Systems with disposable pumping unit

A peritoneal dialysis system comprising:

• a peritoneal dialysis hardware unit including
• a housing defining a first opening, and
• a door hinged to the housing, the door defining a second opening;
• a disposable pumping unit including
• a first surface, and
• a second surface mated to the first surface in a circular seal that forms a fluid pump receptacle;
• and
• wherein the peritoneal dialysis hardware unit and the disposable pumping unit are structured and arranged so that when the door is closed against the housing (i) the first opening in the housing of the peritoneal dialysis hardware unit is aligned with the first surface of the disposable pumping unit near the circular seal, and (ii) the second opening in the door of the peritoneal dialysis hardware unit is aligned with the second surface of the disposable pumping unit near the circular seal.

A peritoneal dialysis system comprising:

• a peritoneal dialysis hardware unit including
• a housing defining a first opening,
• a door coupled to the housing, the door defining a second opening,
• a solid pump piston having a solid piston shaft attached to or integrally formed with a solid piston head, and
• a stepper motor operable to cause the solid pump piston to translate;
• a disposable pumping unit including
• a first surface,
• a second surface opposite the first surface, and
• a fluid pump receptacle extending from the first surface and the second surface so as to fit within the second opening defined in the door of the peritoneal dialysis hardware unit;
• and
• wherein the peritoneal dialysis hardware unit and the disposable pumping unit are structured and arranged to allow the disposable pumping unit to be placed into the peritoneal dialysis hardware unit such that the fluid pump receptacle is aligned with the first opening, the second opening, and the solid piston head when the door is closed against the housing.