# US 12,005,241 B2 · Auto injector with detection of used cartridge and associated method

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,005,241 B2
- Document ID: US12005241B2
- Status: Granted
- Kind: B2
- Application number: 17/529,150
- Filed: 2021-11-17
- Published: 2022-05-19
- Granted: 2024-06-11
- Earliest claimed: 2015-12-30
- Assignees: Ascendis Pharma A/S
- Applicants: Ascendis Pharma A/S
- Inventors: Per Mølgaard Pedersen; Michael Lind; Steen Jensen; Henrik Egesborg
- Web page: https://patentgrep.com/patent/US12005241B2

## CPC

- A61M 5/3158: {the component being manually operated or triggered by an axially moving actuator operated by user, e.g. an axially movable injection button}
- A61M 5/20: Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically (A61M5/142 takes precedence)
- A61M 5/2422: {using emptying means to expel or eject media, e.g. pistons, deformation of the ampoule, or telescoping of the ampoule}
- A61M 5/31511: {Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence)}
- A61M 2005/2086: {having piston damping means, e.g. axially or rotationally acting retarders}
- A61M 2005/2418: {comprising means for damping shocks on ampoule}
- A61M 2005/31588: {electrically driven}
- A61M 2205/276: preventing unwanted use
- A61M 2205/3317: Electromagnetic, inductive or dielectric measuring means
- A61M 2205/332: Force measuring means
- A61M 2205/3327: Measuring
- A61M 2205/3331: Pressure; Flow
- A61M 2205/3365: Rotational speed
- A61M 2205/3368: Temperature
- A61M 2205/50: with microprocessors or computers
- A61M 2205/502: User interfaces, e.g. screens or keyboards
- A61M 2205/60: with identification means
- A61M 2205/6063: Optical identification systems
- A61M 2205/82: Internal energy supply devices
- A61M 2205/8206: battery-operated
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

Disclosed is an auto-injector for administering a medicament, comprising: 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 being configured to: control the drive module to move the plunger rod towards the extended plunger rod position; determine 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.

## Claims

### Claim 1

An auto-injector for administering a medicament, comprising:
a housing;
a cartridge receiver configured to receive a cartridge comprising a first stopper;
a drive module coupled to move a plunger rod between a retracted plunger rod position and an extended plunger rod position, the plunger rod being 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;
wherein the processing unit is configured to:
control the drive module to move the plunger rod towards the extended plunger rod position;
determine 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, and
wherein the processing unit is configured to control the drive module to adjust movement of the plunger rod if the cartridge parameter is indicative of the present plunger rod position having reached a plunger rod threshold and the resistance signal being indicative of resistance against movement of the plunger rod below a low resistance threshold.

### Claim 2 (depends on 1)

The auto injector according to claim 1, wherein the processing unit is further configured to control the drive module to adjust movement of the plunger rod if the cartridge parameter is indicative of the resistance signal being indicative of resistance against movement of the plunger rod above a high resistance threshold.

### Claim 3 (depends on 2)

The auto injector according to claim 2, comprising a code sensor configured to read a cartridge code feature, the processing unit being coupled to the code sensor, the processing unit being configured to receive from the code sensor a code signal indicative of the cartridge code feature and determine the high resistance threshold based on the code signal.

### Claim 4 (depends on 1)

The auto injector according to claim 1, wherein adjusting the movement of the plunger rod comprises stopping the movement of the plunger rod.

### Claim 5 (depends on 1)

The auto injector according to claim 1, wherein adjusting the movement of the plunger rod comprises moving the plunger rod to the retracted plunger rod position.

### Claim 6 (depends on 1)

The auto injector according to claim 1, comprising a code sensor configured to read a cartridge code feature, the processing unit being coupled to the code sensor, the processing unit being configured to receive from the code sensor a code signal indicative of the cartridge code feature and determine the plunger rod threshold or the low resistance threshold based on the code signal.

### Claim 7 (depends on 1)

The auto injector according to claim 1, wherein the resistance sensor is configured to determine electrical power consumed by the drive module.

### Claim 8 (depends on 1)

The auto injector according to claim 1, wherein the resistance sensor is configured to measure pressure or force applied to a plunger rod front end of the plunger rod.

### Claim 9 (depends on 1)

The auto injector according to claim 1, comprising a tachometer configured to provide a tachometer signal indicative of a count of revolutions of the drive module, the processing unit being coupled to the tachometer, and the processing unit being configured to receive the tachometer signal and determine the present plunger rod position based on the tachometer signal.

### Claim 10 (depends on 1)

The auto injector according to claim 1, comprising a user interface coupled to the processing unit, the processing unit being configured to output a user output signal via the user interface based on the cartridge parameter.

### Claim 11 (depends on 1)

A system comprising an auto injector according to claim 1, and a cartridge comprising a first stopper, wherein the cartridge is configured to be received in the cartridge receiver.

### Claim 12

A method for controlling an auto injector, the method comprising:
receiving a cartridge comprising a first stopper;
moving a plunger rod towards an extended plunger rod position;
determining present plunger rod position;
receiving a resistance signal indicative of resistance against movement of the plunger rod;
determining a cartridge parameter based on the resistance signal and the present plunger rod position; and
adjusting the movement of the plunger rod based on the cartridge parameter if the cartridge parameter is indicative of the present plunger rod position having reached a plunger rod threshold and the resistance signal being indicative of resistance against movement of the plunger rod below a low resistance threshold.

### Claim 13 (depends on 12)

The method according to claim 12, further comprising adjusting the movement of the plunger rod based on the cartridge parameter if the cartridge parameter is indicative of the resistance signal being indicative of resistance against movement of the plunger rod above a high resistance threshold.

### Claim 14 (depends on 12)

The method according to claim 12, wherein adjusting the movement of the plunger rod comprises stopping the movement of the plunger rod.

### Claim 15 (depends on 12)

The method according to claim 12, wherein adjusting the movement of the plunger rod comprises moving the plunger rod to a retracted plunger rod position.

### Claim 16 (depends on 12)

The method according to claim 12, comprising receiving a code signal indicative of a cartridge code feature and determining the plunger rod threshold or the low resistance threshold or the high resistance threshold based on the code signal.