Injection monitoring module

Abstract

To provide an injection monitoring module adapted and configured to be removably attached to the proximal extremity of an injection pen system for delivery of a drug.SOLUTION: An injection monitoring module comprises a hollow main body and an injection monitoring system. The hollow main body is coaxially attached with a dose setting wheel at the proximal extremity of the injection pen system to be adapted and configured so as to be co-rotated and engaged with it. A central longitudinal bore has a proximal extremity and a distal extremity. The injection monitoring system is arranged at the proximal extremity, within a cavity. The injection monitoring system is movable along the central longitudinal axis from a first monitoring position to a second monitoring position, within the cavity. The injection monitoring system is not in abutting contact with a proximal surface of an injection activator at the first monitoring position, and the injection monitoring system is in abutting contact with the proximal surface of the injection activator at the second monitoring position.SELECTED DRAWING: Figure 1

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.

[0002] Injection monitoring is a well-known field in the context of injectable drug delivery devices, particularly for example injection systems. Over time, such monitoring systems have recently been introduced into injection pen systems for delivering drugs in an attempt to allow users of such pen injection systems and medical personnel involved in the treatment and follow-up of such patients to monitor their injection regimes and, in many cases, the dose actually administered in more detail, leading to better medical outcomes. These developments have been accompanied by an increase in the use of associated software and portable communication devices, such as tablets or smartphones, which are programmed to receive information from and interact with the monitoring system in order to provide information to the user or medical personnel, either during execution or at regular intervals, via a suitable communication unit included in the monitoring system.

[0003] One of the challenges, particularly with regard to pen injectors, is to provide an easy to use, reliable and highly fail-safe system that can be adapted to the various different variants of such commercially available pen injectors (of which there are many). Previous attempts to provide such monitoring systems have typically involved adapting the body of the pen injector by equipping it with electronic components, together with one or more sensors therein. However, one of the main drawbacks of such systems is that the end product, with all electronic components integrated at once, tends to be very bulky and cumbersome, and therefore more difficult to use from the user's point of view. Also, such conversion systems tend to be highly specific to a particular brand or manufacturer, and therefore of little or no use with other manufacturers. Furthermore, to overcome the problem of bulk and cumbersomeness of the modified pen injectors, there is a tendency to try to make the overall volume of the injection pen body as small as possible by miniaturizing the complex electronic components, but doing so brings its own problems, particularly with regard to electromagnetic interference between the various components due to the close proximity of the circuits providing the required or desired integrated functionality. In such monitoring systems, moving the sensor further away from sources of electromagnetic interference only complicates the problem and can lead to erroneous readings, or requires additional systems to compensate for the sensor's physical separation from other electronic components (e.g., microcontrollers designed to control, command and manage the interactions between the various components).

[0004] The pen injectors discussed are well known per se and typically comprise a proximally located dose setting wheel and an injection actuator, the latter being rotatable about the central longitudinal axis of the pen injector. The wheel is rotated by the user to select the dose of drug to be administered. The pen is typically configured mechanically or electromechanically to perform an injection upon activation of the injection actuator. Such an injection actuator is most commonly a simple press button or push button that is in mechanical or electrical contact with an ejection mechanism located within the pen injection system, the depression of which activates the injection mechanism and injects the drug 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 achieved by including one or more metal parts, for example a helically wound drive spring, located within the housing of the injection pen system and physically coupled to the dose setting wheel. Because such metallic elements are relatively large objects compared to the electronic systems found in many pen injectors today, such large metallic objects can further disrupt the signals that the sensors of such electronic systems are designed to capture and pick up, potentially reducing the accuracy of the system and / or requiring the implementation of complex compensation mechanisms to avoid calculation errors.

[0005] Several attempts to overcome the difficulties of electronic component integration have already been described in the patent literature.

[0006] For example, published PCT patent application WO2014128156A1 relates to a sensor assembly having a first rotating sensor part with a plurality of discrete conductive sensor areas arranged in a pattern and a second rotating sensor part rotatably arranged relative to the first part, the sensor assembly including a plurality of contact structures adapted to contact the conductive sensor areas on the first sensor rotating part. The contact structures are configured to engage and connect with the different sensor areas as the first and second parts of the rotating sensor rotate relative to each other, the connection formed being indicative of a rotational position between the first and second parts. One of the contact structures is an actuatable contact structure axially movable relative to the first part, the actuatable contact structure having a connected position in which the actuatable contact structure is in contact with the sensor areas and a disconnected position in which the actuatable contact structure is not in contact with the sensor areas. The system is contained within the pen injector body and at least partially housed within a space within the dose setting wheel. The system also includes a visual display device, such as an LCD display, located on or in place of the injection activation button.

[0007] In comparison, published PCT application WO2018013419A1 relates to a dose detection system including a dosing member attached to an actuator and movable in a rotational and axial direction relative to a coupling member attached to a dose setting member, the dose detection system comprising a module including an electronic sensor operable to detect the relative rotation of the coupling member and the dosing member and to detect the dose delivered by the drug delivery device. The dose detection module is removably coupled to a proximal end of the pen injection system and is intended to function as a means, when attached to the pen injection system, for detecting the amount of drug dispensed by the pen injection system, storing the detected dose in a memory and transmitting a signal representative of the detected dose to a remote communication device. The system comprises a pair of rotatable and translatable cylinders which interact with each other via electrical contacts provided on the cylinder surfaces to indicate various states or positions of the injection dosing process, including dose setting, the electrical contacts being connected to a collection of electronic components housed on a flexible printed circuit board. The printed circuit boards are arranged in an accordion-style configuration with overlapping folds within the removable assembly, with electrically non-conductive spacer layers insulating the overlapping layers of the circuit boards to prevent potential electrical, electronic and electromagnetic interference.

[0008] It is immediately apparent from the above configuration that, despite the use of a folded flexible printed circuit board to provide multiple surfaces on which the electronic components are located, 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 increases the complexity of the clip-on dose detection module described therein.

[0009] It is therefore one object of the present invention to provide an injection monitoring module adapted and configured to be removably attached to the proximal end of an injection pen system for delivering a drug, the injection pen system having a rotatable dose setting wheel for setting the dose of drug to be injected, said dose setting wheel also rotating during injection, said injection monitoring module being of a much simpler configuration and at the same time eliminating the need for complex shielding or protection solutions to counter unwanted electrical, electronic or electromagnetic effects caused by the relatively high density of electronic components in the monitoring module.

[0010] Another object of the present invention is to provide such an injection monitoring module, which is adapted and configured to detect an injection end point in a pen system having a rotary dose setting wheel that rotates during injection. For the purposes of the present invention, the expression "injection end point" as used herein does not only mean the completion of an injection of a dose of an injectable substance such as a drug (when the user injects the required dose of the injectable substance in one actuation), but also includes any amount of drug actually released by the pen injection system when the injection monitoring module is attached to the pen injection system. This means that when the user performs a series of small repeated injection acts, for example by repeated successive actuations of the injection actuator, a corresponding end point is registered for each injection step and a corresponding amount of injectable substance calculated to have been injected or released from the pen injection system is registered.

[0011] These and other objects of the present invention will become readily apparent from a complete reading of this specification.

[0012] Therefore, in accordance with any of the above objects, there is provided an injection monitoring module adapted and configured to be removably attached to a proximal end of an injection pen system for drug delivery, the injection pen system comprising a proximally disposed dose setting wheel and an injection actuator, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting and during injection, the injection monitoring module comprising a hollow body and an injection monitoring system; the hollow body is adapted and configured to be coaxially mounted to, and to rotate and engage with, the dose setting wheel at the proximal end of the pen injection system; the hollow body includes a central longitudinal lumen having a proximal end and a distal end; the injection monitoring system is disposed within a central longitudinal cavity of the body at a proximal end thereof and extends proximally along the longitudinal axis beyond the proximal end; The injection monitoring system is movable within the longitudinal central cavity of the body along a central longitudinal axis from a first monitoring position to a second monitoring position, where in the first monitoring position the injection monitoring system is not in contact with a proximal surface of the injection actuator and where in the second monitoring position the injection monitoring system is in contact with a proximal surface of the injection actuator.

[0013] As used herein, the terms "pen injection system" and "injection pen system" are used interchangeably to refer to a typical hand-held pen injection system, which is easily familiar as such and is commercially available for use in the treatment of many different medical indications. These systems are also generally designed for self-injection of a drug by a user who is in need of treatment for a given medical indication. This is the case, for example, of insulin intended for the treatment of diabetes, an example of which is the pen injector sold under the brand names Lantus® and SoloSTAR® by Sanofi-Aventis. However, other drugs also fall into this category, and it has become common for patients suffering from or susceptible to such diseases to carry around these devices, for example to deal with potentially life-threatening situations and to be able to immediately administer emergency injections of the required drugs (e.g., anaphylactic shock medications, anticoagulants, opioid receptor agonists and antagonists, etc.).

[0014] The injection pen system adapted and configured for removably mounting the injection monitoring module of the present invention comprises a proximally disposed dose setting wheel and an injection actuator. The dose setting wheel rotates about the longitudinal central axis of the pen injector, allowing the user to set the dose of the drug to be injected. The dose setting wheel is typically rotatable in both clockwise and counterclockwise directions, which typically correspond to an increase in the selected dose and a decrease in the selected dose to be administered, respectively. The injection actuator is often a push button. When the user of the injection system presses the injection actuator distally, it drives a piston connected to a plunger to expel the drug from a chamber in the injection pen body through a needle that the user has inserted into an appropriate injection site (e.g., skin, adipose tissue, muscle, etc., depending on the type of drug to be administered). The dose setting wheel is connected to an injection drive mechanism, which causes the dose setting wheel to also rotate as the injection of the drug proceeds. The function of such an injection system is per se well known in the art.

[0015] The injection monitoring module according to the present invention is therefore adapted and configured to be removably attached to the proximal end of such an injection pen system. The expressions "removably attached" or "removably attachable" as may be used herein should be understood to refer to the possibility of attaching and subsequently detaching the injection monitoring module, for example when transferring the injection monitoring module to another pen injection system, or for example when the monitoring module is damaged during use and requires replacement. Such attachment and subsequent detachment can be achieved by providing the monitoring module with coupling means for releasably engaging with the proximal end of the pen injection system, for example engaging either the dose setting wheel or the injection actuator, or both, via frictional or elastic engagement or other releasable fastening means such as clips, straps, threads and corresponding fastening rings, etc.

[0016] In view of the above, therefore, the removably attached injection monitoring module comprises a hollow body adapted and configured to be coaxially mounted to, and to rotate and engage with, a dose setting wheel at the proximal end of the pen injection system.

[0017] The hollow body of the injection monitoring module comprises a longitudinal central lumen having a proximal end and a distal end. The distal end of the lumen is preferably configured and dimensioned to resiliently engage, e.g., via friction, and surround an outer surface of the dose setting wheel of the pen injection system, such that when the hollow body rotates, the dose setting wheel in turn rotates in the same direction and to substantially the same or identical degree of rotation, and conversely, when the dose setting wheel rotates, the hollow body also rotates. In this manner, the hollow body is said to rotate together with the dose setting wheel. The hollow body is suitably made of any suitable material, e.g., a durable polymer or plastic material. Advantageously, the hollow body is made of a transparent, translucent, or opaque material, so that the user can grasp and recognize any visual cues, such as light emitting diodes, which can optionally be used to indicate various operating states of the injection monitoring system.

[0018] The injection monitoring module also comprises an injection monitoring system disposed within the central longitudinal cavity of the body at its proximal end and extending proximally along said longitudinal axis beyond said proximal end. The injection monitoring system is described in more detail below, but essentially the injection monitoring system comprises a number of different components and means for providing monitoring of the injection status, for example as follows: -Start of injection procedure. - Completion of an injection operation (wherein completion of an injection operation is understood to include both the administration of the entire selected dose of the substance to be injected, or a discontinuous injection operation where the user injects only a portion of the dose or expels a portion of the selected dose from the pen injection system).

[0019] Further in accordance with the subject matter of the present invention, the injection monitoring system is movable within the central longitudinal cavity of the body along the central longitudinal axis from a first monitoring position in which the injection monitoring system is not in contact with the proximal surface of the injection actuator to a second monitoring position in which the injection monitoring system is in contact with the proximal surface of the injection actuator.

[0020] From the above, it will be appreciated that the injection monitoring system is movable from an initial position in which there is no physical contact between the monitoring system and the actuator button to a different position in which physical contact is established between the monitoring system and a proximal face of the injection actuator, such movement generally being a translational movement of the monitoring system from a first position to a second position along a central longitudinal axis within the lumen of the hollow body.

[0021] According to another object of the invention, the monitoring module of the invention comprises a magnetic field generating means, of which various means are known, such as classical magnets, electromagnets, mixed material magnets, etc. Such magnets are usually made of magnetizable materials having magnetic or paramagnetic properties, which generate or induce a magnetic field in said material, either naturally or by passing an electric or other current through or affecting said material. Suitable materials can be selected from the following: - Ferrite magnets, especially sintered ferrite magnets, which contain a crystalline compound of iron, oxygen and strontium. -A composite material consisting of a thermoplastic matrix and isotropic neodymium-iron-boron powder. - A composite material made of a thermoplastic resin matrix and strontium-based hard ferrite powder, where the resulting magnet can contain isotropic, i.e. non-oriented, and anisotropic, i.e. oriented, ferrite particles. -A composite material made of a thermosetting plastic matrix and isotropic neodymium-iron-boron powder. - Magnetic elastomers, produced for example by highly filling strontium ferrite powder and mixing it with synthetic rubber or PVC, followed by extrusion into the desired shape or calendaring into fine sheets. - A flexible calendered composite material, generally having the appearance of a brown sheet, more or less flexible depending on its thickness and composition. These composites are not rubber-like in elasticity and tend to have a Shore hardness in the ANSI Shore D range of 60-65. 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 an arrangement of magnetic particles depending on the calendering process. - A laminated composite material, typically comprising soft iron plates laminated together in a flexible composite material as described above. -Neodymium-iron-boron magnets. -Made from an aluminum-nickel-cobalt alloy and magnetized steel. -An alloy of samarium and cobalt.

[0022] 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 made of a thermoplastic matrix and a strontium-based hard ferrite powder, and composites made of a thermosetting plastic matrix and an 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.

[0023] The magnetic field generating means may be of any suitable general shape, for example a disk shape including a circle, an ellipse or any other suitable polygon, but preferably has only a single dipole, with a pair of diametrically opposed north and south magnetic poles. The magnetic field generating means may be substantially disk shaped, but such disk shape may include a magnet having an orifice substantially in the center of the disk, forming a ring or annular magnet.

[0024] According to one advantageous object of the invention, the magnetic field generating means comprises two diametrically aligned single dipole magnets, the magnets crossing the diameter of the hollow cavity at opposite positions of said diameter and aligned substantially along the circumference of said cavity. The terms "alignment" or "aligned" as used herein mean that the poles of the magnets are aligned along the longitudinal axis of each magnet. Such a configuration can be obtained, for example, by using a bar-shaped or cylindrical magnet having a first and a second end, the first pole being substantially located at the first end and the second and opposite pole being located at the second end of the bar-shaped magnet. Furthermore, each magnet is arranged at opposite positions on the circumference of the hollow cavity, whereby the bar is aligned longitudinally with one end relative to the other end. The magnetic poles of each magnet may be arranged end to end in opposition to the other end, for example in a NS / SN arrangement or a SN / NS arrangement, but preferably and advantageously the magnetic poles are arranged in a repeating configuration, with the poles aligned in a NS / NS arrangement or a SN / SN arrangement.

[0025] In a further object of the present invention, the magnetic field generating means is accommodated in the cavity of the hollow body immovably around the central longitudinal axis. Here, the term "immovable" can be understood to mean that the magnetic field generating means is arranged in a fixed position along the central longitudinal axis relative to the cavity of the hollow body, which also means that the magnetic field generating means does not undergo any longitudinal translational movement within the injection monitoring module. For example, the magnetic field generating means can be arranged or incorporated in the material forming the hollow body, having the effect of generating a magnetic field that extends at least partially within the cavity of said hollow body.

[0026] Alternatively, and advantageously, according to yet another object of the invention, the magnetic field generating means are integrated, inserted or otherwise introduced into a separate magnetic field generating means support, which in this case is advantageously configured and dimensioned to form a disk or an annular disk (i.e. a disk configured to form a disk with a hole substantially in its center). The annular disk is introduced into the cavity of the hollow body and positioned therein, coaxially aligned with the central longitudinal axis and located in a fixed longitudinal position. A disk of such configuration, when formed as an annular disk, advantageously protrudes radially inwardly into the cavity from the inner circumferential surface thereof, forming a narrowing of the cavity diameter at the radially innermost end of such protrusion.

[0027] It will be appreciated that when the magnetic field generating means is immovably arranged (i.e. immovable in terms of longitudinal translational movement) within the lumen of the hollow body, for example in the manner and configurations described above, the magnetic field generating means nevertheless maintains a degree of freedom with respect to the hollow body and its central longitudinal axis that allows it to rotate together with said hollow body, albeit about a fixed longitudinal position. This means that when either the dose setting wheel or the hollow body rotates, the magnetic field generating means also rotates to the same extent about its central longitudinal axis.

[0028] According to another object of the present invention, the injection monitoring system is mounted in a selectively engageable and respectively disengageable clutch assembly. The expression "clutch assembly" as used herein means an assembly configured to selectively move the injection monitoring system from a first engaged position to a second disengaged position, which in the context of the present invention corresponds to the first monitoring position in which the injection monitoring system is not in contact with the proximal surface of the injection actuator and the second monitoring position in which the injection monitoring system is in contact with the proximal surface of the injection actuator, respectively. The concepts of "engagement", "engageable", "disengagement" and "disengageable" as used herein are provided to facilitate understanding of how the clutch assembly functions with respect to the injection monitoring system mounted thereon and will be described in further detail below. One purpose of the clutch assembly is to provide a method or means by which longitudinal translation of the injection monitoring system along a central longitudinal axis can be accomplished.

[0029] In accordance with yet another object of the present invention, a clutch assembly includes a first distal body and a second proximal body, and further includes a biasing member located between the first distal body and the second proximal body. The first and second bodies are physically connected or coupled to one another at suitable locations on the first distal body and the second proximal body, for example by ultrasonic welding. The first and second bodies are advantageously sized and configured to fit within a hollow cavity of the body and to be capable of translational movement therein along a central longitudinal axis.

[0030] According to yet another object of the present invention, the first distal body and the second proximal body of the clutch assembly are connected together along the central longitudinal axis via an elongated hollow connecting member. In this configuration, the elongated hollow connecting member forms a tube between the first distal body and the second proximal body. The connecting member can be integrally formed with either the first distal body or the second proximal body, or alternatively can be partially integrally formed with both the first distal body and the second proximal body and can be formed as a separate hollow elongated connecting member that is bonded together or joined to both the first distal body at its proximal end and the second proximal body at its distal end. Such a connection can be obtained, for example, by ultrasonically welding each of the distal and proximal bodies, or, if the connecting member is not integrally formed with either the first or second body, by assembling and welding each of the distal and proximal bodies with the connecting member.

[0031] According to yet another object of the present invention, the first distal body of the clutch assembly is disposed distal to the magnetic field generating means.

[0032] According to yet another object of the present invention, a second proximal body is arranged proximal to the magnetic field generating means.

[0033] From the above, it will be appreciated that the first distal body and the second proximal body are optimally disposed on either side of the magnetic field generating means and are also connected to each other via an elongated hollow connecting member, with a fixed distance relationship between said first distal body and said second proximal body. As mentioned above, the magnetic field generating means is disposed in a fixed relationship within the hollow body of the injection monitoring module, and the first and second bodies are disposed on either side thereof, which means that the first and second bodies can only translate longitudinally either distally or proximally along said longitudinal central axis from a first position to a second position, for a predetermined travel distance, before one or the other contacts the radially inwardly projecting surface of the annular disk of the magnetic field generating means.

[0034] The bias member is disposed between the first distal body and the second proximal body, and is preferably and advantageously further proximal to the magnetic field generating means and distal to the second proximal body. The bias member is typically a pre-compressed bias member such as a spring, and a suitable selection can be made by one skilled in the art for the desired application. However, for the purposes of the present invention, it has been found advantageous for such pre-compressed bias member to be a flat compression wire spring or a wave spring. Such compression wire springs and wave springs are generally known in the art and are available, for example, from Smalley Steel Ring Company, sold under the CM and CMS markings (CM for plain end wave springs and CMS for shimmer end wave springs). Such springs are typically made of carbon steel or stainless steel.

[0035] The biasing member is designed to bias the second proximal body to an engaged position, i.e. the position when the injection monitoring module is at rest after attachment to the pen injection system and / or the dose setting position when the dose setting wheel is rotated to set the amount of drug to be administered, and the biasing member adopts a relatively uncompressed configuration, which is considered to be the engaged position because the biasing member presses against a distal surface of the proximal body and a corresponding proximal surface of the first distal body is in contact and surface abutment with a distal surface of the magnetic field generating means.

[0036] When the bias member is compressed in the distal direction (e.g. when the distal surface of the second proximal body is moved or displaced longitudinally and distally), this depresses the bias member, transitioning it to a compressed configuration, and due to the rigid connection between the second proximal body and the first distal body, the first distal body moves in unison and due to the fixed relationship between the two, moves to a disengaged position (wherein the proximal surface of the first distal body is no longer in contact with the distal surface of the magnetic field generating means).

[0037] In accordance with yet another object of the present invention, an injection monitoring system includes a single magnetic field sensor.

[0038] In accordance with another object of the present invention, a single magnetic field sensor is disposed on a central longitudinal axis and is movable along said axis from a first proximal position to a second distal position.

[0039] According to yet another object of the present invention, the single magnetic field sensor is arranged on or in a first distal body, which means that the magnetic field sensor is longitudinally movable along a central longitudinal axis from a first proximal position adjacent to the magnetic field generating means to a second distal position arranged away from said first position, as will be readily apparent from the above description of said first distal body, second proximal body, biasing means and magnetic field generating means.

[0040] A magnetic field sensor is used to measure the magnetic field generated by the magnetic field generating means, and movement of the sensor along the central longitudinal axis relative to the fixed magnetic field generating means is used to calculate a translational position of a reference point along said central longitudinal axis, which can be used to correlate to a zero point, an initialization point, an injection start point, an injection end point, and / or a point corresponding to any administered amount of an injectable substance, such as a drug, of the injection monitoring system according to the present invention.

[0041] Means for measuring and determining magnetic fields are generally known in the art. For example, magnetoresistors are well known means. Such magnetoresistors are often referred to by their abbreviations, for example AMR, GMR, TMR sensors, which describe the physical mechanism by which these sensor components function. Giant magnetoresistance (GMR) is a quantum mechanical magnetoresistance effect observed in thin film structures consisting of alternating layers of ferromagnetic and non-magnetic conductive layers. Anisotropic magnetoresistance, or AMR, exists in materials where a dependence of electrical resistance on the angle between the direction of current flow and the direction of magnetization is observed. Tunnel magnetoresistance (TMR) is a magnetoresistance effect occurring in magnetic tunnel junctions (MTJs), components consisting of two ferromagnetic materials separated by a thin insulator. Resistors utilizing various such properties are known per se.

[0042] In view of the above, the injection monitoring module and / or system according to the present invention preferably uses a magnetometer as the magnetic field sensor. Such a magnetometer differs from a GMR, AMR or TMR sensor in that it directly measures the magnetic field strength. Magnetometers measure the magnetic field in two main ways: vector magnetometers measure the vector components of the magnetic field, and total or scalar magnetometers measure the magnitude of the vector magnetic field. Another type of magnetometer is the absolute magnetometer, which measures the absolute magnitude or vector magnetic field using an internal calibration and known physical constants of the magnetic sensor. Relative magnetometers, which measure the magnitude or vector of the magnetic field relative to a fixed but uncalibrated baseline, are also called variometers and are used to measure magnetic field variations.

[0043] Therefore, a preferred magnetometer for use in the injection monitoring module of the present invention is an ultra-low power, high performance, 3-axis Hall effect magnetometer. The magnetometer can be configured to measure the magnetic field about three mutually perpendicular or orthogonal axes, in the present case the magnetic field sensor is preferably configured to measure the magnetic field about only two of the three orthogonal axes (e.g., X-axis and Z-axis), where the Y-axis is coaxial with the longitudinal central axis, so that distance measurements for translational movements of the magnetic field sensor along said longitudinal axis, along the normal line, can be calculated relative to the position of a reference point on said axis, as described above.

[0044] In accordance with yet another object of the present invention, an injection monitoring system includes an electronics board.

[0045] Advantageously, according to a further object of the invention, the single magnetic field sensor is electrically connected to the electronics board.

[0046] Furthermore, the electronics board preferably comprises an integrated control and data processing unit, such as at least one microcontroller, which is electrically connected to the magnetic field sensor for processing the information received from the magnetic field sensor. The electronics board can therefore preferably be, for example, a printed circuit board of corresponding suitable dimensions. In the configuration envisaged by the present invention, such a printed circuit board is advantageously disk-shaped.

[0047] The electronics board is advantageously placed on, integrated with or housed in the first distal body of the clutch assembly. An integrated control and data processing unit with at least one microcontroller processes all electrical communication and signals between the various electronic components of the electronics board and the magnetic field sensor. The electronics board is also involved in performing calculations, making it possible to calculate and determine the exact placement position of the magnetic field sensor, and also processes signals from the autonomous power supply and communication means integrated in the injection monitoring system, and communicates with a local or remote data processing system (e.g. a smartphone). The electronics board can be remotely programmed or receive information and updates at first use, and includes an integrated control and data processing device, similar to other electronic devices today. Such integrated control and data processing units are known per se and often integrate 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.

[0048] According to yet another object of the present invention, the magnetic field sensor is arranged on the proximal surface of the electronics board. In such an embodiment and configuration, when the injection monitoring module is initially mounted on the pen injection system, the magnetic field sensor is substantially in abutment with the magnetic field generating means. Moreover, advantageously, the magnetic field sensor is arranged on the proximal surface of the electronics board as close to the central longitudinal axis as physically possible, preferably on said central longitudinal axis. The purpose of such positioning is to try to avoid, as far as possible, the need for correction calculations performed by the integrated control and data processing unit due to the radial displacement of the magnetic field sensor from the central longitudinal axis, thereby increasing the accuracy of the corresponding calculations and the accuracy in determining the translation reference point along said axis.

[0049] As can be inferred from the above description, another subject of the present invention is an injection monitoring module in a monitoring system, wherein the first distal body is an electronic component board support, and consequently the electronic component board is arranged in the component board support.

[0050] As briefly mentioned above, the electronics board is powered by a standalone power source. Thus, according to one object of the present invention, the injection monitoring system comprises a removable and / or rechargeable power source. Such a removable standalone power source can be usefully, for example, a lithium ion battery, which can be easily replaced when depleted, or a rechargeable battery, which can be recharged when depleted, for example, by connecting it to a rechargeable battery via a corresponding charging port provided on the injection monitoring module, both types of batteries being generally known to the person skilled in the art.

[0051] Advantageously, therefore, according to yet another object of the present invention, the second proximal body is a power source support, the power source being preferably arranged within the power source support. The second proximal body, as exemplified here as a power source support, is usefully and advantageously closed at its proximal end by a removable cap, configured and dimensioned to be pressed by the thumb or other finger of the user when activating the injection monitoring system. The cap usefully covers the power source, prevents the ingress of dust and / or water or moisture, and is made to be press-fitted or elastically engaged with the second proximal body, but is also removable to allow access to the power source, for example to replace the battery.

[0052] From the above and previous paragraphs, it will be clear that the power source is located in the second proximal body and the electronics board is located in the first distal body. Both are advantageously electrically connected via an elongated hollow connecting member, in which the electrical connection, e.g. a standard copper wiring, is arranged. The electrical connection between the power source and the electronics board is configured and dimensioned in the elongated connecting member so as to avoid any detachment or interruption of the electrical connection even when the injection monitoring system rotates in a coaxial rotation with the dose setting wheel. Thus, the use of the elongated connecting member as a conduit for said electrical connection is highly advantageous when said elongated connecting member is arranged along the longitudinal central axis, meaning that even if the user twists and turns the dose setting wheel and the corresponding attached injection monitoring system in various rotations, either alternately or successively, the electrical connection is protected from any substantial rotation, reducing the risk of breakage or disconnection.

[0053] In accordance with another object of the present invention, and as will be apparent from the foregoing description of the relative movements and positions of the various components, the injection monitoring system has an arrangement whereby when the clutch assembly is in a first engaged position, the magnetic field generating means has a distal surface in contact with a proximal surface of the electronics substrate body, and when the clutch assembly is in a second disengaged position, said proximal surface of the electronics substrate body is axially spaced apart from said distal surface of the magnetic field generating means along a central longitudinal axis.

[0054] Further advantageously, the first monitoring position is a position where the proximal surface of the electronics substrate body abuts against the distal surface of the magnetic field generating means and the second monitoring position is a position where the distal surface of the injection monitoring system abuts against the proximal surface of the injection actuator of the pen injection system. In such a configuration, when the biasing member is compressed distally along the longitudinal axis, the proximal surface of the electronics substrate body moves distally away from abutment with the distal surface of the magnetic field means, i.e. away from the first position, to a point where the distal surface of the electronics substrate body contacts and / or abuts with the proximal surface of the injection actuator of the pen injection system. The magnetic sensor relays the measured change in the magnetic field to the integrated control and data processing unit when the sensor moves along the longitudinal central axis away from the magnetic field generating means until it abuts with the injection actuator, a distance of a few millimeters, for example about 15 millimeters. Thus, the entire injection monitoring module can be manufactured with a total length from the distal end of the hollow body to the proximal end of the push cap cover of tens of millimeters, for example, a total length of about 20-30 millimeters.

[0055] In accordance with yet another object of the present invention, there is provided a process for calculating an actual amount of medication released or injected from a pen injection system, comprising the steps of attaching an injection monitoring module, setting a dose, actuating an injector, and determining the injected dose. The step of attaching the injection monitoring module includes attaching an injection monitoring module comprising an injection monitoring system substantially as described herein to a proximal end of a pen injection system for delivering a drug; the pen injection system comprises a proximally disposed dose setting wheel and an injection actuator, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting and during injection; In the step of setting the dose, a dose is set by rotating the dose setting wheel; The step of activating the syringe includes activating the syringe to perform an injection; In the step of determining the injected dose, the injected dose is determined from translational movement of the injection monitoring system caused by actuation of the injection actuator from a first monitoring position where the injection monitoring system is not abutting a proximal surface of the injection actuator to a second monitoring position where the injection monitoring system abuts a proximal surface of the injection actuator. [Brief description of the drawings]

[0056] The invention will now be described in more detail with reference to the accompanying figures, provided for purposes of explanation and example, in which:

[0057] [Figure 1] FIG. 1 is a schematic perspective view of an injection monitoring module according to the present invention for a handheld pen injection system.

[0058] [Diagram 2] FIG. 2 is a schematic diagram of the end of the injection monitoring module of FIG. 1, as viewed from its distal end.

[0059] [Diagram 3] FIG. 3 is a schematic cross-sectional view of the injection monitoring module of FIG. 1 in a first monitoring position.

[0060] [Figure 4]FIG. 4 is a schematic cross-sectional view of the injection monitoring module of FIG. 1 rotated 90° in a first monitoring position.

[0061] [Diagram 5] FIG. 5 is a schematic exploded view of an injection monitoring module according to the present invention taken along a line from a proximal end of the module to a distal end of the module.

[0062] [Figure 6] FIG. 6 is a schematic exploded view of an injection monitoring module according to the present invention, taken along a line from a distal end of the module to a proximal end of the module.

[0063] [Figure 7] 7A and 7B are schematic cross-sectional views of an injection monitoring module according to the present invention, showing the module in a first monitoring position (7A) and in a second monitoring position (7B), respectively.

[0064] [Figure 8] FIG. 8 is a schematic cross-sectional view of an injection monitoring module according to the present invention, showing the module in a second monitoring position.

[0065] Detailed Description Referring now to Figure 1, there is shown a schematic perspective view of an injection monitoring module (1) according to the present invention. The injection monitoring module comprises a hollow body (2) having a distal end (3) and a proximal end (4). The hollow body (2) has a peripheral wall (5) having an inner surface (6) and an outer surface (7) thereby defining a central cavity (8) of the hollow body (2) extending from the distal end (3) to the proximal end (4). The distal end (3) is open such that the injection monitoring module (1) can be inserted over and surround a proximal end (9) of a pen injection system (10) having a dose setting wheel (11) and an injection actuation button (12). The hollow body (2) comprises an index shoulder (13) on an outer surface (7) of the hollow body (2) to facilitate alignment of the body (2) with a corresponding zero point location on the dose setting wheel (11) of the pen injection system (10) corresponding to a zero dose setting. Indicating shoulder (13) comprises a raised area of ​​material making up body (2) and extends in a slope (14) where the thickness of said body material increases from proximal end (15) towards distal end (16). At the proximal end (4) of body (2), cavity (8) is substantially closed by clutch assembly (17), of which only proximal body (18) and covering cap (19), which form part of injection monitoring system (20), are visible.

[0066] 2 is an end view of the injection monitoring module as viewed from the distal end (3) of the body (2). A raised indicator shoulder (13) of the body material can be seen projecting upwardly from the outer surface (7) of the circumferential wall (5) of the body (2). An annular flange (21) projects radially inward from the inner surface (6) of the body (2) thereby narrowing the diameter of the cavity (8) and providing a means for limiting any proximal movement of the injection monitoring module (1) as the body slides over and around the proximal end (9) of the pen injection system (10) since the protruding annular flange (21) has a distal surface (22) that abuts and engages at least a portion of the proximal surface (23) of the dose setting wheel (11). As can be seen in both Figures 1 and 2, the body (2) includes a series of radially spaced, raised, sloped shoulders (24) of body material that project inwardly from the inner surface (6) into the cavity (8) and extend distally along the inner surface (6) in a decreasing thickness from a location distal to the projecting annular flange (21) to the distal end (3) of the body (2). The alternating projecting shoulders form a corresponding series of alternating valleys (25). These inwardly projecting, sloped shoulders (24) and corresponding valleys (25) allow the body (2) to resiliently or frictionally engage with the dose setting wheel (11) of a pen injection system, particularly since the dose setting wheel of such a pen injection system often includes corresponding outwardly projecting shoulders and corresponding alternating valleys on its outer surface. Thus, the two sets of protruding shoulders and valleys can frictionally engage with each other, ensuring that rotation of the dose setting wheel (11) or alternatively the body (2) rotates the other to the same extent and in the same rotational direction. In another mounting arrangement, the inner surface (6) of the cavity can have a layer of elastomer covering said surface at a suitably located position adjacent the distal end (3) of the main body (2), said elastomer layer frictionally or elastically engaging with the outer surface of the dose setting wheel by rotation of a threaded or slide-fit tightening ring attached to and located around the outer surface (7) of the distal end (3) of the main body (2).

[0067] Figures 3 and 4 are schematic cross-sectional views of the injection monitoring module taken along lines A-A' and B-B', respectively, showing the injection monitoring module in more detail, with Figure 4 along line B-B' rotated 90° about the central longitudinal axis 26 of the body (2). Figures 3 and 4 show the injection monitoring module with its various components in a first position, immediately after mounting the various components to the pen injection system or, for example, during dose setting. This relative arrangement of the various components of the injection monitoring module also corresponds to the first monitoring position and also to the "engaged" position as described herein. The first monitoring position relates to the first monitoring position of the injection monitoring system as described in detail hereinafter, and the "engaged" position relates to the clutch assembly as described in detail hereinafter as well.

[0068] 3 and 4, a magnetic field generating means (27) is disposed within the cavity (8) around the circumference of the cavity (8) and in contact with the inner surface (6) of the body. The magnetic field generating means (27) can be, for example, a plastic magnet formed as a substantially annular shaped disk, or alternatively, preferably, a plastic molded annular disk into which a pair of single bipolar permanent magnets (28, FIG. 4) are introduced or encapsulated during molding of the annular shaped disk. The magnets (28, FIG. 4) are preferably arranged in a diametrically opposed NS / NS pole arrangement within the annular shaped disk, whereby the poles are aligned across the annular shaped disk. The disk also comprises a central hole (29) of a diameter smaller than the diameter of the cavity (8). The annular shaped disk of the magnetic field generating means (27) is received within the body (2) adjacent the annular flange (12) of the body (2) and may be held in place by a variety of different means, such as by one or more inner proximal portion (30) projections formed on the inner surface (6) of the body (2) that project radially from said inner surface (6) at least partially into the cavity (8) along the length of the cavity (8) and form a proximal angled shoulder (30a) and a distal flange portion (30b) extending on either side of the projecting shoulder (30a). The annular disk 27 is provided with corresponding recesses 31a, 31b, 31c, 31d located on the periphery 32 of the disk 27 that resiliently or frictionally engage when the disk 27 is inserted coaxially with the central longitudinal axis 26 into the cavity 8 during manufacturing and assembly of the injection monitoring module 1. The recesses 31a, 31b, 31c, 31d cooperate with an inner angled shoulder such that at least a portion of the distal surface 33 of the disk 27 rests against the flange 30b of the proximal angled shoulder 30a. Due to the frictional contact between the recesses (31a, 31b, 31c, 31d) and the inclined shoulder (30a) on the one hand, and the frictional contact between the distal face (33) and the flange (30b) on the other hand, the annular disk (27) is unable to move in any direction along the longitudinal axis and is, for all intents and purposes, immovably contained within the cavity (8) of the body (2).

[0069] Also shown in Figures 3 and 4 is a clutch assembly (17) located within the cavity (8) of the body (2) and extending along the longitudinal axis (26) at least partially beyond the proximal end (4) of the body and outside the cavity (8). The clutch assembly includes a first distal body (34) and a second proximal body (18). Both the first distal body (34) and the second proximal body (18) are connected to one another in a fixed spatial relationship along the central longitudinal axis (26) and are dimensioned to allow the first and second bodies to slide or move longitudinally along the central longitudinal axis within the cavity (8). The first distal body (34) and the second proximal body (18) have a general goblet shape with protruding legs (35, 37) and cups (36, 38), respectively, with the first distal body being inverted compared to the second proximal body (18). The legs (35, 37) are substantially hollow and are each formed as at least one annular wall projecting away from the corresponding base (39, 40) of the cup (36, 38). In the case of the second proximal body (18), the legs are formed by a pair of concentric annular walls (37, 37') that form an annular channel into which the legs (35) of the first distal body are inserted. The legs (35, 37) are held together in a fixed relationship, for example by adhesive, ultrasonic welding, or the like. As can be seen in Figures 3 and 4, the legs thereby form an elongated hollow connecting member between the first distal body (34) and the second proximal body (18), with a distal end of the elongated connecting member opening into the base (39) of the cup (36) and a proximal end of the elongated connecting member opening into the base (40) of the cup (38). The elongated connecting member formed by the legs (35, 37) traverses a central bore (29) of the magnetic field generating means (27) such that the first distal body (34) is located distal to the magnetic field generating means (27) and the second proximal body (18) is located proximal to said magnetic field generating means (27). The elongated connecting member formed by the legs (35, 37) is dimensioned to allow sliding or translational movement of the first distal body (34) and the second proximal body (18) along the central longitudinal axis (26), the maximum predetermined length of such possible longitudinal translation being, for example, about 15 millimeters in total.

[0070] A biasing member (41), e.g., a flat wire spring, is disposed distal to the base (40) of the cup (38) of the second proximal body (18) but proximal to the magnetic field generating means (27). The magnetic field generating means is provided with a receiving protrusion (42) for receiving the biasing member (41), e.g., extending from the proximal face of the disk (27) in a proximal direction along the cavity (8). The biasing member (41) is selected so that it can adopt a relatively compressed or compressed configuration and a relatively uncompressed, relaxed or expanded configuration. By default, and also when the injection monitoring module is initially attached to the pen injection system, the biasing member is in the relatively uncompressed or relaxed configuration. When the biasing member (41) is received on the receiving projection (42) of the proximal surface of the magnetic disk (27) and the disk is immovably blocked within the cavity (8) of the hollow body (2), the biasing member naturally exerts a pressing force against the distal surface (43) of the base (40) of the cup (38) of the second proximal body and tends to engage therewith, which in the context of this specification should be understood as the "engaged" position. This position also corresponds to the first monitoring position of the injection monitoring module. In response to the biasing member (41) adopting a relatively unpressed, spread or relaxed configuration, the biasing effect of the biasing member (41) also causes the base (39) of the cup (36) of the first distal body (34) to move proximally along the central longitudinal axis (26) by the fixed length elongated connecting member formed by the legs (35, 37). As a result, the proximal surface (44) of the base (39) of the first distal body comes into contact with the distal surface (33) of the disk of the magnetic field generating means (27).

[0071] Also shown in Figures 3 and 4 is an injection monitoring system, which is substantially housed within the various components of the clutch assembly. The first distal body (34) serves as an electronics board support, in which an electronics board (45), such as a printed circuit board, is disposed substantially within the cup (36). The electronics board has several electrically connected components, including a microcontroller (46) disposed on the distal surface of the electronics board, and a magnetometer (47) disposed substantially centrally on the proximal surface of the electronics board (45), thereby aligned with the longitudinal central axis (26). In each of the component positions shown in Figures 3 and 4, the magnetometer (47) senses and measures the magnetic field generated by the permanent magnet (28) disposed within the disk (27) and sends a corresponding electrical signal to the microcontroller (46), which is responsible for calculating a series of reference points and deriving the relative and absolute position of the magnetometer with respect to the magnetic field generating means (27) which is at a fixed position within the hollow body (2). The electronic component board (45) also comprises a communication unit (48), for example a Bluetooth® Low Energy circuit, which allows data to be transmitted and received between the electronic component board and a remote terminal device, for example a suitably equipped smartphone, a remote computing system or a distributed computing system, respectively. The second proximal body (18) serves as a power support for the injection monitoring system, and for this purpose accommodates and arranges in its cup (38) an autonomous power source (49), for example, as shown, a replaceable lithium-ion battery or a removable rechargeable battery. The power source (49) is connected via an electrical connector (50, 50') (for example a connection plate suitably arranged for the positive and negative terminals of the battery) arranged in the cup (38) to a further series of flexible electrical connectors (51, 51') (for example a plastic-coated copper wiring or a ribbon connector), which extend from the connection plate (50, 50') through an elongated connection member formed by the legs (35, 37) to the electronic component board (45).The flexible electrical connectors (51, 51') are designed to allow any possible rotational movement of the clutch assembly about the longitudinal central axis (26) without being damaged or breaking the electrical connection between the electronic component board (45) and the power source (49). A removable covering cap (19) (e.g., a push-fit cap) engages with the open end of the cup (38) of the second proximal body (18). In Figures 3 and 4, this is shown as a radially inwardly projecting annular ridge (52) around the inner peripheral wall (53) of the cap (19) that resiliently and / or frictionally engages with a corresponding peripheral groove on the outer surface of the cup (38) of the second proximal body to seal the opening of the cup (38) and prevent the ingress of foreign matter into the cup that may affect the power supply to the component board. Additionally, the cap (19) provides an exterior proximal surface (55) that allows a user to activate the monitoring system and clutch assembly by depressing or pushing against the exterior proximal surface with a digit (e.g., thumb or finger). The first distal body (34) also includes a distal contact surface (56) that effects closure of the cup (36), thereby enclosing the electronics board (45) within said first distal body (34). This distal surface (56) abuts against a proximal surface of an injection activation button during operation of the injection monitoring module.

[0072] 5 and 6 show schematic alternative views of the embodiment in which the various components of the injection monitoring system are arranged along or about a central longitudinal axis 26. Like numerals refer to features and components of the injection monitoring module already described with respect to the previous figures.

[0073] 7A and 7B show the relative positions of the various components of the injection monitoring module during operation, as described below.

[0074] 7A is a diagram of the injection monitoring module when attached to the proximal end (9) of the pen injection system (10). The hollow body (2) surrounds and engages the dose setting wheel (11) at the distal end (3) of the body. The body slides along its central longitudinal axis onto the proximal end (9) of the pen injection system (10) until the distal face of the annular flange (21) of the body (2) abuts and makes surface contact with the proximal face (57) of the dose setting wheel (11). In this position, it can be seen that the injection actuation button (12) extends proximally through the narrowed diameter formed by the annular flange (21) of the body (2), but the proximal face (58) of the injection actuation button does not abut the distal face (56) of the first distal body (34). In effect, the biasing element (41) actively pushes the first distal body (34) away from said proximal face (58) due to the fixed length connection between the first distal body (34) and the second proximal body (18) of the clutch assembly (17). The body (2) rotates together with the dose setting wheel (11) and is free to rotate about the longitudinal central axis (26) and allows the user to set the dose to be administered. In this position, the injection monitoring module is considered to be in the first monitoring position and is registered by the microcontroller and saved in a volatile or non-volatile memory storage provided either in the microcontroller or on the electronics board, whereby it is subsequently communicated via the communication unit to a remote computing device such as a suitably equipped smartphone, a remote computer or a distributed computing system.

[0075] A user can actuate the injection by pushing the proximal surface (55) of the cap cover (19) in a distal direction. Because the cap cover (19) is coupled to the cup (38) of the second proximal body (18), any translational force is imparted to the cup (38) and, through abutment of the distal surface of the cup base (40), to the biasing member (41). In this manner, the second proximal body (18) moves distally, i.e., along the central longitudinal axis (26), until the compression limit of the biasing member is reached. This compression limit is configured such that the fixed length connection between the first distal body and the second proximal body allows the cup base (39) of the first distal body (34) to move away from abutment with the distal surface (33) of the magnetic field generating means and into abutment between the distal contact surface (56) of the cup (39) of the first distal body (34) and the proximal surface (58) of the injection actuation button (12) to follow said axial movement along the central longitudinal axis and enable normal functioning of the injection actuation button (12) to effect an injection of a medication from the pen injection system (10).

[0076] As a result of the displacement along the central longitudinal axis, the electronics board carrying the magnetometer (47) moves distally away from the magnetic field generating means, from a position closer to the magnetic field generating means to a position spaced therefrom. The displacement or longitudinal movement of the magnetometer along the central longitudinal axis affects the magnetic field values ​​seen by the magnetometer and the signals sent to the microcontroller. However, because the magnetometer on the electronics board is centrally located (centered on the central longitudinal axis), the measurements do not require offset correction calculations by the microcontroller. Furthermore, the total distance traveled by the magnetometer, on the order of about 15 mm, is relatively small and is not susceptible to potential interfering magnetic fields that may otherwise be generated by other moving metallic parts present in most common pen-type injectors. As a result, a microcontroller programmed with appropriate logic and instructions to perform various calculations can calculate various reference points from the associated measured and reported magnetic fields and derive absolute and relative positions therefrom without the need for complex correction calculations, thereby indicating successful achievement of the desired injection endpoint (e.g., that the selected dose has been fully injected) via an appropriate signal (e.g., an illuminated LED appropriately located on the electronics board, an audible signal generated by appropriate circuitry also located on the electronics board, etc.). The microcontroller can also calculate any released or injected drug volume and notify the user thereof via an appropriate signal, such as the LED or audible signal system described above, even if the user releases pressure on the cap cover (19) causing the biasing element to move the second proximal body (18) in a proximal direction back toward the engaged position of the clutch assembly. A communication unit can also be activated by the microcontroller at this point, or at any other appropriate point, to transmit the corresponding information or calculation results to a remote device, as described above. In this manner, the injection monitoring system provides a means to determine, at any given translational point along the central longitudinal axis, whether any drug has actually been injected, and if so, the actual and precise amount of drug injected or expelled.

[0077] 8 is a cross-sectional view of the injection monitoring module according to the present invention once it has reached the second monitoring position, in which it can be seen that the cap cover (19) has been depressed, thereby displacing the second proximal body (18) distally along the central longitudinal axis and compressing the biasing member (41) into a depressed configuration, thereby displacing the cup base (39) of the first distal body (34) out of contact with the distal surface (33) of the magnetic field generating means (27) and into a clutch assembly disengaged position, in which the distal contact surface (56) of the cup (36) of the first distal body is in face contact with the proximal surface (58) of the injection activation button (12).

[0078] When the digital pressure on the cap is once again released by the user at the end of the injection, the biasing member (41) assumes a relatively unstressed or relaxed configuration, thereby biasing the cup base (40) of the second proximal body (18) proximally along the central longitudinal axis (26) and moving the distal contact surface (56) of the cup (36) of the first distal body (34) away from abutting surface contact with the proximal surface (58) of the injection actuator until the cup base (39) of the first distal body again abuts the distal surface (33) of the disk of the magnetic field generating means (17). This return position can also be detected and calculated through the interaction of the magnetometer and the microcontroller, providing the user with an appropriate signal if desired (e.g. indicating that the system is once again ready for a new dose setting for the next injection operation).

Claims

1. An injection monitoring module, comprising: the injection monitoring module is adapted and configured to be removably attached to a proximal end of a pen injection system for delivering a medication; The pen injection system includes a proximally disposed dose setting wheel and an injection actuator; the dose setting wheel is rotatable about a central longitudinal axis of the pen injection system during dose setting and during injection; the injection monitoring module comprises a hollow body and an injection monitoring system; the hollow body is adapted and configured to be coaxially mounted to, and to rotate and engage with, the dose setting wheel at the proximal end of the pen injection system; the hollow body includes a central longitudinal lumen having a proximal end and a distal end; the injection monitoring system is disposed within a central longitudinal cavity of the body at a proximal end thereof and extends proximally along the longitudinal axis beyond the proximal end; the injection monitoring system is movable within the central longitudinal cavity of the body along a central longitudinal axis from a first monitoring position to a second monitoring position; In the first monitoring position, the injection monitoring system is not in contact with a proximal surface of the injection actuator; In the second monitoring position, the injection monitoring system abuts a proximal surface of the injection actuator. Injection monitoring module.

2. 10. The injection monitoring module of claim 1, wherein the injection monitoring system is mounted within a selectively engageable and respectively disengageable clutch assembly.

3. An injection monitoring module according to claim 1 or 2, comprising a magnetic field generating means.

4. 4. An injection monitoring module according to claim 3, wherein the magnetic field generating means is housed within a cavity of the hollow body and immovably about the central longitudinal axis.

5. 5. An injection monitoring module according to claim 3 or claim 4, wherein the magnetic field generating means comprises two diametrically aligned single dipole magnets.

6. 6. An injection monitoring module according to any one of claims 1 to 5, wherein the injection monitoring system comprises a single magnetic field sensor.

7. 7. The injection monitoring module of claim 6, wherein the single magnetic field sensor is positioned on the central longitudinal axis and is movable along the axis from a first proximal position to a second distal position.

8. 8. The injection monitoring module according to any one of claims 1 to 7, wherein the injection monitoring system comprises an electronics board.

9. 9. An injection monitoring module according to any one of claims 6 to 8, wherein the single magnetic field sensor is electrically connected to the electronics board.

10. 10. An injection monitoring module according to claim 8 or claim 9, wherein the electronics board comprises at least one microcontroller, the at least one microcontroller being electrically connected to the magnetic field sensor.

11. An injection monitoring module according to any one of claims 8 to 10, wherein the magnetic field sensor is disposed on a proximal surface of the electronics board.

12. 12. An injection monitoring module according to any one of claims 8 to 11, wherein the electronic component board comprises a communication unit, the communication unit being electrically connected to the at least one microcontroller.

13. 3. The injection monitoring module of claim 2, wherein the clutch assembly comprises a first distal body and a second proximal body, and further comprises a bias member located between the first distal body and the second proximal body.

14. 14. The injection monitoring module of claim 13, wherein the first distal body is an electronics board support.

15. 15. An injection monitoring module according to claim 8 and claim 14, wherein the electronic component board is disposed within the component board support.

16. 16. The injection monitoring module according to any one of claims 1 to 15, wherein the injection monitoring system comprises a removable and / or rechargeable power source.

17. 14. The injection monitoring module of claim 13, wherein the second proximal body is a power supply support.

18. 18. An injection monitoring module according to claim 16 or 17, wherein the power supply is disposed in a power supply support.

19. 19. An injection monitoring module according to any one of claims 13 to 18, wherein the first distal body and the second proximal body are connected to each other along a central longitudinal axis via an elongated hollow connecting member.

20. 20. The injection monitoring module according to any one of claims 19, wherein the electronic component board and the power source are electrically connected via the elongated hollow connecting member.

21. 21. An injection monitoring module according to any one of claims 13 to 20, wherein the first distal body is arranged distal to the magnetic field generating means.

22. 22. An injection monitoring module according to any one of claims 13 to 21, wherein the second proximal body is arranged proximal to the magnetic field generating means.

23. 23. An injection monitoring module according to any one of claims 13 to 22, wherein the biasing member is arranged proximal to the magnetic field generating means and distal to the second proximal body.

24. 24. An injection monitoring module as claimed in any one of claims 2 to 23, wherein when the clutch assembly is in a first engaged position, the magnetic field generating means has a distal surface in contact with a proximal surface of the electronic component substrate body, and when the clutch assembly is in a second disengaged position, the proximal surface of the electronic component substrate body is axially spaced apart from the distal surface of the magnetic field generating means along the longitudinal central axis.

25. 1. A method for calculating an actual amount of a drug delivered or injected from a pen injection system, comprising: The method includes the steps of attaching an injection monitoring module, setting a dose, actuating the injector, and determining the injected dose; The step of attaching the injection monitoring module includes attaching an injection monitoring module comprising an injection monitoring system substantially as described herein to a proximal end of a pen injection system for delivering a medication; the pen injection system comprises a proximally disposed dose setting wheel and an injection actuator, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting and during injection; In the step of setting the dose, a dose is set by rotating the dose setting wheel; The step of activating the syringe includes activating the syringe to perform an injection; The method includes determining the injected dose from translational movement of the injection monitoring system caused by actuation of the injection actuator from a first monitoring position in which the injection monitoring system is not abutting a proximal surface of the injection actuator to a second monitoring position in which the injection monitoring system abuts a proximal surface of the injection actuator, wherein the step of determining the injected dose comprises determining the injected dose from translational movement of the injection monitoring system caused by actuation of the injection actuator from a first monitoring position in which the injection monitoring system is not abutting a proximal surface of the injection actuator to a second monitoring position in which the injection monitoring system is abutting a proximal surface of the injection actuator.

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