Auto injector with detection of used cartridge and associated method

Abstract

To provide an auto injector improving the safety of the auto injector and / or the use of the auto injector.SOLUTION: The auto injector comprises: a housing; a cartridge receiver configured to receive a cartridge comprising a first stopper; a drive module coupled to move a plunger rod configured to move the first stopper; a resistance sensor configured to provide a resistance signal indicative of resistance against movement of the plunger rod; and a processing unit coupled to the drive module and to the resistance sensor. The processing unit is configured to: control the drive module to move the plunger rod towards an extended plunger rod position; determine a present plunger rod position; receive the resistance signal; determine a cartridge parameter based on the resistance signal and the present plunger rod position; and control the drive module to adjust the movement of the plunger rod based on the cartridge parameter.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present disclosure relates to an autoinjector such as an electronic autoinjector, a system comprising an autoinjector and a cartridge, and a method for operating an autoinjector.

Background Art

[0002] Hypodermic syringes are widely used to deliver fluids to the body. It is known to have hypodermic syringes applicable to manual operation. However, autoinjectors such as electronic autoinjectors have been developed and are widely used to assist in the administration of fluids or drugs to the body.

[0003] There is an increasing interest in autoinjectors to perform the injection process as automatically as possible, without relying on the correct execution of specific tasks by the user.

[0004] However, for the safety of the user, it is always desirable for such autoinjectors to prevent inconvenient use, ensure or facilitate the proper administration of drugs, and prevent or mitigate the consequences of incorrect use, such as inaccurate dosing or transmission of infection.

[0005] U.S. Patent No. 5,808,203 discloses a pressure measuring device comprising a sensor for detecting a force on at least a part of the contact surface of a syringe plunger when pressurizing a fluid medium in the syringe. This makes it possible to determine the pressure of the fluid medium in the syringe.

[0006] WO 2006 / 116997 pamphlet discloses a handheld motor-driven injection device having a motor for driving a piston rod operably connected to a washer for injecting a fixed amount of medicament from a cartridge containing the medicament. The injection device further comprises means for determining a reaction force generated in response to the motor driving the piston rod, washer, and plunger axially forward within the cartridge.

[0007] US 2002 / 107477 A1 discloses an apparatus for administering an injectable product in portions. The apparatus includes means for determining a malfunction of the apparatus, and a vibration motor is housed within the casing. The means for determining a malfunction activates the vibration motor when a malfunction is determined, generating a warning signal by the vibration.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0009] Despite known solutions, there is a need for an autoinjector having improved safety features to prevent or reduce the risk of improper use of an autoinjector, or risks resulting from improper use of an autoinjector such as health risks. The present disclosure provides an autoinjector, system, and method for improving the safety and / or use of an autoinjector.

Means for Solving the Problems

[0010] Accordingly, an autoinjector for administering a medicament is disclosed. The autoinjector comprises a housing, a cartridge holder, a drive module, a resistance sensor, and a processing unit.

[0011] The cartridge holder is configured to receive a cartridge having a first stopper. The cartridge can contain a medicament.

[0012] The drive module is combined to move a plunger rod between a plunger rod retracted position and a plunger rod extended position. The plunger rod is configured to move the first stopper. The plunger rod can be configured to move the first stopper when the plunger rod is moved towards the plunger rod extended position.

[0013] The resistance sensor is configured to provide a resistance signal representative of the resistance to the movement of the plunger rod.

[0014] The processing unit is connected to the drive module and the resistance sensor. The processing unit is configured to control the drive module to move the plunger rod, for example, from the plunger rod retracted position towards the plunger rod extended position, determine the current plunger rod position, receive the resistance signal, and determine cartridge parameters based on the resistance signal and the current plunger rod position. The processing unit can be further configured to control the drive module to adjust the movement of the plunger rod based on the cartridge parameters.

[0015] Furthermore, a system is disclosed that comprises an autoinjector, such as the autoinjector disclosed above, and a cartridge having a first stopper, the cartridge being configured to be received in a cartridge holder.

[0016] Furthermore, a method for controlling an autoinjector, such as the autoinjector disclosed above, is disclosed. The method includes receiving a cartridge comprising a first stopper, such as a cartridge of the system disclosed above; moving a plunger rod, such as a plunger rod of the autoinjector, towards the first stopper of the cartridge, for example, to a plunger rod extended position; determining a current plunger rod position; receiving a resistance signal indicative of a resistance to the movement of the plunger rod; and determining cartridge parameters based on the resistance signal and the current plunger rod position. The method can further include adjusting the movement of the plunger rod based on the cartridge parameters.

[0017] An advantage of the present disclosure is that it can assist in determining the characteristics of the received cartridge. A further advantage of the present disclosure is that the autoinjector can be operated according to the characteristics of the received cartridge.

[0018] For example, the present disclosure provides a way to determine or notify that the received cartridge is a used cartridge and / or a defective cartridge. Thus, an advantage of the present disclosure can be that the safety of the autoinjector is improved, for example, because the use of non-new cartridges in the autoinjector can be prevented or restricted.

[0019] Thus, a further advantage of the present disclosure is that the safety of the patient is improved, for example, by reducing the risk of transmission of infection and / or further reducing the risk of inaccurate dosing of the drug.

[0020] Any embodiment or element described in connection with any one aspect is considered usable in any other aspect or embodiment with the necessary changes.

[0021] The movement of the plunger rod can be adjusted based on determined cartridge parameters. Adjusting the movement of the plunger rod can include stopping the movement of the plunger rod. Alternatively, or in addition thereto, adjusting the movement of the plunger rod can include moving the plunger rod to a plunger rod retracted position. For example, the cartridge parameters can indicate that the cartridge is not full and / or is empty. The movement of the plunger rod can be adjusted to stop and / or move to the retracted position when the cartridge parameters indicate that the cartridge is not full and / or is empty.

[0022] The cartridge parameters can indicate that the cartridge is not full and / or is empty, such as when the cartridge is used up, for example, when the current plunger rod position has reached a predetermined plunger rod position between the plunger rod retracted position and the plunger rod extended position, and the resistance signal is below a low resistance threshold indicating that the resistance to the movement of the plunger rod, for example, the force required for the movement of the plunger rod, is small, that is, when the first stopper is in the forward position. The low resistance threshold can be between 1 N and 15 N, such as between 5 N and 11 N. The low resistance threshold can be 1 N, 5 N, or 10 N.

[0023] Adjustment of the movement of the plunger rod can include adjusting the movement of the plunger rod, such as stopping the movement of the plunger rod and / or moving the plunger rod to the plunger rod retracted position, when the cartridge parameter indicates that the current plunger rod position has reached the plunger rod threshold value and the resistance signal indicates that the resistance to the movement of the plunger rod is less than the low resistance threshold value. The processing unit can be configured to control the drive module to adjust the movement of the plunger rod, such as stopping the movement of the plunger rod and / or moving the plunger rod to the plunger rod retracted position, when the cartridge parameter indicates that the current plunger rod position has reached the plunger rod threshold value and the resistance signal indicates that the resistance to the movement of the plunger rod is less than the low resistance threshold value.

[0024] The cartridge parameter can indicate that there is a defect in the cartridge and / or the needle is not attached and / or the attached needle is blocked, for example, when the resistance signal indicates a resistance to the movement of the plunger rod that exceeds a high resistance threshold value representing that a large force is required to move the plunger rod, i.e., the forward movement of the plunger rod and / or the first stopper is blocked in some way. The high resistance threshold value can be, for example, between 8N and 25N, such as between 10N and 20N. The high resistance threshold value can be 8N, 11N, or 15N.

[0025] Adjustment of the movement of the plunger rod can include adjusting the movement of the plunger rod, such as stopping the movement of the plunger rod and / or further moving the plunger rod to the plunger rod retracted position when the cartridge parameter indicates that the resistance signal exceeds the high resistance threshold for the movement of the plunger rod. The processing unit can be configured to control the drive module to adjust the movement of the plunger rod, such as stopping the movement of the plunger rod and / or further moving the plunger rod to the plunger rod retracted position when the cartridge parameter indicates that the resistance signal exceeds the high resistance threshold for the movement of the plunger rod.

[0026] Threshold values, such as a plunger rod threshold value, a low resistance threshold value, and / or a high resistance threshold value, can be determined based on the cartridge and / or cartridge code feature. The cartridge can comprise a cartridge code feature and / or the cartridge can form part of a cartridge assembly that comprises a cartridge code feature. The cartridge code feature can represent threshold values, such as a plunger rod threshold value, a low resistance threshold value, and / or a high resistance threshold value.

[0027] The auto-injector can comprise a code sensor configured to read the cartridge code feature. The code sensor can provide a code signal representing the cartridge code feature. The processing unit can be connected to the code sensor. The processing unit can be configured to receive the code signal. The processing unit can be configured to determine threshold values, such as a plunger rod threshold value, a low resistance threshold value, and / or a high resistance threshold value, based on the code signal.

[0028] A resistance signal can be provided by a resistance sensor. The resistance signal can represent the resistance to the movement of the plunger rod, such as the resistance to the movement of the plunger rod in one direction, such as the movement towards the plunger rod extension position, for example, in the first plunger rod direction. For example, the resistance signal can represent the force required for the movement of the plunger rod towards the plunger rod extension position.

[0029] The resistance to the movement of the plunger rod can be determined by measuring and / or determining the power consumed by the drive module, for example, by measuring the electrical resistance, current, and / or voltage of the drive module.

[0030] The resistance sensor can be configured to determine the power consumed by the drive module by measuring, for example, the electrical resistance, current, and / or voltage of the drive module. The resistance sensor can include an electrical resistance sensor, a current sensor, and / or a voltage sensor. The resistance signal can be based on the power consumed by the drive module, such as the power consumed by the drive module determined as described above. The drive module can include a resistance sensor.

[0031] The resistance sensor can be configured to measure the pressure and / or force applied to the front end of the plunger rod of the plunger rod. The front end of the plunger rod can be configured to engage with the first stopper of the cartridge. The resistance sensor can be configured to measure the pressure and / or force between the plunger rod and the stopper. For example, the resistance sensor can include a pressure transducer and / or a force transducer located at the front end of the plunger rod. The plunger rod can include a resistance sensor.

[0032] The system can comprise a cartridge assembly. The cartridge can form part of the cartridge assembly, and for example a cartridge assembly such as the cartridge assembly of the system can comprise a cartridge.

[0033] The cartridge receptacle of the auto-injector can be configured to receive a cartridge and / or a cartridge assembly through a cartridge receptacle opening. Thus, the cartridge and / or the cartridge assembly can be inserted into the cartridge receptacle through the cartridge receptacle opening.

[0034] The cartridge can comprise a cartridge chamber. The cartridge chamber can be configured to contain a medicament. The cartridge chamber can contain a medicament.

[0035] The cartridge can comprise a cartridge outlet, for example at a first cartridge end. The cartridge outlet can be configured to communicate with the cartridge chamber, for example at the first cartridge end. The cartridge can be configured to discharge a medicament through the cartridge outlet. The cartridge outlet can be configured to couple with a needle, such as a hypodermic needle, to effect discharge of the medicament through the needle. The cartridge assembly can comprise a needle and / or a needle assembly comprising a needle.

[0036] The cartridge can comprise a first stopper that can move, for example, in a first stopper direction towards the first cartridge end, and for example towards the cartridge outlet, inside the cartridge chamber. For example, the medicament can be discharged through the cartridge outlet by movement of the first stopper in the first stopper direction and / or towards the cartridge outlet.

[0037] The first stopper can be positioned at an initial position in an unused cartridge, such as a new cartridge. The first stopper can be positioned at a final position in a used cartridge, such as an empty cartridge. The first stopper can be positioned at an advanced position between the initial position and the final position. The first stopper can be positioned at the advanced position after moving in the first stopper direction from the initial position.

[0038] The plunger rod of the auto-injector is configured to move the first stopper. The first plunger rod direction may be the same as the first stopper direction when the cartridge is received in the cartridge receptacle of the auto-injector.

[0039] The cartridge includes a cartridge rear surface at a second cartridge end, such as on the opposite side of the cartridge outlet. The cartridge rear surface may include a cartridge rear end opening. The cartridge rear end opening can provide access to the first stopper by the plunger rod.

[0040] The auto-injector may be an electronic auto-injector. The auto-injector can include a battery. The housing can accommodate the battery. The battery may be a rechargeable battery. For example, the battery may be a Li-ion battery or a NiCd battery or a NiMH battery. The battery can be configured to be charged by connection to a charger.

[0041] The drive module is combined to move the plunger rod, for example actuating it, for example advancing it. The drive module can comprise one or more electrical elements. The drive module can be configured to receive power from a battery. The drive module can be electrically connected to the battery to receive power. The drive module can be housed in a housing. The drive module can comprise a motor such as an electromechanical motor such as a DC motor, for example a brushed or brushless DC motor. The drive module can comprise a solenoid motor. The drive module can comprise a shape memory metal engine. The drive module can comprise a spring device configured to actuate the plunger rod. The drive module can comprise a pressurized gas configured to actuate the plunger rod.

[0042] The plunger rod can be configured to move, for example advance, a first stopper such as a first stopper of the cartridge. The movement of the first stopper can be for discharging the medicament from the cartridge chamber through the cartridge outlet and / or discharging air from the cartridge chamber through the cartridge outlet.

[0043] The plunger rod position, such as the current plunger rod position, such as the plunger rod position at a specific moment, for example, can be determined by a processing unit, for example. The current plunger rod position can be determined based on detection from sensors such as a discharge sensor and / or a tachometer.

[0044] The autoinjector can comprise a discharge sensor configured to detect a discharge such as the discharge of the medicament and / or air in the cartridge chamber. The discharge sensor can be configured to detect the position of the plunger rod and / or the position of the first stopper.

[0045] The auto-injector can be provided with a tachometer, such as a rotation meter of a drive module. The discharge sensor can be provided with this tachometer. The tachometer can be configured to count the rotation of a drive module, such as the rotation of a motor of the drive module, from a predetermined point, such as a point where the position of the plunger rod is known, such as the fully retracted position of the plunger rod, the rotation of the drive module such as the rotation from the position of the plunger rod at a certain moment. The count of the rotation of the drive module can be used to determine the current plunger rod position, that is, the position of the plunger rod at a specific moment.

[0046] The tachometer can be configured to provide a tachometer signal representing the count of the rotation of the drive module. The processing unit can be connected to the tachometer. The processing unit can be configured to receive the tachometer signal. The processing unit can be configured to determine the current plunger rod position based on the tachometer signal.

[0047] The processing unit can be connected to the discharge sensor. The processing unit can receive from the discharge sensor a first discharge sensor signal, such as a tachometer signal indicating the count of the rotation of the drive module. The processing unit can determine the position of the plunger rod based on a first discharge sensor signal, such as a tachometer signal. The processing unit can receive from the discharge sensor, for example, a second discharge sensor signal indicating that the plunger rod is at a known position, such as the fully retracted position of the plunger rod. The processing unit can be configured to determine the position of the plunger rod based on, for example, a first discharge sensor signal, such as a tachometer signal, and the second discharge sensor signal. The processing unit can be configured to determine the current plunger rod position based on the tachometer signal and the plunger rod retracted position. For example, the processing unit can be configured to determine the current plunger rod position based on the number of rotations of the drive module since the plunger rod was at the plunger rod retracted position.

[0048] The auto-injector can be provided with a user interface such as a user interface that enables user input, and / or can provide a user output signal such as a visual output signal and / or an audible output signal to the user.

[0049] The user interface can be provided with one or more input members including a first input member and / or a second input member. The first input member and / or the second input member can be provided with buttons.

[0050] The user interface can be provided with one or more output members including a first output member and / or a second output member. The first output member and / or the second output member can be provided with a speaker and / or a visual display and / or an LED and / or a plurality of LEDs.

[0051] The user interface can be connected to a processing unit. The processing unit can be configured to output a user output signal via the user interface, for example, based on cartridge parameters. The user output signal can be based on cartridge parameters. For example, the user output signal can indicate cartridge parameters. Thus, for example, the auto-injector can be configured to inform the user that the received cartridge is unusable, and / or further can be configured to inform the user of the reason why the received cartridge is unusable.

[0052] The following continues with a more detailed description with reference to the drawings.

Brief Description of the Drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

DETAILED DESCRIPTION OF THE INVENTION

[0054] Hereinafter, various embodiments will be described with reference to the drawings. Like reference numerals refer to like elements throughout. Accordingly, like elements will not be described in detail with respect to the description of each figure. It should also be noted that the drawings are only intended to facilitate the description of the embodiments. These are not intended to describe the invention recited in the claims exhaustively, nor are they intended to limit the scope of the invention recited in the claims. Further, the illustrated embodiments need not have all of the shown aspects or advantages. An aspect or advantage described in connection with a particular embodiment is not necessarily limited to that embodiment and may be implemented in any other embodiment even if not so illustrated or specified.

[0055] FIG. 1 shows a typical auto-injector 4. The auto-injector 4 can be configured to administer a drug. The auto-injector 4 may be an electronic auto-injector.

[0056] The auto-injector 4 comprises a housing 6. The auto-injector 4 comprises a cartridge receiver 300. The cartridge receiver is configured to receive a cartridge and / or a cartridge assembly including the cartridge. The cartridge can accommodate a drug.

[0057] The cartridge receiver 300 has a cartridge receiver opening 301. The cartridge receiver 300 is configured to receive the cartridge and / or the cartridge assembly in a cartridge receiving direction 304 along the longitudinal axis L through the cartridge receiver opening 301.

[0058] The auto-injector 4 can comprise a user interface 1100 as shown in the figure. The auto-injector 4 comprises a trigger member such as a contact member 1102. The contact member 1102 can be configured to be pressed against an injection site. The contact member 1102 can be movable in the cartridge receiving direction 304 relative to the housing when pressed against the injection site. The contact member 1102 can be part of the user interface 1100.

[0059] The user interface 1100 can comprise a first input member 1108 as shown in the figure, such as a button for example. The first input member 1108 can provide a user input from the user. For example, the first input member 1108 can be used to receive a pressing operation from the user to proceed to the next step.

[0060] The user interface 1100 can include a first output member 1110 as shown, for example, a plurality of LEDs. The first output member 1110 can provide a user output to the user. The user interface 1100 can include a second output member (not shown), such as a speaker. The second output member can be configured to provide an audible output to the user. For example, the first output member 1110 and / or the second output member can be used to inform the user of steps in a procedure and / or an error message.

[0061] FIG. 2 shows a typical system 2. The system 2 includes an auto-injector 4 as described in connection with FIG. 1 and a typical cartridge 700 received in a cartridge receptacle 300. The cartridge 700 is shown with a needle cover 908. The needle cover 908 extends out of the contact member 1102 so that the needle cover 908 can be removed from the cartridge 700.

[0062] FIG. 3 schematically shows a typical cartridge 700, such as a cartridge 700 configured to be received in a cartridge receptacle of an auto-injector, such as the auto-injector described in connection with the previous figures.

[0063] The cartridge 700 includes a cartridge chamber 702. The cartridge chamber 702 can be configured to contain a medicament. The cartridge 700 has a first end 718 and a second end 720. The cartridge 700 includes a cartridge outlet 714 at the first cartridge end 718. The cartridge can be configured to eject the medicament through the cartridge outlet 714.

[0064] The cartridge includes a first stopper 708 that can move, for example, in a first stopper direction 722 toward a first cartridge end 718, for example, inside a cartridge chamber 702. For example, a drug can be discharged through a cartridge outlet 714 when the first stopper 708 moves in the first stopper direction 722. The cartridge 700 includes a cartridge rear surface 716 at a second cartridge end 720. The cartridge rear surface 716 includes a cartridge rear end opening for providing access to the first stopper 708 on a plunger rod.

[0065] As shown in the figure, the cartridge 700 may be a two-chamber cartridge. The cartridge includes a second stopper 710 that can move, for example, in a first stopper direction 722 toward a first cartridge end 718, for example, inside a cartridge chamber 702. The cartridge chamber 702 includes a first cartridge sub-chamber 704 and a second cartridge sub-chamber 706. The first cartridge sub-chamber 704 is located between the first stopper 708 and the second stopper 710. The first cartridge sub-chamber 704 can contain a liquid such as sterile water or a buffer solution. The second cartridge sub-chamber 706 is located between the second stopper 710 and the cartridge outlet 714. The second cartridge sub-chamber 706 can contain a drug, for example, a dried drug such as a drug dried by lyophilization. The cartridge includes a bypass portion 712 for providing communication between the first cartridge sub-chamber 704 and the second cartridge sub-chamber 706. The bypass portion 712 provides communication between the first cartridge sub-chamber 704 and the second cartridge sub-chamber 706 when the second stopper 710 is located in the bypass portion 712.

[0066] Figure 4 shows a typical system 2. The system 2 includes an auto-injector 4 as described, for example, in connection with Figure 1, and a typical cartridge assembly 600. The cartridge assembly 600 includes a cartridge 700 having a cartridge chamber 702, a needle assembly 900, and optionally a cartridge code feature 1000. The cartridge assembly 600 is received by the auto-injector 4.

[0067] The cartridge assembly 600 includes a cartridge holder 800. The cartridge holder is configured to hold the cartridge 700 in the cartridge receptacle 300 of the auto-injector 4. The cartridge holder 800 includes a cartridge holding member 808. The cartridge holding member engages the cartridge receptacle 300 to receive the cartridge 700 and the cartridge assembly 600 into the cartridge receptacle.

[0068] The needle assembly 900 includes a needle 902 and a needle hub 904. The needle assembly 900 is attached to the cartridge 700 by a needle hub 904 having a cartridge holder coupling portion 906, such as a threaded portion, that engages, for example, a needle assembly coupling portion 812 of the cartridge holder 808. The needle 902 extends through a cartridge outlet 714 of the cartridge 700. The cartridge outlet 714 can be sealed by an elastomeric seal that is pierced by the needle 902 when the needle assembly 900 is attached to the cartridge 700.

[0069] The auto-injector 4 includes an optional code sensor 24 configured to read the cartridge code feature 1000. When the cartridge assembly 600 is inserted, the cartridge code feature 1000 aligns with the code sensor 24 as shown.

[0070] The auto-injector 4 includes a plunger rod 400. The plunger rod 400 is configured to advance the first stopper of the cartridge 700. The plunger rod 400 includes an outer plunger rod 404 having a female thread and an inner plunger rod 402 having a male thread. The thread of the inner plunger rod 402 engages with the thread of the outer plunger rod 404. Rotation of the outer plunger rod 404 relative to the housing of the auto-injector is prevented. Movement of the plunger rod 400 includes rotation of the inner plunger rod 402. Rotation of the inner plunger rod 402 results in translational movement of the outer plunger rod 404 because rotation of the outer plunger rod 404 is restricted. The outer plunger rod 404 is configured to abut against the first stopper of the cartridge 700 and move the first stopper in the first stopper direction 722 when translating in the first stopper direction 722.

[0071] A drive module 500 is combined to actuate the plunger rod 400. The drive module 500 is electrically connected to a battery to receive power. The drive module 500 includes a motor 502 such as an electromechanical motor like a DC motor. The drive module 500 includes a transmission mechanism 504 for coupling the motor 502 to the inner plunger rod 402 of the plunger rod 400.

[0072] The illustrated example includes a motor 502 which may be an electromechanical motor, but it can be readily understood that an auto-injector 4 having other drive modules including, for example, a solenoid motor, a shape memory metal engine, a spring device, and / or a pressurized gas configured to actuate the plunger rod 400 is also feasible.

[0073] The autoinjector 4 includes a discharge sensor 26 such as a plunger rod position sensor. The discharge sensor 26 is configured to detect the position of the plunger rod 400. In the illustrated example, the discharge sensor 26 includes a tachometer configured to count / detect the rotation of the motor 502. Accordingly, the position of the plunger rod 400 can be clarified. The discharge sensor 26 can detect the discharge of the drug and / or air in the cartridge chamber based on the detection of the position of the plunger rod 400. The position of the plunger rod 400 represents the position of the first stopper 708 of the cartridge 700.

[0074] Figure 5 shows a block diagram of a typical autoinjector 4. The autoinjector 4 includes a plurality of sensors 22, 24, 26, 28, 30, 32, 34, a processing unit 20, a drive module 500, and a user interface 1100. The sensors 22, 24, 26, 28, 30, 32, 34 are connected to the processing unit 20. The user interface 1100 is connected to the processing unit 20. The processing unit is connected to the drive module 500.

[0075] The processing unit 20 receives signals from the sensors 22, 24, 26, 28, 30, 32, 34 and the user interface 1100. The processing unit 20 is configured to control the drive module 500. The processing unit 20 can control the drive module 500 based on one or more of the received signals from the sensors 22, 24, 26, 28, 30, 32, 34 and the user interface 1100.

[0076] The autoinjector 4 includes an orientation sensor 22. The orientation sensor 22 is configured to provide an orientation signal representing the orientation of the cartridge received in the autoinjector 4. For example, the orientation sensor 22 can be configured to detect the orientation of the autoinjector 4. The orientation of the cartridge can be determined based on the orientation of the autoinjector 4. The orientation sensor 22 can be configured to detect the direction of gravity. For example, the orientation sensor 22 can include an accelerometer.

[0077] The processing unit 20 is connected to the orientation sensor 22. The processing unit 20 is configured to receive an orientation signal. The processing unit 20 can determine the orientation of the cartridge based on the orientation signal. The processing unit 20 can control the drive module 500 based on the orientation signal. For example, the processing unit 20 can be configured to control the drive module 500 to move the plunger rod based on the orientation signal. For example, the processing unit 20 can be configured to control the drive module 500 to move the plunger rod towards the plunger rod extended position only when the cartridge outlet is facing upwards. Alternatively, or in addition to this, the processing unit 20 can provide a user output via the user interface 1100 based on the orientation signal.

[0078] The auto-injector 4 comprises a code sensor 24. The code sensor 24 is configured to read the cartridge code feature and provide a code signal representing the cartridge code feature. For example, the code sensor can be configured to read / detect a color code.

[0079] The processing unit 20 is connected to the code sensor 24. The processing unit 20 is configured to receive the code signal. The processing unit 20 can determine the cartridge code feature of the cartridge assembly based on the code signal. The processing unit 20 can be configured to determine a threshold value such as a plunger rod threshold value based on the code signal. The processing unit 20 can control the drive module 500 based on the code signal. For example, the processing unit 20 can be configured to control the drive module 500 to move the plunger rod towards the plunger rod extended position based on the code signal. Alternatively, or in addition to this, the processing unit 20 can provide a user output via the user interface 1100 based on the code signal.

[0080] The auto-injector 4 includes a discharge sensor 26 such as a plunger rod position sensor. The discharge sensor 26 is configured to detect the position of the plunger rod of the auto-injector 4 and provide a discharge sensor signal representing the position of the plunger rod. The discharge sensor 26 can include a tachometer combined with the drive module 500.

[0081] The processing unit 20 is connected to the discharge sensor 26. The processing unit 20 is configured to receive the discharge sensor signal. The processing unit 20 can determine the position of the plunger rod based on the discharge sensor signal. The processing unit 20 can control the drive module 500 based on the discharge sensor signal. For example, the processing unit 20 can be configured to control the drive module 500 to start, stop, or continue the movement of the plunger rod based on the discharge sensor signal. For example, the processing unit 20 can be configured to determine the current plunger rod position based on the discharge sensor signal. Alternatively, or in addition, the processing unit 20 can provide a user output via the user interface 1100 based on the discharge sensor signal.

[0082] The auto-injector 4 includes a cartridge sensor 28. The cartridge sensor 28 is configured to detect the acceptance of the cartridge assembly in the auto-injector 4. The cartridge sensor 28 provides a cartridge sensor signal indicating the acceptance of the cartridge assembly.

[0083] The processing unit 20 is connected to the cartridge sensor 28. The processing unit 20 is configured to receive a cartridge sensor signal. The processing unit 20 can control the drive module 500 based on the cartridge sensor signal. For example, the processing unit 20 can be configured to control the drive module 500 to start the movement of the plunger rod only when the cartridge assembly is received and / or when the cartridge assembly is received. Alternatively, or in addition, the processing unit 20 can provide a user output via the user interface 1100 based on the cartridge sensor signal.

[0084] The code sensor 24 and the cartridge sensor 28 may be the same sensor. For example, the code sensor 24 can be configured to detect the acceptance of the cartridge assembly and then read the cartridge code feature.

[0085] The auto-injector 4 includes a needle sensor 30. The needle sensor 30 is configured to detect the needle of the cartridge assembly and / or the needle assembly and / or the needle cover of the needle assembly when the cartridge assembly is received by the auto-injector 4. The needle sensor 30 provides a needle signal indicating the presence of the needle of the cartridge assembly and / or the needle assembly and / or the needle cover of the needle assembly.

[0086] The processing unit 20 is connected to the needle sensor 30. The processing unit 20 is configured to receive a needle signal. The processing unit 20 can control the drive module 500 based on the needle signal. For example, the processing unit 20 can be configured to control the drive module 500 to start the movement of the plunger rod only when the needle is present and / or alternatively only when the needle cover is removed and does not exist, for example. The detection of the needle cover can represent the presence of the needle. The processing unit 20 can be configured to control the drive module 500 to start only when the needle cover is detected and then removed. Instead of this, or in addition to this, the processing unit 20 can provide a user output via the user interface 1100 based on the needle signal.

[0087] The auto-injector 4 comprises a temperature sensor 32. The temperature sensor 32 is configured to detect a temperature such as the temperature of the auto-injector and / or the cartridge and / or the drug. The temperature sensor 32 is configured to provide a temperature signal representing the temperature.

[0088] The processing unit 20 is connected to the temperature sensor 32. The processing unit 20 is configured to receive a temperature signal. The processing unit 20 can be configured to determine a temperature such as the temperature of the auto-injector and / or the cartridge and / or the drug based on the temperature signal. The processing unit 20 can control the drive module 500 based on the temperature signal. For example, the processing unit 20 can be configured to control the drive module 500 to move the plunger rod towards the plunger rod extended position based on the temperature signal. Instead of this, or in addition to this, the processing unit 20 can provide a user output via the user interface 1100 based on the temperature signal.

[0089] The auto-injector 4 is provided with a resistance sensor 34. The resistance sensor 34 is configured to detect the resistance to the movement of the plunger rod of the auto-injector 4. The resistance sensor 34 can be configured to detect the resistance to the movement of the plunger rod based on the measured value of the drive module 500. For example, the resistance sensor 34 can be configured to detect the current of the motor of the drive module 500. The resistance sensor 34 is configured to provide a resistance signal representing the resistance to the movement of the plunger rod.

[0090] The processing unit 20 is connected to the resistance sensor 34. The processing unit 20 is configured to receive the resistance signal. The processing unit 20 can be configured to determine the resistance to the movement of the plunger rod based on the resistance signal. The processing unit 20 can control the drive module 500 based on the resistance signal. For example, the processing unit 20 can be configured to control the drive module 500 so as to adjust the movement of the plunger rod based on the resistance signal. For example, the processing unit 20 can be configured to control the drive module 500 so as to start, stop, or continue the movement of the plunger rod based on the resistance signal. Instead of or in addition to this, the processing unit 20 can provide a user output via the user interface 1100 based on the resistance signal.

[0091] An auto-injector 4 including all of the above-described sensors is illustrated. However, alternatively, the auto-injector can be provided with only one of the above-described sensors, or any combination consisting of one or more of the above-described sensors.

[0092] The auto-injector is provided with a user interface 1100. The user interface 1100 can be provided with one or more input members for receiving user input, such as a first input member for example. The user interface is configured to provide a user input signal representing the received user input.

[0093] The processing unit 20 is connected to the user interface 1100. The processing unit 20 is configured to receive a user input signal. The processing unit 20 can control the drive module 500 based on the user input signal. For example, the processing unit 20 can be configured to control the drive module 500 to move the plunger rod towards the plunger rod extended position based on the user input signal.

[0094] The auto-injector includes a housing 6 that houses sensors 22, 24, 26, 28, 30, 32, 34, a processing unit 20, a user interface 1100, and a drive module 500.

[0095] Figures 6 and 7 schematically show a typical cartridge assembly 600 and a plunger rod 400. The cartridge assembly 600 includes a cartridge 700 such as the cartridge described in relation to FIG. 3, a cartridge holder 800, and a needle assembly 900. For clarity, an auto-injector with a plunger rod 400 is not shown.

[0096] The cartridge holder 800 includes a cartridge holding member 808. The cartridge holding member 808 is configured to engage with the cartridge receiver of the auto-injector. The cartridge holder 800 includes a needle assembly coupling portion 812. The needle assembly coupling portion 812 is configured to engage with the cartridge holder coupling portion 906 of the needle assembly 900. The needle assembly coupling portion 812 enables attachment of the needle to the cartridge 700.

[0097] The needle assembly 900 includes a needle 902 and a needle hub 904. The needle assembly 900 is attached to the cartridge 700 by a needle hub 904 having a cartridge holder coupling portion 906, such as a threaded portion, that engages with the needle assembly coupling portion 812 of the cartridge holder 800, for example. The needle 902 extends through the cartridge outlet 714 of the cartridge 700.

[0098] FIG. 6 schematically shows a situation where an unused cartridge such as a new cartridge is received. The first stopper 708 is in the initial position. The plunger rod 400 is moving toward the plunger rod extended position. As a result, at the current plunger rod position, the front end portion 410 of the plunger rod 400 of the plunger rod 400 is in contact with the first stopper 708. Therefore, further movement of the plunger rod 400 in, for example, the first plunger rod direction 422 toward the plunger rod extended position causes movement of the first stopper 708 in, for example, the first stopper direction 722. The force required for the movement of the plunger rod 400 toward the plunger rod extended position increases due to, for example, the frictional force between the first stopper 708 and the inner wall of the cartridge chamber 702 after the front end portion 410 of the plunger rod contacts the first stopper 708.

[0099] FIG. 7 schematically shows a situation where a used cartridge such as an empty cartridge is received. The first stopper 708 is in a final position advanced in the first stopper direction 722 compared to, for example, the initial position, such as an advanced position. The plunger rod 400 is moving toward the plunger rod extended position. As a result, at the current plunger rod position, the plunger rod 400 extends into the cartridge 700. Compared with the situation shown in FIG. 6, the force required for the movement of the plunger rod 400 toward the plunger rod extended position does not increase because the front end portion 410 of the plunger rod does not contact the first stopper 708.

[0100] Figure 8 shows a typical transition T of the resistance Re to the movement of the plunger rod depending on the position P of the plunger rod. The plunger rod moves from the retracted position PR to the extended position PE. At the beginning of the movement, the resistance to the movement of the plunger rod is constant (Ex1), for example, the plunger rod has not yet pressed the stopper. Thereafter, the front end portion of the plunger rod of the plunger rod abuts against the first stopper of the cartridge, and the resistance to the movement of the plunger rod increases (Ex2). The increase in resistance is caused, for example, by the resistance to the movement of the first stopper due to frictional force. As shown in the figure, the resistance may slightly decrease after the first stopper starts to move. When the plunger rod approaches the plunger rod extended position PE, the resistance may increase again (Ex3), for example, due to the first stopper approaching the end of the cartridge.

[0101] The transition T is an example of the resistance to the movement of the plunger rod when the received cartridge is a new and / or unused and / or normal cartridge. The determination of the cartridge parameters can be based on the resistance and / or the position of the plunger rod. The determination of the cartridge parameters can be based on one or more thresholds, such as resistance thresholds such as a low resistance threshold Re1 and / or a high resistance threshold Re2, and / or plunger rod thresholds such as a first plunger rod threshold P1 and / or a second plunger rod threshold P2.

[0102] Other situations, such as when the received cartridge is clearly used and / or is a defective product, are illustrated by further typical transitions T2, T3, T4.

[0103] Transition T2 shows a typical situation where the resistance to movement increases beyond the low-resistance threshold Re1 before the plunger rod position reaches the first plunger rod threshold P1. Such a situation may indicate, for example, a defect in the cartridge or something obstructing the movement of the plunger rod. In response to such a situation, the plunger rod can be returned to the plunger rod retracted position, and an error message can be provided via the user interface.

[0104] Transition T3 shows a typical situation where the resistance to movement does not increase beyond the low-resistance threshold Re1 before the plunger rod position reaches the second plunger rod threshold P2. Such a situation may indicate, for example, a used cartridge, such as a cartridge where the first stopper is in the forward position. In response to such a situation, the plunger rod can be returned to the plunger rod retracted position, and an error message can be provided via the user interface.

[0105] Transition T4 shows a typical situation where, for example, after the plunger rod position passes the first plunger rod threshold P1, the resistance to movement increases beyond the high-resistance threshold Re2. Such a situation may indicate, for example, that the movement of the first stopper is obstructed, and for example, the cartridge may be defective. In response to such a situation, the plunger rod can be returned to the plunger rod retracted position, and an error message can be provided via the user interface.

[0106] Threshold values such as the low-resistance threshold Re1, the high-resistance threshold Re2, the first plunger rod threshold P1, and / or the second plunger rod threshold P2 can be determined individually for the received cartridge. For example, the processing unit can be configured to determine one or more of the threshold values based on the cartridge code features of the received cartridge and / or the cartridge assembly.

[0107] FIG. 9 shows a flow diagram of a typical method 3000 for the operation and / or control of an autoinjector, such as the autoinjector described in relation to the previous figures.

[0108] Method 3000 includes a step 3001 of receiving a cartridge having a first stopper, a step 3002 of moving a plunger rod towards a plunger rod extended position, a step 3004 of determining a current plunger rod position, a step 3006 of receiving a resistance signal, a step 3008 of determining cartridge parameters, and a step 3010 of adjusting the movement of the plunger rod.

[0109] The step 3001 of receiving the cartridge can include the step of receiving the cartridge in a cartridge receptacle of the autoinjector.

[0110] The step 3002 of moving the plunger rod can include the step of moving the plunger rod from a plunger rod retracted position. The step 3002 of moving the plunger rod can include the step of moving the plunger rod in a first plunger rod direction.

[0111] The step 3004 of determining the current plunger rod position can be performed by a processing unit of the autoinjector. The step 3004 of determining the current plunger rod position can be based on a detection from a sensor, such as a discharge sensor equipped with a tachometer.

[0112] The step 3006 of receiving the resistance signal can include the step of receiving a resistance signal from a resistance sensor. The resistance signal can indicate a resistance to the movement of the plunger rod, such as a movement towards the plunger rod extended position, such as a movement in a first plunger rod direction.

[0113] Step 3008 of determining the cartridge parameters can include steps of determining the cartridge parameters based on the resistance signal and / or the current plunger rod position. For example, the cartridge parameters can indicate that the cartridge is used up when the current plunger rod position has reached the plunger rod threshold and the resistance signal indicates that the resistance to the movement of the plunger rod is less than the low resistance threshold.

[0114] Step 3010 of adjusting the movement of the plunger rod can be based on the cartridge parameters. For example, step 3010 of adjusting the movement can include steps of stopping the movement of the plunger rod. Instead of this, or in addition to this, step 3010 of adjusting the movement can include steps of moving the plunger rod to the plunger rod retracted position.

[0115] Step 3010 of adjusting the movement of the plunger rod can include steps of adjusting the movement of the plunger rod when the cartridge parameters indicate that the current plunger rod position has reached the plunger rod threshold and the resistance signal indicates that the resistance to the movement of the plunger rod is less than the low resistance threshold, such as when the cartridge parameters indicate that the cartridge is a used-up cartridge.

[0116] Step 3010 of adjusting the movement of the plunger rod can include steps of adjusting the movement of the plunger rod when the cartridge parameters indicate that the resistance signal indicates that the resistance to the movement of the plunger rod exceeds the high resistance threshold, such as when the cartridge parameters indicate that the cartridge is a defective cartridge.

[0117] Each step of the exemplary method 3000, and in particular the step 3002 of moving the plunger rod, the step 3004 of determining the current plunger rod position, the step 3006 of receiving a resistance signal, the step 3008 of determining cartridge parameters, and the step 3010 of adjusting the movement of the plunger rod, can be controlled by a processing unit such as the processing unit of an auto-injector.

[0118] Exemplary auto-injectors, cartridges, systems, and methods are described in the following items.

[0119] Item 1. An auto-injector for administering a medicament, a housing, a cartridge receiver configured to receive a cartridge having a first stopper, a drive module combined to move a plunger rod configured to move the first stopper between a plunger rod retracted position and a plunger rod extended position, a resistance sensor configured to provide a resistance signal representative of the resistance to the movement of the plunger rod, a processing unit connected to the drive module and the resistance sensor and comprising, wherein the processing unit · controls the drive module to move the plunger rod towards the plunger rod extended position, · determines the current plunger rod position, · receives the resistance signal, · determines cartridge parameters based on the resistance signal and the current plunger rod position, · controls the drive module to adjust the movement of the plunger rod based on the cartridge parameters is configured as an auto-injector.

[0120] Item 2. The automatic syringe according to item 1, wherein the adjustment of the movement of the plunger rod includes stopping the movement of the plunger rod.

[0121] Item 3. The automatic syringe according to item 1 or 2, wherein the adjustment of the movement of the plunger rod includes moving the plunger rod to the plunger rod retracted position.

[0122] Item 4. The processing unit is configured to control the drive module to adjust the movement of the plunger rod when the cartridge parameter indicates that the current plunger rod position has reached the plunger rod threshold value and the resistance signal indicates the resistance to the movement of the plunger rod below the low resistance threshold value. The automatic syringe according to any one of items 1 to 3.

[0123] Item 5. The processing unit is configured to control the drive module to adjust the movement of the plunger rod when the cartridge parameter indicates that the resistance signal indicates the resistance to the movement of the plunger rod above the high resistance threshold value. The automatic syringe according to any one of items 1 to 4.

[0124] Item 6. It comprises a code sensor configured to read the cartridge code feature part, the processing unit is connected to the code sensor, the processing unit receives a code signal representing the cartridge code feature part from the code sensor, and is configured to determine the plunger rod threshold value and / or the low resistance threshold value and / or the high resistance threshold value based on the code signal. The automatic syringe according to item 4 or 5.

[0125] Item 7. The resistance sensor is configured to determine the power consumed by the drive module. The automatic syringe according to any one of items 1 to 6.

[0126] Item 8. The automatic syringe according to any one of Items 1 to 7, wherein the resistance sensor is configured to measure the pressure and / or force applied to the front end portion of the plunger rod of the plunger rod.

[0127] Item 9. The automatic syringe according to any one of Items 1 to 8, comprising a tachometer configured to provide a tachometer signal representing the number of rotations of the drive module, wherein the processing unit is connected to the tachometer, and the processing unit is configured to receive the tachometer signal and determine the current plunger rod position based on the tachometer signal.

[0128] Item 10. The automatic syringe according to any one of Items 1 to 9, comprising a user interface connected to the processing unit, wherein the processing unit is configured to output a user output signal via the user interface based on the cartridge parameters.

[0129] Item 11. A system comprising the automatic syringe according to any one of Items 1 to 10 and a cartridge having a first stopper, wherein the cartridge is configured to be received in the cartridge holder.

[0130] Item 12. A method for controlling an automatic syringe, comprising: · receiving a cartridge having a first stopper; · moving the plunger rod towards the plunger rod extended position; · determining the current plunger rod position; · receiving a resistance signal representing the resistance to the movement of the plunger rod; · determining cartridge parameters based on the resistance signal and the current plunger rod position; · adjusting the movement of the plunger rod based on the cartridge parameters. The method comprising the steps.

[0131] Item 13. The method according to item 12, wherein the step of adjusting the movement of the plunger rod includes the step of stopping the movement of the plunger rod.

[0132] Item 14. The method according to item 12 or 13, wherein the step of adjusting the movement of the plunger rod includes the step of moving the plunger rod to the plunger rod retracted position.

[0133] Item 15. The method according to any one of items 12 to 14, wherein the step of adjusting the movement of the plunger rod includes the step of adjusting the movement of the plunger rod when the cartridge parameter indicates that the current plunger rod position has reached the plunger rod threshold value and the resistance signal indicates a resistance to the movement of the plunger rod below the low resistance threshold value.

[0134] Item 16. The method according to any one of items 12 to 15, wherein the step of adjusting the movement of the plunger rod includes the step of adjusting the movement of the plunger rod when the cartridge parameter indicates a resistance to the movement of the plunger rod above the high resistance threshold value.

[0135] Item 17. The method according to any one of items 12 to 16, including the step of receiving a code signal representing a cartridge code feature and determining the plunger rod threshold value and / or the low resistance threshold value and / or the high resistance threshold value based on the code signal.

Claims

1. 1. An automatic injector for administering a medicament, comprising: Housing and a cartridge receiver configured to receive a cartridge having a first stopper; a drive module coupled to move a plunger rod configured to move the first stop between a plunger rod retracted position and a plunger rod extended position; a resistance sensor configured to provide a resistance signal representative of resistance to movement of the plunger rod; a processing unit connected to the drive module and the resistance sensor; Equipped with The processing unit includes: controlling the drive module to move the plunger rod toward the plunger rod extended position; - Determine the current plunger rod position; receiving said resistance signal; determining cartridge parameters based on the resistance signal and the current plunger rod position; Controlling the drive module to adjust movement of the plunger rod based on the cartridge parameters. It is configured as follows: The processing unit is configured to control the drive module to adjust movement of the plunger rod when the cartridge parameters indicate that the current plunger rod position has reached a plunger rod threshold and the resistance signal indicates resistance to movement of the plunger rod below a low resistance threshold.

2. 2. The automatic injector of claim 1, wherein the processing unit is further configured to control the drive module to adjust movement of the plunger rod when the cartridge parameter indicates that the resistance signal indicates resistance to movement of the plunger rod that exceeds a high resistance threshold.

3. 1. An automatic injector for administering a medicament, comprising: Housing and a cartridge receiver configured to receive a cartridge having a first stopper; a drive module coupled to move a plunger rod configured to move the first stop between a plunger rod retracted position and a plunger rod extended position; a resistance sensor configured to provide a resistance signal representative of resistance to movement of the plunger rod; a processing unit connected to the drive module and the resistance sensor; Equipped with The processing unit includes: controlling the drive module to move the plunger rod toward the plunger rod extended position; - Determine the current plunger rod position; receiving said resistance signal; determining cartridge parameters based on the resistance signal and the current plunger rod position; Controlling the drive module to adjust movement of the plunger rod based on the cartridge parameters. It is configured as follows: The processing unit is configured to control the drive module to adjust movement of the plunger rod when the cartridge parameter indicates that the resistance signal indicates resistance to movement of the plunger rod that exceeds a high resistance threshold.

4. 4. The automatic injector of claim 3, wherein the processing unit is further configured to control the drive module to adjust movement of the plunger rod when the cartridge parameter indicates that the current plunger rod position has reached a plunger rod threshold and the resistance signal indicates a resistance to plunger rod movement below a low resistance threshold.

5. 1. An automatic injector for administering a medicament, comprising: Housing and a cartridge receiver configured to receive a cartridge having a first stopper; a drive module coupled to move a plunger rod configured to move the first stop between a plunger rod retracted position and a plunger rod extended position; a resistance sensor configured to provide a resistance signal representative of resistance to movement of the plunger rod and configured to determine power consumed by the drive module; a processing unit connected to the drive module and the resistance sensor; Equipped with The processing unit includes: controlling the drive module to move the plunger rod toward the plunger rod extended position; - Determine the current plunger rod position; receiving said resistance signal; determining cartridge parameters based on the resistance signal and the current plunger rod position; Controlling the drive module to adjust movement of the plunger rod based on the cartridge parameters. The auto-injector is configured as follows:

6. 6. The automatic injector of claim 5, wherein the processing unit is configured to control the drive module to adjust movement of the plunger rod when the cartridge parameters indicate that the current plunger rod position has reached a plunger rod threshold and the resistance signal indicates a resistance to movement of the plunger rod below a low resistance threshold.

7. 7. The automatic injector of claim 5 or 6, wherein the processing unit is configured to control the drive module to adjust movement of the plunger rod when the cartridge parameter indicates that the resistance signal indicates resistance to movement of the plunger rod that exceeds a high resistance threshold.

8. The automatic injector of any one of claims 1 to 7, wherein adjusting the movement of the plunger rod comprises stopping the movement of the plunger rod.

9. The automatic injector of any one of claims 1 to 8, wherein adjusting the movement of the plunger rod comprises moving the plunger rod to the plunger rod retracted position.

10. 10. The automatic injector of claim 1, further comprising a code sensor configured to read a cartridge code feature, the processing unit being connected to the code sensor, the processing unit being configured to receive a code signal representative of the cartridge code feature from the code sensor and to determine the plunger rod threshold and / or the low resistance threshold and / or the high resistance threshold based on the code signal.

11. The automatic injector of any one of claims 1 to 10, wherein the resistance sensor is configured to determine the power consumed by the drive module.

12. The automatic injector of any one of claims 1 to 11, wherein the resistance sensor is configured to measure pressure and / or force applied to a plunger rod front end of the plunger rod.

13. 13. The automatic injector of claim 1, further comprising a tachometer configured to provide a tachometer signal representative of a number of rotations of the drive module, the processing unit being connected to the tachometer, the processing unit being configured to receive the tachometer signal and to determine the current plunger rod position based on the tachometer signal.

14. 14. The automatic injector of any one of claims 1 to 13, comprising a user interface connected to the processing unit, the processing unit configured to output a user output signal via the user interface based on the cartridge parameters.

15. A system comprising the automatic injector of any one of claims 1 to 14 and a cartridge comprising a first stopper, the cartridge configured to be received in the cartridge receiver.

16. 1. A method for controlling an automatic injector, comprising: - receiving a cartridge having a first stopper; moving the plunger rod toward an extended plunger rod position; - determining a current plunger rod position; receiving a resistance signal representative of resistance to movement of the plunger rod; determining cartridge parameters based on the resistance signal and the current plunger rod position; adjusting the movement of the plunger rod based on the cartridge parameters if the cartridge parameters indicate that the current plunger rod position has reached a plunger rod threshold and the resistance signal indicates a resistance to plunger rod movement below a low resistance threshold; The method includes:

17. 17. The method of claim 16, further comprising adjusting movement of the plunger rod based on the cartridge parameter when the cartridge parameter indicates that the resistance signal indicates resistance to movement of the plunger rod that exceeds a high resistance threshold.

18. 1. A method for controlling an automatic injector, comprising: - receiving a cartridge having a first stopper; moving the plunger rod toward an extended plunger rod position; - determining a current plunger rod position; receiving a resistance signal representative of resistance to movement of the plunger rod; determining cartridge parameters based on the resistance signal and the current plunger rod position; adjusting movement of the plunger rod based on the cartridge parameters when the cartridge parameters indicate that the resistance signal indicates resistance to movement of the plunger rod above a high resistance threshold; The method includes:

19. 20. The method of claim 18, further comprising adjusting movement of the plunger rod based on the cartridge parameter when the cartridge parameter indicates that the current plunger rod position has reached a plunger rod threshold value and the resistance signal indicates a resistance to movement of the plunger rod below a low resistance threshold value.

20. 1. A method for controlling an automatic injector, comprising: - receiving a cartridge having a first stopper; moving the plunger rod toward an extended plunger rod position; - determining a current plunger rod position; receiving a resistance signal representative of resistance to movement of the plunger rod, the resistance signal being based on power consumed by the drive module; determining cartridge parameters based on the resistance signal and the current plunger rod position; - adjusting the movement of the plunger rod based on the cartridge parameters; The method includes:

21. 21. The method of claim 20, further comprising adjusting movement of the plunger rod based on the cartridge parameter when the cartridge parameter indicates that the resistance signal indicates resistance to movement of the plunger rod that exceeds a high resistance threshold.

22. The method of claim 20 or 21, further comprising adjusting movement of the plunger rod based on the cartridge parameter when the cartridge parameter indicates that the current plunger rod position has reached a plunger rod threshold value and the resistance signal indicates a resistance to movement of the plunger rod below a low resistance threshold value.

23. The method of any one of claims 16 to 22, wherein adjusting the movement of the plunger rod comprises stopping the movement of the plunger rod.

24. The method of any one of claims 16 to 23, wherein adjusting the movement of the plunger rod comprises moving the plunger rod to the plunger rod retracted position.

25. 25. The method of any one of claims 16 to 24, comprising receiving a code signal representative of a cartridge code feature and determining the plunger rod threshold value and / or the low resistance threshold value and / or the high resistance threshold value based on the code signal.

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