Medical Injection Device with Electric Motor Drive Control

• US 20120116311A1
• Filed: 12/23/2009
• Published: 05/10/2012
• Est. Priority Date: 12/29/2008
• Status: Active Grant

• Current Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Original Assignee: Sanofi-Aventis Deutschland GmbH (Sanofi )
• Inventors: Brüggemann, Ulrich, Preece, Scott, Langley, Chrisopher
• Granted Patent: US 9,297,370 B2
• Time in Patent Office: Days
• US Class Current: 604/154
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: A61M 2205/3365 Rotational speed
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/8212 with means or measures taken for minimising energy consumption
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04

Abstract

This invention relates to an injection device for delivering a medicament to the human or animal body, in particular, but not exclusively, to a device having a replaceable medicament cartridge, including an auto-injector,

• wherein the injector device comprises: a housing; a piston rod for driving a bung of a medicament container; a drive mechanism including a motor for providing an output drive to the piston rod for delivering the medicament; and control means for controlling operation of the device.

Claims

1. An injection device for delivering a medicament to a patient, wherein the injector device comprises:

a housing;

a piston rod for driving a bung of a medicament container;

a drive mechanism including a motor for providing an output drive to the piston rod for delivering the medicament; and

a controller that controlls operation of the device;

wherein;

the controller comprises;

a drive signal generator that generates an input drive signal for the motor;

an encoder that generates an encoder output signal indicative of the output drive of the motor;

wherein the controller varies the operational control of the device in dependence on a comparison between the input drive signal and the encoder output.

2. An injection device according to claim 1, wherein the input drive signal comprises stepper pulses for driving the motor.

3. An injection device according to claim 1, wherein the encoder output signal is a pulsed signal having a timing characteristic that corresponds to the output drive of the motor.

4. An injection device according to claim 1, wherein a plurality of reference points are included in the device, each reference point being indicative of a different operational aspect of the device.

5. An injection device according to claim 4, wherein the reference points include any one or more of:

backstop position;

dose delivered;

door position;

drive position; and

reset threshold.

6. An injection device according to claim 2, wherein the reference points relate to the input drive signal such that respective reference points correspond to respective counts of the stepper pulses with reference to a device datum.

7. An injection device according to claim 3, wherein a comparison between counts of the pulsed encoder output with counts of the stepper pulses is indicative of motor stall or motor slip.

8. An injection device according to claim 7, wherein in the event that motor slip or stall is detected the controller is operative for determining the quantum of slip relative to one of the reference points whereupon said controller adjusts the operational control of the device according to a predetermined criteria.

9. An injection device according to claim 7, wherein the motor is deliberately stalled against a predetermined reference point when the quantum of slip exceeds a predetermined threshold value.

10. An auto-injection device according to claim 1.