An insulin infusion system is provided with a manual insertion device having a dual retraction spring (230) configuration for automatic introducer needle (222) retraction. A button (200) of the insertion device is used to insert the introducer needle (222) and catheter (202), and once the introducer needle (222) and catheter (202) have been fully inserted, a rotating engagement releases the dual retraction springs (230) such that the introducer needle (222) automatically retracts, leaving the catheter (202) in the body of the user. An end of the introducer needle (222) remains in the inserted catheter (202) and/or in the septum (206) of the inserted catheter (202) to provide an uninterrupted fluid path.