Injection device with machine readable coding

Abstract

The present invention provides an injection device comprising a housing and a dose dispensing mechanism employing a threaded piston rod. The injection device is provided with a first position indicator and a second position indicator for indicating the current axial position and current angular position of the threaded piston rod relative to the housing, respectively, and further provides an inspection window allowing simultaneous optical readout of the first and second position indicators.

Description

Technical Field

[0001] This invention relates generally to medical devices, and more specifically to electronic dosing recording for injection devices having a rotatable piston rod. Background Technology

[0002] Injection devices, such as injection pens, are widely used for self-administration of liquid medications by individuals requiring treatment. Many injection devices are capable of repeatedly setting and injecting fixed or variable doses of medication after operating the corresponding dose setting and dispensing mechanisms within the device. Some injection devices are adapted to carry pre-filled drug reservoirs containing a volume sufficient to provide multiple injection doses. When the reservoir is empty, the user replaces it with a new one, thus allowing the injection device to be reused. Other injection devices are delivered to the user pre-filled and can only be used until the drug reservoir is emptied, after which the entire injection device is discarded. Various injection devices typically dispense medication by using a motion-controlled piston rod to advance a piston within the reservoir.

[0003] In some therapeutic areas, patient adherence to prescribed treatment depends on the ease of use of the specific treatment plan. For example, many people with type 2 diabetes are diagnosed at a relatively older age, at which point they are less willing to undergo treatments that excessively interfere with their normal lifestyle. These individuals often dislike being constantly reminded of their condition and therefore do not want to be bogged down in complex treatment protocols or waste time learning how to operate cumbersome delivery systems. Essentially, many believe that less human intervention is better.

[0004] For patients with diabetes, it is important to administer one or more glycemic regulators in a timely manner to maximize the time it takes for blood sugar to return to normal. In this regard, tracking when and how much of such regulators are administered is crucial for establishing an overview of an individual's adherence to a specific treatment regimen. Therefore, it is recommended that patients keep records of the dosage and timing of administration.

[0005] Previously, establishing and maintaining such logs required manual data recording, such as on paper or on a personal computer. However, because this required frequent and active participation, many people overlooked the importance of establishing such an overview. In light of this suboptimal situation, various solutions have been proposed for automatically capturing relevant information from the respective injection devices.

[0006] WO 2013 / 050535 (Novo Nordisk A / S) discloses a reusable add-on unit adapted to attach to a pre-filled injection pen with a rotatable piston rod. A small magnet mounted on the piston rod generates a magnetic field that varies in response to the axial and rotational movements of the piston rod. A magnetometer in the add-on unit measures the amplitude of the generated magnetic field in three perpendicular directions, thereby enabling the detection of the piston rod's position before and after a dose ejection event, with the difference reflecting the ejected dose.

[0007] WO 2018 / 141571 (Novo Nordisk A / S) discloses a pre-filled injection pen with a fully integrated sensor unit arranged as a piston-shield module between the piston rod and the cartridge piston of the dosing dispensing mechanism. The sensor unit functions like a rotary encoder and includes a first sensor portion that is rotationally locked relative to the piston rod and a second sensor portion that is rotationally locked relative to the cartridge piston. During a dosing event, as the piston rod rotates relative to the drug delivery device housing and the cartridge, the relative angular displacement between the two sensor portions is detected electrically and converted into an estimate of the administered dose.

[0008] WO 2018 / 078161 (Novo Nordisk A / S) discloses a pre-filled injection pen and an add-on module with a camera adapted to determine the amount of drug dispensed from the injection pen by capturing image data from a scaling drum.

[0009] While these exemplary solutions provide automatic recording of dosage data, they either require the addition of costly electronic components to the injection pen or the addition of an enlarged measuring device that is not an integral part of the injection pen.

[0010] To avoid any such additions, CH 717 022 (Ypsomed AG) proposes an injection pen with a machine-readable printed code area fixed relative to the housing, and arranged such that the piston or piston rod has a surface that overlaps with and covers a portion of the code area at all times. The current axial position of the piston rod relative to the housing can then be determined from the uncovered portion of the code area using a smartphone or other portable computer equipped with a barcode reader or camera.

[0011] Using smartphones that many people carry with them during the day instead of dedicated add-ons, and using printed code areas in the injection pen instead of sensor electronics, seems to offer a simple and cost-effective system.

[0012] However, for high-precision injection systems with very small piston rod advance increments, such as a typical insulin pen (where insulin is delivered from a 3 ml cartridge, and the piston rod moves the piston axially by only 0.15 mm for each dispensed dose unit), reliable dose capture, especially capture of the minimum expellable dose, seems nearly impossible. This is because in order to detect this type of movement by comparing the coverage of the coded region before and after dose dispensing, the user must keep the smartphone camera completely stationary relative to the injection device and in the exact same position relative to the coded region as when the photo was last taken. This places high demands on the user's agility and eyesight, as well as the smartphone's processor performance. Summary of the Invention

[0013] In the above description, the background art has been placed in the context of diabetes. However, it should be noted that the present invention can relate to other medical specialties where people benefit from parenteral dosing via an injection device, and is therefore not limited to the administration of insulin or other antidiabetic drugs.

[0014] One object of the present invention is to eliminate or reduce at least one disadvantage of the prior art, or to provide a useful alternative to the prior art solutions.

[0015] Specifically, one object of the present invention is to provide an injection device that allows for the accurate capture of dose-related data in a simple and cost-effective manner.

[0016] Another object of the present invention is to provide an injection device or system that allows for the precise capture of dose-related data without integrating sensor electronics into the injection device or using dedicated additional components that are not an integral part of the injection device.

[0017] Another object of the present invention is to provide an injection device or system that allows for precise capture of even the smallest dose increments without requiring excessive motor skills from the user.

[0018] In the disclosure of this invention, aspects and embodiments that achieve one or more of the above-described objectives and / or will achieve objectives that will become apparent from the following description will be described.

[0019] In one aspect, the present invention provides an apparatus according to claim 1.

[0020] Therefore, an injection device is provided, comprising a housing extending along an axis and having an internal nut member, and a dose dispensing mechanism including a threaded piston rod that cooperates with the internal nut member, the threaded piston rod being travelable in a distal direction relative to the housing. The cooperative engagement between the threaded piston rod and the internal nut member results in a helical movement of the threaded piston rod relative to the housing.

[0021] The device further includes a cartridge retainer for holding the cartridge in an axially fixed position distal to the internal nut member. The device may be a pre-filled, disposable type adapted to discharge the contents of a non-replaceable cartridge pre-attached to or pre-inserted into the cartridge retainer, or it may be a reusable type adapted to discharge the contents of multiple attachable / insertable and replaceable cartridges. Regardless of the type of device, the cartridge is axially fixed relative to the housing. The cartridge retainer may be part of the housing or a separate component attached to or attachable to the housing. If the former, the cartridge retainer may include a sleeve portion of the housing adapted to receive the cartridge, or a receiving device within or above the housing adapted to engage with a proximal portion of the cartridge or with a portion of an adapter device that supports and / or receives the cartridge.

[0022] Furthermore, the device includes: a first position indicator adapted to indicate the axial or translational position of the threaded piston rod relative to the housing; a second position indicator rotatably fixed to the threaded piston rod and adapted to indicate the angular or rotational position of the threaded piston rod relative to the housing; and an inspection window that allows simultaneous optical readout of the first and second position indicators, thereby enabling determination of the current angular progress of the threaded piston rod relative to the housing. Therefore, the inspection window allows for optical readout of both the first and second position indicators.

[0023] Simultaneous optical readout of the first and second position indicators can be performed using a smartphone or barcode reader with a camera, or other readout device with an image capture device and possibly an image processing device. In particular, simultaneous optical readout can be adapted to be performed using an image capture device that takes a single photograph.

[0024] In this type of dose dispensing mechanism, the exact helical motion of the threaded piston rod is determined by the pitch of the thread in the internal nut component, and the current angular progression of the threaded piston rod relative to the housing (which represents the cumulative angular displacement of the threaded piston rod since its initial position before use) can be directly converted into the cumulative axial displacement of the threaded piston rod relative to the housing during use.

[0025] Therefore, by comparing the most recent optical readout with the penultimate optical readout, the magnitude of the last discharged dose can be determined using the current angular progression of the threaded piston rod relative to the housing, and, for example, by comparing the most recent optical readout with the optical readout of the threaded piston rod at its initial position before use, the total dose discharged since the device was first operated can be determined.

[0026] Therefore, dose-related data can be captured without integrating electronics into the injection device or using additional components. Accordingly, the injection device can be a sensorless injection device, meaning it does not carry or contain any type of sensor device suitable for detecting or monitoring the operation of the dose delivery mechanism.

[0027] The threaded piston rod can travel on a continuous dose scale, as is known from infusion pumps, or on a discrete dose scale, as is known from variable-dose injection pens. In particular, the threaded piston rod can travel on a discrete dose scale, wherein the threaded piston rod can only travel an integer number of fixed angular increments, each fixed angular increment corresponding to a predetermined dose measurement of a given drug in the current cartridge. For example, a device suitable for delivering a dispensing dose of insulin can be configured to advance the threaded piston rod in angular increments corresponding to ½ IU or 1 IU (International Units).

[0028] The device may further include a dose setting mechanism for setting the dose to be delivered from the current cartridge by the operation of the dose dispensing mechanism. This dose setting mechanism may be configured to allow a user to set the dose in fixed increments, which thus corresponds to a discrete dose scale.

[0029] Determining the magnitude of the last expelled dose and the total dose expelled based on simultaneous optical readout from the first and second position indicators is extremely accurate and reliable because incremental motion in the angular dimension is relatively large and easier to distinguish than incremental motion in the axial dimension.

[0030] In practice, the second position indicator, which determines the exact angular position of the threaded piston rod relative to the housing, is so accurate that the resolution requirement for the first position indicator can be reduced. This is because the first position indicator is only used to determine how many full revolutions the threaded piston rod has made, and since the axial displacement experienced by the piston rod during one full revolution is much greater than the incremental axial displacement, or even the incremental angular displacement, the first position indicator does not need to be so finely graded.

[0031] In summary, incremental motion in the angular dimension is a decisive factor in accuracy, which also means that useful optical readout does not require users to have excessive motor skills or keen eyesight.

[0032] The device may further include a cartridge held by a cartridge holding device. The cartridge may include a cylindrical wall portion and may be filled or substantially filled with a liquid drug.

[0033] Simultaneous optical readout of the first and second position indicators can be achieved by the user manually reading the two scales (in which case the optical readout may be more like quasi-simultaneous), or by capturing an image using a camera device, in which case both the first and second position indicators can be read by the optical devices.

[0034] The second position indicator may include a pattern that has a unique visual appearance for each angular position of the threaded piston rod relative to the housing within the inspection window. In particular, the second position indicator may include a pattern that has a unique visual appearance for each incremental angular position of the threaded piston rod relative to the housing within the inspection window.

[0035] Each possible visual appearance of the pattern in the inspection window can then be correlated with a specific angular position of the piston rod relative to the housing, and thus used as an angular input for dose determination. The correlation between the possible visual appearance of the pattern in the inspection window and the angular position of the piston rod relative to the housing can be pre-identified in the readout device or in another processing device operatively coupled to the readout device.

[0036] In an exemplary embodiment of the invention, the pattern includes circumferentially extending digital scales. This can be interpreted not only by a readout device but also by a human, allowing the user to perform optical readout without the need for a readout device. However, in practice, the user must then manually convert the readings or manually input the readout data into a computing device to obtain a useful dose determination.

[0037] In other exemplary embodiments of the invention, the pattern comprises circumferentially extending micro-dot codes or circumferentially extending matrix codes. These can only be deciphered by a readout device, thus eliminating the risk of confusion for the user in dosage determination.

[0038] The second position indicator can be mounted directly on the piston rod. Alternatively, the second position indicator can be mounted on a sleeve member that is rotatably fixed to the threaded piston rod. This provides a larger and better surface from which the second position indicator can be read through the inspection window.

[0039] The sleeve assembly may include an annular outer surface for carrying a second position indicator, the diameter of which is greater than 80% but less than 100% of the inner diameter of the cylindrical wall portion of the cartridge. The diameter of the annular outer surface must be smaller than the inner diameter of the cylindrical wall portion of the cartridge to allow the sleeve assembly to enter the cartridge during the axial travel of the piston rod without contacting the cartridge and thus avoiding friction. On the other hand, the larger the diameter of the annular outer surface, the greater the distance the second position indicator moves relative to the inspection window during the incremental rotation of the piston rod.

[0040] The second position indicator may be printed, etched, or otherwise fixedly arranged on the sleeve component.

[0041] The sleeve component can be axially fixed to the distal portion of the threaded piston rod. Thus, as the threaded piston rod travels into the cartridge, the sleeve component with the second position indicator will follow the rotational and axial movement of the threaded piston rod. This can be advantageous because the mark for reading the first position indicator will naturally be located on the piston (in this case, the first position indicator indirectly indicates the axial position of the threaded piston rod via the axial position of the piston), or on the sleeve component, and then the simultaneous reading of the first and second position indicators can be performed by focusing a single camera on a small area.

[0042] In an exemplary embodiment of the invention, the cuff member includes a circumferential mark adapted to move relative to a first position indicator during dose dispensing. This circumferential mark allows the first position indicator to be read regardless of the angular position of the cuff member relative to the examination window.

[0043] Alternatively, the sleeve member can be axially fixed relative to the housing and adapted to undergo relative axial displacement relative to the threaded piston rod, such that the second position indicator remains in the same axial position relative to the housing as the threaded piston rod travels into the cartridge. For example, if the initial position of the sleeve member is located at the distal end of the threaded piston rod, the corresponding axial position of the sleeve member relative to the inspection window will be maintained throughout the entire service life of the injection device.

[0044] The first position indicator may include an axially extending scale. This can be interpreted not only by a readout device but also by a human, allowing users to perform optical readout without the need for a readout device.

[0045] Alternatively, the first position indicator may include an axially extending barcode or an axially extending matrix code. Such codes can only be interpreted by a reading device, thus eliminating the risk of confusion for the user regarding dosage determination.

[0046] In another alternative, the first position indicator may include a reference mark and / or an axially extending line of a well-defined length. For example, this would allow an image processor in a standard 4K digital camera to easily estimate the axial position of the mark so that the first position indicator is read along the axially extending line, and / or to estimate the axial distance of the mark from the reference mark using horizontal or vertical lines in the image.

[0047] The first position indicator may be arranged on and / or along a portion of the cartridge holder, or on and / or along a portion of the cartridge, thereby being axially fixed relative to the housing. Alternatively, the first position indicator may be arranged along a measuring rod operably coupled to a threaded piston rod and configured to extend axially from the housing together with the threaded piston rod.

[0048] For example, the inspection window can be configured as an axially extending groove in a cartridge holder, an axially extending groove between the edges of a label adhered to the surface portion of the cartridge, or an axially extending groove in a separate longitudinal structure arranged in the housing extension. Alternatively, the inspection window can, for example, consist only of the transparent portion of the cartridge.

[0049] It should be noted that, in this context, the term "inspection window" includes a single window as well as two or more axially aligned windows, for example, one in a cartridge holder and one in a housing (e.g., in the case where the sleeve member is axially fixed in the housing). The two or more axially aligned windows do not need to be perfectly axially aligned, as long as they are arranged to enable simultaneous optical readout of the first position indicator and the second position indicator.

[0050] The first position indicator may be arranged along the edge, boundary, or frame portion of the inspection window, resulting in close proximity to the second position indicator, making simultaneous optical readout of both position indicators easier. If the inspection window is provided as an axially extending groove between the edges of a label adhered to a portion of the cartridge surface, the first position indicator may be printed on the label. Alternatively, the first position indicator may be arranged within or above a transparent portion of the cartridge.

[0051] The injection device may further include a protective cap configured to be removably attached to the housing to cover the cartridge holder, the protective cap including a camera arrangement for capturing one or more images of the examination window. The camera arrangement may include a battery and one or more flash devices or other means for momentarily or continuously emitting light onto the examination window.

[0052] Injection devices typically feature a protective cap for attachment to the housing to cover the cartridge holder and / or the current cartridge. Such a cap primarily protects the cartridge and the medication contained therein from mechanical impact and sunlight. Introducing a camera arrangement within the cavity of the protective cap provides the opportunity for simultaneous optical readout of both the first and second position indicators without the need for separate readout devices, such as smartphones or add-ons. Furthermore, since the protective cap is a typical component of the injection device and is routinely handled by the user, this solution can be achieved without altering normal usage patterns.

[0053] The housing and protective cap may include respective guide structures configured to interact to ensure that the protective cap is attached to the housing at a predetermined attachment position where the camera arrangement is aligned with the inspection window. This prevents the user from unintentionally attaching the protective cap at an angle where the camera arrangement cannot perform simultaneous optical readout of the first and second position indicators.

[0054] The device may further include a triggering mechanism, for example disposed in the protective cap, configured to trigger a camera arrangement to capture an image in response to the protective cap being in a predetermined attachment position. Thus, when the user reattaches the protective pen to the housing after the injection action, automatic optical readout of the first and second position indicators will be performed.

[0055] The protective cap may further include a processor for processing the read data, a storage device for storing the read data or processed read data, and / or a communication device for relaying the read data or processed read data. The communication device may include a digital display and / or a wireless communication interface, such as Bluetooth.

[0056] Simultaneous optical readout of the first position indicator and the second position indicator can be processed by an image processing device in a readout device (such as a smartphone or protective cap) for performing the optical readout, or by an image processing device in a separate device operatively connected to the readout device.

[0057] The injection device may further include a machine-readable information tag containing drug-related information, such as drug type, batch number, and expiration date. This machine-readable information tag may be positioned next to the inspection window, either at or along its frame, or next to the first position indicator to allow simultaneous optical readout of the first position indicator, the second position indicator, and the information tag. This enables the image processing device to directly correlate dosage determination with drug type each time a simultaneous optical readout occurs. Alternatively, the information tag may be positioned at a distance from the inspection window, requiring separate optical readout.

[0058] In another aspect, the present invention provides an injection system comprising an injection device as described above, combined with a readout device, the readout device including an image capture device capable of simultaneously optically reading out a first position indicator and a second position indicator. The image capture device may include a camera device for acquiring images of the first and second position indicators through an inspection window. The readout device may further include a processing device adapted to process the acquired images and determine the current angular progress of the threaded piston rod relative to its housing.

[0059] In a particular embodiment of the present invention, the readout device is or includes a smartphone.

[0060] The processing device may include an application on a smartphone configured to determine the current angular progress of the threaded piston rod relative to the housing based on simultaneous optical readouts from a first position indicator and a second position indicator.

[0061] In a further aspect, the present invention provides a method for capturing dose-related data from an injection device as described above, the method comprising: (A) operating a readout device including an image capture device and an image processing device to perform simultaneous optical readout of a first position indicator and a second position indicator through an inspection window, and (B) causing the image processing device to process the simultaneous optical readout of the first position indicator and the second position indicator to determine the current angular progress of the threaded piston rod relative to the housing.

[0062] To avoid any ambiguity, in this context, the term "injection device" refers to a device suitable for injecting a fluid medium into a subject, such as by means of an attachable needle device, while the term "drug" refers to a medium used in the treatment, prevention, or diagnosis of a condition, including media that have a therapeutic or metabolic effect in the body. Furthermore, the terms "distal" and "proximal" refer to the location of or along the direction of a drug delivery device, drug reservoir, or needle unit, where "distal" refers to the drug outlet end and "proximal" refers to the end opposite the drug outlet end.

[0063] The term "cartridge" is used for a variable-volume reservoir containing a drug. Cartridges are typically made of glass, but can also be molded from a suitable polymer. It generally comprises a hollow body, primarily cylindrical, sealed at one end by a puncturable membrane and at the opposite end by a slidable stopper or piston (e.g., at least partially made of rubber), with the drug contained in the space between the puncturable membrane and the slidable stopper.

[0064] In this specification, references to a particular aspect or embodiment (e.g., "aspect," "first aspect," "an embodiment," "exemplary embodiment," etc.) indicate that a specific feature, structure, or characteristic described in relation to that aspect or embodiment is included in at least that aspect or embodiment of the invention, or is inherent to at least that aspect or embodiment of the invention, but is not necessarily included in or inherent to all aspects or embodiments of the invention. However, it should be emphasized that any combination of various features, structures, and / or characteristics described in relation to the invention is included within the scope of the invention, unless expressly stated herein or clearly contradicted by the context.

[0065] The use of any and all example or exemplary wording (e.g., such as etc.) in this document is intended to illustrate the invention only and does not constitute a limitation on the scope of the invention, unless otherwise stated. Furthermore, nothing in this specification should be construed as indicating that any unclaimed element is essential to the practice of the invention. Attached Figure Description

[0066] The invention will now be further described with reference to the accompanying drawings, wherein... Figure 1 This is a side view of the injection device, showing the corresponding axial and rotational movements of the threaded piston rod. Figure 2 This is a perspective view of the assembly of the threaded piston rod and the distally arranged sleeve component. Figure 3a and Figure 3b These are, respectively, a longitudinal sectional view and a perspective view of the distal portion of the threaded piston rod. Figures 4-6 This is a perspective view of the distal portion of the injection device housing, showing an assembly of an engaging threaded piston rod and corresponding sleeve members according to three different embodiments of the invention. Figure 7 This is a side view of an injection device according to an embodiment of the present invention. Figure 8 This is a perspective view of an injection device according to another embodiment of the present invention. Figure 9 Capture after injection was shown Figure 8 An exemplary method of using an image of an injection device for determining the injection dose. Figure 10 An exemplary method for presenting determined dose-related data to a user is shown, and Figure 11 This is a partial longitudinal sectional side view of an injection device according to another embodiment of the present invention.

[0067] In the accompanying drawings, similar structures are mainly represented by similar reference numerals. Detailed Implementation

[0068] When / if relative terms such as “up” and “down,” “left” and “right,” “horizontal” and “vertical,” “clockwise” and “counterclockwise” are used below, these terms refer to the accompanying drawings and do not necessarily refer to actual use. The drawings shown are schematic representations, and the configurations of different structures and their relative dimensions are intended for illustrative purposes only.

[0069] Figure 1 This is a side view of a conventional insulin injection device (slightly modified with the addition of a cuff component, see below), illustrating an important aspect of the invention in the context of diabetes management. However, it is clear that this is only one exemplary scenario of the invention.

[0070] The figure shows an automatic injection pen 1' having a housing 2' that houses a spring-powered piston rod advance mechanism (not visible) and a dose setting mechanism (not visible) operable to set the injection dose by rotating a dose dial 3' relative to the housing 2'. A cartridge holder 15' containing a transparent cartridge 10 is attached to the distal end of the housing 2'. The cartridge 10' is sealed proximally by a slidable piston 12' and distally by a self-sealing diaphragm (not visible). A needle assembly 50' is attached to the cartridge holder 15', whereby the rear portion of the injection needle 55' penetrates the self-sealing diaphragm and establishes fluid contact with the interior of the cartridge 10'. The cartridge holder 15' is designed with an elongated inspection window 19' to allow inspection along the entire length of the cartridge 10'.

[0071] The housing 2' has an internal nut component (not visible) that engages with a threaded piston rod 20'. The piston rod 20' is operatively connected to a piston 12' and configured to advance the piston 12' within the cartridge 10' to expel medication from the cartridge 10' via an injection needle 55'. In this figure, the distal portion of the piston rod 20' is covered by a radially enlarged sleeve component 40', the diameter of which is only slightly smaller than the diameter of the cartridge 10'. This means that the outer surface of the sleeve component 40' lies just below the inner surface of the cartridge 10', but does not contact it. The sleeve component 40' is fixed to the piston rod 12' and thus follows its helical movement.

[0072] The piston rod propulsion mechanism is adapted to propel the piston rod 20' helically relative to the housing 2', and the helical motion of the piston rod 20' is converted into axial displacement of the piston 12' in the cartridge 10', which causes the drug to be discharged through the injection needle 55'.

[0073] The dose scale (invisible) set by rotating the dose dial 3' is discrete, and during dose delivery, the piston rod 20' advances according to the set dose. This means that during the dose delivery action, the total movement of the piston rod 20' corresponds to an integer number of minimum settable dose increments. WO 2018 / 078161 teaches an exemplary design of such a dose setting and piston rod advancement mechanism, the relevant sections of which are incorporated herein by reference.

[0074] Injection devices based on the principle of advancing a piston by rotating a threaded piston rod within a fixed thread exhibit a dispensing ratio of X° per dose unit, meaning the minimum settable dose is injected by rotating the piston rod X° around its own axis. In this case, X depends on the drug concentration, the thread inclination (pitch), and the inner diameter of the cartridge.

[0075] In such Figure 1 In the standard injection device shown with a standard 3 ml cartridge and U100 insulin, the piston is displaced axially by 0.15 mm to dispense 1 IU; in this example, this corresponds to a 15° rotation of the piston rod 20'. In the inspection window 19', the reinforced section of the cartridge 10' illustrates the effect of the piston rod rotation. This section highlights the visible portions of the piston 12' and the cuff assembly 40', and the corresponding markings 12a' and 40a' on the piston 12' and cuff assembly 40' indicate how much each of these components moves axially during the delivery of one dose unit, and how much the outer surface of the cuff assembly 40' moves laterally.

[0076] As can be seen, when the piston mark 12a' moves an axial distance of a = 0.15 mm during the discharge of 1 IU, the sleeve member mark 40a' moves a lateral distance of b = 1.15 mm. This is the distance the outer surface of the sleeve member 40' rotates, which is because the sleeve member 40' is fixed to the piston rod 20' and projected onto the viewing plane. Therefore, the captureable angular displacement of the sleeve member 40' is almost eight times the captureable axial displacement of the piston 12', which is an important factor of this invention. Examples of how this can be utilized will be given below.

[0077] Figure 2 This is a perspective view of a piston rod 20 used in an injection device according to an embodiment of the present invention. The piston rod 20 has an elongated body with a thread 21, an axial track 24 in the thread 21 extending along its entire length, a proximal portion 23, and a distal portion including a spearhead 22. Figure 3a ).

[0078] The distal portion of the piston rod 20 is covered by a sleeve member 40. The sleeve member 40 has a proximal sleeve body portion 41 and a distal sleeve body portion 42, the diameter of which is larger than the diameter of the proximal sleeve body portion 41. The distal sleeve portion 42 is adapted to display machine-readable coding, but this coding has been omitted from this view for clarity. A piston washer 30 is arranged at the distal end of the piston rod 20 to distribute the load from the piston rod 20 to the piston 12.

[0079] Figure 3a This is a side view of the distal portion of the piston rod 20, and a cross-sectional view of the sleeve member 40 and the piston washer 30, showing the engagement between the sleeve member 40 and the piston washer 30, and the engagement between the piston washer 30 and the piston rod 20. The piston washer 30 has a circular washer body 31 that fits into a seat 46 of the sleeve member 40, with proximal protrusions 32 having rod hook portions 33 for engaging with the piston rod 20 behind the spearhead 22, and sleeve hook portions 34 for engaging with the inner flange portion 44 of the sleeve member 40. These engagements ensure that both the piston washer 30 and the sleeve member 40 are axially fixed to the distal portion of the piston rod 20.

[0080] Figure 3b This is a proximal perspective view of the distal portion of the piston rod 20, showing a radial protrusion 43 in the proximal cuff portion 41, which is slidably received in the axial track 24, thereby ensuring that the cuff assembly 40 is rotatably fixed to the piston rod 20. The distal cuff body portion 42 is provided here with a circumferential micro-dot pattern 80, presenting machine-readable coding of a first exemplary type, the purpose of which will become apparent below. It should be noted that while the cuff assembly 40 is rotatably fixed to the piston rod 20, the piston washer 30 is not so heavily restricted. This ensures that energy waste during the transition of movement from the piston rod 20 to the piston 12 is minimized during dose delivery, because the piston washer 30 is allowed to remain non-rotatable relative to the piston 12, thus the only friction interface is the friction interface between the washer body 31 and the spearhead 22.

[0081] Figure 4 This is a distal perspective view of the distal portion of the piston rod 20 when it is arranged in the internal nut member 5 of the injection device housing 2. Figure 5 It is a similar view, but shows an alternative exemplary sleeve member 140, on which digital scales 180 are printed as a code. Figure 6 Another alternative exemplary sleeve member 240 is shown, which has etched circumferential matrix codes 280.

[0082] Figure 7This is a side view of an injection device 1 according to an exemplary embodiment of the present invention, whose core structure and function are similar to those of injection device 1'. Therefore, the injection device 1 has a housing 2 that houses a spring-powered piston rod propulsion mechanism (not visible) and a dose setting mechanism (not visible), which is operable to set the dose to be injected by rotating a dose dial 3 about the longitudinal central axis of the housing 2.

[0083] A cartridge holder 15, containing a transparent cartridge 10 filled with liquid medication, is attached to the distal end of the housing 2. The cartridge 10 is sealed proximally by a slidable piston 12 and distally by a self-sealing diaphragm (invisible). A needle assembly 50 is attached to the cartridge holder 15, whereby the rear portion of the injection needle 55 penetrates the self-sealing diaphragm and establishes fluid contact with the interior of the cartridge 10. The cartridge holder 15 is designed with an elongated inspection window 19 to allow inspection along the entire length of the cartridge 10.

[0084] The housing 2 includes an internal nut component 5 that engages threadedly with the piston rod 20. Figure 4 The distal portion of the piston rod 20 is covered by a sleeve member 240, which has a circumferential matrix code 280 along its cylindrical outer surface portion, the diameter of which is only slightly smaller than the diameter of the cartridge 10'. This means that the cylindrical outer surface portion with the circumferential matrix code 280 is located just below the inner surface of the cartridge 10', but does not contact the inner surface.

[0085] The cartridge holder 15 is provided with an axial matrix code 70 adjacent to the inspection window 19. Therefore, a portion of the axial matrix code 70 and the circumferential matrix code 280 displayed in the inspection window 19 can always be optically captured simultaneously. The piston 12 is provided with a circumferential mark 13, which slides along the cartridge holder 15 as the piston 12 advances within the cartridge 10, and visibly marks the current position of the piston 12 relative to the axial matrix code 70.

[0086] Figure 8 This is a perspective view of an alternative variant of the injection device 1, wherein the cartridge holder 15 is provided with a linear axis 170 instead of an axial matrix code 70. The axis 170 is arranged adjacent to the inspection window 19 and extends between a proximal reference point 171 and a distal reference point 172. The axis 170 has a well-defined length between the two reference points 171, 172. The sleeve member 240 is provided with a circumferential mark 245 that moves helically along the cartridge holder 15 as the piston rod 20 rotates in the internal nut member 5, and visibly marks the current position of the sleeve member 240 relative to the axis 170.

[0087] Near the proximal reference point 171 and adjacent to axis 170, a QR code 90 is affixed to the cartridge holder 15. The QR code 90 contains drug-related information, such as drug type, batch number, and expiration date. In this case, a portion of axis 170, proximal reference point 171, distal reference point 172, QR code 90, and circumferential matrix code 280 displayed in inspection window 19 can always be optically captured simultaneously.

[0088] Figure 9 This illustration shows another alternative variant of the injection device 1, a hybrid of previous variants. In this case, the cartridge holder 15 includes an axis 170 and two reference points 171, 172, and the distal portion of the piston rod 20 is covered by a sleeve member 40 with a circumferential micro-dot pattern 80. Furthermore, the cartridge holder 15 has a barcode 190, instead of a QR code, near the inspection window 19. The barcode 190 contains drug-related information such as drug type, batch number, and expiration date.

[0089] The injection device 1 shown in the figure does not have a pen needle assembly attached; instead, a needle mount 18 is exposed at the distal end of the cartridge holder 15. The needle mount 18 includes threads and overlapping bayonet rails for receiving different types of pen needle assemblies.

[0090] The following will mainly be based on Figure 9 The present invention will be illustrated by showing an embodiment of the injection device 1.

[0091] As mentioned earlier, injection devices based on the principle of advancing a piston by rotating a threaded piston rod in a fixed thread exhibit a distribution ratio of X° per dose unit. This means that the injection device is configured to deliver 360 / X dose units per revolution of the piston rod. For each specific injection device, the inclination of the thread is known, and therefore, the axial component of the piston rod displacement corresponding to the delivery of one dose unit is also known.

[0092] The inclination Z of the thread in the internal nut component 5 is 3.6 mm / revolution, which means that the axial component of the piston rod displacement is 3.6 mm for every revolution of the piston rod 20. Furthermore, the distribution ratio X is 15° / dose unit, which corresponds to a discharge Y of 360 / 15 = 24 dose units / revolution, and in turn, a piston rod 20 axial displacement of 0.15 mm / discharge dose unit.

[0093] Therefore, there is a strict, known correlation between the rotational process of the piston rod 20 relative to the housing 2 from its initial pre-use position and the number of dose units dispensed from the cartridge 10 since the first dose dispensing action. This invention utilizes this known correlation to electronically capture the dose size of the last dispensing and the cumulative number of units dispensed since the first use of the injection device 1, and to electronically determine the number of units remaining in the cartridge 10.

[0094] This is achieved by using an electronic device with a camera or barcode reader and processing capabilities to perform one or more optical readouts of the inspection window 19. Figure 9 The text describes an example of such electronic devices in the form of a smartphone 300.

[0095] exist Figure 9 In this process, the piston rod 20 has displaced the piston 12 a significant distance within the cartridge 10, thus the injection device 1 has been used to deliver at least one dose of the drug. After each dose delivery, the user uses a smartphone 300 to take a photograph 301 of the cartridge holder 15, the shooting orientation being such that the inspection window 19, axis 170, and barcode 190 can be captured simultaneously.

[0096] Figure 9 An exemplary result of such an action is displayed on the screen 302 of the smartphone 300. The smartphone 300 includes a dosing application that is capable of reading and processing various information in the photograph 301. These include the current axial position of the circumferential mark 45 on the sleeve member 40 relative to the axis 170, a specific segment of the micro-dot pattern 80 currently visible in the inspection window 19, and the barcode 190.

[0097] Since the injection device 1 is configured to deliver 24 dose units per revolution of the piston rod 20, there are 24 possible positions of the cuff member 40 relative to the cartridge holder 15 per revolution of the piston rod 20. Each position results in a unique segment of the microdot pattern 80 being visible in the inspection window 19. As can be seen from photograph 301, the dosage application is able to determine the exact angular orientation of the cuff member 40 relative to the housing 2, and thus the exact angular orientation of the piston rod 20 relative to the housing 2.

[0098] By understanding the initial position of the piston rod 20 before use (e.g., from a similar photograph taken by the user or injection device manufacturer before the first dose dispensing action), the dosing application then calculates the incremental angular movement of the piston rod 20 since the first dose dispensing. Since the distinctive segment of the micro-dot pattern 80 visible in the inspection window 19 repeats with each full rotation of the cuff member 40, a single rotational position determination cannot provide information beyond the initial 24 dispensing dose units. However, by combining the axial position reading of the circumferential mark 45 relative to axis 170 (which provides information about the cumulative axial movement of the cuff member 40 since the first dose dispensing) with an understanding of the tilt Z (which determines how much the piston rod 20 and cuff member 40 have moved axially when the piston rod rotates a full rotation), the dosing application can determine the exact cumulative angular progression of the piston rod 20 relative to the housing 2 by adding a rounded-down 360° integer corresponding to the cumulative axial travel of the cuff member 40 to the rotational position determination.

[0099] It is worth noting that the axial “scale” does not need to have high resolution because the axial position of the circumferential mark 45 relative to the axis 170 is only used to determine how many full revolutions the piston rod 20 has rotated, and the piston rod moves axially by 3.6 mm for each full revolution. The angular “scale” provides high resolution for dose determination, and since the angular displacement of the sleeve member 40 when dispensing a dose unit is almost eight times the corresponding axial displacement of the piston rod 20 and piston 12, the requirements for the optical readout system and the user's motor skills when photographing the cartridge holder 15 are much less than if a photograph of a single axial dose scale were used as the basis for determining the dispensed dose.

[0100] Therefore, by comparing the information in photograph 301 with the information in photographs taken before the first use of the injection device 1, as mentioned above, the cumulative number of dose units delivered from the cartridge 10 can be determined. Since the movement of the piston rod 20 is well-known and well-defined, minute changes in the fill level of the cartridge 10 can be immediately identified from the initial rotational position of the sleeve member 40 relative to the housing 2. Accordingly, the dosing application can provide the user with reliable information on the remaining liquid volume in the cartridge 10. Furthermore, usage patterns can be established from the user's dispensing dose data log file and used to promptly notify the user when a new injection device should be obtained.

[0101] The smartphone solution also enables users to track the dosage of different injection devices or even different types of injection devices, as the dosage application identifies the specific injection device from the barcode or QR code on the device each time an optical readout is made and assigns the individual readings accordingly.

[0102] To determine the final dose dispensed from the injection device 1, the dosing application compares the last photograph taken of the cartridge holder 15 with the penultimate photograph taken to determine the visual differences in the micro-dot pattern 80 in the inspection window 19 and the axial position differences of the circumferential mark 45 relative to the axis 170. These differences are then processed in a similar manner as described above to obtain the corresponding dose value.

[0103] Dosage value D Obtained as follows, in The rotational increment position of sleeve component 40 was identified in the last photograph taken. The rotational increment position of sleeve component 40 was identified in the second-to-last photograph taken. The approximate axial position of the sleeve component 40 was identified in the last photograph taken. The approximate axial position of the sleeve component 40 was identified in the second-to-last photograph taken. Z It's the tilt. Y It is the number of units discharged per revolution of piston rod 20, and Round the obtained value down to the nearest integer. It should be noted that the first term on the right-hand side of the above equation contributes to the angular position indication, while the last term contributes to the axial position indication.

[0104] The following is an example of reliable dose determination. The user takes an initial photograph, which is processed via a dosing application to locate the presentation of the microdot pattern 80 in the inspection window, corresponding to the angular position of the cuff member 40 at an increment of 3, and the relative axial position of the circumferential mark 45 at a distance of 3 mm from the proximal reference point 171. The user then sets and dispenses 61 dose units, causing the piston rod 20 to rotate 915° (61 × 15° / dose unit) to a position where the microdot pattern 80, as presented in the inspection window 19, indicates the angular position of the cuff member 40 at an increment of 16, and the circumferential mark 45 at a distance of 12.15 mm from the proximal reference point 171. This is equivalent to two full rotations of the piston rod 20, plus 13 increments of 15° rotation.

[0105] The user then takes a second photo, which is processed by the dosing application. Now, even if the image processing software in the smartphone 300 has a slight deviation in estimating the axial position, for example, estimating it as 2.5 mm and 12.5 mm respectively, resulting in an overestimation of the axial displacement of the sleeve member 40 by 0.85 mm, the dosing application still determines the dosage value as... This example demonstrates the robustness of the solution in determining the discharge dose based on simultaneous optical readout from the corresponding position indicator, by combining an accurate estimate of the angular displacement of the piston rod 20 with an approximate estimate of its axial displacement.

[0106] Regarding the axial position estimation, it should be noted that the camera in the smartphone 300 can use its own digital resolution to assist in providing a fine estimate of the position of the circumferential mark 45 relative to the axis 170, for example, by counting the number of horizontal lines between the circumferential mark 45 and the near reference point 171 in the photograph and dividing that number by the line density.

[0107] exist Figure 7 In an alternative variant of the injection device 1 shown, an axial matrix code 70 is included instead of the axis 170, and the axial position estimation can be based on the specific circumferential configuration of the axial matrix code 70 at the circumferential mark 13 position. Therefore, optical detection of the complete number of rotations of the piston rod 20 can be allowed simply by changing the configuration of the axial matrix code 70 every 3.6 mm along the inspection window 19.

[0108] Figure 10 An exemplary presentation of the dosage application results on the display screen of a smartphone 300 is shown. Based on the processing of simultaneous optical readout from diagonal and axial position indicators and based on a continuously updated log file of the specific injection device, the dosage application informs the user in the first display section 310 that a dose of 24 units was recently administered, in the second display section 320 that a dose of 31 units was last administered 9 hours and 23 minutes ago, and in the third display section 330 that 120 units remain in cartridge 10.

[0109] Using a smartphone 300 to simultaneously optically read out and capture the expelled dose while indicating angular and axial positions is advantageous because it eliminates the need for costly electronics in the injection device 1 and a separate additional unit to be attached to the housing 2. Instead, a dose log can be electronically established using a device that many users carry with them throughout the day.

[0110] However, Figure 11 An alternative method for capturing the expelled dose to establish an electronic dose log, etc., is illustrated, showing an injection device 1 combined with a removable protective cap 60. For clarity, the cap 60 and the distal portion of the injection device 1 are cut apart. This solution employs the same dose determination principle as described above, but performs simultaneous optical readout of angular and axial position indicators in a different manner.

[0111] Essentially, the smartphone 300 in the above-described setup is replaced by a cap 60, an improved variant of the cap conventionally equipped with this type of injection device, used to protect the cartridge 10 from mechanical shock and sunlight between injections. The cap 60 includes a hollow cap body 61 and an attachment portion 62, the cap body 61 defining the interior of the cap for receiving the distal portion of the injection device 1, and the attachment portion 62 configured to engage with the housing 2.

[0112] The cap contains a printed circuit board (PCB) 63, which carries an array of five axially distributed camera lenses 65 and accompanying image chips 66, four light-emitting diodes (LEDs) 64 (which are axially distributed such that one LED 64 is located between two consecutive camera lenses 65), a pair of microprocessors 67, a switch 68, a Bluetooth interface 69, and a battery 95.

[0113] The attachment portion 62 and the housing 2 are configured to allow the cap 60 to be attached to the injection device 1 only at a specific angle relative to the housing 2 with respect to the cap body 61. This ensures that the array of camera lenses 65 is aligned with the central axis of the inspection window 19. This allows the camera lenses 65 to capture images of the adjacent portions of the inspection window 19 and the cartridge holder 15, including the axis 170 and the barcode 190.

[0114] In an alternative variant, the injection device 1 may include a QR code 90 instead of a barcode 190, in which case the first camera lens 65 and the first image chip 66 in the array (i.e., Figure 11 The rightmost ones can be used exclusively for reading QR codes, while the remaining four camera lenses 65 and image chip 66 can be used exclusively for reading the corresponding segments of inspection window 19.

[0115] However, in this embodiment, all camera lenses 65 and image chips 66 are dedicated to providing readout of corresponding segments of the inspection window 19. Therefore, when the user has performed an injection and attached the cap 60 to the injection device 1, the new positions of the micro-dot code 80 and circumferential marker 45 in the inspection window 19 allow for determination of the dispensed dose as described above. Since the attachment portion 62 ensures the correct positioning of the cap body 61 relative to the inspection window 19, the end contact switch 68 of the cartridge holder 15 contacts the switch, causing the LED 64 to illuminate, and the camera lenses 65 automatically capture individual images of the inspection window 19. Subsequently, the microprocessor 67 processes the captured images to obtain dose values ​​corresponding to the registered angular and axial displacements of the sleeve member 40.

[0116] The obtained dose values, along with timestamps and other dose-related and drug-related data read or derived from the captured images, can be transmitted to an external device via Bluetooth interface 69. Alternatively, or additionally, the data can also be stored in the cap 60 and / or presented on an electronic display (not shown) on the cap body 61, for example, in a manner similar to presenting data on a smartphone 300.

[0117] Cap 60 is suitable for reuse in a variety of different injection devices, and can reduce production costs, waste disposal and carbon footprint compared to solutions that integrate electronics into disposable injection devices.

Claims

1. An injection device (1), comprising: - A housing (2) extending along the axis and having an internal nut member (5). - A dosage dispensing mechanism comprising a threaded piston rod (20) that engages with the internal nut member (5), the threaded piston rod (20) being movable in a distal direction relative to the housing (2). - A cartridge retaining device (15) for holding the cartridge in an axially fixed position relative to the housing (2) on the distal side of the inner nut member (5). - A first position indicator (70, 170) is used to indicate the axial position of the threaded piston rod (20) relative to the housing (2). - A second position indicator (80, 180, 280) for indicating the angular position of the threaded piston rod (20) relative to the housing (2), the second position indicator (80, 180, 280) being rotatably fixed relative to the threaded piston rod (20), and - Inspection window (19) allows simultaneous optical readout of the first position indicator (70, 170) and the second position indicator (80, 180, 280), thereby enabling determination of the current angular progress of the threaded piston rod (20) relative to the housing (2).

2. The injection device according to claim 1, further comprising a cartridge (10) held by the cartridge holding device (15).

3. The injection device according to claim 1 or 2, wherein the second position indicator (80, 180, 280) comprises a pattern having a unique visual appearance in the inspection window (19) for each angular position of the threaded piston rod (20) relative to the housing (2).

4. The injection device according to claim 3, wherein the pattern comprises circumferentially extending digital scales, circumferentially extending micro-dot codes, or circumferentially extending matrix codes.

5. The injection device according to any one of the preceding claims, wherein the second position indicator (80, 180, 280) is arranged on a sleeve member (40, 140, 240) which is rotatably fixed to the threaded piston rod (20).

6. The injection device according to claim 5, wherein the sleeve member (40, 140, 240) is axially fixed to the distal portion of the threaded piston rod (20).

7. The injection device of claim 6, wherein the sleeve member (40, 140, 240) includes a circumferential marker (45, 245) adapted to move relative to the first position indicator (70, 170) during dose dispensing.

8. The injection device according to any one of the preceding claims, wherein the first position indicator (70, 170) is disposed on a portion of the cartridge holding device (15).

9. The injection device according to claim 2, wherein the first position indicator (70, 170) is disposed on a portion of the cartridge (10).

10. The injection device according to claim 8 or 9, wherein the first position indicator (70, 170) comprises an axially extending scale, an axially extending barcode, an axially extending matrix code, an axially extending line having a defined length, or a reference mark.

11. The injection device according to any one of the preceding claims further includes a machine-readable information label (90, 190) with drug-related information, the machine-readable information label (90, 190) being disposed next to the inspection window (19) or the first position indicator (70, 170).

12. The injection device according to any one of the preceding claims, wherein the simultaneous optical readout is adapted to be performed by an image capture device (300) that takes a single photograph.

13. The injection device according to any one of the preceding claims, further comprising a protective cap (60) configured to be removably attached to the housing (2) to cover the cartridge holder (15), the protective cap (60) including a camera arrangement (65) for capturing one or more images of the inspection window (19).

14. The injection device according to claim 13, wherein the housing (2) and the protective cap (60) include respective guide structures configured to interact to ensure that the protective cap (60) is attached to the housing (2) at a predetermined attachment position where the camera arrangement (65) is aligned with the inspection window (19).

15. The injection device according to claim 14, further comprising a switching mechanism (68) configured to trigger the camera arrangement (65) to capture one or more images in response to the protective cap (60) being in the predetermined attachment position.

16. An injection device according to any one of claims 1-12, combined with a readout device (300), the readout device (300) comprising an image capture device capable of simultaneously optically reading out the first position indicator (70, 170) and the second position indicator (80, 180, 280).

17. The injection device of claim 16, wherein the readout device (300) is a smartphone including a camera.

18. The injection device of claim 17, wherein the smartphone further includes an application configured to determine the current angular progress of the threaded piston rod (20) relative to the housing (2) based on simultaneous optical readouts from the first position indicator (70, 170) and the second position indicator (80, 180, 280).

19. A method for capturing dose-related data from an injection device according to any one of claims 1-12, comprising: - The operation includes a readout device (300) comprising an image capture device and an image processing device, to perform simultaneous optical readout of the first position indicator (70, 170) and the second position indicator (80, 180, 280) through the inspection window (19); and - The image processing device is prompted to optically read out the first position indicator (70, 170) and the second position indicator (80, 180, 280) while processing them, thereby determining the current angular progress of the threaded piston rod (20) relative to the housing (2).

Images