Automated peritoneal dialysis using a fluid pump

A fluid system comprising:

• a fluid pump including a fluid contacting portion and an actuating portion for actuating the fluid contacting portion;
• a pressure sensor including a diaphragm separating a first side of the pressure sensor in fluid communication with the fluid contacting portion of the fluid pump from a second side of the pressure sensor in operable communication with a pressure transducer;
• and
• a control unit configured to:
• (i) cause the diaphragm to be moved to a starting position,
• (ii) actuate the actuating portion of the fluid pump to cause the fluid contacting portion to pump over a full range of positive and negative pressures as read by the pressure transducer and to determine if the diaphragm flexes over the full range,
• (iii) when the diaphragm flexes over the full range, use the starting position of the diaphragm for an upcoming operation, and
• (iv) when the diaphragm does not flex over the full range, repeat (i) to (iv) moving the diaphragm to a different starting position.