Drug delivery devices

Abstract

A drug delivery device comprising a delivery unit (3) and a drive unit (4), the delivery unit comprising a drug container (5) and a pumping system (8) having a pump engine (38), the pump engine comprising a stator (29) and a pump rotor (31), the pump rotor configured to provide an axial piston stroke in accordance with rotation of the pump rotor about its axis of rotation relative to the stator for pumping liquid from the drug container, and the drive unit comprising a housing (2), an electronic control system (6), a pump drive (7) including a motor (16) A drug delivery device comprising a motor output transmission shaft (17) driven sequentially by a motor output transmission shaft (16), a rotor position sensing system (9), and a coupling (21) slidably connected to the motor output transmission shaft (17) and driven sequentially by the motor output transmission shaft, wherein the coupling (21) has a pump-side interface (39) which engages with a drive coupling interface (40) of a pump rotor (31) and is configured to transmit torque from the motor (16) to the pump rotor (31) and to cause an axial displacement in accordance with the axial displacement of the pump rotor (31). An electronic control system (6) comprises a delivery control module configured to control the operation of the motor (16) of the pump drive (7), the delivery control module configured to operate the motor in a sequence of multiple pulses and pauses, the pulse and pause times adjusted to achieve a specific average flow rate, each pulse operation comprising multiple motor output transmission shaft rotations, the average flow rate adjusted by varying the number of rotations per pulse or the duration of pauses between pulses.

Description

Technical Field

[0001] The present invention relates to a drug delivery device for subcutaneous administration of a liquid drug. The drug delivery device may be in the form of a patch device. Background Art

[0002] Drug delivery devices in the form of patch devices that are attached to the skin of a patient for subcutaneous delivery of a liquid drug are known. It is known to provide drug delivery devices in the form of patch devices having a single-use disposable component assembled to a reusable component housing drive and control electronics, or as a single disposable component.

[0003] The reliability, safety, compactness and ease of use of a patient-worn drug delivery device are important. For disposable components, the amount of parts and consequently the cost of the disposable device are also important considerations.

[0004] There is a need to ensure the safety and reliability of automatically operating mechanisms within drug delivery devices, while reducing costs and improving the compactness of medical devices.

[0005] Safety is one of the most important design considerations in drug delivery devices. It is important to ensure that the drug is administered properly and completely, and that occlusion or other factors that may affect a defined delivery rate are reliably monitored.

[0006] One important aspect to monitor is often the delivery amount and delivery rate of the drug to ensure the correct dosage over time.

[0007] For devices such as patch pumps that are worn by the patient and may be activated by the patient outside a medical facility, safety and reliability also depend on the simplicity of operation and the robustness of safety procedures designed to detect failure.

[0008] Many drug delivery devices have a pump mechanism based on a linear motor drive that pushes a plunger in the drug cartridge. These mechanisms are complex and bulky. Furthermore, valves are required to close the fluid passage when no drug is being administered to ensure safe administration. These problems can be overcome by providing drug delivery devices with pump systems such as those described in WO2007074363, WO2015015379, WO2019228895A1, or WO2020069926A1. In the conventional systems described above, the flow rate is controlled by adjusting the speed of the motor drive. This requires a motor configured to operate over a wide range of speeds, resulting in a certain cost and complexity for the motor itself. In such systems, the volume of liquid pumped per revolution of the rotor is determined by the stroke (axial displacement) of the rotor, and thus, some error in stroke measurement can occur due to slight tilting of the rotor. In fact, because the pump engine rotor engages with an elastic sealing member within the stator, the rotor can tilt slightly, which can lead to the tilt angle being incorrectly measured as axial displacement. The small amplitude of axial displacement per rotor cycle necessitates ensuring very accurate stroke measurements, which also helps determine whether the pump is functioning properly or if there are blockages or leaks that could lead to under- or over-delivery of the liquid agent. [Overview of the project] [Problems that the invention aims to solve]

[0009] In view of the foregoing, an object of the present invention is to provide a drug delivery device for administering liquid drugs that is safe, reliable, and compact, comprising a disposable unit, particularly in the form of a patch device or as a completely disposable device.

[0010] Providing user-friendly drug delivery devices is advantageous.

[0011] It is advantageous to provide drug delivery devices that are economical to manufacture. [Means for solving the problem]

[0012] The object of the present invention is achieved by providing a drug delivery device as described in the independent claim. Various advantageous embodiments of the present invention are described in the dependent claims.

[0013] Disclosed herein is a drug delivery device comprising a delivery unit and a drive unit, the delivery unit comprising a drug container and a pumping system having a pump engine, the pump engine comprising a stator and a pump rotor, the pump rotor mounted in the stator, rotatable and axially movable within the stator, and configured to produce an axial piston stroke in accordance with rotation of the pump rotor about its axis of rotation relative to the stator for pumping liquid from the drug container, the drive unit comprising a housing, an electronic control system, a pump drive including a motor, a motor power transmission shaft driven sequentially by the motor, a rotor position sensing system, and a coupling slidably connected to the motor power transmission shaft, which is driven sequentially by the motor power transmission shaft, the coupling having a pump-side interface which engages with a drive coupling interface of the pump rotor and is configured to transmit torque from the motor to the pump rotor, causing an axial displacement in accordance with the axial displacement of the pump rotor.

[0014] The electronic control system includes a delivery control module configured to control the operation of the pump drive motor, which is configured to operate the motor in a sequence of pulses and pauses to deliver a certain volume of liquid, each pulse-and-pause sequence containing one pulse followed by one pause, and each pulse containing multiple pump rotor rotations, with the average flow rate being adjusted by varying the number of rotations per pulse or the duration of the pauses between pulses. The average flow rate is determined by dividing the total volume of liquid pumped over the sequence of pulses and pauses by the total duration of the sequence of pulses and pauses. The sequence of pulses and pauses corresponds to the substantially continuous delivery of a certain volume of liquid.

[0015] In an advantageous embodiment, the drive unit includes a rotor position sensing system connected to an electronic control system, which is configured to supply at least one rotor position measurement to a delivery control module at least once per revolution, and the output transmission shaft is configured to be stopped by the delivery control module at a predetermined park position at the end of each pulse operation.

[0016] In an advantageous embodiment, the delivery control module is configured to operate pulses having at least 3 rotor rotations per pulse, and the average flow rate is adjusted by the duration of the pauses alone, or in combination with the duration of the pulses.

[0017] In an advantageous embodiment, the electronic control system is configured to operate pulses and pauses by switching the motor on and off, and the voltage and current supplied to the motor is configured to operate the motor at a preset optimal power.

[0018] In an advantageous embodiment, the electronic control system includes a motor drive circuit connected to a motor of a pump drive, and at least one rotational position sensor of a rotor position sensing system for controlling the motor and thereby controlling the pumping of drug from a drug container by the pumping system, wherein the motor drive circuit includes a main controller configured to control signals for the operation of the motor, and a monitoring controller separate from the main controller and also connected to the at least one rotational position sensor of the rotor position sensing system, wherein the monitoring controller is connected to an interlock circuit configured to transmit power from a power source to the motor, and the monitoring controller is configured to activate the interlock circuit and cut off power to the motor if the rotor position measurement signal received from the at least one rotational position sensor does not match a set value within a predetermined tolerance threshold.

[0019] In an advantageous embodiment, the main controller includes or comprises an integrated circuit, the monitoring controller includes or comprises an integrated circuit, and the monitoring controller and the main controller are supplied with power and sensing signals independently of each other.

[0020] In an advantageous embodiment, the delivery control module is configured to trigger an alarm condition that defines an occlusion event of the drug delivery device, which is triggered after the axial position of the rotor is measured to exceed an occlusion position threshold, or after the axial displacement amplitude of the rotor is measured to fall below an occlusion displacement threshold, over at least two rotations of the pump rotor within a window of at least 3 to 10 rotations.

[0021] In an advantageous embodiment, the window is within the range of 5 to 8 rotations, and the alarm condition defining an occlusion event of the drug delivery device is triggered after the axial position of the rotor is measured to be above an occlusion threshold, or after the axial displacement amplitude of the rotor is measured to be below an occlusion displacement threshold, for at least 3 rotations of the pump rotor.

[0022] In an advantageous embodiment, the axial rotor position used to determine whether an occlusion position threshold has been exceeded, or the axial rotor displacement used to determine whether an occlusion displacement threshold has been exceeded, is measured within an occlusion window defined by the rotational position of the rotor between the end of discharge and the start of intake of a pump cycle defined by one revolution of the rotor, the occlusion window being within the angular range in which both valves are closed.

[0023] In an advantageous embodiment, the rotor position sensing system comprises at least one rotational position sensor that measures rotation of the motor output transmission shaft, and an axial sensor for measuring axial displacement of the pump rotor, the axial sensor comprising a first axial position sensor statically mounted within the housing of the drive unit, and a second axial position sensor statically mounted within the housing of the drive unit, the first and second axial position sensors being disposed on opposite sides of the rotational axis, and the first and second angular positions are spaced apart by 180°.

[0024] In an advantageous embodiment, the electronic control system is configured to measure the axial position of the coupling-side interface by processing the sum or average of the measurement outputs of the first and second axial position sensors.

[0025] In an advantageous embodiment, the axial position sensor comprises an axial position magnet mounted on the coupling, the magnet having an annular portion surrounding the rotational axis of the coupling, and the first and second axial position sensors comprise first and second magnetic field sensors.

[0026] In an advantageous embodiment, the rotational position sensor comprises an integrated incremental solver in the motor.

[0027] In an advantageous embodiment, the rotor position sensing system comprises at least one rotational index sensor configured to detect a specific reference rotational position of the motor output transmission shaft.

[0028] Further advantageous features of the present invention will become apparent from the following detailed description of embodiments of the invention and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] [Figure 1a] It is a perspective view of a drug delivery device according to an embodiment of the present invention. [Figure 1b] It is a perspective view of a reusable unit and a single-use disposable unit of the drug delivery device of Fig. 1a before connection and use. [Figure 1c] It is a cross-sectional view taken through the drug delivery device shown in Fig. 1a. [Figure 1d] It is a cross-sectional view taken through the drug delivery device shown in Fig. 1a, showing the reusable unit and the single-use disposable unit before connection and use. [Figure 2] It is a functional block diagram of a drug delivery device according to an embodiment of the present invention. [Figure 3] It is a simplified schematic diagram of a drug delivery device according to an embodiment of the present invention. [Figure 4a] It is a perspective cross-sectional view of a part of a drug delivery device according to an embodiment of the present invention. [Figure 4b] It is a side view of a part of the device of Fig. 4a, showing the output part of the pump drive. [Figure 5] It is a diagram showing the functional principle of rotation and axial displacement of the rotor of a pumping system of a drug delivery device according to an embodiment of the present invention. [Figure 6a] It schematically shows an axial position sensor (stroke sensor) of a rotor position sensing system of a drug delivery device according to an embodiment of the present invention. [Figure 6b] It schematically shows an axial position sensor (stroke sensor) of a rotor position sensing system of a drug delivery device according to an embodiment of the present invention. [Figure 7] It schematically shows a plot of flow rate over time for a pump drive and a pumping system of a drug delivery device according to an embodiment of the present invention. [Figure 8]This is a simplified schematic diagram of the electronic control system of the drive unit of a drug delivery device according to one embodiment of the present invention. [Figure 9] This is a functional block diagram of a reusable unit for a drug delivery device according to one embodiment of the present invention. [Figure 10] This is a schematic plot of the axial displacement of the rotor in a pumping system for a drug delivery device according to one embodiment of the present invention, with respect to the rotor rotation angle. The plot shows the normal stroke path and the blocked stroke path. [Figure 11] This is a graphical representation of an observation window used to determine blockage based on a certain number of rotor axial position measurements. [Modes for carrying out the invention]

[0030] Referring to the drawings, the drug delivery device 1 according to an embodiment of the present invention includes a housing 2, a delivery unit 3, and a control or drive unit 4, the delivery unit 3 and the control or drive unit 4 being assembled within the housing 2. The housing 2 may be made of two or more parts that allow the delivery unit, the drive unit, and any other components to be assembled within the housing.

[0031] In the illustrated embodiment, a drug delivery device for subcutaneous administration of a liquid drug includes a disposable portion formed by a delivery unit, which can be assembled to a reusable portion formed by a drive unit, the drive unit including electronics and a power supply. The components of delivery unit 3 are mounted within a first housing portion of the drug delivery device, and the components of drive unit 4 are mounted within a detachable second housing portion, the drive unit 4 can be reused with subsequent delivery units.

[0032] The embodiments shown in the drawings relate to a two-part drug delivery device comprising a disposable unit and a reusable unit, but within the scope of the invention relating to the various embodiments described herein, the entire drug delivery device may be provided as a single-use disposable unit.

[0033] Depending on the medical application, administration may be a single dose over a short period, typically less than an hour, for example, about 30 minutes or less, or it may be a subcutaneous injection of liquid medication over a longer period, ranging from several hours to several days.

[0034] The drug delivery device includes a user interface 46, which may include one or more buttons for activating the drug delivery device, a light and / or audible status indicator, and optionally a screen or other display for presenting information to the device operator.

[0035] The drug delivery device according to embodiments of the present invention may, advantageously, be configured as a patch device for application to a patient's skin.

[0036] Referring to Figures 1a and 1b, in one embodiment, an adhesive layer 51 covered with a protective film 50 may be provided on the outer surface of the skin contact wall 48 of the housing 2, the protective film 50 may be peeled off from the adhesive layer 51 before the adhesive layer is placed at the injection site on the patient's skin. The needle opening on the skin contact side is covered with the protective film 50 before use, allowing a transdermal injection needle (not shown) to extend through it and puncture the patient's skin when the drug delivery device 1 is activated.

[0037] The delivery unit 3 includes a drug container 5 for containing liquid medication, such as a drug cartridge equipped with a stopper that is known in itself, and a liquid flow system for subcutaneously administering the liquid medication to the patient.

[0038] The drug delivery device further includes a pumping system that, once activated, pumps liquid from the drug container into an injection needle (not shown).

[0039] In one embodiment, the delivery unit 3 incorporates a pump engine 38 of a pumping system 8 that pumps liquid from a container into a syringe needle once the drug delivery device is activated. The pump engine 38 includes a drive coupling interface 40 that connects to a complementary coupling interface 39 of a pump drive 7 of a drive unit 4. Thus, the drive unit provides mechanical force via the coupling interfaces 39, 40 to drive the pump engine 38.

[0040] The pump engine 38 within the delivery unit 3 may, advantageously, include a design and configuration similar to the pump engines described in WO2007074363, WO2015015379, WO2019228895A1, or WO2020069926A1, wherein the pump rotor 31 is mounted within the stator 29 and is rotatable and axially movable within the stator 29 to pump fluid from the fluid inlet to the fluid outlet. As can be seen from the aforementioned publications, the pump rotor 31 has a pump shaft having a first diameter and a second diameter surrounded by a seal, the seal opening and closing a fluid channel between the inlet and outlet as the rotor rotates and is axially displaced by a cam mechanism between the stator 29 and the pump rotor 31, thereby performing a pumping action while opening and closing valves between the fluid inlet and the pumping chamber, and between the pumping chamber and the outlet.

[0041] Therefore, the pump engine 38 is: -Status 29 and, - A pump rotor 31 mounted at least partially rotatably and axially slidably within a stator 29, the pump rotor 31 including a first axial extension having a first diameter and a second axial extension having a second diameter larger than the first diameter, -A first valve formed by a first valve seal mounted on the stator around a first axial extension, associated with a first channel in the rotor configured to allow fluid communication across the first valve seal when the first valve is in the open position, -A second valve formed by a second valve seal mounted on the stator around a second axial extension, associated with a second channel in the rotor configured to allow fluid communication across the second valve seal when the second valve is in the open position, Includes.

[0042] A key advantage of using such a pump engine in embodiments of this drug delivery device is that leak-free, and particularly reliable, fluid pumping is ensured in an easy-to-operate configuration, as there is no direct fluid connection between the inlet and outlet at any position of the rotor and no valve operation is required. The pump engine is extremely compact and can be driven directly by a rotating electric motor of the pump drive within the drive unit 4, with or without gearing. In fact, the differential pumping volumetric displacement, defined by the axial displacement of the rotor and the difference between the first and second diameters of the pump shaft, allows the pumping volumetric displacement rotation to be easily set for optimal operation with a given type of electric motor rotating at a constant speed. Furthermore, the pump engine components can be made entirely of polymer material, the rotor can be easily coupled to the pump drive, and a sterile barrier is ensured between the fluid part of the pump engine and the coupling interface.

[0043] The drive unit 4 includes a user interface 46 which may have various configurations depending on the drug to be administered and the intended use. In some applications, the user interface may be very simple, having a start button to initiate the drug delivery process, a status indicator such as a status light, and such as a speaker.

[0044] Embodiments of drug delivery devices in the form of patch pumps may be specifically for administering a predetermined dose. Certain applications may simply require the administration of a predetermined dose of a drug at a specific time after an event.

[0045] One example is the postoperative administration of furosemide after cardiac surgery, which requires administration over several hours and at regular intervals, for example, every 24 to 48 hours, after a certain period of time has elapsed since the surgery. The drug delivery device may include a drive unit that forms a reusable unit, which is connected to a disposable unit containing a delivery unit and a cartridge, and is attached to the patient's skin for a single dose delivery that can last for up to several hours, after which the drug delivery device is removed and the disposable portion is discarded. The reusable portion can be reused with a subsequent disposable device when the patient next requires drug administration, for example, after 48 hours.

[0046] The drive unit 4 further includes a power supply 28 including a battery, an electronic control system 6, and a pump drive 7 that supplies torque to drive the pumping system 8 in the disposable delivery unit 3. The drive unit 4 further includes a rotor position sensing system for monitoring and controlling the pumping operation and for detecting under-delivery or over-delivery due to, for example, blockage or leakage.

[0047] The pump drive 7 includes a motor 16 having an output transmission shaft 17 connected to a coupling 21, the coupling 21 being axially movable relative to the output transmission shaft 17 and biased by a spring 36. The coupling 21 has a pump-side interface 39 configured to bias and engage with the drive coupling interface 40 of the pump rotor 31 of the pump engine 38 of the delivery unit pumping system. The pump-side interface 39 has a complementary form to the drive coupling interface 40 of the pump engine 38, which is configured to transmit torque generated by the motor 16 to the pump engine pump rotor 31. The spring 36 is configured to bias and press the coupling 21 against the pump rotor 31 of the pump engine 38 and to ensure axial pumping displacement of the rotor in relation to the bias of the cam elements on the pump engine rotor 31 against the cam elements on the pump engine stator 29. Thus, the axial stroke of the coupling 21 of the pump drive 7 corresponds to the axial stroke of the pump engine pump rotor 31, and the rotational displacement of the motor output transmission shaft 17 corresponds to the rotational displacement of the pump engine pump rotor 31.

[0048] The coupling 21 is slidably engaged with the motor output transmission shaft 17 so that the coupling 21 can move axially in response to the rotation of the motor output transmission shaft 17, and the axial displacement is determined by the cam structure between the pump rotor 31 and the stator 29 of the pump engine 38, as is known in the prior art rotary piston pumps described above.

[0049] Rotational and axial displacements can be measured on the pump rotor 31 of the pumping system 8 within the delivery unit 3, but to reduce the number, materials, and complexity of components of the disposable delivery unit 3, it is more advantageous to include the rotational measuring system and stroke sensor within the reusable drive unit 4.

[0050] In the illustrated embodiment, the coupling 21 includes a slide groove 19b on the motor-facing side, which is slidably engaged by a slide projection 19a on the coupling-side interface 18 of the motor output transmission shaft 17. However, it should be noted that the groove and projection on the coupling and transmission shaft may be reversed, or other mechanical configurations that allow relative axial movement while enabling torque transmission, such as a spline shaft, may be employed instead of the illustrated embodiment. Multiple projections 19a and corresponding grooves 19b, for example two, three, or four, may be distributed around the circumference for better guidance and positioning of the coupling and to reduce frictional resistance between each projection and the corresponding slide engagement surface of the groove.

[0051] The rotor position sensing system 9 includes a rotational position measuring system and an axial position sensor (stroke sensor) 23. The rotor position sensing system 9 is configured to measure the axial position and rotational position of the pump engine rotor 31, and from there to measure the displacement of the rotor.

[0052] The rotational position measuring system can be directly incorporated into the motor 16, for example, in the form of an increment solver built into the motor, as is known in conventional motors. Other rotational measuring systems known in electric motor drives can also be used within the scope of the present invention.

[0053] In an advantageous embodiment, the rotor position sensing system may further include a rotation index sensor 22 that defines at least one rotation position by a separate magnet or a pair of separate magnets positioned on the circumference of the motor output transmission shaft 17 to detect a specific rotation position of the output transmission shaft 17. For example, a separate reference position magnet may be positioned, and a corresponding magnetic field sensor may be positioned on the circuit board 27 or within a housing portion and connected to the circuit board to detect a specific rotor position. The rotation index sensor 22 may also be used to set a reference rotation position, which is to reset the counting performed by the rotation position sensor 20 to determine the angular position relative to the reference position defined by the rotation index sensor 22. In one embodiment, the rotation index sensor 22 may be incorporated into the motor 16.

[0054] The axial position sensor 23 includes an axial position magnet 23a mounted on the coupling 21, a first axial position sensor 23b in the form of a magnetic field sensor such as a Hall sensor, and a second axial position sensor 23c similar to the first axial position sensor 23b, positioned opposite the coupling and facing the first axial position sensor. The axial position magnet 23a has north-south oriented magnetic poles aligned in the axial direction, and the axial displacement of the annular axial position magnet 23a changes the direction and strength of the magnetic field measured by the first axial position sensor 23b and the second axial position sensor 23c, depending on the axial position relative to the stator.

[0055] If the pump rotor 31 of the delivery unit pumping system 8 has any tilt, the biasing of the coupling 21 to the pump rotor, which follows the tilt and rotational position of the pump rotor 31, causes the first axial position sensor 23b and the second axial position sensor 23c to measure different axial positions. However, the axial position measurements from the first and second axial position sensors can be summed or averaged to determine the true axial position at the centerline of the pump rotor 31, and this true axial position determines the actual or true stroke of the rotor, and thus the volume pumped. By summing the outputs of the first and second axial position sensors, it is possible to amplify the output of the axial measurement signal.

[0056] In addition to providing more accurate measurements of the pump rotor stroke, the second axial position sensor 23c also provides additional stroke measurements to the stroke measurement of the first axial position sensor 23b, which can provide redundant safety measurements of the axial displacement and thus the volume of the agent being pumped. Thus, incomplete stroke measurements can be detected more safely by the two axial position sensors.

[0057] In an advantageous embodiment, the first axial position sensor 23b, which may be in the form of a Hall sensor provided within an integrated circuit chip, may be advantageously mounted on a main circuit board 27, and the second axial position sensor 23c may be connected to the main circuit board via wires or cables and mounted on a secondary circuit board 24 which is held relative to the main circuit board by a housing component or a holder bracket.

[0058] The volume of liquid pumped in one pumping cycle, i.e., a 360° rotation of the pump rotor 31, is a fixed volume determined by the axial stroke of the rotor. In conventional pumps, the liquid flow rate changes by changing the rotational speed of the rotor, and changing the rotational speed of the rotor changes the frequency of the axial stroke, and therefore the flow rate. However, this requires that the motor of the pump drive can supply the necessary power for pumping over a wide range of rotational speeds. However, electric motors usually have a small rotational speed range over which they can deliver maximum power, so motors used over a wide speed range need to be larger and require a more complex control system compared to motors that operate only at a constant speed corresponding to an optimal power-to-size ratio.

[0059] Based on the above, according to one aspect of the present invention, the pump drive is configured to adjust the flow rate by operating the motor at a predetermined rotational speed corresponding to the motor's optimal operating point in terms of torque and speed, and by turning off the motor for pauses between pulses at the predetermined rotational speed. However, it should be noted that there may be multiple predetermined rotational speeds, that is, the motor may have two optimal operating points and may function at two different speeds to adjust a very large operating range through pauses and pulses.

[0060] During the priming operation when the drug delivery device is activated (first use), or when a bolus dose at the maximum flow rate is required, the pumping operation can simply rotate continuously at a predetermined rotational speed without any pauses. The pulses may have a substantially constant duration, for example, 1 to 10 rotations of the rotor, followed by a pause duration that determines the flow rate. Alternatively, the pulse and pause durations may be adjusted to have variable durations, respectively. It should be noted that the concept of a predetermined rotational speed includes a constant nominal speed in steady-state operation, and it is understood that the motor must, of course, accelerate to the nominal operating speed and then decelerate when turned off. However, the motor flow command is determined by the on and off times that define the pulse and pause durations, and the power supply to the motor phase is the same in each pulse cycle.

[0061] It should be noted that the rotor position sensing system 9 may be used to ensure that the rotor is stopped at a specific park position at the end of each pulse duration and then restarted at the same park position on the next pulse, in order to ensure that each pulse duration has a specific, predetermined number of complete (360°) rotor rotations.

[0062] Depending on the required flow rate, different pulse patterns (i.e., turning on and then off) may be implemented.

[0063] The pause and pulse patterns corresponding to the flow rate can be stored in the memory 14 of the electronic control system, for example, in the form of a lookup table accessed by the control system to implement a specific flow rate, or they can be calculated based on a stored function. For certain medical applications, the flow rate and overall flow pattern of the administered drug can be predetermined and factory-set in the memory of the drug delivery device.

[0064] An example of the application of a drug delivery device for 5-hour drug administration, which involves a priming phase upon activation of the drug delivery device, followed by a two-stage delivery with a high infusion rate for the first hour and a lower infusion rate for the next four hours, is shown in the table below. [Table 1]

[0065] Referring particularly to Figures 8, 9 and 2, according to one aspect of the present invention, the electronic control system 6 includes a motor drive circuit 10 which includes a motor driver that controls the operation of a motor 16, the motor driver being controlled by a main controller 11 which receives at least one rotor position sensing signal from a rotor position sensing system 9 which measures the rotation of the output transmission shaft 17 of the motor 16. The main controller receives at least measurement information from a rotation index sensor 22, but may further receive sensing measurements from a rotor position measuring system in the motor and / or from an axial position sensor 23. The main controller determines the operation of the motor driver according to a desired or predetermined flow rate, and thereby, if the delivery control module of the motor drive circuit 10 includes pulse and pause operating modes as described above, the motor main controller 11 commands the pulse operation to be turned on and off.

[0066] The rotor position sensing system 9 is further connected to a monitoring controller 12, which is separate from the main controller 11.

[0067] Both the monitoring controller and the main controller can, advantageously, be in the form of integrated circuits, which are mounted separately on the main circuit board 27 and communicate with each other via an inter-process communication (IPC) protocol. The monitoring controller and the main controller each have their own clock (crystal oscillator) to ensure completely independent operation.

[0068] The monitoring controller monitors the operation of the motor 16 based on the rotor position sensing system input to the main controller and the monitoring controller. If the sensing information does not correspond to the desired or programmed flow rate, the monitoring controller stops sending a toggle signal to the interlock circuit 13 located between the power supply 28 and the motor 16. Power to the motor is supplied through the interlock circuit 13, and if there is a discrepancy between the measured rotor position from the rotor position sensing system 9 and the desired or programmed flow rate, the monitoring controller instructs the interlock circuit 13 to cut off power to the motor 16. The main controller is configured to control motor power using another circuit that is supplied with power via the interlock circuit. Since the “interlock circuit” and “motor driver” are connected in series with the motor, both the main controller and the monitoring controller must power the motor for it to operate.

[0069] More specifically, in one embodiment as an example, the monitoring controller receives a request from the main controller to power on the motor via an IPC interface (by a toggling interlock signal) with a command for motor start, motor speed, and time frame. The time frame is the period during which the next request is expected and is determined by the treatment / delivery pattern. For example, there may be two patterns used, as shown in the following example: the first treatment time is 17 revolutions per minute, delivered every 120 seconds (stage 1), and the subsequent 4-hour treatment is 7 revolutions per minute, delivered every 116 seconds (stage 2). After receiving the request to power on the motor, the monitoring controller starts three internal software (SW) timers, with timeouts equal to 20% longer than the received "time frame" (timer 1), 20% shorter than the received "time frame" (timer 2), and a third timer with a timeout equal to the rotation speed multiplied by the maximum time for one motor revolution (timer 3). The monitoring controller then powers on the motor (starts toggling the interlock). While Timer 3 is running, the monitoring controller monitors the motor speed. If the speed is more than 1 greater than the "speed" requested by the main controller, the monitoring controller cuts off the motor power and sends fault information to the main controller to issue an alarm. If, at the end of Timer 3's timeout, the counted motor speed is more than 1 less than the requested speed, the monitoring controller cuts off the motor power and sends fault information to the main controller to issue an alarm. The monitoring controller also monitors the time elapsed between motor speed requests. The next motor speed request is expected between the end of Timer 1 and Timer 2. If a new request is received before the end of Timer 1, the monitoring controller recognizes an overdelivery condition. If the next request is not received before the end of Timer 2, the monitoring controller recognizes an underdelivery condition. In either case, the monitoring controller cuts off the motor power and sends an alarm request to the main controller.

[0070] Therefore, the separate main controller and monitoring controller independently measure the motor operation, and consequently the pumping operation, while simultaneously providing two separate channels: one main controller controls the function, and the other monitors drug delivery and stops the system if a malfunction is detected.

[0071] The monitoring controller 12's interaction with the interlock circuit provides an economical, simple, reliable safety mechanism to stop drug administration in the event of malfunction. The advantage of using the interlock circuit is that if a technical failure occurs in the monitoring controller and a persistent logical "1" or "0" is generated on the interlock pin connected to the interlock circuit, the motor power will be cut off until the interlock circuit receives a persistent change signal, for example, at a frequency of approximately 100 Hz, to power on the motor.

[0072] Referring to Figures 10 and 11, the delivery monitoring software module installed within the motor drive circuit 10 of the electronically controlled system includes an obstruction detection module configured to detect obstructions according to the operating principle shown in Figure 10. If the fluid flow path is obstructed and drug delivery to the patient is hindered, the axial displacement of the pump engine pump rotor 31 is inhibited, and the axial pump stroke does not follow the intended path. When the fluid flow downstream of the pump engine is blocked, the pump rotor 31 cannot move axially because it cannot empty the pump chamber, and therefore the chamber remains filled or partially filled. An obstruction event can be detected by measuring the axial position of the rotor, where the obstruction event is detected if the axial position is measured to be above an obstruction position threshold, or by measuring the axial displacement amplitude of the rotor, where the obstruction event is detected if the axial displacement is measured below an obstruction displacement threshold.

[0073] As shown by the dotted line in Figure 10 indicating an obstructed stroke pathway, in each pump cycle (360° rotation of the pump rotor 31), a very small amount of fluid, for example in the range of 1 μL to 10 μL, is moved, and very brief, transient obstructions can sometimes cause an obstructed stroke pathway to be detected during drug delivery. Such transient obstructions can occur, for example, when the catheter or cannula moves temporarily against the subcutaneous tissue when the patient moves, or when the cannula bends or the catheter tube becomes pinched, or when the drug delivery device is struck in a way that interferes with axial position measurement, or due to some external factor.

[0074] If an obstruction is detected for one or two cycles due to a temporary event as described above, the average flow rate will remain largely unimpeded and within acceptable limits, and therefore the alarm should not be activated. Accordingly, according to one aspect of the present invention, the obstruction detection module requires at least two rotational cycles of continuously measured obstruction events within an observation window ranging from 2 to 10 cycles to trigger an obstruction detection alarm. Preferably, the observation window is at least 5, for example, 5 to 8, so that the alarm condition is met when obstruction detection occurs at least 3 to 5 times within an observation window of 5 to 8 cycles.

[0075] As best illustrated in Figure 10, the axial position of the pump rotor is preferably measured within a specific rotation angle of the rotor, which defines a closed measurement window in which measurements are taken during each consecutive pump cycle (a cycle corresponding to a full 360° rotation of the pump rotor). This closed window is preferably between the end of the discharge phase and the start of the intake phase, preferably when both the inlet and outlet valves are closed, and is positioned substantially in the center between the end of the pump discharge phase and the start of the intake phase. This ensures that a specific window for detecting the axial position is used consistently throughout each rotation cycle, and that this window is in the closed position for the most reliable position measurement.

[0076] The delivery monitoring software module and delivery control software module installed within the motor drive circuit 10 of the electronic control system 6 can perform various control and safety functions as illustrated in the table below. [Table 2]

[0077] [List of reference symbols] Drug delivery device 1 Housing 2 Skin contact wall 48 Adhesive layer 51 Protective film 50 Delivery unit 3 Drug container 5 Subcutaneous delivery system Injection needle / cannula Needle insertion device mechanism Pumping system 8 Pump engine 38 stator 29 Pump rotor 31 Drive coupling interface 40 Drive unit 4 User Interface 46 speaker Light Start button Electronic control system 6 Motor drive circuit 10 Delivery control module Flow control module Delivery monitoring module Blockage detection module Main circuit board 27 Main controller 11 integrated circuits Crystal oscillator 34 Monitoring controller 12 integrated circuits Crystal oscillator 35 Interlock circuit 13 Memory 14 Event Log power supply 28 battery Pump Drive 7 Motor 16 Motor output transmission shaft 17 Coupling side interface Slide projection / groove 19a Spring 36 Coupling 21 Pump-side interface 39 Motor-side interface 33 Slide groove / projection 19b Rotor position sensing system 9 Rotational position sensor Rotation index sensor 22 Axial position sensor (stroke sensor) 23 Axial position magnet 23a First axial position sensor 23b (e.g., Hall sensor) Second axial position sensor 23c (e.g., Hall sensor) Second circuit board 24 Holder 25 Coupling engagement sensor 26

[0078] [Implementation Method] (1) A drug delivery device, The pumping system includes a delivery unit (3) and a drive unit (4), the delivery unit including a drug container (5) and a pumping system (8) having a pump engine (38), the pump engine comprising a stator (29) and a pump rotor (31), the pump rotor being mounted within the stator, rotatable and axially movable within the stator, and configured to provide an axial piston stroke in accordance with the rotation of the pump rotor about its axis of rotation relative to the stator in order to pump liquid from the drug container, the drive unit including a housing (2), an electronic control system (6), and a motor (16) The system includes a motor (7), a motor output transmission shaft (17) driven sequentially by the motor (16), a rotor position sensing system (9), and a coupling (21) slidably connected to the motor output transmission shaft (17) and driven sequentially by the motor output transmission shaft, wherein the coupling (21) has a pump-side interface (39), which engages with a drive coupling interface (40) of the pump rotor (31) and is configured to transmit torque from the motor (16) to the pump rotor (31) and to cause axial displacement in accordance with the axial displacement of the pump rotor (31). A drug delivery device comprising an electronic control system (6) including a delivery control module configured to control the operation of the motor (16) of the pump drive (7), the delivery control module configured to operate the motor in a sequence of pulses and pauses, each pulse-and-pause sequence comprising one pulse followed by one pause, each pulse comprising a continuous rotation of the motor output transmission device over a plurality of shaft rotations, and an average flow rate, determined by dividing the total volume of liquid pumped for the plurality of pulses and pauses by the total duration of the plurality of pulses and pauses, is adjusted by varying the number of shaft rotations per pulse or the duration of the pauses between pulses. (2) The drive unit includes the rotor position sensing system (9) connected to the electronic control system (6), which is configured to supply at least one rotor position measurement to the delivery control module at least once per revolution, The drug delivery device according to Embodiment 1, wherein the output transmission shaft is configured to be stopped by the delivery control module at a predetermined park position at the end of each pulse operation. (3) The drug delivery device according to Embodiment 1 or 2, wherein the delivery control module is configured to operate pulses having at least three rotations per pulse, and the average flow rate is adjusted by the duration of the pauses alone or in combination with the duration of the pulses. (4) The drug delivery device according to any one of embodiments 1 to 3, wherein the electronic control system is configured to operate pulses and pauses by switching the motor on and off, and the voltage and current supplied to the motor is configured to operate the motor at a preset optimal power. (5) The drug delivery device according to any one of embodiments 1 to 4, wherein the electronic control system (6) includes a motor drive circuit (10) connected to the motor (16) of the pump drive, and at least one rotational position sensor of the rotor position sensing system (9) for controlling the motor and thereby controlling the pumping of drug from the drug container (5) by the pumping system (8), the motor drive circuit (10) includes a main controller (11) for controlling signals for the operation of the motor, and a monitoring controller (12) separate from the main controller (11) and also connected to the at least one rotational position sensor of the rotor position sensing system, the monitoring controller (12) is connected to an interlock circuit configured to transmit power from the power supply (28) to the motor (16), and the monitoring controller is configured to activate the interlock circuit and cut off power to the motor if the rotor position measurement signal received from the at least one rotational position sensor does not match a set value within a predetermined tolerance threshold.

[0079] (6) The drug delivery device according to Embodiment 5, wherein the main controller (11) includes or consists of an integrated circuit, the monitoring controller (12) includes or consists of an integrated circuit, and the monitoring controller and the main controller are supplied with power and sensing signals independently of each other. (7) The drug delivery device according to any one of embodiments 1 to 6, wherein the delivery control module is configured to issue an alarm state defining an occlusion event of the drug delivery device, which is triggered after the axial position of the pump rotor (31) is measured to be above an occlusion position threshold, or after the axial displacement amplitude of the rotor is measured to be below an occlusion displacement threshold, over at least two rotations of the pump rotor (31) within a window of at least 3 to 10 rotations. (8) The drug delivery device according to Embodiment 7, wherein the window is within the range of 5 to 8 rotations, and the alarm condition defining an occlusion event of the drug delivery device is triggered after the axial position of the rotor is measured to be above an occlusion threshold for at least 3 rotations of the pump rotor, or after the axial displacement amplitude of the rotor is measured to be below an occlusion displacement threshold. (9) The drug delivery device according to Embodiment 7 or 8, wherein the rotor axial position used to determine whether the occlusion position threshold has been exceeded, or the rotor axial displacement used to determine whether the occlusion displacement threshold has been exceeded, is measured within an occlusion window defined by the rotational position of the rotor between the end of discharge and the start of intake of a pump cycle defined by one rotation of the rotor, and the occlusion window is within the angular range in which both valves are closed. (10) The drug delivery device according to any one of embodiments 1 to 9, wherein the rotor position sensing system (9) includes at least one rotational position sensor (20, 22) for measuring the rotation of the motor output transmission shaft and an axial sensor (23) for measuring the axial displacement of the pump rotor, the axial sensor (23) includes a first axial position sensor (23b) statically mounted in the housing of the drive unit and a second axial position sensor (23c) statically mounted in the housing of the drive unit, the first axial position sensor and the second axial position sensor are located on opposite sides of the rotation axis and the first angular position and the second angular position are separated by 180°.

[0080] (11) The drug delivery device according to Embodiment 10, wherein the electronic control system (6) is configured to measure the axial position of the coupling side interface (18) by processing the sum or average value of the measurement outputs of the first axial position sensor (23b) and the second axial position sensor (23c). (12) The drug delivery device according to Embodiment 10 or 11, wherein the axial position sensor (23) includes an axial position magnet (23a) mounted on the coupling (21) having an annular portion of the coupling surrounding the axis of rotation of the coupling, and the first axial position sensor and the second axial position sensor include a first magnetic field sensor (23b) and a second magnetic field sensor (23c). (13) The drug delivery device according to any one of embodiments 10 to 12, wherein the rotational position sensor (20) includes an integrated incremental solver in the motor. (14) The drug delivery device according to any one of embodiments 1 to 13, wherein the rotor position sensing system (9) includes at least one rotation index sensor (22) configured to detect a specific reference rotation position of the motor output transmission shaft.

Claims

1. A drug delivery device, The pumping system includes a delivery unit (3) and a drive unit (4), the delivery unit including a drug container (5) and a pumping system (8) having a pump engine (38), the pump engine comprising a stator (29) and a pump rotor (31), the pump rotor being mounted within the stator, rotatable and axially movable within the stator, and configured to provide an axial piston stroke in accordance with the rotation of the pump rotor about its axis of rotation relative to the stator in order to pump liquid from the drug container, the drive unit including a housing (2), an electronic control system (6), and a motor (16) The system includes a motor (7), a motor output transmission shaft (17) sequentially driven by the motor (16), a rotor position sensing system (9), and a coupling (21) slidably connected to the motor output transmission shaft (17) and sequentially driven by the motor output transmission shaft, wherein the coupling (21) has a pump-side interface (39), the pump-side interface engages with a drive coupling interface (40) of the pump rotor (31), and is configured to transmit torque from the motor (16) to the pump rotor (31) and to cause axial displacement in accordance with the axial displacement of the pump rotor (31). A drug delivery device comprising an electronic control system (6) including a delivery control module configured to control the operation of the motor (16) of the pump drive (7), the delivery control module configured to operate the motor in a sequence of pulses and pauses, each pulse-and-pause sequence comprising one pulse followed by one pause, each pulse comprising a continuous rotation of the motor output transmission device over a plurality of shaft rotations, and an average flow rate, determined by dividing the total volume of liquid pumped for the plurality of pulses and pauses by the total duration of the plurality of pulses and pauses, is adjusted by changing the number of shaft rotations per pulse or the duration of the pauses between pulses.

2. The drive unit includes a rotor position sensing system (9) connected to the electronic control system (6), which is configured to supply at least one rotor position measurement to the delivery control module at least once per revolution. The drug delivery device according to claim 1, wherein the output transmission shaft is configured to be stopped by the delivery control module at a predetermined park position at the end of each pulse operation.

3. The drug delivery device according to claim 1, wherein the delivery control module is configured to operate pulses having at least three rotations per pulse, and the average flow rate is adjusted by the duration of the pauses alone or in combination with the duration of the pulses.

4. The drug delivery device according to claim 1, wherein the electronic control system is configured to operate pulses and pauses by switching the motor on and off, and the voltage and current supplied to the motor is configured to operate the motor at a preset optimal power.

5. The drug delivery device according to claim 1, wherein the electronic control system (6) includes a motor drive circuit (10) connected to the motor (16) of the pump drive, and at least one rotational position sensor of the rotor position sensing system (9) for controlling the motor and thereby controlling the pumping of drug from the drug container (5) by the pumping system (8), the motor drive circuit (10) includes a main controller (11) for controlling signals for the operation of the motor, and a monitoring controller (12) separate from the main controller (11) and also connected to the at least one rotational position sensor of the rotor position sensing system, the monitoring controller (12) is connected to an interlock circuit configured to transmit power from the power supply (28) to the motor (16), and the monitoring controller is configured to activate the interlock circuit and cut off power to the motor if the rotor position measurement signal received from the at least one rotational position sensor does not match a set value within a predetermined tolerance threshold.

6. The drug delivery device according to claim 5, wherein the main controller (11) includes or consists of an integrated circuit, the monitoring controller (12) includes or consists of an integrated circuit, and the monitoring controller and the main controller are supplied with power and sensing signals independently of each other.

7. The drug delivery device according to claim 1, wherein the delivery control module is configured to issue an alarm state defining an occlusion event of the drug delivery device, which is triggered after the axial position of the pump rotor (31) is measured to exceed an occlusion position threshold, or after the axial displacement amplitude of the rotor is measured to fall below an occlusion displacement threshold, over at least two rotations of the pump rotor (31) within a window of at least 3 to 10 rotations.

8. The drug delivery device according to claim 7, wherein the window is within the range of 5 to 8 rotations, and the alarm state defining an occlusion event of the drug delivery device is triggered after the axial position of the rotor is measured to exceed an occlusion position threshold for at least 3 rotations of the pump rotor, or after the axial displacement amplitude of the rotor is measured to be below an occlusion displacement threshold.

9. The drug delivery device according to claim 7, wherein the rotor axial position used to determine whether the occlusion position threshold has been exceeded, or the rotor axial displacement used to determine whether the occlusion displacement threshold has been exceeded, is measured within an occlusion window defined by the rotational position of the rotor between the end of discharge and the start of intake of a pump cycle defined by one revolution of the rotor, the occlusion window is within the angular range in which both valves are closed.

10. The drug delivery device according to claim 1, wherein the rotor position sensing system (9) includes at least one rotational position sensor (20, 22) for measuring the rotation of the motor output transmission shaft and an axial sensor (23) for measuring the axial displacement of the pump rotor, the axial sensor (23) includes a first axial position sensor (23b) statically mounted in the housing of the drive unit and a second axial position sensor (23c) statically mounted in the housing of the drive unit, the first axial position sensor and the second axial position sensor are located on opposite sides of the rotation axis and the first angular position and the second angular position are separated by 180°.

11. The drug delivery device according to claim 10, wherein the electronic control system (6) is configured to measure the axial position of the coupling side interface (18) by processing the sum or average value of the measurement outputs of the first axial position sensor (23b) and the second axial position sensor (23c).

12. The drug delivery device according to claim 10, wherein the axial position sensor (23) includes an axial position magnet (23a) mounted on the coupling (21) having an annular portion surrounding the rotation axis of the coupling, and the first axial position sensor and the second axial position sensor include a first magnetic field sensor (23b) and a second magnetic field sensor (23c).

13. The drug delivery device according to claim 10, wherein the rotational position sensor (20) includes an integrated incremental solver in the motor.

14. The drug delivery device according to claim 1, wherein the rotor position sensing system (9) includes at least one rotation index sensor (22) configured to detect a specific reference rotation position of the motor output transmission shaft.

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