract

An add-on device adapted to be releasably attached to a drug delivery device is provided, the add-on device being adapted to determine, when mounted to a drug delivery device housing, an amount of movement of an indicator member, the add-on device comprising type identifier means adapted to detect a pre-defined type identifier on the drug delivery device. The add-on device is further adapted to be activated from an initial non-operational state to a permanent operational state corresponding to a pre-defined state, the pre-defined state cor- responding to an identified pre-defined type identifier.

Description

ACCESSORY DEVICE WITH PAIRING FEATURE

The present invention generally relates to medical devices for which the generation, collecting and storing of data are relevant. In specific embodiments the invention relates to devices and systems for capturing and organizing drug delivery dose data in a reliable and user- friendly way.

BACKGROUND OF THE INVENTION

In the disclosure of the present invention reference is mostly made to drug delivery devices comprising a threaded piston rod driven by a rotating drive member, such devices being used e.g. in the treatment of diabetes by delivery of insulin, however, this is only an exemplary use of the present invention.

Drug Injection devices have greatly improved the lives of patients who must self-administer drugs and biological agents. Drug Injection devices may take many forms, including simple disposable devices that are little more than an ampoule with an injection means or they may be durable devices adapted to be used with prefilled cartridges. Regardless of their form and type, they have proven to be great aids in assisting patients to self-administer injectable drugs and biological agents. They also greatly assist care givers in administering injectable medicines to those incapable of performing self-injections.

Performing the necessary insulin injection at the right time and in the right size is essential for managing diabetes, i.e. compliance with the specified insulin regimen is important. In order to make it possible for medical personnel to determine the effectiveness of a prescribed dosage pattern, diabetes patients are encouraged to keep a log of the size and time of each injection. However, such logs are normally kept in handwritten notebooks, and the logged information may not be easily uploaded to a computer for data processing. Furthermore, as only events, which are noted by the patient, are logged, the note book system requires that the patient remembers to log each injection, if the logged information is to have any value in the treatment of the patient's disease. A missing or erroneous record in the log results in a misleading picture of the injection history and thus a misleading basis for the medical personnel's decision making with respect to future medication. Accordingly, it may be desirable to automate the logging of injection information from medication delivery systems.

Though some injection devices integrate this monitoring/acquisition mechanism into the de- vice itself, e.g. as disclosed in US 2009/0318865 and WO 2010/052275, most devices of today are without it. The most widely used devices are purely mechanical devices being either durable or prefilled. The latter devices are to be discarded after being emptied and so inexpensive that it is not cost-effective to build-in electronic data acquisition functionality in the device it-self. Addressing this problem a number of solutions have been proposed which would help a user to generate, collect and distribute data indicative of the use of a given medical device.

For example, WO 2013/120776 describes an electronic supplementary device (or "add-on module") adapted to be releasably attached to a drug delivery device of the pen type. The device includes a camera and is configured to perform optical character recognition (OCR) on captured images from a rotating scale drum visible through a dosage window on the drug delivery device, thereby to determine a dose of medicament that has been dialled into the drug delivery device. A further external device for a pen device is shown in WO 2014/161952. As the external device is designed to detect signals or events originating from the device to which it is attached it is important that the two devices are correctly paired to each other to ensure proper operation and prevent incorrect measurements.

Having regard to the above, it is an object of the present invention to provide devices and methods allowing secure, easy and cost-effective operation of a drug delivery assembly comprising a user-mountable add-on module.

DISCLOSURE OF THE INVENTION

In the disclosure of the present invention, embodiments and aspects will be described which will address one or more of the above objects or which will address objects apparent from the below disclosure as well as from the description of exemplary embodiments.

Thus, in a first aspect of the invention an add-on device adapted to be releasably attached to a drug delivery device is provided. The drug delivery device comprises a housing, a drug- filled reservoir, a type identifier indicative of the type of drug contained in the reservoir, drug expelling means comprising dose setting means allowing a user to set a dose amount of drug to be expelled, actuation means actuatable between a first and a second state, the first state allowing a dose amount to be set, the second state allowing the drug expelling means to expel a set dose, and an indicator member adapted to move relative to the housing during dose setting and/or dose expelling, the amount of movement corresponding to the dose set and/or amount of drug expelled from the reservoir by the drug expelling means. The add-on device is adapted to determine, when mounted to a drug delivery device housing, an amount of movement of the indicator member relative to the housing, and comprises mounting means adapted to releasably mount the add-on device to the drug delivery device housing in a predetermined position, processor means and therewith associated sensor means adapted to determine dose amounts based on detected movement of the indicator member, and type identifier means adapted to detect at least one pre-defined type identifier. The add-on device is adapted to be activated from an initial (as supplied to the user) non-operational state to a permanent operational state corresponding to a pre-defined state, the pre-defined state corresponding to a pre-defined type identifier, and the processor means is adapted to activate the add-on device from the initial state to the permanent operational state when a predefined type identifier has been detected by the type identifier means, the operational state corresponding to the detected type identifier.

By this arrangement the pairing process takes place only once when the user mounts the device for the first time where it can be assumed that the user or a relevant health care person is fully focused and motivated to perform the pairing process, this reducing the risk of errors. Further, as the pairing is intended to take place when the add-on device is brand new just out of the box, the risk of sensor mal function due to e.g. wear, dirt or moisture is reduced.

The drug-filled reservoir may be embedded in the drug delivery device. The term "embed- ded" indicates that the reservoir cannot be removed from the drug delivery device without damaging the device, i.e. the device being "prefilled". Such a design would give freedom to arrange a type identifier on a desired place on the drug delivery device.

Alternatively, the drug-filled reservoir may be replaceable. In the latter case it has to be en- sured that the detected type identifier corresponds to the presently mounted drug-filled reservoir, e.g. by providing the type identifier on the drug-filled reservoir or by assuring that a given durable drug delivery device provided with a given type identifier can only be used in combination with a corresponding drug-filled reservoir, e.g. by means of a mechanical coding.

The type identifier means may be adapted to detect a plurality of pre-defined type identifiers, the add-on device being adapted to be activated from the initial non-operational state to a corresponding plurality of pre-defined states. The term "permanent" indicates that the add-on device is designed in such a way that once the add-on device has been set in a given operational state as a result of a performed pairing process, the operational state from the user's perspective cannot be changed, e.g. by mounting the add-on device on a different type of drug delivery device anew, and thus can be considered "permanent". The permanent state may be a "truly" permanent state in which the state cannot by any means be reset or changed or a "functional" permanent state in which the add-on device comprises administrator-accessible means allowing the permanent operational state to be changed, e.g. a code or software only known/accessible by the supplier or a responsible medical person.

To indicate a given type of drug the drug delivery device is provided with a drug-type specific identifier and the add-on device is in exemplary embodiments provided with corresponding sensor means allowing the identifier to be captured and recognized. For example, (i) the identifier may be in the form of a colour and the add-on device may comprise a colour sen- sor, (ii) the identifier may be in the form of geometrical features and the add-on device may comprise one or more mechanically actuated switches, (iii) the identifier may be in the form of a magnetic field and the add-on device may comprise a magnetic sensor, (iv) the identifier may be in the form of a barcode (2D or 3D) and the add-on device may comprise a barcode reader, (v) the identifier may be in the form of a numeric code and the add-on device may comprise a numeric code reader, (vi) the identifier may be in the form of a character code and the add-on device may comprise a character code reader, or (vii) the identifier may be a code embedded in a NFC chip and the add-on device may comprise a NFC reader. The latter type of coding would be suitable for use with e.g. a replaceable cartridge, this allowing the cartridge code to be read from a small distance, e.g. with the add-on device mounted on the proximal end of a pen drug delivery device. Alternative two or more different types of identifiers may be used.

In case the code is a simple code indicating a single property, e.g. a colour, only pre-defined identifiers can be detected and only pre-defined operational modes can be activated. Thus, alternatively or in addition, the type identifier may be in the form of a code coding for a number of pre-defined properties, e.g. drug type, drug concentration and/or drug name, this allowing the add-on device to be tailored to later-introduced variations of the platform device or cartridge. Alternatively or in addition, the add-on device software may be adapted to be updated with new pre-defined identifiers. The add-on device may be adapted to require a confirmation input before entering a predefined permanent state. For example, when a pre-defined identifier has been detected the add-on will initiate a confirmation process in which a pairing confirmation request is transmitted to an external device, e.g. via Bluetooth® to a smartphone provided with a corresponding app. When communication has been established the smartphone will indicate the detected type of pen and drug (or indicate that no pen has been identified), and the user will be requested to confirm that the detected type is correct, e.g. a given type of insulin in a given concentration. When confirmation is received the add-on device will enter a permanent operational condition corresponding to the detected and confirmed type of pen and drug and the user will receive a corresponding return-confirmation. As indicated above, a pre-defined identifier may be in the form of an identifier coding for a combination of pre-defined properties. Alternatively, the add-on device may be provided with a display and user operated input means allowing the confirmation process to take place. The add-on device may be provided with a mounting sensor adapted to be actuated between an off state and an on state when the add-on device is being been mounted in the predetermined position on a drug delivery device, the processor means being adapted to activate the add-on device from the initial state to the permanent operational state only when the mounting sensor is in the on state.

In exemplary embodiments the add-on device comprises a mounting sensor adapted to be actuated between an off and an on state when the add-on device is being mounted in the predetermined position on a drug delivery device, wherein the type identifier means is operated when the mounting sensor is actuated, and an error event is generated when no type identifier or a different type identifier than the one corresponding to the permanent operational state is detected. In this way sensor mal function issues due to e.g. wear, dirt or moisture is reduced can be addressed, e.g. by cleaning the sensor or replacing the add-on device.

In exemplary embodiments the add-on device comprises an actuation member adapted to engage and actuate the actuation means, the type identifier means being activated when the actuation member is actuated, this allowing an error event to be generated when no type identifier or a different type identifier than the one corresponding to the permanent operational state is detected. The indicator member may be adapted to rotate relative to the housing during dose setting and/or dose expelling, with the processor being adapted to determine an expelled or set dose amount based on determined rotational positions and/or rotational movement of the indicator member.

The indicator member may comprise a magnetic member, with the add-on device comprising magnet sensor means adapted to determine a property value corresponding to a rotational position and/or rotational movement of the indicator member. The amount of rotation of the indicator member may be determined during expelling of a dose of drug. Alternatively, the indicator member comprises a plurality of indicia, the currently observable indicia indicating to a user the size of a currently set dose amount of drug to be expelled, the add-on device comprising optical sensor means, e.g. a camera, adapted to determine a property value corresponding to the observable indicia.

In a further aspect of the invention an add-on device as described above is provided in combination with a drug delivery device as described above.

In a yet further aspect of the invention a method of pairing a combination of a first unit and a second unit is provided. The method comprises the steps of (i) providing a first unit comprising an identifier, (ii) providing a second unit comprising mounting means adapted to releasa- bly mount the second unit on the first unit in a predetermined position, and identifier means adapted to detect at least one pre-defined identifier, (iii) mounting the second unit on the first unit, (iv) detecting the identifier, and (v) if the detected identifier corresponds to a pre-defined identifier, activating the second unit from an initial non-operational state to a permanent operational state corresponding to a pre-defined state, the pre-defined state corresponding to a pre-defined identifier.

In an exemplary embodiment the first unit is in the form of a drug delivery device and the second unit is in the form of an add-on logging device. The drug delivery device comprises an embedded drug-filled reservoir, drug expelling means allowing a user to set a dose amount of drug to be expelled, with the identifier being a type identifier indicative of the type of drug contained in the reservoir. The add-on logging device comprises processor means and therewith associated sensor means adapted to determine set and/or expelled dose amounts, e.g. by magnetic or optical means as described above.

As used herein, the term "insulin" is meant to encompass any drug-containing flowable medicine capable of being passed through a delivery means such as a cannula or hollow needle in a controlled manner, such as a liquid, solution, gel or fine suspension, and which has a blood glucose controlling effect, e.g. human insulin and analogues thereof as well as non- insulins such as GLP-1 and analogues thereof. In the description of exemplary embodiments reference will be made to the use of insulin, however, the described module could also be used to create logs for other types of drug, e.g. growth hormone or drugs for haemophilia treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following embodiments of the invention will be described with reference to the drawings, wherein fig. 1A shows a drug delivery device,

fig. 1 B shows the drug delivery device of fig. 1 A with the pen cap removed,

fig. 2A shows an add-on device mounted on the housing of a drug delivery device, fig. 2B shows the assembly of fig. 2A with the pen cap removed,

fig. 3 shows the add-on device of fig. 2A,

fig. 4 shows a further embodiment of an add-on device adapted to be mounted on the housing of a drug delivery device,

figs. 5A and 5B show a first assembly of a drug delivery device and a therefor adapted addon dose logging device,

figs. 6A and 6B show a second assembly of a drug delivery device and a therefor adapted add-on dose logging device,

figs. 7A and 7B illustrate a pairing process between the drug delivery device and add-on dose logging device of fig. 5A,

fig. 8 shows a further embodiment of add-on device in combination with a drug delivery de- vice,

figs. 9A and 9B show cross-sectional views of the add-on device of fig. 8, and

fig. 10 shows in a sectional view an assembly comprising the add-on device of fig. 8 mounted on a drug delivery device. In the figures like structures are mainly identified by like reference numerals.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

When in the following terms such as "upper" and "lower", "right" and "left", "horizontal" and "vertical" or similar relative expressions are used, these only refer to the appended figures and not necessarily to an actual situation of use. The shown figures are schematic representations for which reason the configuration of the different structures as well as their relative dimensions are intended to serve illustrative purposes only. When the term member or element is used for a given component it generally indicates that in the described embodiment the component is a unitary component, however, the same member or element may alternatively comprise a number of sub-components just as two or more of the described compo- nents could be provided as unitary components, e.g. manufactured as a single injection moulded part. The term "assembly" does not imply that the described components necessarily can be assembled to provide a unitary or functional assembly during a given assembly procedure but is merely used to describe components grouped together as being functionally more closely related.

Before turning to embodiments of the present invention per se, an example of a prefilled drug delivery will be described, such a device providing the basis for the exemplary embodiments of the present invention. Although the pen-formed drug delivery device 100 shown in figs. 1A and 1 B may represent a "generic" drug delivery device, the actually shown device is a Flex- Touch® prefilled drug delivery pen as manufactured and sold by Novo Nordisk A S, Bag- svaerd, Denmark.

The pen device 100 comprises a cap part 107 and a main part having a proximal body or drive assembly portion with a housing 101 in which a drug expelling mechanism is arranged or integrated, and a distal cartridge holder portion in which a drug-filled transparent cartridge 1 13 with a distal needle-penetrable septum is arranged and retained in place by a nonremovable cartridge holder attached to the proximal portion. The cartridge holder comprises openings allowing a portion of the cartridge to be inspected, distal coupling means 1 15 allowing a needle assembly to be releasably mounted as well as proximal coupling means in the form of two opposed protrusions 1 14 allowing the cap 107 to be releasably mounted covering the cartridge holder. The cartridge is provided with a piston driven by a piston rod forming part of the expelling mechanism and may for example contain an insulin, GLP-1 or growth hormone formulation. A proximal-most rotatable dose setting member 180 serves to manually set a desired dose of drug and which can then be expelled when the button 190 is actuat- ed. The expelling mechanism comprises a helically rotatable scale drum member 105 with a plurality of indicia in the form of dose size numerals printed thereon, the dose size number corresponding to the currently set dose size being shown in display opening (or window) 102. Depending on the type of expelling mechanism embodied in the drug delivery device, the expelling mechanism may comprise a spring as in the shown embodiment which is strained during dose setting and then released to drive the piston rod when the release button is actuated. Alternatively the expelling mechanism may be fully manual in which case the dose member and the actuation button may be arranged to move proximally during dose setting corresponding to the set dose size, and then to be moved distally by the user to expel the set dose, e.g. as in a FlexPen® manufactured and sold by Novo Nordisk A/S. Although fig. 1 B shows a drug delivery device of the prefilled type, i.e. it is supplied with a pre-mounted cartridge and is to be discarded when the cartridge has been emptied, in alternative embodiments the drug delivery device may be designed to allow a loaded cartridge to be replaced, e.g. in the form of a "rear-loaded" drug delivery device in which the cartridge holder is adapted to be removed from the device main portion, or alternatively in the form of a "front-loaded" device in which a cartridge is inserted through a distal opening in the cartridge holder which is non-removable attached to the main part of the device.

Figs. 2A and 2B show a drug delivery assembly 1 with a pen-formed drug delivery device 200 on which an electronic add-on logging device (or module) 300 is mounted. The drug de- livery device may correspond to the above-described device 100 or it may be modified internally to cooperate with the attached logging module such that the logging module is capable of registering events indicative of expelling activity, e.g. the amount of drug expelled during an expelling event. More specifically, the logging module 300 comprises a body portion 310 and a ring-formed portion 320 allowing the module to be mounted on a generally cylindrical pen device. The body portion comprises electronic circuitry and sensor means allowing a property to be detected representing an amount of drug being expelled from the cartridge, as well as a display 330 for displaying data to a user. The ring portion comprises coupling means allowing the module to be securely and correctly mounted on the pen body. The electronic circuitry and the sensor means may in part be arranged in the ring portion. Fig. 3 shows the logging module 300 before being mounted, the module comprising coupling means 314 adapted to engage corresponding protrusions 1 14 (see fig. 1 B) on the drug delivery device. The logging module 300 may be adapted to detect expelling activity in a number of ways, e.g. the logging module may be adapted to determine the size of an expelled and/or set dose by detecting sounds generated by the expelling mechanism during dose setting and/or dose expelling. The drug delivery device may be provided with a window or an opening allowing the logging module to optically detect motion of a component of the expelling mechanism. Alternatively the drug delivery device may be provided with electronic circuitry transmitting signals to be received by the logging module, e.g. by RF transmission. In the shown embodiment the logging module comprises a sensor assembly adapted to measure magnetic fields. The drug delivery device is provided with an indicator element comprising a magnet moving together therewith, the magnet being configured to generate a spatial magnetic field which relative to the sensor assemblies varies corresponding to the spatial orientation of the magnet and thus the indicator element, thereby generating a spatial magnetic field which varies during movement of the indicator element, e.g. rotation during an expelling event. The logging module further comprises processor means configured to determine on the basis of measured values from the sensor assembly rotational movement of the indicator element on the basis of which the size of an expelled dose can be calculated. In the shown embodiment the processor is adapted to calculate the size of an expelled dose based on the captured data during dose expelling and control the display 330 to show the calculated value to a user. Alternatively or in addition the captured data and/or the calculated values may be transmitted to an external device for further processing and display, e.g. by NFC or Bluetooth® to a smartphone device. The data may be fully or partly encrypted. A sensor is provided to detect whenever the add-on device is attached to or detached from a pen. A more detailed description of this concept is disclosed in WO 2014/161952 which is hereby incorporated by reference. Fig. 4 shows a further embodiment of an add-on device 400, the module comprising a housing 401 , a display window 441 , and proximally arranged user accessible add-on dial member 480 and user accessible add-on release button 490. The add-on device housing forms a bore 405 with a distally-facing opening 408 adapted to receive the generally cylindrical proximal portion of a pen device of the above-described type, the bore being defined by a gener- ally cylindrical mounting surface adapted to face the pen device. A firm grip between the two structures is provided by a locking structure 404 on the add-on device adapted to engage the pen device and securing a firm grip. A sensor is provided to detect when the add-on device is mounted on or removed from a pen device. The add-on device is adapted to determine the amount of drug expelled from the drug delivery device during an expelling event, i.e. the subcutaneous injection of a dose of drug. In the shown embodiment determination of an expelled dose of drug is based on determination of scale drum position at the beginning and at the end of the expelling event. To determine the rotational position of the scale drum 105, 205 the dose numerals as seen in the display open- ing/window 102, 202 may be captured and used, this allowing an unmodified pen device to be used. Actual determination of scale drum position may be performed using e.g. optical character recognition (OCR) or template matching. For the shown embodiment the add-on device covers the display window for which reason the current dose size shown in the display window has to be captured and displayed on the electronic display 441 . Alternatively, the add-on device may be designed to allow the user to view the display window.

The add-on device 400 is provided with a user accessible add-on dial member 480 adapted to engage the pen dose setting member 180, and a user accessible add-on release button 490 adapted to engage the pen release button 190, this arrangement allowing sensors and switches to be incorporated in the add-on device for detecting motion of the dose setting member and the release button. A more detailed description of the add-on device 400 as well as logging devices based on scale drum image capture in general is disclosed in e.g. patent application EP2017/062905 which is hereby incorporated by reference.

The logging module 400 may be adapted to detect expelling activity in a number of alterna- tive ways, e.g. the logging module may be adapted to determine the size of an expelled and/or set dose by detecting sounds generated by the expelling mechanism during dose setting and/or dose expelling. The drug delivery device may be provided with a window or an opening allowing the logging module to optically detect motion of a component of the expelling mechanism. Alternatively the drug delivery device may be provided with electronic cir- cuitry transmitting signals to be received by the logging module, e.g. by RF transmission. In case the add-on device is designed to allow the user to view the display window during dose setting, an electronic display can be dispensed with. However, a display may be provided to allow the user to retrieve logging data directly from the add-on device without having to rely on an external device.

In an exemplary embodiment the logging module 400 comprises a sensor assembly adapted to measure magnetic fields. As in the embodiment of fig. 2A the drug delivery device is provided with an indicator element comprising a magnet moving together therewith, the magnet being configured to generate a spatial magnetic field which relative to the sensor assemblies varies corresponding to the spatial orientation of the magnet and thus the indicator element, thereby generating a spatial magnetic field which varies during movement of the indicator element, e.g. rotation during an expelling event. Whereas in the embodiment of fig. 2A a magnet is arranged in the distal portion of the expelling assembly, for a drug delivery device adapted to cooperate with a proximally mounted add-on device a magnet is arranged in the proximal portion of the expelling assembly. Prefilled drug delivery devices, e.g. of the type described above with reference to figs. 1 and 2, will often be used as a platform device to be used in combination with different types of drugs, e.g. different types of drugs per se or the same type of drug in different concentrations as is the case for the FlexTouch® and FlexPro® family of devices from Novo Nordisk A/S. For different concentrations of the same drug the scale drum will typically be different just as for different types of drug the units of measurement may be different, e.g. "mg" for GLP-1 drugs instead of "IU" for insulin, resulting in a different scale drum. Correspondingly, if an add-on device can be mounted on drug delivery devices utilized for different types or concentrations of drug it is necessary that a given add-on device can only be used in combination with the drug for which it is intended (e.g. fast or long acting insulin) or, alternatively, the device may be generic and adapt itself to the actual drug or concentration if necessary.

A "generic" add-on device may adapt itself in different ways. For example, a given add-on device may be adapted to detect a number of pre-defined type identifiers, each identifier providing that the add-on device is set in a corresponding operational mode. Indeed, using this concept the "generic" add-on device may be adapted to recognize only a single type identifier. As appears, by this set-up only pre-defined identifiers can be detected and only pre-defined operational modes can be activated. Thus, alternatively or in addition, the type identifier may be in the form of a code coding for a number of pre-defined properties, e.g. drug type, drug concentration and/or drug name, this allowing the add-on device to be tailored to later-introduced variations of the platform device.

To indicate a given type of drug the drug delivery device is provided with a drug-type specific identifier and the add-on device is in exemplary embodiments provided with corresponding sensor means allowing the identifier to be captured and recognized. For example, (i) the identifier may be in the form of a colour and the add-on device may comprise a colour sensor, (ii) the identifier may be in the form of geometrical features and the add-on device may comprise one or more mechanically actuated switches, (iii) the identifier may be in the form of a magnetic field and the add-on device may comprise a magnetic sensor, (iv) the identifier may be in the form of a barcode (2D or 3D) and the add-on device may comprise a barcode reader, (v) the identifier may be in the form of a numeric code and the add-on device may comprise a numeric code reader, or (vi) the identifier may be in the form of a character code and the add-on device may comprise a character code reader. Alternative two or more different types of identifiers may be used. A generic add-on device may thus be adapted to be attached to a number of different members of a device platform, each member containing a different type of drug or different concentrations of a given type of drug. When a prefilled drug delivery has been emptied, or when it for other reasons is desirable to change the device, then the add-on device can be trans- ferred to a new drug delivery device.

A generic add-on device is intended to detect the type of prefilled drug delivery device to which it is attached, and thereby the contained type of drug, when it is attached to the drug delivery device. The device type may be detected each time the add-on device is attached to a drug delivery device or each time data representing the size of a dose amount being set or expelled is captured.

As the dose related information determined and presented, directly or indirectly, to the user by the add-on device thus relies on the correct type identifier having been identified, the iden- tification process should be reliable in respect of the sensor system embodied in the add-on device per se as well as simple in respect of the needed involvement of the user during initial pairing set-up and subsequent daily use.

Addressing the above issue, the present invention provides in different aspects a concept for safe and cost-effective pairing of an add-on device and a corresponding drug delivery device onto which the add-on device is mounted.

More specifically, in an exemplary embodiment the drug delivery device comprises a housing, an embedded drug-filled reservoir, a type identifier indicative of the type of drug con- tained in the reservoir, and drug expelling means. The drug expelling means comprises dose setting means allowing a user to set a dose amount of drug to be expelled, actuation means actuatable between a first and a second state, the first state allowing a dose amount to be set, the second state allowing the drug expelling means to expel a set dose, and an indicator member adapted to move relative to the housing during dose setting and/or dose expelling, the amount of movement corresponding to the dose set and/or amount of drug expelled from the reservoir by the drug expelling means.

The add-on device is adapted to determine, when mounted to a corresponding drug delivery device housing, an amount of movement of the indicator member relative to the housing. In an exemplary embodiment the add-on device comprises mounting means adapted to releas- ably mount the add-on device to the drug delivery device housing in a predetermined posi- tion, processor means and therewith associated sensor means adapted to determine dose amounts based on detected movement of the indicator member, and type identifier means adapted to detect at least one pre-defined type identifier. The add-on device is adapted to be activated from an initial non-operational state to a permanent operational state corresponding to a pre-defined state, the pre-defined state corresponding to a pre-defined type identifier, and the processor means is adapted to activate the add-on device from the initial state to the permanent operational state when a pre-defined type identifier has been detected by the type identifier means, the operational state corre- sponding to the detected type identifier.

With reference to figs. 5A and 5B a first assembly of a pre-filled pen-formed drug delivery device 200 and a therefor adapted add-on dose logging device 500 will be described. The add-on device is adapted to be mounted on the proximal end portion of the pen device and is provided with dose setting and dose release means 580 covering the corresponding means on the pen device, this corresponding to the embodiment of fig. 4. In the shown embodiment the add-on device comprises a colour sensor adapted to detect the colour of the proximal dose release button 290 on the pen device, the dose button colour indicating the type of drug.

With reference to figs. 6A and 6B a second assembly of a pre-filled pen-formed drug delivery device 200 and a therefor adapted add-on dose logging device 600 will be described. The add-on device is adapted to be mounted centrally on the pen device and does thus not interfere with normal operation of the pen device, this corresponding to the embodiment of fig. 3. In the shown embodiment the pen device is provided with a mechanical drug type coding formed as part of the cartridge holder 210, the add-on device comprising an array of switches adapted to engage the geometrical coding structures when the add-on device is mounted on the pen device, e.g. a number of switches each having a non-activated and an activated state. In an alternative embodiment the add-on device may be adapted to detect an identifier arranged on the drug-filled reservoir, this allowing a durable drug delivery device to be used.

With reference to figs. 7A and 7B an example of an initial pairing process between an end- mounted add-on logging device 500 and a corresponding prefilled pen-formed drug delivery device 200 comprising a given type of drug formulation will be described. In the shown ex- ample the pen device comprises a drug X and is provided with a release button 291 in a corresponding specific colour. The add-on device is supplied to the user in an initial non-operational state and is adapted to be activated to a permanent operational state corresponding to a pre-defined state after the add-on device has been mounted on the pen device (fig. 7A). When the add-on device has been correctly mounted the pairing/activation process may start automatically, e.g. by a switch being activated, or the user may have to start the process, e.g. by actuating the proximal release button 580. When a pre-defined identifier has been detected, e.g. the colour of release button 291 , the add-on will initiate the confirmation process in which a pairing confirmation request is transmitted to an external device 700, e.g. via Bluetooth® to a smartphone provided with a corresponding app. When communication has been established the smartphone will indicate the detected type of pen and drug 705 (or indicate that no pen has been identified), and the user will be requested to confirm that the detected type is correct, e.g. a given type of insulin in a given concentration. When confirmation is received the addon device will enter a permanent operational condition corresponding to the detected and confirmed type of pen and drug and the user will receive a corresponding return- confirmation. As indicated above, a pre-defined identifier may be in the form of an identifier coding for a combination of pre-defined properties.

Turning to figs. 8 and 9A a further exemplary embodiment of an add-on dose logging device 800 adapted to be mounted on a pen-formed drug delivery device 900 will be described in greater detail. The drug delivery device essentially corresponds to the drug delivery devices described with reference to fig. 1A and thus comprises a housing 901 , a rotatable dose setting member 980 allowing a user to set a dose amount of drug to be expelled, a release member 990 actuatable between a proximal dose setting position and a distal dose release position, a scale drum as well as a reset tube. In order to cooperate with the add-on logging device 800 the drug delivery device has been modified to comprise a generally ring-formed magnet 960M attached to or formed integrally with the reset tube 960 proximal end (see fig. 10), the magnet serving as an indicator rotating during expelling of a dose amount, the amount of rotational movement being indicative of the size of the expelled dose amount. Fur- ther, the housing proximal portion 902 has been provided with a number of protuberances 901 P just distally of the dose setting member serving as a coupling means for the add-on device. In the shown embodiment three coupling protrusions are located equidistantly on the housing. The add-on device 800 comprises an outer assembly releasably attachable to the drug delivery device housing as well as an inner assembly (see below). The outer assembly comprises a generally cylindrical distal coupling portion 819 defining a general axis for the add-on device, the coupling portion having a generally cylindrical bore adapted to receive a corresponding generally cylindrical coupling portion of the drug delivery pen 900 and being adapted to be mounted axially and rotationally locked on the drug delivery housing by means of a number of bayonet coupling structures 815 adapted to engage the corresponding coupling protuberances 901 P on the pen housing and releasably snap into engagement. The add-on device further comprises a proximal dose setting member 81 1 mounted freely rotata- ble on the coupling portion and which is coupled to the pen dose setting member 980 such that rotational movement of the add-on dose setting member 81 1 in either direction is trans- ferred to the pen dose setting member. The add-on device further comprises a dose release member 890 which during dose setting rotates with the dose setting member 81 1 . A first biasing spring 818 supported on an inner circumferential flange on the dose setting member provides a proximally directed biasing force on the dose release member 890. The inner and outer assemblies are rotationally locked to each other during dose setting, but rotationally de- coupled from each other during dose expelling.

The inner assembly comprises (see fig. 9A) an inner housing 881 and a therein arranged axially moveable sensor module 860. The inner housing comprises a proximal wall portion 882 from which a hollow transmission tube structure 883 extends proximally, a distal inner cir- cumferential flange portion 884 serving as support for a second biasing spring 868, and a distally extending circumferential skirt portion 887 adapted to engage the pen dose setting member drive grooves 982 (see fig. 8) to thereby rotationally lock the two members to each other, the engagement allowing some axial play during mounting and operation of the add-on device. In the shown embodiment the structures engaging the dose setting member drive grooves 982 are in the form of flexible fingers 851 allowing for ease of mounting. The hollow tube 883 comprises at the proximal end a number of flange portions 888 having distally facing stop surfaces adapted to engage a circumferential inner flange 895 of the dose release member 890, as well as a number of axially oriented splines adapted to engage the locking splines 896 on the dose release member 890 to thereby rotationally lock the inner assembly to the dose release member and thus the outer assembly.

The sensor module 860 comprises a sensor portion and a proximally extending actuation rod portion 862. The sensor portion comprises a generally cylindrical sensor housing 861 in which the electronic circuitry 865 (see below) is arranged. The sensor housing comprises a distal spacer cap 864 covering the magnet sensors and being adapted to engage the pen actuation member 990. In the initial dose setting mode (i.e. with the dose release member 890 in the initial proximal position) the sensor housing is biased proximally by the second bias spring 868 into engagement with the inner housing proximal wall portion 882 and with the actuation rod 862 extending from the transmission tube 883 into the interior of the dose release member 890, an axial gap being formed between the proximal end 863 of the actuation rod and an inner actuation surface of the dose release member.

The electronic circuitry comprises electronic components including processor means, sensors 866, an activation switch, e.g. a dome switch actuated by an axial force exerted on the actuation rod portion 862, wireless transmitter/receiver means and an energy source.

The sensors comprise a number of magnetometers 866M adapted to measure a magnetic field generated by the pen magnet, this allowing rotational movement of the pen reset tube and thus the size of an expelled dose to be determined, see e.g. WO 2014/0161952. Further sensor means is provided allowing the type of the device to be recognized, e.g. a light emit- ter and a colour sensor adapted to determine the colour of the pen release member, the colour serving as an identifier for the drug type contained in the prefilled pen device. The colour sensor and light emitter may operate with visible (to the human eye) light or light fully or partly outside the visible spectrum. The processor means may be in the form of a generic microprocessor or an ASIC, non-volatile program memory such as a ROM providing storage for embedded program code, writable memory such as flash memory and/or RAM for data, and a controller for the transmitter/receiver.

A more detailed description of the embodiment of figs. 8, 9A and 9B and the operation thereof can be found in EP application 17205062.7 which is hereby incorporated by reference.

As described above with reference to figs. 7A and 7B the type identifier means is in the form of colour sensing circuitry allowing the colour of release button 890 to be determined when the add-on release button 990 is actuated, this allowing a pairing process to take place when the add-on device is mounted on the pen device 900. Indeed, the pairing process could be initiated without the add-on device being mounted on the pen device, however, this would not result in a pre-defined button colour being identified and thus not result in a successful pairing.

As the pairing process takes place only once when the user mounts the device for the first time it can be assumed that the user or a relevant health care person is fully focused and motivated to perform the pairing process, this reducing the risk of errors. Further, as the pair- ing takes place when the add-on device is brand new just out of the box, the risk of sensor mal function due to e.g. wear, dirt or moisture is reduced.

As the add-on device is intended to be used for a longer period and thus to be mounted on a new pen device numerous times, there may be a risk of the device being mounted on an incorrect type of pen, i.e. a pen device belonging to the same platform family but containing a different drug. Correspondingly, the add-on device may be adapted to perform an identifier check each time the device is mounted on a (new) pen or each time it is actuated by the user. If a different or no identifier is detected an error message will be transmitted to the external device allowing the user to take appropriate action, e.g. cleaning the sensor and/or the pen device or mounting the add-on device on a correct type of pen device.

In the above it is described that the add-on device from its initial non-operational state can enter a permanent state corresponding to a detected type identifier. The permanent state may be a "truly" permanent state in which the state cannot by any means be reset or changed or a "functional" permanent state in which the add-on device by "special means" to which the user has no access can be reset. The special means may e.g. be a different means of communication or it may be a code known only by e.g. the supplier or a responsible medical person.

In the above description of exemplary embodiments, the different structures and means providing the described functionality for the different components have been described to a degree to which the concept of the present invention will be apparent to the skilled reader.

The detailed construction and specification for the different components are considered the object of a normal design procedure performed by the skilled person along the lines set out in the present specification.

Claims

1. An add-on device (300, 400, 500, 600, 800) adapted to be releasably attached to a drug delivery device (200), the drug delivery device comprising: - a housing (201 , 901 ),

a drug-filled reservoir (213),

a type identifier (291 ) indicative of the type of drug contained in the reservoir, drug expelling means comprising:

dose setting means (280, 980) allowing a user to set a dose amount of drug to be expelled,

actuation means (290, 990) actuatable between a first and a second state, the first state allowing a dose amount to be set, the second state allowing the drug expelling means to expel a set dose, and

an indicator member (205) adapted to move relative to the housing during dose setting and/or dose expelling, the amount of movement corresponding to the dose set and/or amount of drug expelled from the reservoir by the drug expelling means, the add-on device being adapted to determine, when mounted to a drug delivery device housing, an amount of movement of the indicator member relative to the housing, the add-on device comprising: mounting means (314, 404, 815) adapted to releasably mount the add-on device to the drug delivery device housing in a predetermined position,

- processor means (860) and therewith associated sensor means (866) adapted to determine dose amounts based on detected movement of the indicator member, and

type identifier means (866) adapted to detect at least one pre-defined type identifier, wherein:

- the add-on device is adapted to be activated from an initial non-operational state to an operational state corresponding to a pre-defined state, the pre-defined state corresponding to a pre-defined type identifier,

the processor means is adapted to activate the add-on device from the initial state to the operational state when a pre-defined type identifier has been detected by the type identi- fier means, the operational state corresponding to the detected type identifier, and

the operational state is a permanent operational state.

2. An add-on device as in claim 1 , wherein:

the type identifier means (860) is adapted to detect a plurality of pre-defined type identifiers, and

- the add-on device is adapted to be activated from the initial non-operational state to a corresponding plurality of pre-defined states.

3. An add-on device as in claim 1 or 2, comprising administrator-accessible means allowing the permanent operational state to be changed.

4. An add-on device as in claim 1 or 2, wherein the permanent operational state cannot be changed.

5. An add-on device as in any of claims 1 -4, wherein the type identifier means com- prises at least one of:

a colour sensor (866),

one or more mechanically actuated switches,

a magnetic sensor,

a barcode reader,

- a numeric code reader,

a character code reader, and

an NFC reader.

6. An add-on device as in any of claims 1-5, comprising: a mounting sensor adapted to be actuated between an off and an on state when the add-on device is being been mounted in the predetermined position on a drug delivery device, wherein the processor means can only activate the add-on device from the initial state to the permanent operational state when the mounting sensor is in the on state.

7. An add-on device as in any of claims 1-5, comprising: a mounting sensor adapted to be actuated between an off state and an on state when the add-on device is being mounted in the predetermined position on a drug delivery device, wherein:

the type identifier means is operated when the mounting sensor is actuated, and an error event is generated when no type identifier or a different type identifier than the one corresponding to the permanent operational state is detected.

8. An add-on device as in any of claims 1-7, comprising an actuation member (490, 890) adapted to engage and actuate the actuation means, the type identifier means being activated when the actuation member is actuated.

9. An add-on device as in claim 8, wherein an error event is generated when no type identifier or a different type identifier than the one corresponding to the permanent operational state is detected.

10. An add-on device as in any of claims 1-9, wherein:

the indicator member (205) is adapted to rotate relative to the housing during dose setting and/or dose expelling, and

the processor means (860) is adapted to determine an expelled or set dose amount based on determined rotational positions and/or rotational movement of the indicator member.

1 1 . An add-on device as in claim 10, wherein:

the indicator member comprises a magnetic member, and

the add-on device comprises magnet sensor means (866M) adapted to determine a property value corresponding to a rotational position and/or rotational movement of the indicator member.

12. An add-on device as in claim 10 or 1 1 , wherein the amount of rotation of the indicator member during expelling of a dose of drug is determined.

13. An add-on device as in claim 10, wherein:

- the indicator member comprises a plurality of indicia, the currently observable indicia indicating to a user the size of a currently set dose amount of drug to be expelled, and the add-on device comprises optical sensor means adapted to determine a property value corresponding to the observable indicia.

14. A method of pairing a combination of a first unit (500, 800) and a second unit (600, 900), comprising the steps of: providing a first unit (200) comprising an identifier (291 ), providing a second unit (500, 600) comprising:

mounting means adapted to releasably mount the second unit on unit in a predetermined position, and

identifier means adapted to detect at least one pre-defined identifier, mounting the second unit on the first unit, detecting the identifier, and

(v) if the detected identifier corresponds to a pre-defined identifier, activating the second unit from an initial non-operational state to a permanent operational state corresponding to a pre-defined state, the pre-defined state corresponding to a pre-defined identifier.

15. A method as in claim 14, wherein the first unit is a drug delivery device (200) and the second unit is an add-on logging device (500, 600), the drug delivery device comprising: a drug-filled reservoir,

- drug expelling means allowing a user to set a dose amount of drug to be expelled, the identifier being a type identifier indicative of the type of drug contained in the reservoir, the add-on logging device comprising:

- processor means and therewith associated sensor means adapted to determine set and/or expelled dose amounts.