Injection monitoring module

Abstract

To provide an injection monitoring module equipped with a rotatable dose setting wheel and an injection operation mechanism, which is mounted on a body of an injection pen system having a longitudinal central axis.SOLUTION: An injection monitoring module comprises a hollow main body including a longitudinal central bore, magnetic field generating means located on the hollow main body at a proximal tip of the bore, an injection monitoring system comprising at least one magnetic sensor, and an inner sleeve located within the bore that engages with an outer surface of a dose wheel during dose setting and co-rotates therewith without axial translation, the inner sleeve being connected to the monitoring system so as to allow both the sleeve and the monitoring system to co-rotate about an axis during dose setting and to allow the monitoring system to translate along the axis without rotating during injection of medication from a pen.SELECTED DRAWING: Figure 2

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, making it more difficult for users 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. A user rotates the wheel to select a 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. This is typically achieved by including one or more metal components, such as a helically wound drive spring, located within the injection pen system's housing body and physically coupled to the dose setting wheel. Because such metal elements are relatively large objects compared to the electronic component systems included in many pen injection systems today, these large metal objects can further disturb the signals that are designed to be captured or picked up by sensors within such electronic component systems, potentially reducing the accuracy of the system and / or requiring complex compensation mechanisms to be put in place to avoid calculation errors.

[0005] There have already been several attempts in the patent literature to overcome the difficulties of integrating electronic components.

[0006] For example, U.S. Patent No. 6,299,949 relates to a sensor assembly having a first rotary sensor portion with a plurality of individual conductive sensor regions arranged in a pattern, and a second rotary sensor portion with a plurality of contact structures arranged to rotate relative to the first portion and adapted to contact the conductive sensor regions on the rotary portion of the first sensor. The contact structures are configured to engage and connect with different sensor regions as the first and second portions of the rotary sensor rotate relative to each other, with the formed connection indicating a rotational position between the first and second portions. One of the contact structures is an actuatable contact structure axially movable relative to the first portion, having a connected position in which the actuatable contact structure contacts the sensor region and a disconnected position in which the actuatable contact structure does not contact the sensor region. The system is contained within the pen injector body, at least partially within the volume inside the dose setting wheel. The system also includes a visual display, such as an LCD display, located on or in place of the injection activation mechanism button.

[0007] In contrast, U.S. Patent No. 5,999,623 relates to a dose detection system including a dosing component mounted on an actuator and rotatably and axially movable relative to a coupling component mounted on a dose setting member, and a module including an electronic sensor operable to detect relative rotation of the coupling component and the dosing component to detect the dose delivered by the medication delivery device. The dose detection module is removably coupled to the proximal end of the pen injection system and is intended to function as a means for detecting the amount of medication dispensed by the pen injection system while attached thereto, storing the detected dose in memory, and transmitting a signal representing the detected dose to a remote communication device. The system includes a pair of rotatable and translatable cylinders that interact with each other via electrical contacts provided on the cylinder surfaces to indicate various states or positions of the injection dispensing operation, including dose setting. The electrical contacts are connected to a collection of electronic components housed on a flexible printed circuit board arranged in an accordion-like configuration of overlapping folds within the removably coupled body and insulated by non-conductive spacer layers between overlapping layers of the circuit board to prevent possible electrical, electronic, and electromagnetic interference.

[0008] One immediate observation of the above configuration is that despite the use of folded flexible printed circuit boards to provide multiple surfaces for positioning the electronic components, their relative spatial density and positioning relative to one another necessitates the provision of non-conductive spacers between layers of electronic components, which directly results in an increased height of the module and necessarily an increased complexity of the clip-on dose detection module described therein. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2014 / 128156 [Patent Document 2] International Publication No. 2018 / 013419 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, one object of the present invention is to provide an injection monitoring module that is adapted and configured to be removably attached to the proximal tip of an injection pen system for delivering a drug, wherein the injection pen system has a dose setting wheel that is rotatable about the longitudinal central axis of the pen injection system to set the dose of drug to be injected and that is fixed so as not to rotate during injection, in which case the construction of the injection monitoring module is much simpler and at the same time there is no need for complex shielding or protection solutions to deal with any unwanted electrical, electronic or electromagnetic effects caused by the relatively high density of electronic components in the monitoring module.

[0011] Another object of the present invention is to provide such an injection monitoring module, wherein the monitoring module is adapted and configured to determine the injection endpoint in a pen injection system in which the dose setting wheel does not rotate during injection. For purposes of the present invention, the expression "injection endpoint," as used herein, refers not only to the completion of injection of a dose of an injectable substance, such as a medication, when a user injects the required dose of the injectable substance with a single action, but also includes any amount of medication actually dispensed by the pen injection system after selecting or dialing the dose via the dose setting wheel when the injection monitoring module is mounted on the injection pen system. This means that when a user performs a series of short, repetitive injection actions, for example, by repeated, successive actuations of the injection actuation mechanism, the corresponding endpoints of each injection step are registered and the corresponding amounts of injectable substance are calculated as having been injected or dispensed from the pen injection system.

[0012] It is yet another object of the present invention to provide an injection monitoring module as above, wherein the module is adapted and configured to detect or calculate a dose or user set amount of an injectable substance contained within a pen injection system, an injection initiation or start point in said pen injection system, and an injection end point, and therefrom to determine whether the dose or amount set by a user of the pen injection system has been fully dispensed from said pen system.

[0013] These and other objects of the present invention will become readily apparent upon a complete reading of this specification. [Means for solving the problem]

[0014] Therefore, in accordance with any of the above objects, there is provided 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, the injection monitoring module comprising: a hollow main body adapted and configured to be coaxially mounted about the body of a 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 together with the dose setting wheel about the longitudinal central axis without axial translation along the longitudinal central axis, The inner sleeve is connected to an injection monitoring system. An injection monitoring module is provided in which the connection between the inner sleeve and the injection monitoring system is adapted and configured to cause both the inner sleeve and the injection monitoring system to co-rotate about the central longitudinal axis during dose setting, and to cause the injection monitoring system to translate along the central longitudinal axis but not rotate about the central longitudinal axis during injection and / or ejection of a drug from the pen injection system.

[0015] 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 in the treatment of many different medical indications. These systems are also often designed entirely for the user to self-inject medication when treatment for a given medical indication is needed. This is the case, for example, with regard to insulin intended to treat diabetic conditions; one such example is the pen injector marketed by Novo Nordisk under the FlexTouch® brand name. However, other drugs also fall within this category of medical devices that allow for immediate emergency injection of needed medications, such as anaphylactic shock medications, anticoagulants, opioid receptor agonists and antagonists, and the like, needed to address potentially life-threatening situations, to the extent that it has become common for patients suffering from or susceptible to such conditions to carry these devices on their person.

[0016] The injection monitoring module of the present invention is adapted and configured to be removably attached to an injection pen system including a proximally located dose setting wheel and an injection actuation mechanism. The dose setting wheel rotates about the central longitudinal axis of the pen injection system, allowing a user to set a dose of medication for injection. The dose setting wheel is generally rotatable in both clockwise and counterclockwise directions, which generally correspond to increasing the selected dose to be administered and decreasing 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 then presses the injection actuation mechanism distally, driving a piston connected to a plunger to expel 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 per se well known in the art. However, the monitoring module of the present invention is mounted on a pen injection system in which the dose setting wheel does not rotate during the delivery / injection phase of operation.

[0017] The injection monitoring module of the present invention is therefore 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 can 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, screw thread and corresponding fastening ring, and engages either the dose setting wheel or the injection actuation mechanism, or both.

[0018] 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.

[0019] 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 so as not to translate axially along said longitudinal central axis but to co-rotate together with the dose setting wheel about the longitudinal central axis, such that when the inner sleeve rotates, the dose setting wheel also rotates in the same direction and to substantially the same or identical degree of rotation. In this way, the inner sleeve can be said to co-rotate with the dose setting wheel.

[0020] 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.

[0021] 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 the central longitudinal axis during dose setting, and to translate the injection monitoring system along the central longitudinal axis but not rotate about the 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 to selectively rotate about the central longitudinal axis and then selectively translate along said longitudinal axis, the two movements being mutually exclusive of each other.

[0022] According to another object, the hollow main body further comprises a distal body portion, at a location distal from the dose setting wheel, that extends around and frictionally engages the outer surface of the body of the injection pen system. 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.

[0023] The injection monitoring module also includes an injection monitoring system that includes at least one or more magnetic sensors and is located at the proximal tip of the bore of the hollow main body. The injection monitoring system is described in more detail below, but essentially the injection monitoring system includes several different components and means that provide monitoring of the injection status, such as: - the start of the injection movement, Completion of an injection action, in this case completion of an injection action, should be understood to include both the complete administration of a selected dose of the substance to be injected, or a separate injection action in which the user injects only a partial dose or expels a partial selected dose from the pen injection system.

[0024] In accordance with yet another object of the present invention, the injection monitoring system is movable along the central longitudinal axis from a first monitoring position in which the injection monitoring system is not in abutting contact with a proximal surface of the injection actuation mechanism to a second monitoring position in which the injection monitoring system is in abutting contact with a proximal surface of the injection actuation mechanism. The injection monitoring system is advantageously mounted to the proximal tip of the bore and completely covers, or at least substantially covers, said proximal tip of the bore.

[0025] From the above, it will be appreciated that the injection monitoring system can be moved from an initial position where there is no physical contact between the monitoring system and the actuation mechanism button to a different position where physical contact is established between the monitoring system and the proximal surface of the injection actuation mechanism. Such movement generally results in translation of the monitoring system along its central longitudinal axis from a first position to a second position. The injection monitoring module is further configured such that, after setting a dose by rotating the inner sleeve and correspondingly coupling the dose setting wheel, translation of the injection monitoring system along its central longitudinal axis, as described above, is responsible for detecting or determining the injection start and / or end points. For example, the monitoring module can be configured to detect the start point of an injection when the monitoring system translates distally. Conversely, the monitoring system can be configured to detect the end point of injection or delivery of an injectable substance when the monitoring system translates proximally, thereby releasing physical contact between the actuation mechanism button of the pen injection system and the monitoring system. One way to accomplish this is, for example, by determining the amount of time that has elapsed while the injection monitoring system is in physical contact with the pen actuation mechanism of the pen injection system. Translational movement in the direction opposite to the direction of injection, i.e., proximal translation of the monitoring system back toward the user's hand or thumb, is suitably achieved in such pen injection systems by either directly or indirectly utilizing the repulsive energy of a detent spring located within the injection pen after the user releases the actuation mechanism button, for example, by removing pressure of the thumb or other fingers on said button, which repulsive energy acts against anything in contact with the proximal surface of the pen injection system's actuation mechanism button, thus moving the injection monitoring system away from the pen's actuation mechanism button so that it is no longer in contact with the pen's actuation mechanism button.

[0026] According to another object of the present invention, the monitoring module of the present invention comprises magnetic field generating means disposed on or in the hollow main body at the proximal end of the longitudinal central bore. By the expression "disposed on or in the hollow main body", it is understood that the magnetic field generating means may be located, for example, on a proximally facing surface of the hollow main body at the proximal end of the central bore. Alternatively, the magnetic field generating means may be located in a cavity or recess provided in the hollow main body at the proximal end of the central bore.

[0027] Various means for generating magnetic fields are known, including conventional magnets, electromagnets, and mixed-material magnets. Such magnets can typically be made from magnetizable materials that are magnetic or paramagnetic, whether naturally occurring or in which a magnetic field is generated or induced when an electric current or other energizing current passes through the material. Suitable materials can be suitably selected from the following: ferrite magnets, in particular sintered ferrite magnets, such as crystalline compounds of iron, oxygen, and strontium; - a composite material consisting of a thermoplastic matrix and an isotropic neodymium-iron-boron powder; - composite materials consisting of a thermoplastic matrix and strontium-based hard ferrite powder, in which case the resulting magnets may contain isotropic, i.e. non-oriented, or anisotropic, i.e. oriented, ferrite particles; - a composite material consisting of a thermosetting plastic matrix and an isotropic neodymium-iron-boron powder; - magnetic elastomers, for example made from heavily charged strontium ferrite powder mixed with synthetic rubber or PVC, which are then extruded into the desired shape or calendered into fine sheets; - A calendered flexible composite that generally has the appearance of a brown sheet and is more or less flexible depending on its thickness and its composition. These composites are by no means rubber-like and tend to have Shore hardnesses ranging from about 40 to 70 Shore D ANSI. Such composites are generally formed from synthetic elastomers filled with strontium ferrite particles. The resulting magnets can be anisotropic or isotropic, and the various sheets generally have alignment of the magnetic particles resulting from the calendering process. - laminated composites, generally including flexible composites as described above, laminated with soft iron plates; -Neodymium-iron-boron magnets, - magnetized steel made of aluminum-nickel-cobalt alloy, -An alloy of samarium and cobalt.

[0028] Of the above list of magnetic field generating means suitable for use in the present invention, those selected from the group consisting of neodymium-iron-boron permanent magnets, magnetic elastomers, composites consisting of a thermoplastic matrix and strontium-based hard ferrite powder, and composites made of a thermosetting plastic matrix and isotropic neodymium-iron-boron powder are preferred. Such magnets are known for their ability to be sized to relatively small sizes while maintaining relatively high magnetic field strengths.

[0029] The magnetic field generating means may be of any suitable overall shape, for example disc-shaped, including circular, elliptical, or any other suitable polygonal shape, but preferably has only a single dipole with a single pair of diametrically opposed north and south magnetic poles. The magnetic field generating means may also optionally be substantially disc-shaped, but such a disc shape preferably also includes a magnet having an opening substantially in the center of the disc to form a ring- or annular-shaped magnet. Such a ring- or annular-shaped magnet may usefully be located at the proximal tip of the hollow main body, on its proximally-facing annular outer circumferential surface.

[0030] According to yet another object, the hollow main body further comprises translational abutment means adapted and configured to prevent axial translational movement of the inner sleeve along the central longitudinal axis when the injection monitoring module is in a loaded position on the injection pen system, the translational abutment means being shaped and dimensioned to prevent axial translational movement of the inner sleeve beyond a predetermined point within the hollow main body at least in a distal direction along the central longitudinal axis, but advantageously and preferably also in a proximal direction along said central longitudinal axis.

[0031] According to a further object, the translational abutment means of the hollow main body is formed as an annular groove or annular slot provided on the inner surface of the hollow main body.

[0032] In accordance with another further object, the translational abutment means is formed from a distally facing surface on the hollow main body and a corresponding proximally facing surface on the distal body portion, the distally facing surface and the proximally facing surface together forming a cooperating translational abutment surface for the inner sleeve.

[0033] According to another object, the inner sleeve further comprises surface engagement means located adjacent to or substantially at the distal tip of the inner sleeve, the surface engagement means configured to engage an inner surface of at least the distal body portion of the hollow main body when the injection monitoring module is in a loaded position on the injection pen system, thereby preventing distal and / or proximal translational movement of the inner sleeve.

[0034] In accordance with yet another further object, the surface engaging means comprises at least one continuous projection or a plurality of individual projections extending radially outward from the outer surface of the inner sleeve.

[0035] Advantageously, and according to a further object, the surface engagement means comprises at least one distally facing surface, said distally facing surface of the surface engagement means engaging a corresponding proximally facing surface of translation abutment means provided on the inner surface of the hollow main body.

[0036] In accordance with yet another object, the surface engagement means comprises at least one continuous protrusion or a plurality of separate protrusions extending radially outward from the outer surface of the inner sleeve, and the translation abutment means of the hollow main body is formed as an annular groove or annular slot on the inner surface of the hollow main body, the annular groove or annular slot adapted and dimensioned to receive in cooperating proximal and distal surface engagement the at least one continuous protrusion or a plurality of separate protrusions extending radially outward from the outer surface of the inner sleeve.

[0037] In summary, the translation abutment means of the hollow main body and the surface engagement means of the inner sleeve are provided with suitably shaped surfaces and areas which cooperate with each other to prevent any translational movement in either the proximal or distal direction when the hollow main body is mounted on the body of the pen injection system.

[0038] According to yet another object, the inner sleeve further comprises at least one or more elastically deformable surfaces extending inwardly from said inner sleeve towards the central longitudinal axis forming at least one or more frictional engagement surfaces for frictionally engaging with an outer surface of the dose setting wheel.

[0039] According to another object, at least one or more elastically deformable surfaces extending inwardly from the inner sleeve toward the central longitudinal axis are rings of elastically deformable material, the rings having a plurality of coaxially aligned and radially spaced teeth extending in the same direction from the rings, the rings being located at a proximal tip of the inner sleeve, the teeth being oriented to extend distally along the outer and / or inner surface of the sleeve. Advantageously, the elastically deformable material is a suitable elastomer, such as an SEBS elastomer.

[0040] According to yet another object, the inner sleeve further comprises a plurality of coaxially aligned and radially spaced openings extending through the inner sleeve from its outer surface to its inner surface.

[0041] Advantageously, according to another object, at least one or more of the resiliently deformable surfaces extend through radially spaced openings through the inner sleeve.

[0042] As will be readily understood from the preceding paragraphs, the elastically deformable surface advantageously extends from one side of the inner sleeve, e.g., the outer surface, through and through the body material of the inner sleeve to the other side, e.g., the inner surface of the inner sleeve.

[0043] According to yet another object, the inner sleeve further comprises at least one injection monitoring system connection surface extending from an inner surface of the sleeve and projecting inwardly toward the central longitudinal axis of the bore.

[0044] Advantageously, and according to yet another object, the connection surface of the at least one injection monitoring system extending from the inner surface of the sleeve and projecting inwardly towards the central longitudinal axis of the bore comprises at least one or more recesses provided in said inwardly projecting connection surface.

[0045] According to yet another object, an injection monitoring system includes a housing, the housing of the injection monitoring system including at least one connecting surface extending distally from the housing.

[0046] According to yet another further object, the connecting surfaces of the at least one injection monitoring system and the connecting surfaces of the housing of the at least one injection system are adapted and configured to inter-engage with each other in a first position in which rotation of the injection monitoring system housing causes the inner sleeve to co-rotate, and to engage with each other in a second position in which the injection monitoring system only translates distally or proximally along the central longitudinal axis of the injection monitoring system housing without rotation about said central longitudinal axis.

[0047] As can be readily understood from the above, the connection surface of the at least one injection monitoring system and the connection surface of the housing of the at least one injection system are mated with one another such that in a first position, for example during dose setting, the respective surfaces engage with one another and rotate together about the central longitudinal axis, and in a second position, the connection surface of the housing of the at least one injection system abuts the connection surface of the at least one injection monitoring system and translates distally or proximally depending on whether the activation button is pressed or correspondingly released.

[0048] According to a further object, at least one connecting surface extending from the housing of the injection monitoring system comprises at least one or more distally extending protrusions extending from a distal tip of the housing and coaxially aligned with the central longitudinal axis.

[0049] According to yet another object, in the first position, the at least one or more distally extending projections of the injection monitoring housing each include an outwardly facing connecting surface that frictionally engages a corresponding inwardly facing surface of at least one or more recesses provided in the inwardly projecting connecting surface.

[0050] According to another further object, in the second position, the at least one or more distally extending protrusions extending from the housing of the injection monitoring system further comprise at least one distally facing contact surface for contacting the injection actuation mechanism.

[0051] According to another further object, the injection monitoring system is further configured to determine the amount of time that has elapsed while the injection monitoring system is in physical contact with a pen actuation mechanism, e.g., a pen actuation mechanism push button, of the pen injection system.

[0052] A magnetic field generating means is provided which enables the magnetic field sensor to detect any change in the magnetic field during dose setting due to, for example, rotational movement of the inner sleeve relative to the magnetic field generating means, thereby determining the dialed dose set via the dose setting wheel. Furthermore, during injection, when finger pressure is applied in a distal direction along the central longitudinal axis against the housing of the injection monitoring system, the magnetic field sensor will detect a change in the magnetic field due to translation of the sensor along the longitudinal axis in a distal direction towards the magnetic field generating means and then in an opposite proximal direction upon release of finger pressure from the injection monitoring system.

[0053] The magnetic field sensor is thus used to measure the magnetic field generated by the magnetic field generating means. Movement of the magnetic field sensor about its longitudinal central axis as the dose wheel rotates, via the inner sleeve in contact therewith, relative to the fixed hollow body proximal tip location of the magnetic field generating means is used to calculate or determine the dose of injectable substance in the injection pen system dialed or set by the user. Once the dose is set, actuation of the proximal actuation mechanism button, which results in translational movement along the longitudinal central axis of the injection monitoring system housing and the correspondingly housed magnetic field sensor therewith, is used to determine or calculate whether an injection has been initiated. Conversely, correspondingly, when pressure from a finger or thumb is released on the proximal actuation mechanism button, recoil energy within the injection pen causes the pen injection actuation mechanism button to recoil, inducing proximal translation along the longitudinal central axis of the injection monitoring system housing toward the user's thumb or finger, thereby also moving the magnetic field sensor housed within the injection monitoring system proximally. The changes in the magnetic field signal detected by the magnetic field sensor during this movement are processed by the injection monitoring system to determine the end of the corresponding injection or delivery operation. Processing the generated signals for the start and end of injection allows a determination to be made of the dose actually injected between the injection start and end signals.

[0054] Means for measuring the magnetic field to be determined are known in the art. For example, magnetoresistors are well-known. Such magnetoresistors are often referred to by their abbreviations, e.g., AMR, GMR, and TMR sensors, which indicate the physical mechanism by which these sensor components function. Giant magnetoresistance (GMR) is a quantum-mechanical magnetoresistance effect observed in thin-film structures composed of alternating ferromagnetic and non-magnetic conductive layers. Anisotropic magnetoresistance, or AMR, is said to exist in materials in which a dependence of electrical resistance on the angle between the direction of current and the direction of magnetization is observed. Tunnel magnetoresistance (TMR) is the magnetoresistance effect occurring in magnetic tunnel junctions (MTJs), which are components consisting of two ferromagnetic materials separated by a thin insulator. Resistors using these various properties are known per se.

[0055] In light of the above, the injection monitoring module and / or system according to the present invention preferably uses one, more, or a plurality of magnetometers as one, more, or a plurality of magnetic field sensors. Such magnetometers differ from GMR, AMR, or TMR sensors in that they directly measure magnetic field strength. Magnetometers measure magnetic fields in two main ways: vector magnetometers measure the vector components of a magnetic field, and total-field or scalar magnetometers measure the magnitude of a vector magnetic field. Another type of magnetometer is the absolute magnetometer, which measures the absolute magnitude or vector magnetic field using the magnetic sensor's internal calibration or known physical constants. Relative magnetometers, which measure the magnitude or vector magnetic field relative to a fixed but uncalibrated baseline, are also called geomagnetic variance meters and are used to measure magnetic field fluctuations.

[0056] A preferred type of magnetometer for use in the injection monitoring module of the present invention is, in this case, an ultra-low power, high performance, three-axis Hall effect magnetometer. While it is possible to configure a magnetometer to measure the magnetic field along three mutually perpendicular or orthogonal axes, in the present application, it is preferred that the magnetic field sensor be configured to measure the magnetic field along only two of the three orthogonal axes, e.g., the X-axis and the Z-axis.

[0057] According to yet another object of the present invention, an injection monitoring system includes an electronic component board.

[0058] Advantageously, and in accordance with a further object of the invention, one or more magnetic field sensors are electrically connected to the electronic component substrate, which may be usefully arranged on the electronic component substrate at diametrically opposed positions on the electronic component substrate or otherwise radially distributed about the central longitudinal axis, with a single magnetic field sensor preferably arranged on the central longitudinal axis.

[0059] Even more advantageously, the electronic component board comprises an integrated control and data processing unit, e.g., at least one microcontroller, electrically connected to one or more or a plurality of magnetic field sensors for processing information received from the magnetic field sensors. The electronic component board is therefore preferably, for example, a printed circuit board of correspondingly suitable dimensions. In the configuration envisaged by the present invention, such a printed circuit board is advantageously disk-shaped, the centre of which coincides with the intersection with the longitudinal central axis.

[0060] The electronic component board is advantageously housed in a housing disposed proximally of the hollow main body, preferably in a housing of the injection monitoring system disposed beyond the proximal tip of the central bore. Furthermore, the electronic component board is advantageously held such that a horizontal surface of the component board is disposed in a plane substantially perpendicular to the central longitudinal axis. The electronic component board is further disposed in a fixed rotational relationship with the inner sleeve in the first position, e.g., during dose setting, such that rotation of the hollow main body causes the electronic component board to rotate in a synchronous movement aligned with the movement of the inner sleeve. This means that when the inner sleeve is rotated, the at least one or more magnetometers disposed on the electronic component board also rotate about the central longitudinal axis. The fixed rotational relationship of the injection monitoring system to the inner sleeve in the first position can be ensured via any suitable coupling established between the inner sleeve and the injection monitoring system in the first position, e.g., as described herein above with respect to the coupling formed by the at least one injection monitoring system connecting surface and the at least one injection system housing connecting surface.

[0061] An integrated control and data processing unit, comprising at least one microcontroller, handles all electrical communication and signal transmission between the various electronic components of the electronic component board and the magnetic field sensor. This unit is also responsible for performing calculations that allow the precise position of the magnetic field sensor to be calculated and determined, as well as handling signals from the autonomous power supply and communication means integrated into the injection monitoring system, which communicate with a local or remote data processing system, for example on a smartphone. Such integrated control and data processing units are known per se and often incorporate a central processing unit, a real-time clock, one or more memory storage systems, and optionally a communication system or subsystem, along with other desired components.

[0062] According to yet another object, the electronic component board comprises a communication unit in electrical connection with the at least one microcontroller, such communication unit being one or more of any number of communication units known per se, such as a wireless communication unit, for example Bluetooth®, Bluetooth LE® or any other short-range or long-range wireless communication technology.

[0063] According to another further object of the present invention, the electronic component board optionally comprises a rechargeable, self-sustaining power source, for example a lithium-ion battery that can be easily replaced when depleted, or alternatively a rechargeable battery, such as a rechargeable lithium-ion battery. If a rechargeable battery is provided, the rechargeable battery can be recharged once depleted via a corresponding charging port, for example a USB charging port, provided in the injection monitoring module and connected to the rechargeable battery. Non-rechargeable, i.e., single-use batteries, as well as rechargeable batteries, are generally known per se to those skilled in the art. Advances in charging technology have nowadays made wireless charging possible, and such wirelessly rechargeable batteries, for example using an inductive charging system, are also foreseen as a possibility within the scope of the present invention.

[0064] These and other objects of the present invention will become apparent and will be described in more detail in the following description relating to the figures and exemplary monitoring modules.

[0065] The invention will now be described in more detail with reference to the accompanying figures, which are provided for purposes of illustration and description. [Brief explanation of the drawings]

[0066] [Figure 1] 1 is a schematic perspective representation of an injection monitoring module mounted on a one-handed pen injection system. [Figure 2]Figure 1 is a schematic cross-sectional representation of the injection monitoring module mounted on a single-handed pen injection system. [Figure 3] FIG. 3 is a schematic perspective representation of the injection monitoring module of FIG. 1 or FIG. 2. [Figure 4] 3 is a schematic axial representation of the injection monitoring module of FIG. 1 or FIG. 2, viewed from its distal tip along the longitudinal central axis of the module. [Figure 5] FIG. 3 is a schematic perspective exploded view of the injection monitoring module of FIG. 1 or FIG. 2. [Figure 6A] 3 is a schematic cross-sectional representation of the injection monitoring module of FIG. 1 or FIG. 2 in a first and second position about a central longitudinal axis in a dose setting position. [Figure 6B] 3 is a schematic cross-sectional representation of the injection monitoring module of FIG. 1 or FIG. 2 in a first and second position about a central longitudinal axis in a dose setting position. [Figure 7] 3 is a schematic cross-sectional representation of the injection monitoring module of FIG. 1 or FIG. 2 in a dose ejection or administration position. [Figure 8] 6 is a schematic perspective view of a housing of the injection monitoring system forming part of the injection monitoring module of FIG. 1 or FIG. 2 and also shown in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0067] 1 and 2, there is shown a schematic perspective representation 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) comprising 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 includes an actuation button (10) located proximally 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 Figures 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. Examples of such pens are available in the FlexTouch® line of insulin injection pens commercially available from Novo Nordisk.

[0068] The injection monitoring module (1) comprises a hollow main body (11) that is dimensioned and sized to be coaxially mounted around the body (3) of the pen injection system (2). To this end, 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). The hollow main body further comprises a distal body portion (15) that extends around and frictionally engages the outer surface (4) of the body (3) of the injection pen system (2) at a location on the pen body (3) distal from the dose setting wheel (6). 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 to provide a push-fit or slip-fit ​​engagement between the distal portion 15 and the outer surface 4 of the pen body 3; such frictional engagement materials are readily known per se in the art. The hollow main body extends proximally beyond the confines of the actuation mechanism button 10 of the pen injection system 2, with a bore 12 accommodating the dose setting wheel 6 and the actuation mechanism button 10, with the dose setting wheel being free to rotate within the bore 12. The proximal tip 13 of the bore corresponds to the proximal tip of the hollow main body 11.

[0069] 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 (N) pole 18a, 19a and a south (S) pole 18b, 19b, respectively, with the pole pairs preferably oriented in axial alignment from north to south along the longitudinal central axis, with the north pole positioned proximally and the south pole positioned distally. See, e.g., FIG. 5 . The dipole magnets 18, a, 18b, 19a, 19b may be suitably formed into rod shapes, or alternatively, as disks, rings, or any other suitable shapes. The magnets are located in 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 a corresponding annular recess in the proximal tip (13) of said hollow main body. From the above, it will be appreciated that the magnetic field generating means is not free to rotate about its central longitudinal axis because the hollow main body (11) is mounted on the pen body (3) in fixed relationship thereto about said central longitudinal axis (9) and is frictionally held in place at its distal portion over the outer surface (4) of the pen body (3) via frictional engagement means (16).

[0070] 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 together with the dose setting wheel (6) about the longitudinal central axis (9). The inner sleeve (22) is described in more detail below, particularly in relation to Figures 5, 6A and 6B.

[0071] FIG. 3 shows a schematic 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). FIG. 3 also shows that the main hollow body (11) is shaped with a gradually expanding diameter from the proximal tip to a point (23) of the distal section (15) adjacent or adjacent to the distal tip (14). This expanding diameter corresponds to the expanding 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 distal portion (15) has a correspondingly shaped narrowing diameter extending from the widest diameter point (23) of the hollow main body (11) toward the distal tip (14). As described in more detail below with reference to Figures 5, 6A, and 6B, the widest diameter point (23) is also the point at which the hollow main body (11) and the distal portion (15) are preferably configured to prevent translational movement along the central longitudinal axis of the inner sleeve (22).

[0072] FIG. 4 is a schematic representation of an injection monitoring module according to the present invention, as viewed from the distal tip 14 of the distal portion 15 of the hollow main body 11 along the bore 12 and the central longitudinal axis 9, where the central longitudinal axis 9 is represented by the intersection of crosshairs A'-A'' and B'-B'. In this view, the inner circumferential surface 17 of the distal portion 15 of the hollow main body is shown, as is the inner sleeve 22. Also shown are contact or engagement surfaces 24 at the proximal tip of the inner sleeve 22 and corresponding contact or engagement surfaces 25 on the injection monitoring system housing 26 extending distally therefrom into the bore 12, where the engagement surfaces 24 and 25 cooperate as described in more detail below.

[0073] 5 presents a schematic, exploded perspective view of the components of an exemplary injection monitoring module according to the present invention. The hollow main body 11 and distal portion 15 are shown in this representation as separate components that can be assembled together when the distal portion 15 and hollow main body are mounted onto the body 3 of the pen injection system 2. While not required, such a two-component presentation is particularly advantageous in that it not only facilitates insertion of the inner sleeve 22 into the bore 12 and its placement against the exterior surface of the body 3 of the pen injection system 2, but also facilitates its relative positioning with respect to the distal portion 15 and hollow main body, such that translation of the inner sleeve in either the proximal or distal direction is blocked when the monitoring module is mounted onto the body 3 of the pen injection system. For this purpose, the widest diameter point (23) of both the hollow main body (11) and the distal portion (15) is preferably the point where these components are joined together when the injection monitoring module is attached, for example by providing the hollow main body (11) on its distal tip (29) with a distal annular skirt (27) and a proximally projecting distal annular wall (28) of reduced diameter compared to the skirt (27), and the distal portion's proximal tip (31) with a corresponding distally projecting annular wall (30) that engages with the distally projecting annular wall (28) and the corresponding distal annular skirt (27). The hollow main body 11 and the distal portion 15 may be suitably clipped, glued, and / or joined together at their widest points 23, for example, using ultrasonic welding or any other suitable form of joining technique or other engagement means that allows the hollow main body 11 and the distal portion 15 to be held firmly together. Alternatively, both the hollow main body 11 and the distal portion 15 may be provided as a single unit that is appropriately sized and configured to fit around and engage a corresponding injection pen body 3.

[0074] The inner sleeve (22) further comprises at least one or more elastically deformable surfaces (32) extending inward from the inner sleeve (22) towards the central longitudinal axis (9), forming at least one or more frictional engagement surfaces (32) for frictionally engaging with the outer surface of a dose setting wheel. The at least one or more elastically deformable surfaces (32) extending inward from the inner sleeve (22) towards the central longitudinal axis (9) may suitably be provided as a ring (33) of elastically deformable material, the ring (33) comprising a plurality of coaxially aligned and radially spaced teeth extending in the same direction from the ring (33), the ring (33) being usefully located at a proximal tip (34) of the inner sleeve (22), the teeth oriented to extend distally along the outer and / or inner surface of the sleeve (22). Advantageously, the elastically deformable material is a suitable elastomer, for example an SEBS elastomer, which is commonly known per se. The elastically deformable surfaces 32 or teeth extend through a corresponding plurality of coaxially aligned and radially spaced openings 35 that penetrate the inner sleeve 22 from its outer surface 36 to its inner surface 37. As can be easily understood from the above, the elastically deformable surfaces advantageously extend from one side, e.g., from the outer surface 36 of the inner sleeve 22, through and penetrating the body material of the inner sleeve 22 to the other side, e.g., the inner surface 37 of the inner sleeve, thereby providing one or more friction-engaging contact surfaces that contact the outer surface of the dose setting wheel 6 of the pen injection system, ensuring that any rotation of the inner sleeve is transmitted to the dose setting wheel, and vice versa.

[0075] As has been described above, and as shown in more detail in Figures 6A and 6B, which are representative cross-sectional views of an injection monitoring device according to the present invention, the inner sleeve (22) is blocked from translational movement in either the proximal or distal direction along the central longitudinal axis (9). Figures 6A and 6B depict the injection monitoring module in a first or dose setting position, i.e., the position in which the monitoring module will be located after mounting on the injection pen body. The difference between Figures 6A and 6B is simply the rotation of the cross-section about the central longitudinal axis (9). The hollow main body (11) therefore further comprises translational abutment means (38) adapted and configured to prevent axial translational movement of the inner sleeve (22) along the central longitudinal axis when the injection monitoring module (1) is in its mounted position on the injection pen system (2). The translation abutment means 38 is shaped and dimensioned to prevent axial translation of the inner sleeve beyond a predetermined point 23 in or on the hollow main body, at least in the distal direction along the central longitudinal axis 9, but advantageously and preferably also in the proximal direction along said central longitudinal axis 9. To this end, the translation abutment means of the hollow main body 11 is formed as an annular groove 38 or annular slot on the inner surface 17 of the hollow main body 11. The annular groove 38 may preferably be formed by cooperating surfaces, formed from a distally facing surface 39 on the hollow main body 11 and a corresponding proximally facing surface 40 of the distal body portion 15.

[0076] Furthermore, the inner sleeve further comprises a surface engagement means (41) disposed adjacent to or substantially at the distal tip of the inner sleeve, the surface engagement means being configured to engage with the annular groove (38) formed by at least the inner surfaces, e.g., the distal-facing surface (39) and the proximal-facing surface (40), of the distal body portion (15) and the hollow main body (11) when the injection monitoring module (1) is in its mounted position on the injection pen system (2), thereby preventing distal and / or proximal translation of the inner sleeve. To this end, the surface engagement means (41) may suitably be formed by at least one continuous protrusion (41) or a plurality of separate protrusions (41a, 41b, 41c, etc.) extending radially outward from the outer surface (36) of the inner sleeve (22). The protrusions (41) have at least one distally facing surface (42) that engages a corresponding proximally facing surface (40) of an annular groove (38) on the inner surface (17) of the hollow main body (11). When the injection monitoring module is mounted on the pen injection system, the interaction between the cooperating surfaces of the protrusions (41) and the annular groove (38) and corresponding surfaces (39, 40) prevents any substantial translational movement of the inner sleeve (22) along the central longitudinal axis (9), although the groove (38) and protrusions (41) are appropriately and correspondingly sized to nevertheless permit rotation of the inner sleeve (22) about the central longitudinal axis (9), such that the protrusions (41) are free to move within the grooves (38) about the axis (9) when rotational or advancing forces are applied to the inner sleeve (22), for example, during dose setting.

[0077] As can be seen from the figures, particularly Figures 5, 6A, and 6B, the inner sleeve is further connected to an injection monitoring system (43), shown in square brackets, which comprises several components, among them the injection monitoring system housing (26). The injection monitoring system housing (26) is shaped and configured like a cup with legs, having a base wall (44) extending substantially perpendicular to the central longitudinal axis over substantially the same or similar diameter as the hollow main body (11), and a first annular wall (45) extending from the outer periphery of the base wall (44) and proximally away from said base wall (44) to form a cup-shaped portion having an interior volume closed by a proximal cap (46) forming a push button, which is secured to said proximally extending first annular wall (45) at a proximal tip (47) of said first annular wall by a snap fit, a press fit, adhesive, or otherwise. The base wall (44) further includes a second annular wall (48) extending distally from the base wall (44) at a location radially spaced from the central longitudinal axis (9) and having a diameter smaller than the diameter of the hollow main body bore (12). The second annular wall (48) is closed at its distal tip (49) by a transverse wall (50) to form a leg of a cup. The leg of the cup fits within the hollow main body bore (12). The injection monitoring system housing (26) is defined by a cup-shaped interior volume and receives and anchors an electronic component board (51). The interior volume of the leg formed by the second annular wall (48) and the transverse wall (50) receives a self-sustaining power source (52), such as a single-use or rechargeable battery, e.g., a lithium-ion battery, electrically connected to and powering the electronic component board (51). The electronic component board (51) is generally a printed circuit board suitably sized to be placed within the interior volume of the cup formed by the base wall (44) and the proximally extending first annular wall (45).The injection monitoring housing (26) optionally further comprises a light-guiding window (54) integrated into or part of the first annular wall (45), e.g., a molded translucent, opaque, or transparent material with crystalline properties selected to guide light waves from the interior volume of the cup, e.g., as generated by an optionally present light-emitting diode or other light-wave generating component, to the outside of the injection monitoring system housing (26).

[0078] The electronic component board (51) further comprises at least one magnetometer (53), advantageously disposed on the longitudinal central axis, and in the case of a substantially circular component board, substantially at its center so as to be aligned with the longitudinal central axis. In addition to the magnetometer (53), the injection monitoring system (43) also comprises an integrated control and data processing unit (55), electrically connected to the magnetometer (53), for processing information received from the magnetometer. The integrated control and data processing unit (55) handles all electrical communication and signaling between the various electronic components of the injection monitoring system. This unit is also responsible for performing calculations that allow for calculating and determining the precise position of the dosage management system and the magnet, as well as handling signals from the autonomous power source (52). The electronic component board is further connectable to a USB port 56, which can be configured as a power recharging port for the rechargeable battery 52 and / or to allow basic setup of any programmable memory on the electronic component board or to configure the data processing unit 55. The integrated control and data processing unit 55 also typically includes communication means, such as wireless communication circuitry, for communicating with a local or remote data processing system on a smartphone, e.g., a Bluetooth® or Bluetooth LE® wireless communication system, to name just two of many types of suitable communication means. The integrated control and data processing unit 55 can be suitably programmed remotely upon first use or receive and update information, e.g., wirelessly or via any other suitable link, such as the USB port 56, in a manner similar to other electronic devices today that include integrated control and data processing units. Such integrated control and data processing units are known per se and often incorporate a central processing unit, a real-time clock, one or more memory storage systems, and optionally a communication system or subsystem, together with other desired components.The electronic component board (51) is mounted or positioned within the cup formed by the base wall (44) and the first annular wall (45) of the injection monitoring system housing (26) substantially along the horizontal plane of the circuit board, i.e., vertically and generally perpendicular to the central longitudinal axis (9).

[0079] The injection monitoring housing further comprises a third annular wall (57) around the periphery of the base wall (44) and extending distally from said base wall (44) toward the hollow main body (11). As can be seen in Figures 6A, 6B, and 7, this third annular base wall (57) provides axial stability to the injection monitoring system housing (26), particularly to the extent that it is sized to surround the periphery of the hollow main body at its proximal tip (13), both when in the first dose set position and when the actuation mechanism button (10) is being actuated, i.e., during injection and / or ejection of a substance from the injection pen system.

[0080] Figures 7 and especially 8 both show some of the details relating to the physical connection between the inner sleeve 22 and the injection monitoring system housing 26. In particular, this connection is adapted and configured to allow co-rotation of both the inner sleeve 22 and the injection monitoring system housing 26 about the central longitudinal axis 9 in a first position, i.e., during dose setting, and then to allow translation, but not rotation, of the injection monitoring system housing 26 along the central longitudinal axis 9 in a second position, i.e., during injection and / or delivery of a medication from the pen injection system.

[0081] Advantageously, the connection between the inner sleeve 22 and the injection monitoring system housing is provided through a series of interacting and interoperating connection surfaces 24, 25. Accordingly, the inner sleeve 22 includes at least one injection monitoring system connection surface 24, i.e., a surface that connects, contacts, or engages with the injection monitoring system, extending from the inner surface 22 of the sleeve and projecting inward toward the central longitudinal axis 12 of the bore. As shown in FIG. 7 , where the injection monitoring module 1 is moved to the discharge or injection position to activate the actuation mechanism button of the pen injection system, the connection surface 24 is an annular surface formed on the innermost periphery 58 of an annular shoulder 59 that extends radially inward from the proximal tip of the inner sleeve 22 into the bore 12. Usefully, such connection surface 24 further includes at least one or more recesses 60 on the inwardly projecting connection surface.

[0082] The injection monitoring housing 26, in turn, includes at least one corresponding connecting surface 25 extending distally from the housing 26. As shown, the connecting surface 25 extending distally from the injection monitoring housing 26 is provided as a plurality of one or more small projections 61, one or more of which further include a distal tip contact surface 62. The small projections 61 extend from either the base wall 44, the distal tip 49 of the second annular wall 48, and / or the transverse wall 50, and are radially spaced apart from one another about the central longitudinal axis 9. Some of the small projections 61, e.g., three small projections, are shaped and dimensioned to fit into corresponding recesses 60 in the inwardly projecting annular shoulder 59. The remaining small protrusion (61) then provides a rotational lock between the inner sleeve (22) and the injection monitoring system housing (26) in the first dose set position. The remaining small protrusion (61) protrudes further distally and has a length sufficient to engage and contact the actuation mechanism button (10) of the pen injection system when an injection and / or delivery operation is performed using the pen injection system, e.g., to deliver a dose of an injectable substance, such as a medication, when the injection monitoring module is moved from the first dose set position to the second dose delivery and / or injection position.

[0083] The cooperating connecting or contacting surfaces (24, 25) then engage one another in a first position, and rotation of the injection monitoring system housing (26) by the user using the fingers and / or thumb, in accordance with the normal mode of operation of an injection pen system of the type described, causes co-rotation of the inner sleeve (22), which also engages the outer surface of the dose setting wheel (6), thereby enabling the dose to be set. Once the dose has been set, pushing the cap distally with the thumb and / or fingers causes the connecting surfaces (24, 25) to translate along the central longitudinal axis (9) without any rotational movement into sliding engagement with one another. In doing so, the small protrusion (61) is moved within the bore (12) along the central longitudinal axis (9) until the distal tip contacting surface (62) contacts the actuation mechanism button (10), which corresponds to the second position. Because the longitudinal distance between the actuation mechanism button's non-contact with the distal surface 62 and its contact is only a few millimeters, and this axial translational distance is known, the data processing unit can be configured to calculate how long the distal tip contact surface remains in contact with the actuation mechanism button. For example, an elapsed time method can be used in such situations, calibrated for a predetermined detectable change in the magnetic field along the longitudinal axis when the magnetic field sensor is moved from a first dose set position to a second dose delivery / injection position and then back due to repulsive energy imparted to the actuation mechanism button 10 of the injection system 2 by an internal detent spring of such a pen injection system. The elapsed time calculation by the data processing unit also enables further preprogrammed calculations for determining the injection start point and the corresponding injection end point, which are temporarily stored in the data processing unit of the injection monitoring module for later transmission via the communication unit, e.g., wireless communication, to a remote device, such as a smartphone, tablet, or other remote computing device.

[0084] The following is an example of how the injection monitoring module can be used: The monitoring module is mounted on a pen injection device, such as a Flextouch® insulin pen. The user holds the body of the pen in one hand while rotating the housing of the injection monitoring system using the fingers and / or thumb of the other hand. Rotation of the injection monitoring system housing (26), which is rotationally locked to the inner sleeve (22) via the connecting surfaces (24, 25), causes rotation of the dose setting wheel (6) of the injection pen due to frictional contact between the inner sleeve and the outer surface of the dose setting wheel (6); Rotation of the magnetometer (53) about the longitudinal central axis (9) during dose setting causes the magnetometer (53) to register variations in the magnetic field as a function of the angular position of the magnetometer relative to the magnet using a data processing unit. When the user presses the proximal cap (46), the injection monitoring housing (26) translates distally along the central longitudinal axis (9). As a result of this translation, the magnetometer also translates distally along said axis and any change in the detected magnetic field is signaled to a data processing unit. The distal contact surface (62) of the small protrusion (61) contacts the actuation mechanism button, thereby initiating the injection / dispensing action. No further translational movement in the proximal direction occurs during the injection / dispensing operation because the actuation mechanism button has a predetermined constrained limit of longitudinal movement, typically less than 1 mm. When the user releases the pressure of their thumb or finger on the cap (46), the actuation mechanism button, under the momentum of the recoil energy imparted to it by the pen system, recoils just enough to transfer said recoil energy to the distal surface (62) of the protuberance (61), thereby moving the injection monitoring housing (26) proximally from the second position back to the first position. The magnetometer moves the same translational distance along its central axis away from the magnet and sends the corresponding magnetic field change as a signal to the data processing unit. The data processing unit then performs calculations to determine the injection start point, injection end point, and the actual dose expelled and / or injected, for example using time-flight correlation methods based on the known travel distance and the signaled magnetic field.

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 proximally located dose setting wheel 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 secured against rotation during injection, the injection monitoring module comprising: 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 located on or in 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 located at the proximal tip of the bore of the hollow main body; Equipped with the hollow main body further comprises an inner sleeve located 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 together 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; an injection monitoring module, wherein 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.

2. 10. The injection monitoring module of claim 1, wherein the hollow main body further comprises a distal body portion at a location distal from the dose setting wheel that extends around and frictionally engages an outer surface of the body of the injection pen system.

3. 2. The injection monitoring module of claim 1, wherein the hollow main body further comprises a translation abutment means adapted and configured to prevent axial translation of the inner sleeve along the central longitudinal axis when the injection monitoring module is in the mounted position on the injection pen system.

4. 4. The injection monitoring module of claim 3, wherein the translational abutment means of the hollow main body is formed as an annular groove or annular slot provided on the inner surface of the hollow main body.

5. 5. The injection monitoring module of claim 3 or 4, wherein the translational abutment means is formed from a distally facing surface on the hollow main body and a corresponding proximally facing surface of the distal body portion, the distally facing surface and the proximally facing surface together forming a cooperating translational abutment surface for the inner sleeve.

6. 2. The injection monitoring module of claim 1, wherein the inner sleeve further comprises a surface engagement means located adjacent to or substantially at a distal tip of the inner sleeve, the surface engagement means configured to engage an inner surface of at least a distal body portion of the hollow main body when the injection monitoring module is in the mounted position on the injection pen system, thereby preventing distal and / or proximal translational movement of the inner sleeve.

7. 7. The injection monitoring module of claim 6, wherein the surface engaging means comprises at least one continuous protrusion or a plurality of separate protrusions extending radially outward from the outer surface of the inner sleeve.

8. 8. The injection monitoring module of claim 6 or 7, wherein the surface engagement means comprises at least one distally facing surface, the distally facing surface of the surface engagement means engaging a corresponding proximally facing surface of a translation abutment means provided on an inner surface of the hollow main body.

9. 9. An injection monitoring module according to claim 3, wherein the surface engagement means comprises at least one continuous protrusion or a plurality of separate protrusions extending radially outward from an outer surface of the inner sleeve, and the translation abutment means of the hollow main body is formed as an annular groove or annular slot provided on the inner surface of the hollow main body, the annular groove or annular slot adapted and dimensioned to receive in cooperating proximal and distal surface engagement the at least one continuous protrusion or a plurality of separate protrusions extending radially outward from the outer surface of the inner sleeve.

10. 2. The injection monitoring module of claim 1, wherein the inner sleeve further comprises at least one or more resiliently deformable surfaces extending inward from the inner sleeve toward the central longitudinal axis forming at least one or more frictional engagement surfaces for frictionally engaging an outer surface of the dose setting wheel.

11. 11. The injection monitoring module of claim 10, wherein the at least one or more elastically deformable surfaces extending inward from the inner sleeve toward the central longitudinal axis are a ring of elastically deformable material, the ring comprising a plurality of coaxially aligned and radially spaced teeth extending in the same direction from the ring, the ring being located at a proximal tip of the inner sleeve, and the teeth being oriented to extend distally along an outer and / or inner surface of the sleeve.

12. 10. The injection monitoring module of claim 1, wherein the inner sleeve further comprises a plurality of coaxially aligned and radially spaced openings extending through the inner sleeve from the outer surface to the inner surface.

13. 13. The injection monitoring module of claim 10, 11, or 12, wherein the at least one or more elastically deformable surfaces extend through the plurality of radially spaced openings through the inner sleeve.

14. 10. The injection monitoring module of claim 1, wherein the inner sleeve further comprises at least one injection monitoring system connection surface extending from an inner surface of the sleeve and projecting inward toward the central longitudinal axis of the bore.

15. 15. The injection monitoring module of claim 14, wherein a connection surface of the at least one injection monitoring system extending from an inner surface of the sleeve and projecting inwardly toward the central longitudinal axis of the bore comprises at least one or more recesses provided on the inwardly projecting connection surface.

16. 10. The injection monitoring module of claim 1, wherein the injection monitoring system comprises a housing, the housing of the injection monitoring system comprising at least one connecting surface extending distally from the housing.

17. 17. The injection monitoring module of claims 15 and 16, wherein the connecting surfaces of the at least one injection monitoring system and the connecting surfaces of the housing of the at least one injection system are adapted and configured to interengage with each other in a first position in which rotation of the housing of the injection monitoring system causes the inner sleeve to co-rotate, and to interengage with each other in a second position in which the injection monitoring system only translates distally or proximally along the central longitudinal axis without rotating the housing of the injection monitoring system about the central longitudinal axis.

18. 17. The injection monitoring module of claim 16, wherein the at least one connecting surface extending from the housing of the injection monitoring system comprises at least one or more distally extending protrusions extending from a distal tip of the housing and coaxially aligned with the central longitudinal axis.

19. 19. The injection monitoring module of claim 14, wherein in the first position, the at least one or more distally extending protrusions of the injection monitoring system housing each include an outwardly facing connecting surface that frictionally engages a corresponding inwardly facing surface of the at least one or more recesses in the inwardly protruding connecting surface.

20. 20. The injection monitoring module of claim 14, wherein in the second position, the at least one or more distally extending protrusions extending from the housing of the injection monitoring system further comprise at least one distally facing contact surface for contacting the injection actuation mechanism.

21. 10. The injection monitoring module of claim 1, wherein the injection monitoring system is further configured to determine an amount of time that has elapsed while the injection monitoring system is in physical contact with a pen actuation mechanism of the pen injection system.

22. The injection monitoring module of claim 1 , wherein the injection monitoring system further comprises an electronic component board.

23. 23. The injection monitoring module of claims 1 and 22, wherein the one or more magnetic field sensors are electrically connected to the electronic component board.

24. 23. The injection monitoring module of claim 21 or 22, wherein the electronic component board comprises at least one microcontroller in electrical communication with the one or more magnetic field sensors.

25. 25. The injection monitoring module of claims 22 and 24, wherein the electronic component board comprises a communication unit in electrical communication with the at least one microcontroller.

26. 23. The injection monitoring module of claim 22, wherein the electronic component board comprises a rechargeable power source.

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