Drug solution administration device

A drug solution administration device comprising:

• a pusher configured to push a drug solution in a drug solution container filled with the drug solution;
• a drive mechanism configured to move the pusher forward and backward with respect to a distal end opening of the drug solution container;
• a microcomputer configured to control operation of the drive mechanism,
• wherein the drive mechanism includes a motor configured to generate a driving force for moving the pusher forward and backward, and an encoder configured to detect rotation of the motor,
• the microcomputer has an operation confirmation function of confirming an operating condition of the motor based on a detection result of the encoder, and
• the microcomputer is configured to start a reverse rotation of the motor to determine whether or not the pusher moves backward after confirming that the motor is stopped by the operation confirmation function;
• a gasket configured to be slidable on an inner wall of the drug solution container and separable from the pusher, wherein a distal end of the pusher is configured to push the gasket to push the drug solution from within the drug solution container toward the distal end opening of the drug solution container;
• and
• wherein the microcomputer is configured to determine whether or not the pusher is in contact with the gasket by rotating the motor forward after causing the pusher to move backward by reverse rotation of the motor.