Medical pump with flow control

A medical pump for delivering fluid to a patient, comprising:

• a pump cavity which is surrounded by a rigid wall and which includes a diaphragm opening;
• a diaphragm disposed over and sealed to the diaphragm opening of the pump cavity;
• a pump chamber defined by an inside surface of the rigid wall of the pump cavity and an inside surface of the diaphragm which disposed over and sealed to the pump cavity;
• a pressure actuator including a piston with a distal end that is operatively coupled to the diaphragm;
• an inlet conduit which is in fluid communication with the pump chamber;
• a check valve which is operatively coupled to the inlet conduit and which is oriented to allow a flow of liquid to the pump chamber but prevent a flow of liquid from the pump chamber back towards the check valve;
• an outlet conduit which is in fluid communication with the pump chamber;
• an outlet port which is in fluid communication with the outlet conduit;
• and
• a flow control valve which is operatively coupled to the outlet conduit between the pump chamber and the outlet port, the flow control valve comprising:
• a rigid base having a surface and an orifice disposed adjacent the surface, and
• a distensible membrane secured to the surface of the rigid base in a normally closed relation relative to the orifice so as to be in approximation with the surface of the rigid base forming a sealed distensible channel between the orifice and an inside surface of the distensible membrane, the distensible membrane being normally closed.