Infusion medium delivery system, device and method with needle inserter and needle inserter device and method

A needle injector system comprising a plunger device and a needle injector device for connection in fluid-flow communication with a reservoir, the needle injector device comprising:

• a moveable needle supported for movement between a retracted position and an extended position;
• a carriage supported for movement with the moveable needle, between the retracted position and the extended position;
• a hollow needle or cannula attached to the carriage and moveable with the carriage between the retracted position and the extended position, the hollow needle or cannula having a hollow interior defining a fluid flow channel through at least a portion of the hollow interior;
• a locking structure for locking the carriage and the hollow needle or cannula in the extended position, upon the carriage and the hollow needle or cannula being moved to the extended position;
• a first fluid flow passage arranged to be out of fluid flow communication with the fluid flow channel of the hollow needle or cannula when the carriage and the hollow needle or cannula are in the retracted position and to operatively couple the fluid flow channel of the hollow needle or cannula in fluid flow communication with the reservoir, upon the carriage and the hollow needle or cannula being moved to the extended position;
• and
• a bias member operatively coupled to the moveable needle, for imparting a force to move the moveable needle toward the retracted position to a location at which the moveable needle is outside of the fluid flow channel of the hollow needle or cannula and outside of the first fluid flow passage, once the carriage and the hollow needle or cannula are locked in the extended position by the locking structure;
• and
• the plunger device configured for selective engagement and disengagement with the needle injector device, the plunger device having a moveable plunger arranged to impart a force to move the moveable needle from the retracted position to the extended position when the plunger device is in engagement with the needle injector device, and to release the moveable needle and allow the moveable needle to move toward the retracted position under the force imparted by the bias member when the plunger device is in disengagement with the needle injector device.