Injection monitoring module with magnetic rotation sensing

Abstract

To provide an injection monitoring module removably mounting to a proximal end of an injection pen comprising a pen body, a proximally disposed dose setting wheel, and an injection actuator.SOLUTION: A dose setting wheel rotates about a central longitudinal axis of a pen during dose setting. An injection monitoring module comprises: a hollow body mounted coaxially with and in co-rotationally engaging the dose setting wheel, the body including a longitudinal bore having a proximal end and a distal end, and a central longitudinal axis; one or more magnets disposed on or in the body; and an injection monitoring system including at least one magnetic sensor translatable along the central axis within the bore from a first monitoring position to a second monitoring position, the injection monitoring module further comprising rotation stop means for preventing rotational movement of the monitoring system about the central axis during dose selection.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. [Background technology]

[0002] Infusion monitoring is a well-known field related to injectable drug delivery devices, particularly with respect to infusion systems, for example. Over time, such monitoring systems have more recently been transferred to infusion pen systems for drug delivery, allowing users of such pen infusion systems, as well as medical professionals involved in the treatment and follow-up of such patients, to more closely monitor their infusion status and, in many cases, the actual dose administered, with the aim of providing better medical outcomes. These developments have been accompanied by the associated increased 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 in order to provide on-the-fly or periodic information to the user or medical professional via a suitable communication unit included in the monitoring system.

[0003] With regard to pen injection systems in particular, one challenge has been to provide an easy-to-use, reliable, and fairly fail-safe monitoring system that can be adapted to the various variations of many 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 therein along with one or more sensors. However, one major drawback of such systems is that the integration of all of the electronic components tends to make the final product rather bulky and unwieldy, thus making it more difficult to use from a user's perspective. Furthermore, such modified systems tend to be highly specific to a given brand or manufacturer and therefore rarely or never used with pen injection devices from other manufacturers. Furthermore, the miniaturization of complex electronic components has led to a trend toward reducing the overall volume of the injection pen body as much as possible, which creates its own problems, particularly with regard to electromagnetic interference between various components due to the proximity of circuits providing necessary or desired integrated functions. Moving the sensors in such monitoring systems further away from sources of electromagnetic interference only complicates the problem further, potentially resulting in erroneous readings, or requiring additional systems to compensate for the physical separation of the sensors from other electronic components, such as microcontrollers designed to control and command the various components and manage their interactions.

[0004] The injection pen systems in question are well known and generally include a proximally located dose setting wheel and an injection actuator, the dose setting wheel being rotatable about the central longitudinal axis of the pen injection system. The wheel is rotated by the user to select the dose of medication to be administered. The pen is generally mechanically or electromechanically configured to initiate an injection upon activation of the injection actuator. Such an injection actuator is very commonly a simple press or push button that mechanically or electrically contacts a dispensing mechanism located within the pen injection system, and upon depression, the injection mechanism fires and injects 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 generally 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 systems included in many pen injection systems today, these large metal objects can further disrupt the signals that sensors within such electronic systems are designed to capture or pick up, potentially reducing the accuracy of the system and / or requiring complex compensation mechanisms to be deployed to avoid calculation errors.

[0005] Some attempts to overcome the difficulties of electronics integration have already been described in the patent literature.

[0006] For example, published PCT application WO 2014128156 relates to a sensor assembly having a first rotary sensor portion having a plurality of individual conductive sensor regions arranged in a pattern, and a second rotary sensor portion rotatably disposed relative to the first portion and including a plurality of contact structures adapted to contact the conductive sensor regions on the first sensor portion. The contact structures are configured to engage and connect different sensor regions as the first and second portions of the rotary sensor rotate relative to each other, with the connection created indicating the rotational position between the first and second portions. One of the contact structures is an actuatable contact structure that is axially movable relative to the first portion and has 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 housed at least partially within a volume within the dose setting wheel within the pen injector body. The system also includes a visual display, such as an LCD display, located on or in place of the injection actuator button.

[0007] In comparison, published PCT application WO 2018013419 relates to a dose detection system including a dosing part mounted on an actuator and rotationally and axially movable relative to a coupling part mounted on a dose setting member, and comprising a module including an electronic sensor operative to detect relative rotation between the coupling part and the dosing part to detect a dose delivered by the medication 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 for detecting an amount of medication dispensed by the pen injection system while attached to the pen injection system, storing the detected dose in memory, and transmitting a signal representative of the detected dose to a telecommunications 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 administration process including dose setting, the electrical contacts being connected to an assembly of electronic components housed on a flexible printed circuit board and arranged in a stacked, folded accordion-style arrangement within a removably coupled body, with insulation between overlapping layers of the circuit board by non-conductive spacer layers to prevent potential electrical, electronic and electromagnetic interference.

[0008] One direct observation of the above-described configuration is that, despite the use of a folded flexible printed circuit board to provide multiple surfaces for positioning the electronic components, their relative spatial density and positioning relative to one another necessitated the provision of non-conductive spacers between layers of electronic components. A direct consequence of this is an increase in module height and consequential increase in the complexity of the clip-on dosage detection module described therein.

[0009] Additionally, various other injection monitoring modules for injection pen systems are known from published PCT applications WO 2019 / 175790, WO 2019175615, WO 2018138542, WO 2017013464, and WO 2017013463. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. 2014128156 Brochure [Patent Document 2] International Publication No. 2018013419 Brochure [Patent Document 3] International Publication No. 2019 / 175790 Brochure [Patent Document 4] International Publication No. 2019175615 Brochure [Patent Document 5] International Publication No. 2018138542 Brochure [Patent Document 6] International Publication No. 2017013464 Brochure [Patent Document 7] International Publication No. 2017013463 Brochure Summary of the Invention

[0011] Accordingly, one object of the present invention is to provide an infusion monitoring module adapted and configured to be removably attached to the proximal end of an injection pen system for delivery of a medication, the injection pen system having a dose setting wheel that can be rotated about a central longitudinal axis of the pen injection system to set the dose of medication to be injected, and that can optionally be fixed against rotation during injection, while eliminating the need for complex shielding or protective solutions to counter undesirable electrical, electronic, or electromagnetic effects caused by the relatively high density of electronic components within the monitoring module.

[0012] Another object of the present invention is to provide an injection monitoring module as above, which is adapted and configured to determine a set dose and an injection start point. For the purposes of the present invention, the expression "injection start point" as used herein means the point at which the injection mechanism in the pen is activated. This is typically achieved by distally moving an injection actuator, such as a push button located at the proximal end of the pen injection system.

[0013] It is yet another object of the present invention to provide an injection monitoring module as above, said module adapted and configured to detect or calculate a user-set dose or amount of injectable substance contained within a pen injection system, an injection start point in said pen injection system, and an injection end point, and therefrom determine whether the entire dose or amount of injectable substance set by the user of the pen injection system has been dispensed from said pen system.

[0014] These and other objects of the present invention will become readily apparent from a complete reading of this specification.

[0015] 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 end of an injection pen system for delivery of a medication, the injection pen system having a pen body, a proximally located dose setting wheel connected to said body, and an injection actuator, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting, the injection monitoring module comprising: a hollow body adapted and configured to be coaxially mounted to and co-rotatably engaged with a dose setting wheel at a proximal end of the injection pen system, the hollow body comprising a central longitudinal bore having a proximal end and a distal end, and a central longitudinal axis; a magnetic field generating means disposed on or within the hollow body at the proximal end of the central longitudinal bore; an injection monitoring system comprising at least one or more magnetic sensors disposed at a proximal end of the hollow body and translatable along said central longitudinal axis within the bore of the hollow body from a first monitoring position in which the injection monitoring system is not in abutting contact with the proximal face of the injection actuator to a second monitoring position in which the injection monitoring system is in abutting contact with the proximal face of the injection actuator; Equipped with The injection monitoring module further comprises a rotation stop means configured and adapted to prevent rotational movement of the injection monitoring system about said central longitudinal axis during dose setting.

[0016] As used herein, the terms "pen injection system" and "injection pen system" are used interchangeably to refer to a generally handheld pen-type injection system, which is readily known and commercially available for use in the treatment of many different medical indications. These systems are also often generally designed for self-injection of medication by a user needing treatment for a given medical indication. This is the case, for example, with insulin, which is supplied in various forms for use in the treatment of diabetes; for example, pen injection systems marketed under the trade names FlexPen®, commercialized by Novo Nordisk, Kwikpen®, commercialized by Eli Lilly, and Lantus Solostar®, commercialized by Sanofi, are just three of the most well-known. Other medications are also used with medical devices in this category, for example, to allow immediate emergency infusion of necessary medications needed to deal with potentially life-threatening situations, such as anaphylactic shock treatment, anticoagulants, opioid receptor agonists and antagonists, to the extent that it is becoming common for patients suffering from or susceptible to such illnesses to carry these devices with them.

[0017] An injection pen system in which an injection monitoring module according to the present invention is adapted and configured for removable attachment includes a proximally located dose setting wheel and an injection actuator. The dose setting wheel rotates about a central longitudinal axis of the pen injection system to allow a user to set a dose of medication for injection. During the dose setting or dose "dialing" step, 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, depending on the manufacturer. The injection actuator is typically located proximal to the dose setting wheel and is often represented by a push button located at the proximal end of the injection pen system in most injection pens. After the dose is set, or "dialed," as this term is commonly known in the art, a user of the injection system pushes the injection actuator distally, driving a piston connected to a plunger that expels the medication from a chamber in the injection pen body through a needle inserted into the appropriate injection site, e.g., skin, fatty tissue, or muscle, depending on the type of medication being administered. Depending on the manufacturer and model of the injection pen, the dose setting wheel may, but is not necessarily, coupled to the injection drive mechanism so that it can also rotate as the injection of medication progresses. The functionality of such injection systems is per se well known in the art. The monitoring module envisioned in accordance with the present invention is intended for mounting on pen injection systems in which the dose setting wheel can be configured to rotate during the ejection / injection phase of operation, or conversely, not rotate during the ejection / injection phase of operation of the pen injection system. For example, the Kwikpen® injection pen mentioned above does not have a dose setting wheel that rotates during injection, while the dose setting wheels of the Lantus Solostar® and FlexPen® injection pens rotate during injection.

[0018] Accordingly, the injection monitoring module according to the present invention is adapted and configured to be removably attached to the proximal end of such an injection pen system. As used herein, the terms "removably attached," "removably attachable," "removably mounted," or "removably attachable" 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 removability may be achieved by providing the monitoring module with coupling means that releasably engage with the proximal end of the pen injection system, for example, via frictional or elastic engagement, or via other releasable fastening means, such as clips, straps, threads, and corresponding clamping rings that engage with either the dose setting wheel or the injection actuator, and / or even the body of the pen injection system.

[0019] The above-mentioned rotation stopping means should be understood as means by which rotation of the injection monitoring system about the central longitudinal axis is physically prevented during dose setting / dose dialing and, optionally and advantageously, when the injection monitoring system is moved from the first injection monitoring position to the second injection monitoring position and vice versa, i.e., when the injection monitoring system returns from the second monitoring position to the first injection monitoring position.

[0020] An advantage of providing such a rotation stop means in an injection monitoring module as envisioned by the present invention is that while the setting or "dialing" of a dose in a first injection monitoring position is identified as the selected dose by the injection monitoring system, such identification of the dialed dose as the selected dose will not necessarily be correct if the injection monitoring system is somehow allowed to rotate during dialing of the dose by rotation of the dose setting wheel. A further advantage of such a rotation stop or stop monitoring module provided by the present invention is that it does not actually matter whether the injection monitoring system rotates, either accidentally or by design, during selection of the dose to be expelled or during subsequent injections, thereby eliminating the need for other corrective measures for determination of the selected dose that might otherwise be necessary.

[0021] According to one object, the rotation stop means therefore comprises a rotatably fixed coupling arranged parallel to the central longitudinal axis, the rotatably fixed coupling connecting the injection monitoring system to the main body of the pen injection system. The rotatably fixed coupling is configured and adapted to prevent rotation of the injection monitoring system about the central longitudinal axis during dose setting or dialing, but more generally and advantageously when the injection monitoring system translates from the first monitoring position to the second monitoring position, and more preferably when the injection monitoring system translates from the second monitoring position back to the first monitoring position. In this way, it can be ensured that no accidental or intentional rotation of the injection monitoring system occurs when the user releases digital pressure on the injection actuator cap of the injection monitoring system, but in particular no rotation occurs during dose selection or dose dialing, and preferably no rotation occurs during injection of the dialed dose or even after injection is completed.

[0022] According to yet another object, the rotation stopping means is further configured and adapted to allow translational movement of the injection monitoring system from the first injection monitoring position to the second injection monitoring position and vice versa, i.e. from the second injection monitoring position to the first injection monitoring position, during injection.

[0023] Therefore, according to a further object, a rotatably fixed coupling is provided, at least one elongated rod member, or a plurality of elongated rod members, extending distally from the infusion monitoring system parallel to the longitudinal axis and bypassing an exterior surface of the hollow body; a sheath member mounted on the body of the injection pen system, the sheath member adapted and configured to receive at least one or more elongated rod members in sliding engagement with said sheath member during translational movement of the injection monitoring system from a first monitoring position to a second monitoring position; Equipped with.

[0024] From the above, it will be appreciated that the elongate rod member and the corresponding sheath member cooperate with one another to permit sliding engagement of the elongate rod member within the sheath member when the injection monitoring system moves from a first injection monitoring position to a second injection monitoring position, and vice versa, i.e., from the second injection monitoring position back to the first injection monitoring position. The sliding engagement between the elongate rod member and the sheath member occurs substantially parallel to the central longitudinal axis.

[0025] As described above, at least one elongated rod member or members extend parallel to the central longitudinal axis distally from the injection monitoring system, i.e., away from the proximal ends of both the injection pen system and the injection monitoring module. The one or more rod members are further shaped and dimensioned to be positioned outside the outer surface of the hollow body and bypass the hollow body thereon, thereby not interfering with the dose setting function of the hollow body, which must rotate to enable setting a dose in the pen injection system through co-rotating contact with the dose setting wheel. Similarly, the shape and dimensions of the one or more elongated rod members are configured and adapted such that, if the pen injection system manufacturer configures the pen to function similarly to, for example, a Sanofi Solostar® or Flexpen® pen injection system, the one or more rod members also do not interfere with any rotation of the dose setting wheel during injection.

[0026] According to another object, one or more elongate rod members have a proximal end that is seated or secured within a portion of a holder body or housing of the injection monitoring system, for example by providing an enlarged proximal cross section at the proximal end of such elongate rod member, and a correspondingly shaped recess having a reduced cross-sectional exit diameter provided in the body or housing of the injection monitoring system, which prevents withdrawal of the elongate rod member from said housing.

[0027] Alternatively, according to yet another object, at least one or more elongated rod members are integrally formed with the infusion monitoring system holder.

[0028] Preferably, in accordance with yet another object, at least one or more elongated rod members are integrally formed with an actuation cap of the injection monitoring system holder. The injection monitoring system is provided with a cap that a user presses to actuate an injection, the cap enclosing a magnetic field sensor within the injection monitoring system holder body or housing. Thus, in accordance with this object, the one or more rod members extend from the cap in a distal direction parallel to the central longitudinal axis, bypassing the hollow body that contacts the dose setting wheel on the pen.

[0029] According to a still further object, at least one or more elongate rod members include at least one portion thereof defining an elliptical spline extending distally from the injection monitoring system parallel to the central longitudinal axis. By "elliptical spline," it is understood that the elongate rod member extends in a direction substantially parallel to the central longitudinal axis, while, according to the further object, being at least partially defined along its length by an elliptical spline curve, i.e., a curve similar to the curve of an ellipse extending toward the body of the injection pen system. Generally, the spline curve portion of the elongate rod member is configured to maintain a sufficient distance between the elongate rod member and the body of the injection pen system as the injection monitoring system moves from a first monitoring position to a second monitoring position and back again, so that the elongate rod member never contacts the outer surface of the body of the injection pen system.

[0030] The elongated rod member is appropriately dimensioned, for example, with a corresponding thickness of material that renders the rod member semi-rigid along its length. Suitable materials for the elongated rod member are, for example, semi-rigid plastic materials such as blends of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) copolymers, commonly known as PC / ABS blends, although other suitable polymers and polymer blends that provide suitable rigidity are commonly known to those skilled in the art, and thus the elongated rod member can be made of or constructed of any such suitable rigid material.

[0031] As described above, the rotatably fixed coupling also includes a sheath member having at least one or more runnels configured and adapted to receive at least one or more elongated rod members, respectively, in sliding engagement. Therefore, according to another object, the at least one or more runnels extend parallel to the central longitudinal axis. The sheath member runnels are aligned with the elongated rod members, so that the rod members are inserted into and received by the runnels when the injection monitoring module is attached to the pen injection system. The one or more runnels are generally shaped and dimensioned as grooves having sidewalls, a base, and an opening, the base and sidewalls of the groove being located on the underside of the sheath member, and the opening of the groove being oriented to face the body of the injection pen system when the sheath member is attached to the injection pen.

[0032] As is apparent from the preceding paragraph, the sheath member is mounted to the body of the injection pen system. Thus, according to yet another object, the sheath member further comprises a body mounting portion configured and adapted to allow removable mounting of the sheath member to the body of the pen injection system. The body mounting portion of the sheath member can comprise a wall of material, for example a plastic or polymer material such as polycarbonate (PC), acrylonitrile butadiene styrene (ABS) copolymer, or a mixture thereof known as a PC / ABS blend, whereby the wall extends circumferentially around the body of the pen injection system and is dimensioned to allow insertion of the pen body into the bore formed by the circumferentially extending wall, while at the same time providing elastic frictional engagement with the outer surface of said pen body due to appropriate dimensions of the bore of the sheath member. Optionally and preferably, the circumferentially extending wall may be provided with softer, more elastic wall portions, for example made of elastomer SEBS or similar elastomeric polymers, for engaging and gripping corresponding surface portions of the body of the pen to prevent undesired axial sliding movement of the pen within the bore of the circumferentially extending wall of the sheath member. Suitable elastomeric materials for performing this function are known per se in the art.

[0033] According to a further object, the sheath member further comprises a retaining bridge configured and adapted to retain each of the at least one or more elongated rod members in a corresponding one of the at least one or more runnels. The retaining bridge is generally located on the underside of the sheath member that contacts the outer surface of the body of the pen injection system when the injection monitoring module is attached to the injection pen. The retaining bridge functions to maintain the elongated rod members in their corresponding runnels as the injection monitoring system moves from the first monitoring position to the second monitoring position and back again. The retaining bridge can be integrally formed as part of the sheath member, or can be provided as an insertable block that is configured to receive the retaining bridge and is seated, for example, by snap-fitting or ultrasonic welding, in a corresponding portion located on the underside of the sheath member opposite the opening of the corresponding runnel. In such a configuration, the retaining sheath member allows the lower surface of the retaining bridge to slide against the upper surface of the retaining bridge, retaining the rod in its corresponding runnel of the sheath member. Alternatively, the retaining bridge may be formed by suitable shaping of the runnel, for example, by providing the runnel with one or more mutually positioned protruding portions or shoulders extending from a first inner wall surface of the runnel toward a second, opposite inner wall surface of the runnel, optionally along at least a portion of the length of the runnel. The retaining bridge thus formed prevents the elongated rod member from accidentally falling out of the runnel as the elongated rod member slides along the runnel parallel to the central longitudinal axis when the injection monitoring system is moved from the first position to the second position, and vice versa.

[0034] According to a still further object, the rotatably fixed coupling further comprises a removable link configured and adapted to temporarily position the sheath member and at least one or more elongated rod members in a predetermined spaced-apart relationship along an axis parallel to the central longitudinal axis upon mounting of the injection monitoring module to the body of the injection pen system. The removable link functions to maintain the injection monitoring system with the protruding elongated rod members and the sheath member connected to the hollow body as a single mountable unit in a predetermined spatial relationship upon mounting of the monitoring module to the pen injection system to avoid any accidental, undesired axial displacement of the monitoring module upon mounting of the hollow body onto the dose setting wheel of the pen injection system. Thus, the removable link is configured to engage and retain both a portion of the housing or holder body of the injection monitoring system and a portion of the sheath member.

[0035] Therefore, in accordance with another object, the sheath member and the injection monitoring system each include a recess configured to receive a portion of the removable link and engage the portion of the removable link in a temporary positioning relationship.

[0036] Thus, the sheath member and the holder body or housing of the injection monitoring system may be provided with, for example, appropriately shaped recesses for receiving corresponding, complementary-shaped protruding portions of the removable link. For example, the complementary shapes suitable for engaging with the corresponding recesses on the sheath member and the injection monitoring system housing may take the form of butterfly wings, extending on either side of a central body defining a predetermined space required to maintain the sheath member and the injection monitoring system in their respective positions when the injection monitoring module is attached to the injection pen system. The butterfly body may further extend circumferentially around the holder body or housing of the injection monitoring system and resiliently engage therewith, such as with a circlip or, more generally, a spring clip. The resilient engagement of the injection monitoring system with the holder body and the butterfly wings engaging with the corresponding recesses on the sheath member and the body of the injection monitoring system, respectively, prevent the holder body of the injection monitoring system from inadvertently moving axially, thereby avoiding the inadvertent induction of erroneous readings in the injection monitoring system. Once the injection monitoring module is installed and the hollow body is correctly positioned on the dose setting wheel of the injection pen system, the removable link is removed. To facilitate its reuse, for example when the injection monitoring module is removed from the injection pen system, the removable link is conveniently stored in a corresponding recess provided in another position on the sheath member, the recess having a diameter sufficient to retain the link but allowing its removal if desired.

[0037] The hollow body of the infusion monitoring module includes a central longitudinal bore having proximal and distal ends, the bore being dimensioned to allow for coaxial mounting of the hollow body over and around the body of the pen injection system. The hollow body is suitably made of any suitable material, for example, a durable polymer or plastic material such as high-density or high-impact polypropylene or polycarbonate. Preferably, the hollow body is made of a transparent, translucent, or opaque material to allow a user to understand and recognize any visual cues, such as light-emitting diodes, that may also be provided on or incorporated into the infusion monitoring module, which can optionally be used to indicate various operating states of the infusion monitoring system.

[0038] Therefore, according to another object, the hollow body further comprises translational abutment means adapted and configured to prevent axial translational movement of the hollow body along the central longitudinal axis when the injection monitoring module is in a mounted position on the injection pen system. The translational abutment means defines a limit to axial translational movement of the hollow body along the central longitudinal axis relative to the actuator button of the pen injection system when the injection monitoring module is mounted on the pen injection system. Preferably, according to yet another object, the translational abutment means of the hollow body comprises an annular flange extending inwardly into the bore from an inner surface of the hollow body towards the central longitudinal axis. When the injection monitoring module is mounted on the injection pen system, the annular flange has a distal surface that contacts a proximal facing surface of the pen's actuator button, thereby preventing further translational movement of the hollow body along the central longitudinal axis.

[0039] According to a further object, the hollow body further comprises a distal body portion that extends around and frictionally and resiliently engages the outer surface of the dose setting wheel. Such a distal body portion can, for example, extend substantially from the annular flange described in the previous paragraph, or can be represented by a separately attachable hollow distal portion of the hollow body that is connectable thereto, for example, via a socket and bayonet mount, or a threaded or snap-lock mount, and that is configured and dimensioned to have a bore that matches the dimensions of the dose setting wheel of the injection pen system. The frictional and resilient engagement can be provided, for example, on the inner circumferential surface of the distal portion of the hollow body via a suitable elastomeric coating or deposit, for example, arranged in one or more zones, or as a continuous, contiguous, or semi-continuous / contiguous coating deposited on said inner circumferential surface of the distal portion of the hollow body. The purpose of such a frictional and resilient coating or deposit is to provide a frictional grip between the distal body portion and the dose setting wheel to maintain accurate positioning of the hollow distal body portion relative to the dose setting wheel. Suitable types of elastomeric materials capable of providing a corresponding frictional engagement are known per se in the art; a suitable elastomeric material is, for example, SEBS.

[0040] As noted elsewhere herein, the injection monitoring module includes an injection monitoring system. Such a system includes at least one or more magnetic sensors, and the injection monitoring system is positioned substantially at or adjacent to the proximal end of the bore of the hollow body. The injection monitoring system is described in more detail below, but essentially the injection monitoring system includes several different components and means for providing monitoring of the injection status, such as, for example: Initiation of injection action; The end or termination of an injection operation, which should be understood to include both the complete administration of a selected dose of the substance to be injected, or a discrete injection operation in which the user injects only a portion of the dose or expels a portion of the selected dose from the pen injection system.

[0041] Furthermore, in accordance with 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 the proximal face of the injection actuator to a second monitoring position in which the injection monitoring system is in abutting contact with the proximal face of the injection actuator. The injection monitoring system is advantageously mounted in the proximal end of the bore of the hollow body, preferably completely covering, or at least substantially covering, said proximal end of the bore.

[0042] From the above, it will be appreciated that the injection monitoring system can be moved from a first position, in which there is no physical contact between the injection monitoring system and the actuator button of the pen injection system, to a second position, in which physical contact is established between the monitoring system and the proximal face of the injection actuator of the pen injection system. Such movement is generally a translational movement of the monitoring system along the central longitudinal axis from the first position to the second position. The injection monitoring module is configured such that, because the injection monitoring system is locked against rotational movement about the central axis during dose setting, rotation of the hollow body and the correspondingly coupled dose setting wheel results in a determination that the set or dialed dose is the selected dose. The start of the injection is also determined by detecting an increase in the magnetic norm as the injection monitoring system begins to translate along the central longitudinal axis from the first monitoring position to the second monitoring position. The injection monitoring system is configured to detect the endpoint of injection or delivery of the injectable substance when the monitoring system translates proximally, i.e., from the second monitoring position to the first monitoring position, thereby removing physical contact between the actuator button of the pen injection system and the monitoring system. One way to achieve this is to configure a reference point corresponding to the first monitoring location and detect, e.g., using a suitably configured sensor, when the injection monitoring system returns to that reference point from another point.

[0043] Translational movement opposite to the direction of injection, i.e., translation of the monitoring system in a proximal direction back toward the user's hand or thumb, may be suitably provided by utilizing the recoil energy of a biasing spring that is compressed during injection actuation and relaxed upon release of the actuator button, suitably provided within the bore and that may also form part of the injection monitoring system. After the actuation cap is released by the user, for example, by directly or indirectly removing thumb or finger pressure on the actuation cap, the recoil energy of the compressed biasing spring within the bore moves the injection monitoring system away from the pen actuator button and urges the injection monitoring system back to the first monitoring position.

[0044] According to another object of the present invention, the monitoring module of the present invention comprises magnetic field generating means disposed on or within the hollow body adjacent to or at the proximal end of the central longitudinal bore. By the expression "disposed on or within the hollow body", it is to be understood that the magnetic field generating means may be seated on a proximally facing surface of the hollow body, for example at the proximal end of the central bore. Alternatively, and preferably, the magnetic field generating means may be seated in a cavity or recess provided in the hollow body at or adjacent to the proximal end of the central bore.

[0045] Various means for generating magnetic fields are known, such as classical magnets, electromagnets, and mixed-material magnets. Such magnets are typically made from magnetizable materials that have magnetic or paramagnetic properties, whether naturally or when an electric or other current passes through or influences the material to generate or induce a magnetic field within the material. Suitable materials can be suitably selected from: ferrite magnets, in particular sintered ferrite magnets, which contain, for example, crystalline compounds of iron, oxygen and strontium; - composite materials made of a thermoplastic matrix and isotropic neodymium-iron-boron powder; - composite materials composed of a thermoplastic matrix and strontium-based hard ferrite powder, in which the resulting magnets can be isotropic, i.e., non-oriented, or anisotropic, i.e., contain oriented ferrite particles; - composites made of a thermosetting plastic matrix and isotropic neodymium-iron-boron powder; - magnetic elastomers, for example, made using highly charged strontium ferrite powder mixed with synthetic rubber or PVC and subsequently extruded into the desired shape or calendered into fine sheets; - Flexible calendered composites, which generally have the appearance of a brown sheet and are more or less flexible depending on their thickness and composition. These composites are not as elastic as rubber and tend to have Shore hardnesses in the range of about 40 to about 70 Shore D ANSI. Such composites are generally formed from synthetic elastomers filled with strontium ferrite particles. The resulting magnets may be anisotropic or isotropic, with the sheet type generally having magnetic particle alignment due to the calendering process. -Laminated composites, generally comprising flexible composites as described above, co-laminated with soft iron plates; -Neodymium-iron-boron magnets; - steel made of aluminum-nickel-cobalt alloy and magnetized; -An alloy of samarium and cobalt.

[0046] 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 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.

[0047] The magnetic field generating means may be disc-shaped, including any suitable general shape, such as a circle, an ellipse, or any other suitable polygon, but preferably has only a single dipole, a 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 may also preferably include a magnet with an orifice substantially in the center of the disc to form a ring- or annular-shaped magnet. Such a ring- or annular-shaped magnet may be usefully seated on a peripheral annular and proximally-facing surface of the hollow body at the proximal end of the hollow body. Preferably, for purposes of the currently envisioned configuration of the infusion monitoring module, the dipole magnets are rod-shaped or cylindrical dipole magnets, one positioned in an opposite polarity orientation relative to the other, e.g., NS aligned with SN, so that the magnets are positioned flat along their own longitudinal axes across a horizontal plane that bisects and is perpendicular to the central longitudinal axis, with each magnet positioned on opposite sides of the central longitudinal axis, e.g., rotated 180° from one another about the central longitudinal axis.

[0048] The magnetic field generating means is provided to enable the magnetic field sensor to detect changes in the magnetic field during dose setting, for example due to rotational movement of the hollow body relative to the magnetic sensor, thereby determining the dial dose set via the dose setting wheel.

[0049] The magnetic field sensor is used to measure the magnetic field generated by the magnetic field generating means. Movement of the hollow body and magnetic field generating means about the central longitudinal axis relative to the rotatably fixed magnetic field sensor(s) as the dose wheel is rotated 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 actuator cap and correspondingly housed magnetic field sensor(s) along the central longitudinal axis, leading to translation of the injection monitoring system housing, is used to determine or calculate whether an injection has begun. Conversely, and respectively, when finger or thumb pressure is released on the proximal actuator cap, recoil energy in a biasing spring disposed within the injection monitoring system housing distal to said housing recoils the injection monitoring system, inducing translation of the injection monitoring system housing along the central longitudinal axis proximally toward the user's thumb or finger, thereby also moving the magnetic field sensor(s) housed within the injection monitoring system proximally.

[0050] As described above, during injection, when distal digital pressure along the central longitudinal axis is applied to the housing of the injection monitoring system, the magnetic field sensor detects a change in the magnetic field as the sensor translates distally along the longitudinal axis toward the magnetic field generating means and then in the reverse proximal direction when digital pressure is released from the injection monitoring system.

[0051] Furthermore, the compressibility of the biasing spring and the degree of resistance it provides to distal movement of the injection monitoring system can be advantageously used as a means for increasing the sensitivity of the monitoring system's detection of the start of an injection. For example, in the event of uncontrolled distal movement, a user may suddenly depress the activation cap of the monitoring module, potentially inducing an error in the injection monitoring system regarding the start of an injection due to a sudden increase in the magnetic field detected by the magnetic field sensor. Due to the compressibility of the biasing spring, such a rapid distal movement of the injection monitoring system and the corresponding induced increase in the magnetic field are damped to a level that the magnetic sensor can easily and unerringly process, thereby more safely and reliably initiating the determination of the injection point. To that extent, the biasing spring can be seen to represent, more generally, a damping means for assisting in the accurate determination of an injection start event.

[0052] With respect to magnetic sensors in general, means for measuring magnetic fields to determine their properties are generally known in the art. For example, magnetoresistance is a well-known technique. Such magnetoresistors are often designated by their abbreviations, e.g., AMR, GMR, and TMR sensors, to designate the physical mechanisms 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. Tunneling magnetoresistance (TMR) is the magnetoresistance effect that occurs in magnetic tunnel junctions (MTJs), which are components consisting of two ferromagnetic materials separated by a thin insulator. Resistors utilizing these various properties are known per se.

[0053] In light of the above, the infusion monitoring module and / or system according to the present invention preferably uses one or more magnetometers as one or more 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 an absolute magnetometer, which measures the absolute magnitude or vector magnetic field using the magnetic sensor's internal calibration or known physical constants. Relative magnetometers, also known as variometers, measure the magnitude or vector magnetic field relative to a fixed but uncalibrated baseline and are used to measure magnetic field fluctuations.

[0054] Thus, a preferred type of magnetometer for use in an infusion monitoring module according to the present invention is an ultra-low power, high performance, three-axis Hall effect magnetometer. While it is possible for a magnetometer to be configured to measure the magnetic field along three mutually perpendicular or orthogonal axes, in this case the magnetic field sensor is preferably configured to measure the magnetic field along only two of the three orthogonal axes, e.g., the X and Z axes.

[0055] As understood from the previous paragraph, and according to yet another object, the injection monitoring module further comprises an injection start determination means. For example, the injection start determination means is suitably represented by a magnetic field sensor, such as one or more magnetometers, located within the injection monitoring system and described elsewhere herein. Thus, in order to detect the start of an injection, the injection monitoring system is configured to detect, via values ​​measured and reported by one or more magnetometers present within the injection monitoring system, an increase in the magnetic norm, i.e., the magnetic field vector determined along an axis extending substantially parallel or coaxially to the central longitudinal axis, when said injection monitoring system starts to move from a first monitoring position towards a second monitoring position, without any concomitant effect on the magnetic field vector due to rotation of the injection monitoring system.

[0056] Preferably, according to a further object, the injection monitoring module comprises an end of injection determination means, which may be contact-based, i.e., requiring physical or electrical contact between two surfaces or the removal of such contact, such as, for example, a mechanical or electrical switch, or may be based on any number of known contactless detection means, such as, for example, wave-based sensors such as sound or light sensors, or any other sensors applying the principles of propagating waveforms and including an emitter, a receiver, and optionally a reflective surface, a chemically or biologically reactive sensor, a quantum effect sensor, etc., all of which are generally known per se in the art.

[0057] Preferably, according to a further object, the injection start and / or injection end determining means comprises an optical sensor and a corresponding reflective surface.

[0058] According to yet another object, an optical sensor is disposed on the injection monitoring system adjacent to at least one or more elongate rod members. The optical sensor may be suitably disposed, for example, in an actuation cap or in a holder body or housing of the injection monitoring system. Preferably, the optical sensor is positioned within the cap and / or housing of the injection monitoring system so as to receive reflected light from a correspondingly suitably disposed reflective surface.

[0059] Therefore, for yet another purpose, the reflective surface of the optical sensor is disposed on the sheath member opposite and in optical axial alignment with the optical sensor on the injection monitoring module.

[0060] The optical sensor and the reflective surface are thus positioned such that reflected light coming from the reflective surface travels to the optical sensor. The optical sensor is suitably configured to determine, for example, from the intensity of the reflected light and / or the time it takes for the reflected light to travel the path between the reflective surface and the optical sensor, the distance traveled by the optical sensor, and thus a predetermined reference position in the injection monitoring system, parallel to and along the central longitudinal axis. The optical sensor is therefore suitably equipped with a light-emitting source, such as may be provided by a light-emitting diode, for example. The optical sensor may further comprise a focusing or diffusion system for such a light source, depending on the characteristics of the reflective surface, the output of the light-emitting source, etc., as is known per se and in the art.

[0061] In injection pen systems in which the dose setting wheel rotates during injection, the magnetic field vector value provided by the magnetic field sensor of the injection monitoring system can be used to determine the end of injection due to the fact that the magnetic field vector value recorded by the magnetic sensor varies depending on, for example, the number of times the hollow body containing the magnet has rotated about its central longitudinal axis, coupled with the relative change in the magnetic field vector related to the distance of the magnetic sensor from the magnet. Such a configuration, in this case, makes it possible to record the end of an injection event using only the magnetometer.

[0062] However, for example in the case of an injection pen system in which the dose setting wheel does not rotate during injection, a non-contact sensor as described above, e.g. an optical sensor, is particularly advantageous as the injection monitoring system is configured to use such a non-contact sensor to send a signal when the injection monitoring device returns via axial translation along the central longitudinal axis from the second injection monitoring position back to the first injection monitoring position, and therefore assign an end of injection event to such return position.

[0063] In accordance with yet another object of the present invention, an infusion monitoring system includes an electronics board.

[0064] Preferably, in accordance with a further object of the present invention, one or more magnetic field sensors are electrically connected to the electronics substrate, and the one or more magnetic field sensors may be usefully positioned at diametrically opposed positions or otherwise radially distributed on the electronics substrate about the central longitudinal axis, with a single magnetic field sensor preferably positioned on the central longitudinal axis.

[0065] Even more preferably, the electronics board comprises an integrated control and data processing unit, such as at least one microcontroller, electrically connected to the one or more magnetic field sensors for processing information received from the magnetic field sensors. Therefore, the electronics board may suitably be, for example, a printed circuit board of correspondingly suitable dimensions. In the configuration envisaged by the present invention, such a printed circuit board is preferably disk-shaped, the center of which corresponds to the intersection with the central longitudinal axis.

[0066] As described above, the injection monitoring system includes an optical sensor. According to yet another aspect, the optical sensor is electrically connected to at least one microcontroller. The microcontroller controls the function of the optical sensor and processes signals and / or data received from the optical sensor to calculate, for example, the end of an injection sequence as described elsewhere herein, and further, how far the injection monitoring system has moved along the central longitudinal axis. This information is used to calculate whether the injection is complete.

[0067] The electronics board is preferably housed within an infusion monitoring system housing or holder body located mostly proximally of the hollow body, generally beyond the proximal end of the central bore. A distal portion of the infusion monitoring system housing is disposed within the bore. The infusion monitoring housing is free to translate within the hollow body bore, but rotation is prevented by rotational stops, such as those embodied by a sheath member and an elongated rod member.

[0068] Preferably, the electronics board is held such that a horizontal surface of the board is disposed in a plane substantially perpendicular to the central longitudinal axis. Thus, the electronics board is disposed in a fixed rotational relationship in the first injection monitoring position during dose setting relative to the hollow body, such that rotation of the hollow body does not cause a corresponding rotation of the electronics board. This means that when the hollow body is rotated to "dial" or set a dose for an injection, at least one or more magnetometers disposed on the electronics board are prevented from rotating about the central longitudinal axis.

[0069] According to yet another object of the present invention, the electronic component board comprises a communication unit electrically connected to 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.

[0070] According to a further object of the present invention, the electronic component board includes an autonomous, optionally rechargeable power source, such as a lithium-ion battery or alternatively a rechargeable battery, which can be easily replaced when depleted. If a rechargeable battery is provided, said rechargeable battery can be recharged when depleted via a corresponding charging port, such as a USB charging port provided in the infusion monitoring module and connected to the rechargeable battery. Both non-rechargeable, i.e., disposable batteries and rechargeable batteries are generally known per se to those skilled in the art. Advances in charging technology nowadays also make 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.

[0071] The integrated control and data processing unit, which comprises at least one microcontroller, handles all electrical communication and signaling between the different electronic components of the electronic component board, including the magnetic field sensor(s) and the optical sensor. The integrated control and data processing unit is also responsible for performing calculations that allow the calculation and determination of the exact position of the magnetic field sensors, as well as processing signals from the autonomous power source and communication means that are integrated into the injection monitoring system and 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 integrate 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.

[0072] These and other objects of the present invention will become apparent and will be explained in more detail in the following description of the drawings and exemplary monitoring module.

[0073] The invention will now be described in more detail with reference to the accompanying drawings, which are provided for purposes of illustration and example, in which: [Brief explanation of the drawings]

[0074] [Figure 1] 1 is a schematic exploded perspective view of an injection monitoring module mounted in a handheld pen injection system. FIG. [Figure 2] 2 is a schematic cross-sectional view of the injection monitoring module of FIG. 1 installed in a handheld pen injection system prior to use. [Figure 3] FIG. 3 is a schematic perspective view of a detail of the infusion monitoring module of FIG. 1 or FIG. 2. [Figure 4] 3 is a schematic perspective view of another detail of the infusion monitoring module of FIG. 1 or FIG. 2. [Figure 5A] FIG. 5 is a schematic perspective view of a detail of FIG. 4, seen from an angle. [Figure 5B] FIG. 5 is a schematic perspective view of the detail of FIG. 4, seen from another angle. [Figure 6]3 is a schematic perspective view of another detail of the infusion monitoring module of FIG. 1 or FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0075] 1 and 2, there are shown schematic diagrams of an injection monitoring module (1) according to the present invention. The injection monitoring module (1) is mounted to a handheld injection pen system (2) comprising a pen injection system body (3) having an outer peripheral surface (4), a pen cap (5) covering the distal end of the pen injection system, a dose setting or dial wheel (6) located at the proximal end of the pen injection system body (3), and a dialed dose visualization window (7) located distal to the dose setting wheel (6) and displaying the dose dialed by a user of the pen injection system. The injection monitoring module (1) according to the present invention is mounted on, covers, and surrounds the proximal end (8) of the injection pen system (2), and is also mounted on the pen body (3) and at least partially covers and contacts the outer peripheral surface (4). The injection monitoring module (1) extends proximally beyond the proximal end (8) of the pen body (3), particularly beyond the dose setting wheel (6). Also shown is a central longitudinal axis (9) that intersects the longitudinal centers of both the injection monitoring module (1) and the injection pen system body (3). The injection pen system (2) includes an actuator button (10) located proximally from the dose setting or dial wheel (6), as found in some commercially available injection pen systems. In pen injection systems (2) of the type shown in Figures 1 and 2, the dose setting wheel (6) is rotated about the central longitudinal axis (9) during dose setting, but is fixed for rotation during injection, i.e., the dose setting wheel does not rotate about the central longitudinal axis (9) during injection.

[0076] The injection monitoring module (1) comprises a hollow body (11) dimensioned and sized to be coaxially mounted around the body (3) of the pen injection system (2). To this end, the hollow body (11) comprises a central longitudinal bore (12) having a proximal end (13) and a distal end (14), and a central longitudinal axis coincident with the central longitudinal axis (9). The hollow body (11) further comprises a distal body portion (15) that extends around and frictionally engages the outer surface of the dose setting wheel (6). Frictional engagement between the hollow body (11) and the outer surface (4) of the dose setting wheel (6) can be achieved, for example, by fabricating the distal body portion from an elastomeric friction material (16) or, alternatively, by providing a coating of such an elastomeric friction material on the inner circumferential surface (17) of the hollow body; such elastomeric frictional engagement materials are readily known in the art for providing a push-fit or slide-fit engagement of the distal portion (15) with the outer surface (4) of the pen body (3). A suitable elastomeric friction material (16) for the distal body portion (15) can be, for example, a thermoplastic elastomer such as SEBS or a polystyrene-poly(ethylenebutylene)-polystyrene block copolymer.

[0077] The hollow body (11) is shown in more detail in Figure 6 and extends proximally beyond the limits of the actuator button (10) of the pen injection system (2), such that the bore (12) accommodates both the dose setting wheel (6) and the actuator button (10), and is shown in the distal body portion (15) of the hollow body (11). The hollow body (11) further comprises magnetic field generating means (18, 19) disposed above the bore (12) of the hollow body (11), i.e., as shown in Figure 6. The magnetic field generating means (18, 19) is suitably provided by a pair of single dipole magnets (18, 19) arranged diametrically opposite each other, each magnet having a respective north and south pole, the poles of each pair preferably oriented in opposite polarity alignment across the central longitudinal axis, i.e., NS / SN, with the first magnet having its north pole across a horizontal plane perpendicular to the central longitudinal axis and the opposite magnet lying in the same plane perpendicular to the central longitudinal axis, with its south pole facing in the same planar orientation as the north pole of the first magnet. The dipole magnets may be suitably formed in the shape of a rod or brick, or a disk or ring, or any other suitable shape. The magnets are positioned in appropriately sized recesses (20, 21) in the hollow body (11), which are located at or adjacent to the proximal end (13) of the body (11). Alternatively, the magnetic field generating means may be a single dipole ring-shaped magnet, which is seated on the circumferential proximal surface at the proximal end (13) of said hollow body or in a corresponding annular recess in the hollow body (11). From the above, it will be appreciated that the hollow body (11) in which the magnet is positioned is itself mounted on and frictionally engages with the dose setting wheel about said central longitudinal axis (9), so that the magnetic field generating means is free to rotate about the central longitudinal axis.

[0078] The hollow body (11) is disposed within the central longitudinal bore (12) and further comprises an inner guide sleeve (22) extending from the inner surface (17) of the hollow body (11) into the bore (12) via an annular flange portion (23), the sleeve (22) extending proximally from the inward end of the flange (23) toward the proximal end (13) of the hollow body (11). The inner guide sleeve (23) receives and guides the injection monitoring system as it translates within the bore (12) from a first monitoring position to a second monitoring position, as described in more detail herein.

[0079] The hollow body 11 also includes a translational abutment means 24 adapted and configured to prevent axial translational movement of the hollow body 11 along the central longitudinal axis 9 when the injection monitoring module 1 is in a mounted position on the injection pen system 2. As shown in FIG. 2, the translational abutment means may include an annular flange 24 extending inwardly into the bore from the inner surface 17 of the hollow body toward the central longitudinal axis. The annular flange 24 may preferably be configured for abutting contact with a proximal-facing surface of the distal body portion 15, thereby providing a distal-facing surface on the annular flange that abuts a proximal-facing surface of the actuator button 10 of the pen injection system 2 when the injection monitoring module is coaxially mounted in the pen, thereby preventing axial movement of the injection monitoring module in the distal direction.

[0080] As shown in Figures 1, 2, and 3, the infusion monitoring system (25) is at least partially disposed within the bore (12) and is translatable within the bore (12) from a first monitoring position to a second monitoring position. The infusion monitoring system (25) comprises several components, among them an infusion monitoring system housing (26). The infusion monitoring system housing (26) is shaped and configured like a cup having a stem that extends across substantially the same or similar diameter as the hollow body, a base wall (27) that is substantially perpendicular to the central longitudinal axis (9), and a first wall (28) that extends proximally away from the periphery of the base wall (27), thereby forming a cup-shaped portion having an interior volume that is closed by a proximal cap (29) that forms an actuator button that is snap-fit, press-fit, glued, or otherwise secured onto the proximally extending first wall (28) at the proximal end of the first wall (28). The base wall (27) further includes a second annular wall (30) extending distally from the base wall (27) at a position radially spaced from the central longitudinal axis (9) and having a diameter smaller than the diameter of the hollow body bore (12), allowing the housing (26) to translate within the sleeve (24) and bore (12) of the hollow body (11). The second annular wall (30) is closed at its distal end by a flexible cross wall (31) to form a stem of a cup. The flexible cross wall may be made of, for example, a flexible membrane material that can deform upon contact with the actuator button (10) of the pen injection system (2). The stem of the cup is located within the bore (12) of the hollow body (11). The infusion monitoring system housing (26), defined by a cup-shaped interior volume, receives and seats an electronics board (32). The interior volume of the stem formed by the second annular wall (30) and the cross wall (31) receives and powers an autonomous power source (33), such as a disposable or rechargeable battery, e.g., a lithium-ion battery, electrically connected to an electronics board (32), which is suitably and typically a printed circuit board sized to be positioned within the interior volume of the cup formed by the base wall (27) and the proximally extending first wall (28).The injection monitoring housing (26) optionally further includes a light guide window integrated into or part of the first wall (28), e.g., a translucent, opaque, or transparent material with crystalline properties selected to guide light waves from the interior volume of the cup, such as those generated by an optionally present light emitting diode or other light wave generating component, to the outside of the injection monitoring system housing (26).

[0081] The electronics board (32) preferably is disposed on the central longitudinal axis (9), and in the case of a substantially circular-shaped electronics board, further comprises at least one magnetometer (34) disposed substantially at its center so as to be coaxially aligned with the central longitudinal axis (9). In addition to the magnetometer (34), the infusion monitoring system (25) also comprises an integrated control and data processing unit electrically connected to the magnetometer (34) for processing information received from the magnetometer. The integrated control and data processing unit handles all electrical communication and signaling between the different electronic components of the infusion monitoring system. It is also responsible for the execution of the dosage management system and the calculations that enable the calculation and determination of the precise position of the magnet, as well as the processing of signals from the autonomous power source (33). The electronics board can further be connected to a USB port (35), which can be configured as a power recharge port for the rechargeable battery (33) and / or can be configured to enable basic setup of any programmable memory on the electronics board or to configure the data processing unit. The integrated control and data processing unit also typically includes a wireless communication circuit, e.g., a Bluetooth® or Bluetooth LE® wireless communication system, to name just two of many types of suitable communication means, for communicating with a local or remote data processing system, e.g., on a smartphone. The integrated control and data processing unit, like other modern electronic devices that include integrated control and data processing units, can be remotely programmed upon first use or receive information and updates, e.g., wirelessly or via any other suitable link, such as a USB port. 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, along with other desired components. The electronics board (32) is seated or positioned vertically within the cup formed by the base wall (27) and first wall (28) of the infusion monitoring system housing (26), substantially along the horizontal plane of the circuit board, i.e., approximately perpendicular to the central longitudinal axis (9).

[0082] The second annular wall (30), together with the cross wall (31), further defines a chamber housing (36) for a biasing means (37), such as a compression spring, which presses against the cross wall (31) at the proximal end of the second annular wall (30) and is constrained against a seating nub (38) at the proximal end of the chamber (36). Compression of the biasing means (37) causes the cross wall (31) to flex distally. The cross wall (31) is disposed at the distal end of the second annular wall (30) via a snap- or clip-fitting protrusion that fits into a corresponding recess in the second annular wall (30). The biasing means (37) also functions as a damper for the injection monitoring system (25) when it begins to move from the first monitoring position under digital pressure on the cap actuation button after a dose has been selected. The interaction of the compression spring, optionally assisted by a flexible cross wall, damps the initial acceleration of the injection monitoring system (25) upon contact with the activation button (10) on the injection pen (2). Considering that the distance traveled between the first and second injection monitoring positions may be very small, for example, on the order of a few tenths of a millimeter to at most a few millimeters depending on the dimensions of the injection pen, the biasing means not only accommodates variations in the axial geometry and molding tolerances of the various components of different pens, but also facilitates the detection of an increase in the magnetic norm, which increases as the magnetometer (34) in the injection monitoring system (25) moves along the central longitudinal axis (9) toward the magnets (18, 19).

[0083] The injection monitoring housing (26) further comprises a third annular wall (39) extending distally from the base wall (27) around the base wall (27) toward the hollow body (11). This third annular base wall (36) provides further axial stabilization for the injection monitoring system housing (26), in particular insofar as it is dimensioned to be surrounded and guided by the inner periphery of the hollow body (11) at the proximal end (13) of the hollow body (11) both in the first monitoring position and during actuation of the actuator button (10), in other words, during injection and / or expulsion of a substance from the injection pen system (2), and during return of the injection monitoring housing (26) from the second position to the first position.

[0084] 3 and 4 illustrate various components of a rotation stop means configured and adapted to prevent rotational movement of the injection monitoring system about said central longitudinal axis (9) during dose setting. The rotation stop means comprises a rotatably fixed coupling disposed parallel to the central longitudinal axis (9). The rotatably fixed coupling connects the injection monitoring system (25) to the body (3) of the pen injection system (2), as described below. The rotatably fixed coupling prevents rotation of the injection monitoring system (25) about the central longitudinal axis (9) not only during dose setting or dialing, but more generally during translation of the injection monitoring system (25) from a first monitoring position to a second monitoring position, and then translation from the second monitoring position back to the first monitoring position. In this way, it can be ensured that rotation of the injection monitoring system (25), whether accidental or intentional, does not occur, and particularly during dose selection or dose dialing, where such rotation would be a source of error in determining the selected or dialed dose. The rotation stop means is further configured and adapted to allow translational movement of the injection monitoring system from the first injection monitoring position to the second injection monitoring position and vice versa, i.e., from the second injection monitoring position to the first injection monitoring position, during injection while maintaining a rotational block. As is apparent from the foregoing description, the rotation stop means thus physically prevents rotation of the injection monitoring system (25) about the central longitudinal axis (9) while at the same time providing a translational guide system that accommodates permitted and configured translation of the injection monitoring system (25) in both distal and proximal directions.

[0085] The rotatably fixed coupling comprises at least one elongated rod member (40, 41), or multiple elongated rod members (40, 41), extending distally from the infusion monitoring system parallel to the longitudinal axis and bypassing the exterior surface of the hollow body (11), as shown in Figures 3, 4, and 5. Although the figures show the presence of two elongated rod members, the rotatably fixed coupling can also include only a single elongated rod member positioned in any suitable position.

[0086] The rotatably fixed coupling also includes a sheath member (42) that is mounted to the body (3) of the injection pen system (2), e.g., via coaxial mounting about the pen body (3), e.g., by sliding the sheath member (42) over the pen body (3). The sheath member (42) is adapted and configured to receive at least one elongated rod member (40, 41) or multiple elongated rod members (40, 41) that slidingly engage with said sheath member (42) during translation of the injection monitoring system (25) from a first monitoring position to a second monitoring position.

[0087] The elongated rod members (40, 41) and corresponding sheaths (42) cooperate with one another to permit sliding engagement of the elongated rod members (40, 41) within the sheath members (42) when the injection monitoring system (25) moves from a first injection monitoring position to a second injection monitoring position, and vice versa, i.e., from the second injection monitoring position back to the first injection monitoring position. The sliding engagement between the elongated rod members (40, 41) and the sheath members (42) occurs substantially parallel to the central longitudinal axis (9).

[0088] At least one elongated rod member (40, 41) or multiple elongated rod members (40, 41) extend parallel to the central longitudinal axis (9) in a distal direction from the injection monitoring system (25), i.e., away from the proximal ends of both the injection pen system (25) and the injection monitoring module (1). The rod member (40) or multiple rod members (40, 41) are further shaped and dimensioned to be positioned outside the outer surface of the hollow body (11) and bypass the hollow body (11) thereon, thus not interfering with the dose setting function of the hollow body (11). This means that the hollow body (11) can rotate unhindered by the elongated rod members (40, 41), thereby rotating the hollow body (11) and co-rotating the dose setting wheel (6), allowing a dose to be set in the pen injection system. Similarly, the shape and dimensions of the elongated rod member (40) or rod members (40, 41) are configured and adapted such that the rod member or members also do not interfere with any rotation of the dose setting wheel during injection, if the pen injection system manufacturer configures the pen to function in that manner.

[0089] The elongated rod member(s) 40, 41 have a proximal end that is seated or secured within a portion of the infusion monitoring system housing 26, for example, by providing the proximal end of the elongated rod member(s) 40, 41 with an enlarged proximal cross-section and a correspondingly shaped recess in the infusion monitoring system housing 26 with a reduced cross-sectional exit diameter, thereby preventing withdrawal of the elongated rod member(s) 40, 41 from the housing 26. Alternatively, at least one or more of the elongated rod members 40, 41 are preferably formed integrally with the infusion monitoring system housing 26, and in particular, with an actuation cap 29 of the infusion monitoring system housing 26. The cap 29 is therefore configured and dimensioned to extend beyond the nominal diameter of the hollow body 11. In this manner, the elongated rod members (40, 41) extend freely from the cap (29) in a distal direction parallel to the central longitudinal axis (9) and bypass the hollow body (11) without touching or contacting it.

[0090] At least one or more elongated rod members (40, 41) further includes at least one portion defining an elliptical spline extending distally from the cap (29) parallel to the central longitudinal axis (9). The "elliptical spline" shape of the elongated rod members facilitates contactless passage of the rods around the relatively enlarged diameter of the hollow body, while simultaneously reducing the need to increase the diameter of the injection monitoring system housing (26). Thus, the spline curved portions of the elongated rod members (40, 41) are configured to maintain a sufficient distance between the elongated rod members (40, 41) and both the hollow body (11) and the body of the pen (3) as the injection monitoring system (25) moves from a first monitoring position to a second monitoring position and back again, such that the elongated rod members (40, 41) preferably never contact the outer surface (4) of the injection pen system body.

[0091] The elongated rod members (40, 41) are further appropriately dimensioned, for example, with a corresponding thickness of material that renders the rod members (40, 41) semi-rigid along the length of the elongated rod members (40, 41). Suitable materials for the elongated rod members are, for example, semi-rigid plastic materials such as blends of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) copolymers, commonly known as PC / ABS blends, although other suitable polymers and polymer blends that provide suitable rigidity are commonly known to those skilled in the art, and thus the elongated rod members can be made of or comprised of any such suitable rigid material.

[0092] The sheath member (42) includes a generally elongated, flat body (43) that extends parallel to and generally conforms to the outer surface (4) of the pen body (3). The sheath member (42) further includes at least one or more runnels (44, 45) configured and adapted to receive at least one or more elongated rod members (40, 41) in sliding engagement, respectively. The at least one or more runnels (44, 45) also extend parallel to the central longitudinal axis (9). The runnels (44, 45) of the sheath member (42) are axially aligned with the elongated rod members (40, 41), such that the rod members (40, 41) are inserted into and received by the runnels (44, 45) when the infusion monitoring module (1) is attached to the pen infusion system (2). The runnel (44) or runnels (44, 45) are generally shaped and sized as a groove having side walls (46, 47), a base (48), and defining an opening, the base (48) and side walls (46, 47) of the groove being disposed on the underside (49) of the sheath member (42). The openings of the runnels (44, 45) are oriented to face the body (3) of the injection pen system (2) when the sheath member (42) is attached to the injection pen body (3).

[0093] To properly position the sheath member 42 on the exterior surface 4 of the body 3 of the injection pen 2, the sheath member further comprises a body mount 50 configured and adapted to allow for removable attachment of the sheath member to the body 3 of the pen injection system 2. The body mount 50 comprises a wall 51 of a material, for example, a plastic or polymeric material such as polycarbonate (PC), acrylonitrile butadiene styrene (ABS) copolymer, or a blend thereof known as a PC / ABS blend, whereby the wall 51 extends circumferentially around the body 3 of the pen injection system 2 and is dimensioned to allow insertion of the pen body into a bore 52 formed by the circumferentially extending wall 51 while simultaneously providing resilient frictional engagement with the exterior surface 4 of said pen body 3 through appropriate dimensioning of the bore 52. The circumferentially extending wall (51) is provided with a softer, more resilient wall portion (53), made for example of elastomer SEBS or a similar elastomeric polymer, for engaging and gripping a corresponding surface portion (4) of the body (3) of the pen (2) to prevent undesired axial sliding movement of the pen within the bore (52) of the circumferentially extending wall (51).

[0094] The sheath member may further include a retaining bridge (54) configured and adapted to retain each of the at least one or more elongated rod members (40, 41) in their corresponding at least one or more runnels (44, 45). The retaining bridge (54) is generally positioned on an underside of the sheath member (42) of the body (43) that contacts the outer surface (4) of the body (3) of the pen injection system (2) when the injection monitoring module (1) is attached to the injection pen (2). The retaining bridge (54) functions to maintain the elongated rod members (40, 41) within their corresponding runnels (44, 45) as the injection monitoring system (25) moves from the first monitoring position to the second monitoring position and back again. The retaining bridges (54) may be integrally formed as part of the body (43) of the sheath member (42), or may be provided as insertable blocks configured to receive the retaining bridges and seated, for example, by snap-fit ​​or ultrasonic welding, in corresponding locations on the underside (49) of the sheath opposite the openings in the corresponding runnels (44, 45). In such a configuration, the retaining sheath (54) allows the undersides (55, 56) of the elongated rod members (40, 41) to slide against the upper surfaces (57, 58) of the retaining bridges (54), retaining the rods (40, 41) within the corresponding runnels (44, 45) of the sheath member (42). Alternatively, the retaining bridge (54) may be formed by suitable shaping of the runnels (44, 45), for example, by providing the runnels (44, 45) with one or more mutually positioned protrusions or shoulders extending from the first inner wall surface (46) of the runnel toward the second, opposite inner wall surface (47) of the runnel, optionally along at least a portion of the length of the runnels (44, 45). The retaining bridge (54) prevents the elongated rod members (40, 41) from accidentally disengaging from the runnels (44, 45) as they slide along the runnels (44, 45) parallel to the central longitudinal axis (9) when the injection monitoring system (25) moves from the first position to the second position, and vice versa.

[0095] The rotatably fixed coupling further comprises a removable link (59) configured and adapted to temporarily position the sheath member (52) and at least one or more elongated rod members (40, 41) in a predetermined spaced-apart relationship along an axis parallel to the central longitudinal axis (9) when mounting the injection monitoring module (1) on the body (3) of the injection pen system (2). The removable link functions to maintain the injection monitoring system (25) with its protruding elongated rod members (40, 41) and the sheath member (42) connected to the hollow body (11) as a single mountable unit in a predetermined spatial relationship when mounting the monitoring module (1) on the dose setting wheel (6) of the pen injection system (2) to avoid any undesired axial displacement of the monitoring module (1) when mounting the hollow body (11) on the dose setting wheel (6) of the pen injection system (2). Thus, the removable link is configured to engage and retain both a portion of the injection monitoring system housing (26) and a portion of the sheath member (42).

[0096] Accordingly, the sheath member (42) and the infusion monitoring system (25) each include a recess (60, 61) configured to receive a portion of the removable link and engage the portion of the removable link in a temporary positioning relationship. The recess (60) of the infusion monitoring system is provided in a peripheral region of the cap (29), while the recess of the sheath member is provided in the proximal end of the body (43) of the sheath member (42), and the two recesses are axially aligned with each other parallel to the central longitudinal axis (9) when the removable link (59) is inserted into the recesses (60, 61).

[0097] The removable coupling link 59 includes corresponding, complementary shaped protruding portions 62, 63. For example, the complementary shapes suitable for engaging with the corresponding recesses 60, 61 provided in the sheath member 42 and the infusion monitoring system housing 26 can take the form of butterfly wings, the wings 62, 63 extending on either side of a central body 64 that defines a predetermined space required to maintain the sheath member 42 and the infusion monitoring system housing 26 in their respective positions when the infusion monitoring module 1 is attached to the injection pen system 2. The butterfly body 64 can further extend circumferentially around the infusion monitoring housing 26 and resiliently engage therewith, such as with a circlip or, more generally, a spring clip. The butterfly wings 62, 63, which resiliently engage with the injection monitoring system housing 26 and engage corresponding recesses 60, 61 in the sheath member 42 and housing body 26, respectively, prevent the housing body 26 from accidentally moving axially, thereby avoiding the inadvertent triggering of erroneous readings in the injection monitoring system 25. Once the injection monitoring module 1 is attached to the pen 2 and the hollow body 11 is properly positioned on the dose setting wheel 6, the removable link 59 is removed. To facilitate its reuse, for example, when the injection monitoring module 1 is removed from the injection pen system 2, the removable link 59 is conveniently stored in another location on the sheath member 42, for example, in a corresponding recess 65, 66, 67 located at or near the mounting portion 51 of the sheath member 42, with the recess 65 having a diameter sufficient to retain the removable link 59 but allowing for its removal as needed.

[0098] Figures 3, 5A, and 5B illustrate another specific embodiment of the infusion monitoring module 1, in which an optical sensor 68 is present as a suitable example of a non-contact sensor. The optical sensor 68 is disposed on the infusion monitoring system housing 26 adjacent to at least one or more elongated rod members 40, 41, and is suitably positioned in the actuation cap 29 portion of the housing 26, as shown in Figure 3. In this embodiment, the optical sensor 68 is positioned between the two elongated rod members 40, 41 so as to receive reflected light from a correspondingly suitably positioned reflective surface 69 located at the proximal end of the body 43 of the sheath member 42. The optical sensor 68 and the reflective surface 69 are therefore positioned such that reflected light from the reflective surface 69 travels to the optical sensor 68. Optical sensor 68 is suitably configured to determine, for example, from the intensity of the reflected light and / or the time it takes for the reflected light to travel the path between reflective surface 69 and optical sensor 68, the distance that optical sensor 68, and thus a predetermined reference position within injection monitoring system 25, has traveled parallel to and along the central longitudinal axis. Optical sensor 68 is therefore suitably equipped with a light-emitting source, such as may be provided by a light-emitting diode, for example. Optical sensor 68 may further comprise a focusing or diffusion system for such a light source, as known per se and as known in the art for the function and operation of such optical sensors, depending on the characteristics of reflective surface 69, the output of the light-emitting source, etc.

[0099] In operation, the monitoring module (26) functions according to the following brief description after the monitoring module (1) is mounted and accurately positioned on the injection pen body (1). The removable link (59) that initially holds the hollow body, injection monitoring system, elongated rod members (40, 41), and sheath member (42) together is removed and optionally placed in the corresponding recesses (65, 66, 67). The dose is set by rotating the hollow body, which co-rotates the dose setting wheel. Because the elongated rod members (40, 41) are already engaged with the runnels of the sheath member (42), the injection monitoring housing (26) is prevented from rotating within the bore (12) of the hollow body. The monitoring system (25) then receives only the signal from the magnetometer corresponding to the actual dose selected by rotation of the dose setting wheel (6). Without a rotation lock, the injection monitoring module of the present invention could suffer from inadvertent relative rotation, potentially causing errors in these readings, necessitating additional correction measures to determine whether the dialed dose was actually the selected dose. The set or dialed dose has been verified as the selected dose by the processing unit, and the monitoring system now determines whether the injection operation has begun, i.e., whether the injection monitoring system has begun translating along the central longitudinal axis (9) from the first monitoring position to the second monitoring position. This is accomplished when the magnetometer signals an increase in the magnetic norm to the processing unit, since an increase in the magnetic norm is synonymous with the magnetometer moving toward the magnet. In this way, the monitoring system knows that the injection operation has begun. In injection pens that rotate a dose wheel during injection, the magnetic field vector values ​​captured by the magnetometer can similarly be used to calculate the injection endpoint. However, in pens without rotating dose setting wheels, it is usually impossible for the user to know when the injection has finished because the injection monitoring system 25 may remain in contact with the injection activation button 10 of the pen 2 for an indeterminate period of time, or may barely be in contact with the activation button 10. Therefore, the measurement of the time elapsed at the second monitoring position may contain an error that requires correction.Thus, in such a configuration, the optical sensor is used to provide a reference point for the injection monitoring system, and thus the optical sensor determines when the injection monitoring system returns from the second monitoring position to the reference point of the first monitoring position, thereby signaling the end of the injection.

[0100] Thus, as can be seen from the foregoing, the infusion monitoring module of the present invention makes it possible to reliably determine, in a significantly more efficient manner than previously possible, that the dialed dose is actually the selected dose, the point at which the infusion begins, and the point at which the infusion ends.

Claims

1. 1. An injection monitoring module adapted and configured to be removably mounted to a proximal end of an injection pen system for delivery of a medication, the injection pen system having a pen body, a proximally located dose setting wheel connected to the body, and an injection actuator, the dose setting wheel being rotatable about a central longitudinal axis of the pen injection system during dose setting, the injection monitoring module comprising: a hollow body adapted and configured to be coaxially mounted to and co-rotatably engage the dose setting wheel at the proximal end of the injection pen system, the hollow body comprising a central longitudinal bore having a proximal end and a distal end and a central longitudinal axis; a magnetic field generating means disposed on or within the hollow body at the proximal end of the central longitudinal bore; an injection monitoring system comprising at least one or more magnetic sensors disposed at a proximal end of a hollow body and translatable along the central longitudinal axis within the bore of the hollow body from a first monitoring position in which the injection monitoring system is not in abutting contact with a proximal face of the injection actuator to a second monitoring position in which the injection monitoring system is in abutting contact with the proximal face of the injection actuator; Equipped with the infusion monitoring module further comprising a rotation stop means configured and adapted to prevent rotational movement of the infusion monitoring system about the central longitudinal axis during dose selection; Injection monitoring module.

2. 2. The injection monitoring module of claim 1, wherein the rotation stop means comprises a rotatably fixed coupling arranged parallel to the central longitudinal axis, the rotatably fixed coupling connecting the injection monitoring system to the main body of the pen injection system.

3. 2. The injection monitoring module of claim 1, wherein the rotation stop means is further configured and adapted to allow translational movement of the injection monitoring system from the first injection monitoring position to the second injection monitoring position and vice versa during injection.

4. the rotatably fixed coupling at least one elongated rod member, or a plurality of elongated rod members, extending distally from the infusion monitoring system parallel to the longitudinal axis and bypassing an exterior surface of the hollow body; a sheath member mounted on the body of the injection pen system, the sheath member adapted and configured to receive the at least one or more elongated rod members in sliding engagement with the sheath member during translational movement of the injection monitoring system from the first monitoring position to the second monitoring position; 4. An injection monitoring module according to claim 2 or claim 3, comprising:

5. The infusion monitoring module of claim 4 , wherein the at least one or more elongated rod members are integrally formed with the infusion monitoring system holder.

6. The infusion monitoring module of claim 5 , wherein the at least one or more elongated rod members are integrally formed with a cap of the infusion monitoring system holder.

7. 7. The injection monitoring module of claim 4, wherein the at least one or more elongated rod members include at least one portion of the elongated rod member defining an elliptical spline extending distally from the injection monitoring system parallel to the central longitudinal axis.

8. 7. The injection monitoring module of claim 4, wherein the sheath member comprises at least one or more runnels configured and adapted to receive the at least one or more elongate rod members, respectively, in sliding engagement.

9. The infusion monitoring module of claim 8 , wherein the at least one or more runnels extend parallel to the central longitudinal axis.

10. 10. The injection monitoring module of claim 4, wherein the sheath member further comprises a body attachment portion configured and adapted to allow removably attachment of the sheath member to the body of the pen injection system.

11. 11. The injection monitoring module of claim 4, wherein the sheath member further comprises a retaining bridge configured and adapted to retain each of the at least one or more elongated rod members in a corresponding one of the at least one or more runnels.

12. 12. The injection monitoring module of claim 4, wherein the rotatably fixed coupling further comprises a removable link configured and adapted to temporarily position the sheath member and the at least one or more elongate rod members in a predetermined spaced-apart relationship along an axis parallel to a central longitudinal axis when the injection monitoring module is mounted on the body of the injection pen system.

13. 13. The injection monitoring module of claim 4, wherein the sheath member and the injection monitoring system each further comprise a recess configured to receive a portion of the removable link and engage with the portion of the removable link in a temporary positioning relationship.

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

15. 15. The injection monitoring module of claim 14, wherein the translational abutment means of the hollow body comprises an annular flange extending inwardly into the bore from an inner surface of the hollow body toward the central longitudinal axis.

16. 16. The injection monitoring module of claim 15, wherein the hollow body further comprises a distal body portion that extends around and frictionally engages an outer surface of the dose setting wheel.

17. 2. The injection monitoring module of claim 1, further comprising an injection start determining means.

18. The injection monitoring module of claim 1 , further comprising an injection end determination means.

19. 2. The injection monitoring module of claim 1, wherein the injection start and / or end determining means comprises an optical sensor and a corresponding reflective surface.

20. 20. The infusion monitoring module of claim 4 and claim 19, wherein the optical sensor is positioned on the infusion monitoring system adjacent the at least one or more elongated rod members.

21. 20. The injection monitoring module of claim 4 and claim 19, wherein the reflective surface of the optical sensor is positioned on the sheath member opposite and in optical axial alignment with the optical sensor on the injection monitoring module.

22. 10. The infusion monitoring module of claim 1, wherein the infusion monitoring system further comprises an electronics board and at least one microcontroller electrically connected to the one or more magnetic field sensors.

23. 23. The infusion monitoring module of claims 19 and 22, wherein the at least one microcontroller is in electrical communication with the optical sensor.

24. 24. The infusion monitoring module of claim 23, wherein the electronics board comprises a communications unit in electrical communication with the at least one microcontroller.

25. 24. The infusion monitoring module of claim 23, wherein the electronics board comprises an autonomous power source.

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