Abstract: The present invention relates to a method for ensuring a constant target speed of a battery driven electrical motor, the battery driven electrical motor being adapted to move a piston rod in an injection device so as to inject a set dose of medicine from the injection device, the method comprising the steps of setting a first target speed to be reached by the motor, determining whether the first target speed can be reached, and, if the first target speed can be reached, maintaining the first target speed until a set dose of medicine has been injected from the injection device, or if the first target speed cannot been reached, setting a second target speed.

Abstract: The present invention relates to a method for ensuring a constant target speed of a battery driven electrical motor, the battery driven electrical motor being adapted to move a piston rod in an injection device so as to inject a set dose of medicine from the injection device, the method comprising the steps of setting a first target speed to be reached by the motor, determining whether the first target speed can be reached, and, if the first target speed can be reached, maintaining the first target speed until a set dose of medicine has been injected from the injection device, or if the first target speed cannot been reached, setting a second target speed.

Abstract: The present invention relates to a method for ensuring a constant target speed of a battery driven electrical motor, the battery driven electrical motor being adapted to move a piston rod in an injection device so as to inject a set dose of medicine from the injection device, the method comprising the steps of setting a first target speed to be reached by the motor, determining whether the first target speed can be reached, and, if the first target speed can be reached, maintaining the first target speed until a set dose of medicine has been injected from the injection device, or if the first target speed cannot been reached, setting a second target speed.

Abstract: The present invention relates to a method for moving a piston rod in an injection device, the piston rod being operatively connected to a motor shaft of an electrical motor so that a rotational movement of the motor shaft is transformed to a translational movement of the piston rod, the piston rod being adapted to be moved between two end positions, the method comprising the steps of providing a first supply voltage level to the electrical motor, measuring sets of corresponding values of current provided to the motor and a corresponding position of the piston rod, and providing a second supply voltage level to the electrical motor when the measured position of the piston rod equals predetermined positions, the second supply voltage level having a RMS value being smaller than the RMS value of the first supply voltage level. The present invention further relates to an apparatus for carrying out the method.

Abstract: The present invention relates to a method for ensuring a constant target speed of a battery driven electrical motor, the battery driven electrical motor being adapted to move a piston rod in an injection device so as to inject a set dose of medicine from the injection device, the method comprising the steps of setting a first target speed to be reached by the motor, determining whether the first target speed can be reached, and, if the first target speed can be reached, maintaining the first target speed until a set dose of medicine has been injected from the injection device, or if the first target speed cannot been reached, setting a second target speed.

Abstract: The present invention relates to a method for testing an electronic circuit comprising a plurality of switching elements arranged in a H-bridge configuration, the electronic circuit being adapted to drive an associated DC-motor operatively connected to the H-bridge, the DC-motor being adapted to move an associated piston rod in an injection device, the method comprising the steps of providing a test signal to the electronic circuit, and measuring a value of a return signal in response to the provided test signal and determining whether the value of the return signal is in agreement with an expected value, the providing of the test signal and the measuring of the return signal being performed while one or more switching elements is/are switched off.