Reciprocating diaphragm pumps for blood treatment systems and methods

A reciprocating diaphragm pump comprising:

• a flexible diaphragm;
• a first rigid body having a curved pumping chamber wall;
• a second rigid body having an opposing curved control chamber wall;
• wherein the flexible diaphragm is interposed between the pumping chamber wall and the control chamber wall to define a pumping chamber and a control chamber;
• wherein the control chamber is an air actuation chamber including an entrance hole for air actuating the pump, and the pumping chamber for pumping liquid comprises a fluid inlet side having an inlet, and a fluid outlet side having an outlet;
• and
• wherein the flexible diaphragm comprises:
• a peripheral bead arranged to locate the flexible diaphragm between the first rigid body and the second rigid body when the reciprocating diaphragm pump is assembled in an operable configuration;
• a diaphragm body having a relaxed or unstressed shape that is curved, semi-spheroid or a domed shape with a control side of the diaphragm body facing and generally conforming to an inner surface of the curved control chamber wall, and with a pumping side of the diaphragm body facing the pumping chamber wall when the reciprocating diaphragm pump is assembled in an operable configuration;
• and
• a transition region between the peripheral bead and the diaphragm body, the transition region pinched or clamped between a clamping region of the first rigid body and an opposing clamping region of the second rigid body when the reciprocating diaphragm pump is assembled in an operable configuration;
• wherein the transition region of the flexible diaphragm has a relaxed, unstressed shape causing the diaphragm body to naturally curve away from the pumping chamber wall as the transition region emerges from contacting the clamping region of the first rigid body and the opposing clamping region of the second rigid body when the reciprocating diaphragm pump is assembled in an operable configuration, resulting in an elastic force generated by the flexible diaphragm during operation of the reciprocating diaphragm pump resisting deployment of the diaphragm body into the pumping chamber and preventing a peripheral portion of the diaphragm body from contacting the pumping chamber wall.