Liquid medicine administration device

A liquid medicine administration device comprising:

• a liquid medicine container containing liquid medicine and including a distal end opening;
• a plunger movable relative to the liquid medicine container to discharge the liquid medicine through the distal end opening of the liquid medicine container;
• a supply path communicating the distal end opening of the liquid medicine container with a needle to administer the liquid medicine from the needle when the needle is pierced into a living body;
• a drive mechanism that advances the plunger toward the distal end opening of the liquid medicine container to discharge the liquid medicine from the liquid medicine container;
• a control unit configured to control operation of the drive mechanism;
• the drive mechanism including a DC motor that applies, to the plunger, a drive force for advancing the plunger toward the distal end opening of the liquid medicine container;
• and
• the control unit being configured to measure a value of a motor current flowing in the DC motor, and detect an abnormality in administration of the liquid medicine when the measured value of the motor current exceeds a predetermined upper limit current value.

A liquid medicine administration device comprising:

• a liquid medicine container containing liquid medicine and including a distal end opening;
• a plunger movable relative to the liquid medicine container to discharge the liquid medicine through the distal end opening of the liquid medicine container;
• a supply path communicating the distal end opening of the liquid medicine container with a needle in order to administer the liquid medicine from the needle when the needle is pierced into a living body;
• a drive mechanism that advances the plunger toward the distal end opening of the liquid medicine container to discharge the liquid medicine from the liquid medicine container, the drive mechanism including a DC motor that applies, to the plunger, a drive force for advancing the plunger toward the distal end opening of the liquid medicine container;
• a control unit configured to control operation of the drive mechanism;
• and
• a current limiting circuit that limits a current so that any current equal to or greater than a predetermined current does not flow in the DC motor.