Rotational metering pump for medication patch

A rotational metering pump comprising:

• a manifold comprising a reservoir port in fluid communication with a fluid reservoir and a cannula port in fluid communication with a cannula;
• a sleeve comprising a side hole, the sleeve adapted to rotate axially within the manifold between a first orientation with said side hole aligned with the reservoir port and a second orientation with said side hole aligned with the cannula port, the sleeve further comprising a helical groove having a first end and a second end;
• a plunger adapted to rotate and translate axially within the sleeve, wherein axial translation of the plunger within the sleeve changes a pump volume, the pump volume being in fluid communication with the side hole of the sleeve, the plunger further comprising a coupling member adapted to move within the helical groove and between the first end and the second end of the helical groove to cause the plunger to translate axially within the sleeve as the plunger is rotated;
• a motor adapted to rotate the plunger in a first direction causing the pump volume to increase when the sleeve is in the first orientation, and to rotate the sleeve and plunger together when the coupling member reaches the first end of the helical groove, such that the sleeve moves into the second orientation;
• the motor adapted to rotate the plunger in a second direction causing the pump volume to decrease when the sleeve is in the second orientation, and to rotate the sleeve and plunger together when the coupling member reaches the second end of the helical groove, such that the sleeve moves into the first orientation;
• and
• an anti-premature rotation feature disposed on the manifold and that cooperates with the sleeve prevent rotation of the sleeve when a torque applied to the sleeve is below a predetermined threshold, and wherein the anti-premature rotation feature permits the sleeve to rotate when the torque exceeds the predetermined threshold.