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EP-3749395-B1 - PRESSURE SENSOR ASSEMBLY FOR INJECTION DEVICES

EP3749395B1EP 3749395 B1EP3749395 B1EP 3749395B1EP-3749395-B1

Inventors

  • SCHAUDERNA, Florian

Dates

Publication Date
20260513
Application Date
20190201

Claims (8)

  1. A drug delivery device comprising: a housing (110); a drug container (114) configured to be contained in the housing (110) of the drug delivery device (100), the drug container (114) comprising a stopper (200) configured to contain a medicament (40) in the drug container (114); a drive mechanism (106) configured to exert a force onto the stopper (200) of the drug container (114) to drive the stopper (200) into the drug container (114) and expel a dose of the medicament (40) from the drug delivery device (100) during a drug delivery operation; a processor (343); a pressure sensor (341) arranged in the stopper (200) to measure a pressure in the medicament (40) due to a force applied by the drive mechanism (106) to the stopper (200) and output a measurement signal to the processor (343, 810); at least one non-transitory computer readable medium (344) storing instructions operable to cause the processor to perform operations comprising: activating the pressure sensor (341) during the drug delivery operation, receiving the measurement signal during the drug delivery operation, and determining if the dose of the medicament (40) was expelled from the drug delivery device (100) by comparing the received measurement signal to a reference measurement signal for the dose stored on the non-transitory computer readable medium (344) based on the received measurement signal; and an alert mechanism (541) configured to provide an audible or visible alert (542) to a user of the drug delivery device (122), wherein the operations include: the non-transitory computer readable medium generating a drug delivery indication based on the determining if the dose of the medication (40) was expelled from the drug delivery device (100), wherein the drug delivery indication is capable of indicating at least one of a successful completion of the drug delivery operation, a calculated amount of medicament that was delivered and one or more possible failure modes in case that the amount of medicament that was delivered is less than an expected amount due to the one or more possible failure modes and activating the alert mechanism (541) based on the drug delivery indication, wherein the alert mechanism (541) comprises at least one of: - a visual alert mechanism comprising a display or series of LED lights arranged to illuminate a different color to a user based on the sensed pressure or force signal and a determined indication of the quality of a drug delivery operation, and - an acoustic alert mechanism that is capable to produce different sounds or beeps to convey the same or different information as the visual alert mechanism.
  2. The drug delivery device of claim 1, wherein the drug delivery device (100) comprises a dose selection mechanism (112) configured to set the dose and output a dose signal to the processor (343) corresponding to the set dose, wherein the operations include receiving the dose signal and calculating the reference measuring signal for the dose.
  3. The drug delivery device of any of claims 1 or 2, wherein the instructions include comparing a force or pressure represented by the measurement signal to an expected maximum force or pressure, and wherein the determining if the dose of the medicament (40) was expelled from the drug delivery device (100) includes detecting a blocked fluid path condition based on the comparing, and wherein the drug delivery indication represents the blocked fluid path condition.
  4. The drug delivery device of any of claims 1 to 3, wherein the operations include: calculating a time delay between an initiation of the drug delivery operation and an increase in the pressure or force represented by the measurement signal, wherein determining if the dose of the medicament (40) was expelled from the drug delivery device (100) includes detecting a priming gap between the drug container (114) and the drive mechanism (106) based on the time delay, and wherein the drug delivery indication represents the priming gap.
  5. The drug delivery device of any of claims 1 to 4, wherein the operations include comparing the pressure or force represented by the measurement signal to an expected minimum pressure or force at the end of the drug delivery operation, wherein the determining if the dose of the medicament (40) was expelled from the drug delivery device (100) includes determining when an internal force in the drive mechanism (106) has normalized based on the comparing.
  6. The drug delivery device of any of claims 1 to 5, comprising a wireless module (345) configured to transmit a wireless signal (482) to an external device (480), and wherein the instructions include: generating a drug delivery indication based on the determining if the dose of the medicament (40) was expelled from the drug delivery device (100), and transmitting the drug delivery indication to the external device.
  7. The drug delivery device of any of claims 1 to 6, wherein the alert mechanism (541) is configured to alert the user of a successful drug delivery operation and/or of any issues detected during the drug delivery operation based on the sensed pressure.
  8. The drug delivery device of any of claims 1 to 7, further comprising: a position sensor (342) configured to detect the position of one or more of the stopper (200) and the drive mechanism (106) and output a position signal to the processor, wherein the instructions include receiving the position signal at least one of: before, during, and after the drug delivery operation, and wherein determining if the dose of the medicament (40) was expelled from the drug delivery device (100) is based on the received measurement signal and the received position signal.

Description

This description relates to an electronics assembly with pressure or force sensing capabilities for use in a drug delivery device. A variety of diseases exist that require treatment by injection of a medicament. Such injections can be performed using drug delivery devices, which can be applied either by medical personnel or by patients themselves. As an example, type-1 and type-2 diabetes can be treated by patients themselves by injection of drug doses, for example once or several times per day. For instance, a pre-filled disposable drug pen or autoinjector can be used as a drug delivery device. Alternatively, a re-usable pen or autoinjector may be used. A re-usable pen or autoinjector allows replacement of an empty medicament cartridge by a new one. Either type of pen or autoinjector may come with a set of one-way needles that are replaced before each use. WO 2017/189153 describes a plunger head for a fluid injection device that includes a transducer disposed in the plunger head to measure a compressive force applied to the plunger head. The plunger head also includes a power source and a microcontroller disposed in the plunger head. The microcontroller is configured to enter a high-power mode in response to sensing application of the compressive force to the plunger head. US 2017/312455 describes a medication injection device that includes a barrel, plunger, and a dosage tracking system. The dosage tracking system is configured to output data indicative of a fluid dispensed. The medication injection device also includes a controller that can determine, based on data received from the dosage tracking system, whether an air shot event occurred while dispensing the fluid. WO 2013/054165 describes a pressure regulating syringe that includes a barrel assembly terminating with a tubular tip that is in fluid communication with a fluid chamber, a plunger that is manually and axially displaceable within a barrel of the barrel assembly and a pressure sensor mounted onto the plunger, adjacent to its distal end, for generating one or more electrical signals representative of a change in pressure within the fluid chamber. US 2015/289896 describes a fluid ejection device that includes a fluid accommodation portion that has a fluid outlet connected to a fluid connection tube having a channel. A fluid pressing unit causes the fluid to flow out of the fluid outlet. A fluid ejection unit ejects, in a pulsed manner, fluid received from the fluid connection tube. A pressure detection unit detects pressure when the fluid pressing unit operates. A control unit causes the fluid pressing unit to operate in a state in which the channel is closed, and determines that the pressure detection unit has failed if the detected pressure when the fluid pressing unit comes into contact with the fluid accommodation portion is lower than a first determination value, or if the detected pressure when the fluid pressing unit does not come into contact with the fluid accommodation portion is equal to or higher than a second determination value. This disclosure relates to drug delivery devices having electronics capable of sensing pressure or force in the drug delivery device, specifically, in some instances, during a drug delivery operation in order to determine a quality of the drug delivery operation. In some instances, a force sensor is disposed in or around a cartridge being acting upon by a plunger rod of the drug delivery device, or in the plunger rod itself, in order to sense the force applied to a medicament in the cartridge. In other, the electronics and/or pressure sensor are housed directly within the bung or stopper of the cartridge. In a representative overview, an electronics assembly is inserted into the stopper of the cartridge. A pressure sensor in the electronics assembly detects pressure or force put on the stopper of the cartridge by the plunger rod as a head of the plunger rod contacted the stopper and drives the stopper into the cartridge to force a medicament from the cartridge. In some instances, the position of the plunger rod or stopper is also detected. The shape of the pressure curve (e.g., pressure vs. time) in the cartridge or plunger rod varies as the drug delivery operation occurs and the pressure sensor of the electronics assembly senses this change and can, in some instances, use the sensed to calculate an indication of the quality of the drug delivery operation. The indication may represent a successful completion of the drug delivery operation, or indicate a calculated amount of medicament that was delivered, which may be less than the expected amount due to one or more possible failure modes, which can also be indicated. For example, a drug delivery pathway (e.g., a needle) may be blocked or constricted, which raises the pressure in the cartridge during delivery. In another example, the initial construction or priming of the drug delivery device may leave a head of the plunger rod spaced a small distance away