Injection Monitoring Module

Abstract

The injection monitoring module is adapted and configured to be removably mounted on the end of an injection pen having a body connected to a dose setting wheel and an injection actuation mechanism. The dose setting wheel is rotatable about a central longitudinal axis of the pen injection system during dose setting and is fixed against rotation during injection. The injection monitoring module comprises a hollow main body having a distal body portion extending around an outer surface of the injection pen body at a location distal from the dose setting wheel, the distal body portion comprising diameter changing means configured to dynamically change an inner diameter of a central bore of the distal body portion from a first value to a second value different from the first value upon mounting the injection monitoring module on the injection pen body.

Description

[Technical Field]

[0001] The present invention relates generally to monitoring systems for injectable drug delivery devices, and more particularly to injection monitoring for injection pen systems. [Background technology]

[0002] Injection monitoring is a well-known field related to injectable drug delivery devices, for example, particularly infusion systems. Over time, and more recently, such monitoring systems have transitioned to injection pen systems for delivering drugs, enabling users of such pen injection systems, as well as healthcare professionals involved in the treatment and follow-up of such patients, to more closely monitor the patient's injection regime and often the actual dose administered, with the intent of providing better healthcare outcomes. These developments have been accompanied by an associated increase in the use of software and portable communication devices, such as tablets or smartphones, that are programmed to receive information from and interact with the monitoring system to provide the user or healthcare professional with information on the fly or at regular intervals via an appropriate communication unit included in the monitoring system.

[0003] For example, with particular reference to pen injection systems, one long-standing challenge has been to provide an easy-to-use, reliable, and reasonably fail-safe system that can be adapted to the many different variations of such commercially available pen injection systems. Previous attempts to provide such monitoring systems have typically involved adapting the body of the pen injection system by including electronic components along with one or more sensors therein. However, one of the major drawbacks of such systems is that, when all electronic components are incorporated, they make the final product rather bulky and unwieldy, thus making it more difficult for the user to use. Furthermore, such modified systems tend to be specific to a given brand or manufacturer and therefore of little or no use with other manufacturers. Furthermore, to overcome the bulkiness and unwieldy nature of modified pen injection systems, there has long been a trend to attempt to minimize the overall volume of the injection pen body as much as possible through the miniaturization of complex electronic components. However, this results in its own problems, particularly with regard to electromagnetic interference between the various components, due to the close proximity of multiple circuits providing the necessary or desired integrated functionality. Moving the sensors in such monitoring systems further away from the source of electromagnetic interference only complicates matters further, potentially leading to erroneous readings or requiring additional systems to compensate for the physical separation of the sensors from other electronic components, such as microcontrollers that are designed to control and command the various components and manage their interactions.

[0004] The injection pen systems in question are well known and typically include a proximally located dose setting wheel and an injection actuation mechanism, with the dose setting wheel rotatable about the central longitudinal axis of the pen injection system. The user rotates the wheel to select the dose of medication to be administered. The pen is typically configured to perform an injection, either mechanically or electromechanically, upon actuation of the injection actuation mechanism. Such an injection actuation mechanism is very commonly a simple press or push button in mechanical or electrical contact with a dispensing mechanism located within the pen injection system, which, when pressed, causes the injection mechanism to fire and inject the medication contained within the pen injection system. In some pen injector systems, the dose setting wheel is configured to rotate not only during dose setting but also during injection.

[0005] For example, WO 2021 / 260404 (Patent Document 1) discloses an injection monitoring module adapted and configured to be removably mounted on the proximal tip of an injection pen system for delivering a drug, the injection pen system having a pen body, a dose setting wheel located proximally and connected to the body, and an injection actuation mechanism, the dose setting wheel being rotatable about the longitudinal central axis of the pen injection system during dose setting and fixed so as not to rotate during injection. The injection monitoring module, in particular, a hollow main body adapted and configured to be coaxially mounted about an actuation mechanism body of an actuation mechanism pen injection system, the hollow main body having a longitudinal central bore with proximal and distal tips and a longitudinal central axis; a magnetic field generating means disposed on or within the hollow main body at the proximal tip of the longitudinal central bore; an injection monitoring system comprising at least one or more magnetic sensors disposed at a proximal tip of the bore of the hollow main body; the hollow main body further comprises an inner sleeve disposed within the longitudinal central bore and configured to frictionally engage an outer surface of the dose setting wheel during dose setting and to co-rotate with the dose setting wheel about the longitudinal central axis without axial translation along said longitudinal central axis; The inner sleeve is connected to an injection monitoring system. The connection between the inner sleeve and the injection monitoring system is adapted and configured to co-rotate both the inner sleeve and the injection monitoring system about the central longitudinal axis during dose setting, and to translate the injection monitoring system along the central longitudinal axis but not rotate the injection monitoring system about the central longitudinal axis during injection and / or ejection of a drug from the pen injection system.

[0006] As used herein, the terms "pen injection system" and "injection pen system" are used interchangeably to designate a pen-shaped injection system that is generally held in one hand, although such systems are well known in their own right, commercially available, and used to treat many different medical indications. Furthermore, these systems are often designed for public use to allow users needing treatment for a given medical indication to self-inject a drug, which may be selected from a number of therapeutically or biologically active substances or combinations of substances, and in this case, it has become common for patients suffering from or susceptible to such a medical indication to carry these devices with them when they may need them.

[0007] The injection pen system includes a proximally located dose setting wheel and an injection actuation mechanism, and the injection monitoring module is adapted and configured to be removably attached to the injection pen system. The dose setting wheel rotates about the central longitudinal axis of the pen injection system, allowing the user to set a dose of medication for injection. The dose setting wheel is typically rotatable in both clockwise and counterclockwise directions, which typically correspond to increments of the selected dose to be administered and decrements of the selected dose, respectively. The injection actuation mechanism is often represented by a push button, typically located proximal to the dose setting wheel and, in most injection pens, at the proximal tip of the injection pen system. After setting the dose, the user of the injection system pushes the injection actuation mechanism distally, which typically mechanically or electromechanically drives a piston connected to a plunger, expelling the medication from a chamber in the injection pen body through an appropriate injection site, e.g., skin, fatty tissue, or muscle, depending on the type of medication the user wishes to administer. The dose setting wheel is often, but not necessarily, coupled to the injection drive mechanism so that it also rotates as the injection of the medication progresses. The manner in which such injection systems function is well known per se in the art. However, monitoring modules such as those described in US Pat. No. 5,649,293 are typically mounted on pen injection systems in which the dose setting wheel does not rotate during the delivery / injection phase of operation.

[0008] The injection monitoring module is adapted and configured to be removably attached to the proximal tip of such an injection pen system. The terms "removably attached," "removably attachable," "removably mounted," or "removably attachable," as used herein, should be understood to refer to the ability to attach or mount and subsequently remove the injection monitoring module, for example, when transferring the injection monitoring module to another pen injection system, or, for example, if the monitoring module is damaged during use and requires replacement. Such attachment and subsequent removal may be achieved by a coupling means on the monitoring module that releasably engages the proximal tip of the pen injection system, for example, via frictional or elastic engagement, or other releasable fastening means, such as a clip, strap, thread and corresponding fastening ring, and engages either the dose setting wheel or the injection actuation mechanism, or both.

[0009] The hollow main body of the injection monitoring module has a longitudinal central bore with a proximal tip and a distal tip, the bore being sized to allow coaxial mounting of the hollow main body over the body of the pen injection system.

[0010] The hollow main body further comprises an inner sleeve disposed within the central longitudinal bore and configured to frictionally engage an outer surface of the dose setting wheel during dose setting and to co-rotate with the dose setting wheel about the central longitudinal axis without axial translation along said central longitudinal axis, such that when the inner sleeve is rotated, the dose setting wheel also rotates in the same direction and with the same or identical degree of rotation. In this way, the inner sleeve can be said to co-rotate with the dose setting wheel.

[0011] The hollow main body is suitably constructed from any suitable material, for example, a durable polymer or plastic material, such as high-density or high-impact polypropylene. Advantageously, the hollow body is constructed from a transparent, translucent, or opaque material to allow the user to grasp and recognize any visual cues, such as light-emitting diodes, which may be provided on or incorporated into the injection monitoring module and which may optionally be used to indicate various states of operation of the injection monitoring system. Similarly, the inner sleeve is also suitably constructed from a suitable material, for example, a durable polymer or high-impact plastic material, such as ABS.

[0012] The inner sleeve is also further connected or coupled to an injection monitoring system. The connection or coupling between the inner sleeve and the injection monitoring system is adapted and configured to co-rotate both the inner sleeve and the injection monitoring system about a central longitudinal axis during dose setting, and to translate the injection monitoring system along the central longitudinal axis but not rotate said injection monitoring system about said central longitudinal axis during injection and / or delivery of a medication from the pen injection system. To this end, the connection between the inner sleeve and the injection monitoring system is configured for selective rotation about and then selective translation along said central longitudinal axis, the two movements being mutually exclusive of each other.

[0013] The hollow main body further comprises a distal body portion that extends around and frictionally engages the outer surface of the body of the injection pen system at a location distal from the dose setting wheel. In this way, the hollow main body is maintained in position on and around the pen injection system distal from the dose setting wheel, which consequently can rotate freely within the bore of the hollow main body. Such a frictional, resilient configuration can be provided, for example, by a suitable elastomeric coating or deposit disposed on the inner circumferential surface of the hollow main body, e.g., in one or more sections, or alternatively, as a continuous, continuous, or partially continuous coating deposited on said inner circumferential surface of the hollow main body. The purpose of such a frictional, resilient coating or deposit is to provide a frictional grip between the distal body portion and the injection pen body in order to maintain proper positioning of the hollow distal body portion relative to the injection pen body. Suitable types of elastomeric materials capable of providing a corresponding frictional engagement are known per se in the art.

[0014] The injection monitoring module also includes an injection monitoring system that includes at least one or more magnetic sensors and is disposed at the proximal tip of the bore of the hollow main body.

[0015] Despite the utility of the device described in U.S. Patent No. 6,277,523, Applicant has discovered that some pen injection systems on the market include pen bodies that are shaped near the proximal end of the injection pen in a manner that can make it difficult for a user, particularly among younger or frail or otherwise disabled users of those injection pen systems, to properly attach or reposition an injection monitoring module to, or correspondingly remove it from, the proximal end of the pen body. For example, injection pen systems such as the FlexTouch®, FlexTouch®, Connect™, and Ozempic® all include pen bodies with an enlarged outer diameter at the proximal end of the pen body compared to the remainder of the injection pen body and compared to the outer diameters of the dose setting wheel and actuator button, respectively, which enlarged diameter tapers to a smaller outer diameter toward the distal tip of the pen body. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] International Publication No. 2021 / 260404 Summary of the Invention [Problem to be solved by the invention]

[0017] The Applicant proposes by the present invention to address the shortcomings of known injection monitoring modules as described in the previous paragraph. [Means for solving the problem]

[0018] Accordingly, one aspect of the present invention provides an injection monitoring module adapted and configured to be removably mounted to a proximal tip of an injection pen system for delivering a medication, the injection pen system having a pen body, a dose setting wheel located proximally and connected to the body, and an injection actuation mechanism, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting, the injection monitoring module comprising: a hollow main body adapted and configured to be coaxially mounted about an actuation mechanism body of an actuation mechanism pen injection system, the hollow main body having a longitudinal central bore with proximal and distal tips and a longitudinal central axis; a magnetic field generating means disposed on or within the hollow main body at the proximal tip of the longitudinal central bore; an injection monitoring system comprising at least one or more magnetic sensors disposed at a proximal tip of the bore of the hollow main body; the hollow main body further comprises an inner sleeve disposed within the longitudinal central bore, the inner sleeve configured to frictionally engage an outer surface of the dose setting wheel during dose setting and to co-rotate with the dose setting wheel about the longitudinal central axis without axial translation along said longitudinal central axis; the inner sleeve is connected to an injection monitoring system, the connection between the inner sleeve and the injection monitoring system being adapted and configured to co-rotate both the inner sleeve and the injection monitoring system about the central longitudinal axis during dose setting and to translate the injection monitoring system along the central longitudinal axis during injection and / or ejection of the medication from the pen injection system; The hollow main body further comprises a distal body portion extending around the outer surface of the body of the injection pen system at a location distal from the dose setting wheel, the distal body portion comprising a diameter changing means configured to dynamically change the inner diameter of the longitudinal central bore of the distal body portion from a first value to a second value different from the first value, the second value being an injection monitoring module.

[0019] According to another aspect, the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the central longitudinal bore of the distal body portion from a first value to a second value that is smaller than the first value.

[0020] According to another aspect, the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the central longitudinal bore of the distal body portion from a first value to a second value greater than the first value.

[0021] According to another aspect, the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the longitudinal central bore of the distal body portion from a first diameter at which the distal body portion is not in frictional contact with the outer surface of the injection pen device when attached to the injection pen device, to a second diameter smaller than the first diameter at which the distal body portion is in frictional contact with the outer surface of the injection pen device, said frictional contact preventing axial and radial movement of the distal body portion along and around the outer surface of the injection pen device.

[0022] From the above, it will be appreciated that the diameter altering means comprises one or more components that, when manipulated, activated, or actuated, function to dynamically alter the inner diameter of the central longitudinal bore of the distal body portion. The inner diameter of the central longitudinal bore, as referred to herein, is considered to be a diameter defined or definable by the diameter formed by the radially innermost surface portion of the distal body portion. The dynamic alteration of the inner diameter of the central longitudinal bore of the distal body portion may be configured, for example, in conjunction with the interaction between the components of the diameter altering means to result in either a controlled or controllable decrease or a controlled or controllable increase of the inner diameter of the central longitudinal bore of the distal body portion. For example, a controlled decrease in the inner diameter of the central longitudinal bore of the distal body portion may be appropriate when the injection monitoring module is secured to the outer surface of an injection pen system, more particularly, to the outer surface of an injection pen body. Similarly, and in the opposite sense, a controlled increase in the inner diameter of the longitudinal central bore of the distal body portion may be appropriate when releasing or dismounting the injection monitoring module from the outer surface of the injection pen system, more particularly from the outer surface of the injection pen body, or when repositioning the injection monitoring module if the need arises.

[0023] Thus, according to one aspect, the diameter changing means comprises a first rotatable outer component and a second non-rotatable inner component, the diameter changing means being configured to dynamically change the inner diameter of the longitudinal central bore of the distal body portion via rotation of the first rotatable outer component relative to and about the second non-rotatable inner component.

[0024] The hollow main body comprising the distal body portion is advantageously constructed from a suitable material, such as a molded plastic material selected from the group consisting of ABS (acrylonitrile butadiene styrene polymer), PC (polycarbonate polymer), POM (polyoxymethylene monomer), and ABS-PC (acrylonitrile butadiene styrene polycarbonate copolymer), with ABS-PC being advantageously preferred. Optionally, and advantageously, at least a portion of the hollow main body comprising the distal body portion may be made from a transparent or translucent material, such as one of those identified above, that facilitates visualization of the axial positioning of the injection monitoring module relative to the proximal end of the injection pen system when mounting the injection monitoring module on the injection pen system.

[0025] According to another embodiment, the first rotatable outer component is a rigid outer ring, which may be made of one or more of the plastic materials identified above, but is preferably and advantageously made of a transparent plastic material, such as a polycarbonate polymer and / or an acrylonitrile butadiene styrene polycarbonate copolymer.

[0026] According to another aspect, the second non-rotatable inner component is preferably configured as a deformable inner ring. For example, when formed as a ring, the non-rotatable inner component includes a proximal end and a distal end, and a wall extending from the proximal end to the distal end defining a bore having an inwardly facing surface defining an inner diameter and an outwardly facing surface defining an outer diameter. The non-rotatable inner component is physically connected to the hollow main body at the distal end of the hollow main body, for example, by welding or adhesive bonding, e.g., ultrasonic welding, or alternatively, by a frictional surface engagement, e.g., a press-fit or snap-fit ​​engagement, between the proximally facing end surface of the non-rotatable inner component and the distally facing end surface of the hollow main body. In this manner, when the injection monitoring module is attached to the pen injection system, the non-rotatable component is not permitted to rotate about the body of the pen injection system. As indicated above, the second non-rotatable inner component is deformable. Generally speaking, the deformation of the second non-rotatable inner component is advantageously configured to be actuated by a reduction in the inner diameter of the second non-rotatable inner component due to the application of radially inwardly directed pressure to the outward-facing surface of the second non-rotatable inner component. This construction can be achieved in a number of different ways, for example, the second non-rotatable, deformable inner component, as exemplified by a ring, can be provided with at least one or more cut or removed portions of wall material, the cut or removed areas being distributed radially around the periphery of the second non-rotatable, deformable inner component, for example at equally regularly spaced intervals around the diameter of the second non-rotatable, deformable inner component, and preferably also extending along an axis perpendicular to the inner diameter of the second non-rotatable, deformable inner component, for example extending at least partway distally along the wall from a first proximal end of the deformable inner component, or alternatively terminating adjacent the distal end of the non-rotatable inner component. The removed or cut-away portions of material allow the inner non-rotatable component to flex or elastically deform when radial pressure acts in a radially inward direction against the outward-facing wall surface of the inner non-rotatable component.

[0027] According to another embodiment, the second, non-rotatable inner component, e.g., formed as a deformable inner ring, comprises a radially inwardly facing surface portion of elastomeric material. The elastomeric material can be distributed along the entire or only a portion of the radially inwardly facing surface of the second, non-rotatable inner component. The elastomeric material is selected so as to provide a frictional gripping force of the radially inwardly facing surface of the second, non-rotatable inner component when the second, non-rotatable inner component is in frictionally engaging contact with the outer surface of the injection pen system, e.g., the pen body, thereby preventing the injection monitoring module from moving or being moved to an improper position along the body of such an injection pen system. Suitable elastomers for this task are thermoplastic elastomers, such as SEBS or polystyrene-poly(ethylenebutylene)-polystyrene block copolymers, which are known per se in the art.

[0028] According to another aspect, the radially inwardly facing surface portion of the elastomeric material has a first thickness at a first point along the radius of curvature of the inwardly facing surface portion and a second thickness at a second point along the radius of curvature of the inwardly facing surface portion that is different from the first thickness. The thickness of the inwardly facing surface portion along the radius of curvature is varied so that the deformability established in the second non-rotatable inner component can be amplified by applying a relatively small force to the outwardly facing surface of the second non-rotatable inner component. In this way, the application of a relatively small force to the outwardly facing surface of the second non-rotatable inner component has a diameter-changing effect that varies not only with the thickness of the elastomeric material along the radius of curvature but also with the diameter of the outwardly facing surface of the injection pen body, thereby ensuring a perfect fit of the elastomeric material to the injection pen body.

[0029] According to another aspect, the first rotatable outer component of the diameter change means comprises at least one or more radially inwardly facing portions configured to press against and deform the second non-rotatable inner component when the first rotatable outer component is rotated relative to and around the second non-rotatable inner component. It will be appreciated that the first rotatable outer component of the diameter change means is thus configured, through the presence of the at least one or more radially inwardly facing portions, to provide a bearing force against the second deformable non-rotatable inner component, and that this force causes deformation of the second non-rotatable inner component as rotation of the first rotatable outer component occurs.

[0030] According to another aspect, at least one or more radially inwardly facing portions of the first rotatable outer component configured to press against the second non-rotatable inner component are equally spaced from one another along the inner circumference of the first rotatable outer component.

[0031] According to another aspect, the at least one or more radially inwardly facing portions of the first rotatable outer component include three equally spaced radially inwardly facing portions.

[0032] According to another aspect, the radially outwardly facing surface of the second, non-rotatable, inner component of the diameter change means is configured to receive at least one or more radially inwardly facing portions of the first, rotatable, outer component, where "configured to receive" is understood to mean that the radially outwardly facing surface of the second, deformable, non-rotatable, inner component of the diameter change means is suitably and suitably adapted, dimensioned, shaped, equipped, and / or comprises physically defined features that allow the second inner component to receive at least one or more radially inwardly facing portions of the first, rotatable, outer component in a manner such that the at least one or more radially inwardly facing portions of the first, outer component physically engage with the radially outwardly facing surface of the second, non-rotatable, inner component, the latter deforming appropriately upon said physical engagement to change the inner diameter of the second inner component.

[0033] According to another aspect, the radially outwardly facing surface of the second, non-rotatable, inner component of the diameter changing means comprises an annular groove configured to receive and frictionally engage at least one or more radially inwardly facing portions of the first, rotatable, outer component.

[0034] According to another aspect, when rotated, at least one or more radially inwardly facing portions of the first rotatable outer component engage with and press against an annular groove in the radially outwardly facing surface of the second, non-rotatable, inner component, causing the at least one or more radially inwardly facing portions of the first rotatable outer component to move from a first radial position to a second radial position different from the first radial position about the rotational axis of the first rotatable outer component, thereby dynamically changing the inner diameter of the second, non-rotatable, inner component from the first inner diameter to the second inner diameter.

[0035] According to another aspect, the first rotatable outer component includes an alignment marker located or disposed on an outward-facing surface of the first rotatable outer component, the alignment marker configured to move from a first radial position non-longitudinal aligned with the alignment marker disposed on the outward-facing surface of the hollow main body to a second radial position longitudinally aligned with the alignment marker disposed on the outward-facing surface of the hollow main body as the first rotatable outer component is rotated about the axis of rotation. The alignment marker disposed on the first rotatable outer component functions to provide visual feedback to a user and to indicate when the first rotatable outer component is in a proper position for detaching the injection monitoring module from the injection pen body, or to indicate that the injection monitoring module is otherwise properly positioned and secured on the pen body and ready to be used to monitor dose setting and injection operations. The corresponding alignment markers may be suitably provided, for example, by appropriately shaped raised or additional portions of material disposed on the outward-facing surfaces of the corresponding rotatable outer components and hollow main body, or alternatively, by one or more colored areas disposed on said outward-facing surfaces, or by a suitable combination of raised and colored areas. For example, when the alignment marker on the first rotatable outer component is in longitudinal alignment, i.e., when the alignment marker is located on the outward-facing surface of the hollow body along the length of the injection monitoring module, the user knows that the injection monitoring is correctly positioned and secured, and the pen injection system and injection monitoring module are ready for use. When the alignment marker on the first rotatable outer component is not longitudinally aligned with the alignment marker disposed on the outward-facing surface of the hollow main body, the user knows that the injection monitoring module is not yet ready for use and may, optionally, be positioned to be removed or detached from the pen injection system.

[0036] According to another aspect, instead of or in addition to providing alignment markers or colored areas, the user may be suitably indicated the proper position to reach for securing the injection monitoring module to the injection pen body or for corresponding removal or detachment from the injection pen body via an alternative or complementary position feedback means distinct from the corresponding alignment markers or colored areas. The first outer rotatable element and the second non-rotatable inner element may thus be shaped, configured, and dimensioned to provide the user with alternative or complementary position feedback, e.g., expressed as resistance to rotation, when the first rotatable outer element reaches a predetermined allowable limit of rotation about its central longitudinal axis. Each rotation limit of the first rotatable outer element relative to the second non-rotatable inner element, and thus the corresponding resistance to rotation, corresponds to a position where the injection monitoring module can be freely removed or detached from the injection pen body, or conversely, a position where the injection monitoring module is rigidly secured to the injection pen body and is unable to undergo any axial movement along the injection pen body or any radial or rotational movement around the injection pen body. Alternatively or additionally, an alternative or complementary position feedback means may be provided by an audible signal, e.g., a click, generated by physical interaction of a first, outer, rotatable component with a second, non-rotatable, inner component, such as a groove on one of the corresponding components of the distal portion and a protrusion on the other corresponding component, the protrusion configured to engage and be retained in the groove via elastic deformation at or substantially adjacent to the point of greatest rotational resistance, such an audible signal thus informing the user that each corresponding rotational stop position has been reached.

[0037] The invention will now be described in more detail with reference to examples accompanied by the following figures. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a schematic perspective representation of an injection monitoring module installed in an injection pen system ready for use. [Figure 2] 2 is a schematic cross-sectional representation of the injection monitoring module when attached to the injection pen system shown in FIG. 1. [Figure 3] Figure 1 is a schematic exploded perspective representation of the injection monitoring module. [Figure 4] FIG. 3 is a schematic perspective representation of one part of the injection monitoring module of FIGS. 1 and 2. [Figure 5] FIG. 3 is a schematic end view representation of components of the distal portion of the injection monitoring module of FIGS. 1 and 2. [Figure 6] 3 is a schematic perspective representation of different parts of the distal portion of the injection monitoring module of Figures 1 and 2. [Figure 7A] 3 is a schematic cutaway end representation of the relative radial positions of components of a distal portion of the injection monitoring module of FIGS. 1 and 2 in a first position; FIG. [Figure 7B] FIG. 7B is a schematic perspective representation of the outward-facing surface of the distal portion of the injection monitoring module according to FIG. 7A. [Figure 8A] 3 is a schematic cutaway end representation of the relative radial positions of components of the distal portion of the injection monitoring module of FIGS. 1 and 2 in a second position. FIG. [Figure 8B] FIG. 8B is a schematic perspective representation of the outward-facing surface of the distal portion of the injection monitoring module according to FIG. 8A. DETAILED DESCRIPTION OF THE INVENTION

[0039] 1, 2, and 3, there are shown schematic perspective, cross-sectional, and exploded perspective representations of an injection monitoring module (1) according to the present invention. The injection monitoring module (1) is mounted on a single-handed injection pen system (2) that includes a pen injection system body (3) having an outer circumferential surface (4), a pen cap (5) covering the distal tip of the pen injection system, a dose setting or dialing wheel (6) located at the proximal tip of the pen injection system body (3), and a dialed dose visualization window (7) located distal to the dose setting wheel (6) that displays the dose dialed by a user of the pen injection system. The injection monitoring module (1) of the present invention is positioned adjacent to the proximal tip (8) of the injection pen system (2), particularly in contact with it around at least a portion of the outer circumferential surface (4), surrounding and contacting the pen body (3), and extending proximally beyond the proximal tip (8) of the pen body (3), particularly beyond the dose setting wheel (6). A central longitudinal axis (9) is also shown passing through the longitudinal centers of both the injection monitoring module (1) and the injection pen system body (3). The injection pen system (2) includes an actuation mechanism button (10) located proximally (2) from the dose setting or dialing wheel (6), as can be found in some commercially available injection pen systems. In pen injection systems of the type shown in FIGS. 1 and 2, the dose setting wheel is rotated about the central longitudinal axis (9) during dose setting but is fixed against rotation during injection. There are currently a number of commercially available injection pens that function in this way, such as the FlexTouch® and FlexTouch Connect™, Ozempic®, and Norditropin® FlexPro®, all available from Novo Nordisk A / S.

[0040] The injection monitoring module (1) comprises a hollow main body (11) dimensioned and sized to be coaxially mounted around the main body (3) of the pen injection system (2). The hollow main body (11) comprises a longitudinal central bore (12) having a proximal tip (13) and a distal tip (14) and a longitudinal central axis that coincides with the longitudinal central axis (9).

[0041] The hollow main body further comprises a distal body portion (15) located on the pen body (3) distal from the dose setting wheel (6) that, when installed in a ready-to-use position, surrounds and frictionally engages the outer surface (4) of the body (3) of the injection pen system (2). The frictional engagement between the hollow main body (11) and the outer surface (4) of the pen body (3) can be achieved by providing an elastomeric friction material (16) on the inner circumferential surface (17) of the hollow main body. The hollow main body (11) extends proximally beyond the confines of the actuation mechanism button (10) of the pen injection system (2), with a bore (12) that accommodates both the dose setting wheel (6) and the actuation mechanism button (10) and allows the dose setting wheel to rotate freely within the bore (12). The proximal tip (13) of the bore corresponds to the proximal tip of the hollow main body (11).

[0042] The hollow main body 11 further comprises magnetic field generating means 18, 19 disposed on or within the hollow main body 11 at the proximal tip 13 of the longitudinal central bore 12. The magnetic field generating means 18, 19 are preferably provided by a pair of diametrically opposed single dipole magnets 18, 19, each having a north and a south pole, the pole pairs preferably oriented in axial alignment from north to south along each longitudinal central axis, with the north pole positioned proximally and the south pole positioned distally. The dipole magnets 18, 19 may be suitably formed in the shape of a rod, or alternatively as a disk or ring or any other suitable shape. The magnets are located in corresponding, suitably dimensioned recesses (20, 21) in the hollow main body (11), which in turn are located at the proximal tip (13) of the body (11). Alternatively, the magnetic field generating means may be a single ring-shaped dipole magnet located on the proximal periphery of the hollow main body (11) or in corresponding annular recesses in the proximal tip (13) of said hollow main body. From the above, it will be appreciated that when the injection monitoring module is in a usable state, the hollow main body (11) is mounted to the pen body (3) about said central longitudinal axis (9) in a fixed relationship to the pen body (3), and therefore the magnetic field generating means is not free to rotate about the central longitudinal axis.

[0043] The hollow main body (11) further comprises an inner sleeve (22) disposed within the longitudinal central bore (12) and configured to frictionally engage the outer surface of the dose setting wheel (6) during dose setting so as not to translate axially along said longitudinal central axis but to co-rotate with the dose setting wheel (6) about the longitudinal central axis (9).

[0044] Figure 3 shows a schematic exploded perspective representation of the injection monitoring module, depicting a hollow main body (11), a distal section (15), and corresponding proximal and distal tips (13, 14). Figure 3 also shows that the main hollow body (11) is shaped with an inner diameter that gradually widens from the proximal tip to a point (23) of the distal section (15) adjacent to or adjacent to the distal tip (14). This widening diameter corresponds to the widening of the bore (12) that allows the hollow main body to be threaded over the pen's proximal tip and fit over the pen's dose setting wheel (6), leaving sufficient room within the bore to accommodate an inner sleeve (22) that can engage the outer surface of the dose setting wheel. The inner sleeve (22) is accordingly provided with a suitable contact or engagement surface (24) on its inward facing surface, and a corresponding contact or engagement surface (25) is provided on the injection monitoring system housing (26), which extends distally from the injection monitoring system housing into the bore (12), the engagement surface (24) and the engagement surface (25) cooperating to form engagement surfaces that frictionally contact and engage with the outer surfaces of the dose setting wheel (6) and the actuator button (10), respectively.

[0045] Although distal portion 15 is shown in Figure 3 as a primarily two-component system separate from hollow main body 11, as can be seen in Figure 2, it is pre-assembled with hollow main body 11 when distal portion 15 and hollow main body 11 are attached to body 3 of pen injection system 2. Distal portion 15 and hollow main body 11 may preferably be joined together during factory assembly of the injection monitoring module, for example, via spot welding between a proximal-facing surface of one of the distal portion components and a distal-facing surface of the hollow main body. Alternatively and / or additionally, the hollow main body 11 may be provided at its distal end 14 with a radially outwardly extending distal annular skirt 27 and a distal annular wall 28 extending from the hollow main body 11 and terminating in the radially outwardly extending distal annular skirt 27. The distal annular wall 28 has a reduced outer diameter compared to the outer diameter of the skirt 27. The distal body portion 15 is designed and configured to extend around the outer surface 4 of the injection pen body 3 at a location distal to the dose setting wheel. The distal body portion 15 includes a diameter varying means configured to dynamically vary the inner diameter of the longitudinal central bore of the distal body portion from a first value to a second value different from the first value. Thus, the diameter varying means provides a controlled, dynamic decrease or increase in the inner diameter of the bore 12 in the distal body portion 15. In operation, the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the longitudinal central bore of the distal body portion (15) from a first diameter at which the inwardly facing surface (17) of the distal body portion is not in frictionally engaging contact with the outer surface (4) of the injection pen device when mounted on the injection pen device, to a second diameter, smaller than the first diameter, at which the inwardly facing surface (17) of the distal body portion is in frictionally engaging contact with the outer surface (4) of the injection pen body (3), said frictionally engaging contact preventing axial movement of the distal body portion (15) along the outer surface (4) of the injection pen body (3). As noted elsewhere herein, the inner diameter of the longitudinal central bore is considered to be a diameter defined by or definable to be the diameter formed by the radially innermost surface portion of the distal body portion (15).

[0046] Further details of the features of hollow main body 11 are shown in Figure 4, of which distal annular wall 28 and distal annular skirt 27 have already been identified and discussed. In addition, Figure 4 shows that hollow main body 11 is provided with a plurality of notches 29a, 29b, 29c, 29d, 29e, 29f disposed in distal annular skirt 27 and extending through distal annular wall 28 from distal end 14 to distal tip 30 of annular skirt 27. Notches 29a-29f are oriented parallel to longitudinal central axis 9 and are advantageously equally spaced about the circumference formed by distal annular skirt 27. The notches (29a-29f) are shaped, sized, and configured to receive and engage correspondingly shaped, sized, and configured proximal elements of a portion of the distal portion (15), as described below with reference to FIG. 6. The distal annular skirt further includes a proximally facing surface (31) configured, sized, and shaped to provide a contact surface for a portion of the distal portion (15), as described below. The hollow main body (11) further includes an alignment marker (33) disposed on a radially outwardly facing surface (32) of the hollow main body (11) and extending radially outwardly from the radially outwardly facing surface (32) along and parallel to the central longitudinal axis (9). The length and height of the alignment marker can be adapted as needed to suit the intended user and / or manufacturing constraints. The alignment marker (33) serves as an indexing and positioning element for the hollow main body (11) relative to the dose visualization window (7) of the injection pen body (3) when the hollow main body (11) is attached to the pen body (3), and the dose visualization window (7) is typically provided with a dose marker (34, Figure 1).

[0047] In the embodiment shown in Figures 3, 5, 6, 7, and 8, the diameter varying means of the distal body portion (15) comprises a first rotatable outer component (15A) and a second, non-rotatable inner component (15B), such that the inner diameter of the longitudinal central bore (12) of the distal body portion (15A / 15B) is dynamically variable by rotation of the first rotatable outer component (15A) relative to and about the second, non-rotatable inner component (15B). The first rotatable outer component (15A) is generally shaped, sized, and configured as a rigid ring (35) having an outward-facing surface (36) and an inward-facing surface (37). Outwardly facing surface (36) may be provided with optional gripping means, such as at least one or more ridges (38) extending radially outward from outwardly facing surface (36) and aligned parallel to longitudinal axis (9), to enable a user to grasp rigid outer ring with their hand or fingers and rotate it about longitudinal axis (9). At the proximal end (39) of rigid outer ring (35), ring (35) is provided with a radially inwardly projecting shoulder (40) having a distally facing surface (41). When distal portion 15 is assembled to hollow main body 11, distally facing surface 41 of protruding shoulder 40 rests against and slidingly engages proximally facing surface 31 of distal annular skirt 27 in a surface-to-surface engagement, allowing rigid outer ring 35 to be rotated about longitudinal axis 9 while being supported by proximally facing surface 31 of distal annular skirt 27. Rigid outer ring 35 is also provided with at least one (see FIG. 1), or as shown in FIG. 5, a plurality of radially inwardly facing and extending portions 42a, 42b, 42c, each portion 42a, 42b, 42c defining a corresponding inwardly facing surface 43a, 43b, 43c facing into bore 12. As illustrated in FIG. 5, there are three radially inwardly facing portions (42a, 42b, 42c) and corresponding inwardly facing surfaces (43a, 43b, 43c), although fewer or more than three may be provided if deemed necessary.Each of the radially inwardly facing and radially inwardly extending portions (42a, 42b, 42c) and corresponding inwardly facing surfaces (43a, 43b, 43c) is shaped, sized, and configured to bear against and deform the second, non-rotatable, inner component (15B) when the rigid outer ring (35) is rotated relative to and around the second, non-rotatable, inner component (15B). It will thus be understood that the inwardly facing and radially inwardly extending portions (42a, 42b, 42c) and corresponding inwardly facing surfaces (43a, 43b, 43c) provide a bearing force against the second, deformable, non-rotatable inner component (15B), and that this force causes deformation of the second, non-rotatable inner component (15B) as rotation of the rigid outer ring (35) occurs. Advantageously, each of the inwardly facing, radially inwardly extending portions (42a, 42b, 42c) is equally spaced around the circumference of the rigid outer ring's inwardly facing surface (37). As can be seen in Figure 5, the inwardly facing, radially inwardly extending portions (42a, 42b, 42c) have distally facing surfaces (44a, 44b, 44c) formed or provided with seating recesses (45a, 45b, 45c), for example, defined by a pair of parallel-extending ridges (46, 47) of material extending distally from the distally facing surfaces (44a, 44b, 44c). The rigid outer ring (35) is further provided with alignment markers (48) on the outward facing surface (36) of the ring (35) which serve to visualize the alignment or non-alignment of the rigid outer ring (35) with the alignment markers (33) on the hollow main body (11).If the two markers (33, 48) parallel to the longitudinal axis (9) of the injection monitoring module are not aligned, it means that the injection monitoring module (1) is not securely attached to the pen body (3) and that the injection monitoring module (1) may be removed from the injection pen (2), whereas if the two markers (33, 48) parallel to the longitudinal axis (9) of the injection monitoring module (1) are aligned, it means that the injection monitoring module (1) is securely attached to the injection pen body (3) and is ready to be used to monitor injections.

[0048] As shown in Figure 6, the second, non-rotatable inner component (15B) is configured as a deformable inner ring (49). The deformable inner ring (49) has a proximal end (50) with a proximally-facing surface (51), a distal end (52), and a wall (53) extending from the proximal end (50) to the distal end (52) defining a bore (54) having an inward-facing surface (55) defining an inner diameter and an outward-facing surface (56) defining an outer diameter. The deformable inner ring (49) is physically connected to the hollow main body (11) at its distal end (14) via a series of one or more noses (57a, 57b, 57c, 57d, 57e, 57f) extending proximally beyond the proximal end (50) and the proximally-facing surface (51). The noses 57a-57f engage with the notches 29a-29f via a resilient frictional engagement and / or are welded or glued to the notches 29a-29f, for example, by ultrasonic welding. The proximal end 50 and noses 57a-57f may further be configured with a tapered frustoconical surface 58 diverging distally from the proximal end 50 to facilitate insertion into, reception by, and engagement with the notches 29a-29f. In this manner, the non-rotatable, deformable inner ring is prevented from rotating about the injection pen body 3 when the injection monitoring module 1 is attached to the pen body 3. As indicated above, the inner ring 49 is deformable. Deformation of the inner ring 49 is aided by providing at least one, or as shown in FIG. 6, multiple, cut or removed portions 59a, 59b, 59c of material in the wall 53, e.g., the cut or removed areas are distributed radially around the deformable inner ring 49, e.g., at equally regularly spaced intervals around the circumference of the inner ring 49. The cut portions 59a, 59b, 59c also preferably extend along an axis perpendicular to the inner diameter of the inner ring 49, e.g., extending at least partway distally along the wall 53 from the proximal end 50 of the deformable inner component, or alternatively terminating adjacent the distal end 52 of the non-rotatable inner ring 49.The removed or cut-out portions (59a, 59b, 59c) of material in wall (53) allow the non-rotatable inner ring to flex or elastically deform when radial pressure acts in a radially inward direction against the outward-facing wall surface (56) of the non-rotatable inner ring, and to flex radially outward again to a predetermined position when such radial pressure is removed or reduced.

[0049] As described above, the deformable inner ring (49) has a radially inwardly facing surface (55) provided with a portion of elastomeric material at least partially covering the inwardly facing surface (55). The elastomeric material can be distributed along the entire or only a portion of the radially inwardly facing surface (55) of the second, non-rotatable inner ring (49). The elastomeric material is selected to provide a frictional gripping force to the radially inwardly facing surface (55) when the non-rotatable inner ring (49) is in frictionally engaging contact with the outer surface (4) of the injection pen body (3), thereby preventing the injection monitoring module (1) from moving or being displaced to an improper position along the body (3). Suitable elastomers for this task are thermoplastic elastomers, such as SEBS or polystyrene-poly(ethylenebutylene)-polystyrene block copolymers, known per se in the art.

[0050] The elastomeric material has a first thickness (t1) at a first point (r1) along the radius of curvature of the inward-facing surface (55) and a second thickness (t2) at a second point (r2) along the radius of curvature of the inward-facing surface (55), the second thickness (t2) being different from the first thickness (t1). The thickness is varied along the radius of curvature of the inward-facing surface (55) so that the deformability established in the non-rotatable inner ring (49) can be amplified by applying a relatively small force to the outward-facing surface (56) of the non-rotatable inner ring wall (53). In this way, the application of a relatively small force to the outward-facing surface (56) of the non-rotatable inner ring wall (53) has a diameter-changing effect that varies not only with the thickness of the elastomeric material along the radius of curvature but also with the diameter of the outward-facing surface (4) of the injection pen body (3), thereby ensuring a snug fit of the elastomeric material with the injection pen body (3).

[0051] The deformable, non-rotatable inner ring 49 is further provided with at least one seating projection 61 a, 61 b, 61 c, e.g., located near the distal end 52 on the outward-facing surface 56 of the wall 53 of the inner ring 49. The seating projection is shaped, sized, and configured to fit into a recess 45 a, 45 b, 45 c in the distal-facing surfaces 44 a, 44 b, 44 c of the inward-facing, radially inward-extending portions 42 a, 42 b, 42 c, and serves to temporarily hold the inward-facing, radially inward-extending portions 42 a, 42 b, 42 c in a given radial position about the central longitudinal axis 9 when no rotational force is applied to the rigid outer ring 35.

[0052] The deformable, non-rotatable inner ring 49 also includes rotation stops 62a, 62b, and 62c. The rotation stops extend from adjacent the proximal end 50, e.g., distal to the frustoconical surface 58 of the proximal end, toward the distal end 52. The rotation stops 62a, 62b, and 62c also extend radially outward, thereby defining raised transverse bars extending on the outward-facing surface 56. Each rotation stop 62a, 62b, and 62c, together with the adjacent rotation stop 62a, 62b, and 62c, defines an arc of permissible movement of the inward-facing, radially inward-extending portion 42a, 42b, and 42c of the outer ring 35 about the axis 9. The stops are positioned circumferentially around the outward-facing surface 56 of the inner ring wall 53 such that corresponding locations of the inward-facing, radially inward-extending portions 42 a, 42 b, 42 c of the outer ring 35 exert either a minimum or, in some cases, a maximum radially directed force against the outward-facing surface 56 of the inner deformable ring, resulting in either a minimum or maximum radial compression of said ring. In other words, the rotation stops 62 a, 62 b, 62 c and the corresponding proximal and distal ends 50 and 52 of the inner deformable, non-rotatable ring 49 define an annular groove separated into a series of arcuate segments through which rotational movement of the inward-facing, radially inward-extending portions 42 a, 42 b, 42 c of the outer ring 35 is permitted.

[0053] The function of the distal portion will now be described with particular reference to Figures 7A, 7B, 8A, and 8B. Figure 7A shows a cutaway end view of the injection monitoring module (1) in a first, unlocked position around the pen body (3) and the relative radial positions of the various elements of the rotatable, rigid outer ring (35) and the non-rotatable, deformable inner ring. Figure 7B shows a perspective view of the injection monitoring module (1) attached to the injection pen body (3) but unlocked. The unlocked attachment is indicated by the lack of alignment between the alignment marker (33) on the hollow main body (11) and the alignment marker (48) located on the outer surface (36) of the outer ring (35). In these relative positions, it can be seen from Figure 7A that the inward-facing, radially inward-extending portions 42a, 42b, 42c of the outer ring 35 do not radially engage, press against, or compress the inner ring 49, or, if they do, involve minimal radially inward force. For example, it can be seen that the inward-facing, radially inward-extending portion 42c is rotationally positioned against the rotation stop 62c, but in this position does not exert a radially inward force on either the outward-facing surface 56 of the inner ring 49 or on the reduced-thickness portion t1 at the radial point r1. The arrow on the left side of Figure 7A indicates the direction of the rotational force or effort that the user applies to the outer ring 35 when the user wishes to secure the distal portion 15 and the injection module 1 as a whole to the injection pen body 3. Although the rotation is counterclockwise in this illustration, the distal portion may be configured to function by applying an opposite, i.e., clockwise, rotational effort or force to the outer ring (35). When a user rotates the outer ring in a counterclockwise direction, the inward-facing, radially inward-extending portions (42a, 42b, 42c) rotate in a counterclockwise direction.In doing so, these portions 42a, 42b, 42c move along the arc of the groove defined between the rotation stops 62a, 62b, 62c and the outward-facing surface 56 of wall 53, pressing against and compressing the outward-facing surface 56 of wall 53, until they contact and press against the increased thickness portion t2 at radial point r2. Wall 53 simultaneously deforms under radially inward pressure due to the presence of the multiple cutouts or removals 59a, 59b, 59c in wall 53, thereby reducing its inner diameter. The reduction in the inner diameter of the bore brings the elastomeric portion located on the inner ring's inward-facing surface 55 into elastic, frictionally engaging contact with the pen body's outward-facing surface 4, thereby securing the distal portion to said pen body 3.

[0054] Figures 8A and 8B show the fixed or secured mounting of the injection module 1 with its distal portion in a properly aligned position on the pen body 3 and the relative radial positions of the elements of the distal portion 15. In Figure 8A, for example, it can be seen that the inwardly facing and radially inwardly extending portions 42a, 42b, 42c of the outer ring 35 are all pressed against the outer surface 56 of the inner ring 49 at a position r2 about the axis 9 where the thickness of the elastomer is at a maximum t2. Additionally, the inwardly facing, radially inwardly extending portions of the outer ring (42a, 42b, 42c) rotate against the rotation stops (62a, 62b, 62c) and additionally simultaneously seat on the inner ring seating projections (61a, 61b, 61c) by engagement of the projections within recesses (45a, 45b, 45c) in the inwardly facing, radially inwardly extending portions of the outer ring (42a, 42b, 42c). Figure 8B shows that in these relative positions, the alignment markers (33) on the hollow main body (11) and the alignment markers on the outer ring (35) of the distal portion (15) are visible, thereby informing the user that the injection monitoring module is securely attached to the pen body. Additionally, when the outer ring is rotated to the rotation stop position, the inward-facing, radially inward-extending portions (42a, 42b, 42c) and recesses (45a, 45b, 45c) of the outer ring move relative to the seating protrusions (61a, 61b, 61c) of the inner ring, providing physical or tactile feedback to the user. This physical or tactile feedback is experienced by the user as an increase in resistance to rotation as the protrusions (46, 47) defining the recesses (45a, 45b, 45c) press against and ride up on the seating protrusions (61a, 61b, 61c), causing the protrusions (46, 47) to elastically deform and resiliently engage the seating protrusions within the recesses (45a, 45b, 45c), which generates an audible signal, such as a click.The click sound in this case is a form of feedback to the user indicating either that the distal portion of the injection monitoring module is securely fastened to the injection pen body, or that the distal portion of the injection monitoring module can be detached from the injection pen body when the protrusions (61a, 61b, 61c) are engaged in the recesses (45a, 45b, 45c) at the opposite rotational stop positions. Thus, to detach the injection monitoring module (1) from the pen body (3), the outer ring is rotated in the opposite direction, i.e., clockwise in this illustrated example, to release or remove the radially inward force of the outer ring from pressing against the inner ring, allowing the inner ring to return to its predetermined nominal dimension.

Claims

1. 1. An injection monitoring module adapted and configured to be removably mounted to a proximal tip of an injection pen system for delivering a medication, the injection pen system having a pen body, a dose setting wheel located proximally and connected to the body, and an injection actuation mechanism, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting and being fixed against rotation during injection, a hollow main body adapted and configured to be coaxially mounted around the body of the pen injection system, the hollow main body having a longitudinal central bore with proximal and distal tips and a longitudinal central axis; a magnetic field generating means disposed on or within the hollow main body at the proximal tip of the longitudinal central bore; an injection monitoring system comprising at least one or more magnetic sensors disposed at the proximal tip of the bore of the hollow main body; the hollow main body further comprises an inner sleeve disposed within the longitudinal central bore, the inner sleeve configured to frictionally engage an outer surface of the dose setting wheel during dose setting and to co-rotate with the dose setting wheel about the longitudinal central axis without axial translation along the longitudinal central axis; the inner sleeve is connected to the injection monitoring system, the connection between the inner sleeve and the injection monitoring system being adapted and configured to co-rotate both the inner sleeve and the injection monitoring system about the central longitudinal axis during dose setting, and to translate the injection monitoring system along the central longitudinal axis but not rotate the injection monitoring system about the central longitudinal axis during injection and / or expulsion of a drug from the pen injection system; the hollow main body further comprising a distal body portion extending around an outer surface of the body of the injection pen system at a location distal from the dose setting wheel, the distal body portion comprising diameter varying means configured to dynamically vary an inner diameter of the central longitudinal bore of the distal body portion from a first value to a second value different from the first value.

2. 2. The injection monitoring module of claim 1, wherein the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the central longitudinal bore of the distal body portion from a first value to a second value that is smaller than the first value.

3. 2. The injection monitoring module of claim 1, wherein the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the central longitudinal bore of the distal body portion from a first value to a second value greater than the first value.

4. 2. The injection monitoring module of claim 1, wherein the diameter varying means of the distal body portion is configured to dynamically vary the inner diameter of the central longitudinal bore of the distal body portion from a first diameter at which the distal body portion is not in frictional contact with an outer surface of the injection pen device when attached to the injection pen device, to a second diameter smaller than the first diameter at which the distal body portion is in frictional contact with the outer surface of the injection pen device, the frictional contact preventing axial movement of the distal body portion along the outer surface of the injection pen device.

5. 2. The injection monitoring module of claim 1, wherein the diameter altering means of the distal body portion comprises a first rotatable outer component and a second non-rotatable inner component, the diameter altering means configured to dynamically alter the inner diameter of the central longitudinal bore of the distal body portion via rotation of the first rotatable outer component relative to and about the second non-rotatable inner component.

6. 10. The injection monitoring module of claim 1, wherein the first rotatable outer component is a rigid outer ring.

7. 10. The injection monitoring module of claim 1, wherein the second non-rotatable inner component is a deformable inner ring.

8. 8. The injection monitoring module of claim 7, wherein the deformable inner ring comprises a surface portion of elastomeric material facing radially inward.

9. 9. The injection monitoring module of claim 8, wherein the radially inwardly facing surface portion of the elastomeric material has a first thickness at a first point along a radius of curvature of the inwardly facing surface portion and a second thickness at a second point along the radius of curvature of the inwardly facing surface portion that is different from the first thickness.

10. 6. The injection monitoring module of claim 5, wherein the first rotatable outer component comprises at least one or more radially inwardly facing portions configured to press against a radially outwardly facing surface of the second non-rotatable inner component to deform the second non-rotatable inner component when the first rotatable outer component is rotated relative to and around the second non-rotatable inner component.

11. 11. The injection monitoring module of claim 10, wherein the at least one or more radially inwardly facing portions of the first rotatable outer component configured to press against the radially outwardly facing surface of the second non-rotatable inner component are equally spaced from one another along an inner circumference of the first rotatable outer component.

12. 12. The injection monitoring module of claim 10 or 11, wherein the at least one or more radially inwardly facing portions of the first rotatable outer component comprise three radially inwardly facing portions equally spaced from one another.

13. 11. The injection monitoring module of claim 10, wherein the radially outwardly facing surface of the second non-rotatable inner component of the diameter changing means is configured to receive the at least one or more radially inwardly facing portions of the first rotatable outer component.

14. 11. The injection monitoring module of claim 10, wherein the radially outwardly facing surface of the second non-rotatable inner component of the diameter changing means comprises an annular groove configured to receive and frictionally engage the at least one or more radially inwardly facing portions of the first rotatable outer component.

15. 15. The injection monitoring module of claim 14, wherein, upon rotation, the at least one or more radially inwardly facing portions of the first rotatable outer component engage with and press against the annular groove in the radially outwardly facing surface of the second, non-rotatable inner component, causing the at least one or more radially inwardly facing portions of the first rotatable outer component to move from a first radial position to a second radial position different from the first radial position about the axis of rotation of the first rotatable outer component, thereby dynamically changing the inner diameter of the second, non-rotatable inner component from a first inner diameter to a second inner diameter.

16. 6. The injection monitoring module of claim 5, wherein the first rotatable outer component comprises an alignment marker located on an outward-facing surface of the first rotatable outer component, the alignment marker configured to move from a first radial position non-longitudinal aligned with an alignment marker located on the outward-facing surface of the hollow main body to a second radial position longitudinally aligned with the alignment marker located on the outward-facing surface of the hollow main body when the first rotatable outer component is rotated about a rotation axis.

17. 6. The injection monitoring module of claim 5, wherein the distal portion comprises position feedback means configured to provide position feedback regarding rotation of the first rotatable outer component relative to the second non-rotatable inner component about the central longitudinal axis.

18. 18. The injection monitoring module of claim 17, wherein the position feedback means is configured to define an area of ​​the first rotatable outer component that has increased resistance to rotation compared to the second non-rotatable inner component, i.e., a rotation stop.

19. 18. The injection monitoring module of claim 17, wherein the position feedback means is configured to generate an audible signal, such as a click, indicating that a rotational stop position of the first rotatable outer component relative to the second non-rotatable inner component has been reached.

Images