Peritoneal dialysis system using incompressible fluid

A peritoneal dialysis system comprising:

• a cycler including:
• a pumping actuator configured to move a fluid,
• a motor-driven linkage, and
• a control unit;
• and
• a disposable set including
• a chamber including an opening,
• at least one plate located within the chamber and configured to facilitate uniform expansion and contraction of the chamber, and
• a disposable linkage in mechanical communication with the at least one plate,
• wherein the control unit is programmed to cause:
• (i) the motor-driven linkage to move the disposable linkage, thereby expanding the at least one plate to create negative pressure within the chamber to pull fresh or used dialysis fluid into the chamber through the opening, and
• (ii) the pumping actuator to move the fluid to close the chamber, thereby forcing the fresh or used dialysis fluid out of the chamber through the opening.