Peritoneal dialysis systems and methods employing a liquid distribution and pump cassette with self-contained air isolation and removal

A method for performing peritoneal dialysis comprising steps of

• establishing flow communication among a patient's peritoneal cavity, a source of fresh dialysis solution, and a drain through a pump chamber having spaced ends, the pump chamber being oriented for use in a generally vertical plane so that one end which comprises a non-critical gas-liquid extracorporeal circuit end is spaced generally above the other end which comprises a critical liquid patient circuit end to form within the pump chamber an upper non-critical gas-liquid extracorporeal circuit region and a lower critical liquid patient circuit region and a diaphragm on the pump chamber,
• operating the pump chamber, with the upper non-critical gas-liquid extracorporeal region and the lower critical liquid patient circuit region oriented generally vertically, by applying fluid pressure to the diaphragm, the pump chamber being operable in an infusion direction through the pump chamber to deliver fresh dialysis solution to the patient's peritoneal cavity and also being operable in a direction reverse to the infusion direction,
• directing spent dialysis solution from the patient's peritoneal cavity into the lower critical liquid patient circuit region of the pump chamber,
• directing the spent dialysis solution in the direction reverse to the infusion direction through the pump chamber and from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber to a drain so that outgoing flow of spent dialysis solution carries gas from the pump chamber to the drain,
• directing fresh dialysis solution from the source into the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber and
• pumping the fresh dialysis solution from the pump chamber to the patient's peritoneal cavity only from the lower critical liquid patient circuit region of the pump chamber in the infusion direction through the pump chamber to deliver fresh dialysis solution to the patient's peritoneal cavity so that the fresh dialysis solution directed to the patient's peritoneal cavity is isolated from gas in the pump chamber.

A method for performing peritoneal dialysis comprising steps of

• establishing flow communication among a patient's peritoneal cavity, a source of fresh dialysis solution, a reservoir for heating the fresh dialysis solution, and a drain through a pump chamber having spaced ends, the pump chamber being oriented for use in a generally vertical plane so that one end which comprises a non-critical gas-liquid extracorporeal circuit end is spaced generally above the other end which comprises a critical liquid patient circuit end to form within the pump chamber an upper non-critical gas-liquid extracorporeal circuit region and a lower critical liquid patient circuit region and a diaphragm on the pump chamber,
• operating the pump chamber, with the upper noncritical gas-liquid extracorporeal circuit region and the lower critical liquid patient circuit region oriented generally vertically, by applying fluid pressure to the diaphragm, the pump chamber being operable in an infusion direction through the pump chamber to deliver fresh dialysis solution to the patient's peritoneal cavity and also being operable in a direction reverse to the infusion direction,
• directing spent dialysis solution from the patient's peritoneal cavity into the lower critical liquid patient circuit region of the pump chamber,
• directing the spent dialysis solution in the direction reverse to the infusion direction through the pump chamber and from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber to a drain, so that the outgoing flow of spent dialysis solution carries air from the pump chamber to the drain,
• directing fresh dialysis solution from the source into the upper non-critical gas-liquid extracorporeal region of the pump chamber,
• directing the fresh dialysis solution from the upper non-critical gas-liquid extracorporeal region of the pump chamber to the reservoir for heating in the reservoir, the fresh dialysis solution being directed to the reservoir from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber to carry air from the pump chamber to the reservoir,
• directing the heated fresh dialysis solution from the reservoir into the upper non-critical gas-liquid extracorporeal region of the pump chamber, and
• pumping the heated fresh dialysis solution only from the lower critical liquid patient circuit region of the pump chamber in the infusion direction through the pump chamber to deliver heated fresh dialysis solution to the patient's peritoneal cavity so that the heated fresh dialysis solution directed to the patient's peritoneal cavity is isolated from gas in the pump chamber.

A system for performing peritoneal dialysis comprising

• a pump including a pump chamber having generally spaced ends including an upper non-critical gas-liquid extracorporeal circuit end and a lower critical liquid patient circuit end and a diaphragm on the pump chamber, the pump operating the chamber in an infusion direction through the pump chamber to deliver liquid dialysate to the patient's peritoneal cavity and in a direction reverse to the infusion direction through the pump chamber,
• a conduit for establishing flow communication with a patient's peritoneal cavity through the pump chamber,
• an actuator for holding the pump chamber generally vertically so that the upper non-critical gas-liquid extracorporeal circuit end is spaced generally above the lower critical liquid patient circuit end to form within the pump chamber an upper non-critical gas-liquid extracorporeal circuit region and a lower critical liquid patient region while applying fluid pressure to the diaphragm to move liquid through the pump chamber, and
• paths for directing liquid flow through the pump chamber including
• a path for directing liquid dialysate in the direction reverse to the infusion direction through the pump chamber and removing gas from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber, and
• a path for directing liquid dialysate in the infusion direction through the pump chamber to deliver the dialysate to the patient's peritoneal cavity only from the lower critical liquid patient circuit region of the pump chamber.

A system for performing peritoneal dialysis comprising

• a pump including a pump chamber having generally spaced ends including an upper non-critical gas-liquid extracorporeal circuit end and a lower critical liquid patient circuit end and a diaphragm on the pump chamber, the pump operating the chamber in an infusion direction throuqh the pump chamber to deliver liquid dialysate to the patient's peritoneal cavity and in a direction reverse to the infusion direction through the pump chamber,
• conduits for establishing flow communication among a patient's peritoneal cavity, a source of fresh dialysis solution, and a drain through the pump chamber,
• an actuator holding the pump chamber generally vertically so that the upper non-critical gas-liquid extracorporeal end is spaced generally above the lower critical liquid circuit end to form within the pump chamber an upper non-critical gas-liquid extracorporeal region and a lower critical liquid patient circuit region while applying fluid pressure to the diaphragm to move liquid through the pump chamber, and,
• paths to direct flow through the pump chamber including
• a path to direct spent dialysis solution from the patient's peritoneal cavity into the lower critical liquid patient circuit region. of the pump chamber,
• a path to direct the spent dialysis solution from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber in the direction reverse to the infusion direction through the pump chamber to the drain, and
• a path to direct the fresh dialysis solution only from the lower critical patient circuit region of the pump chamber in the infusion direction through the pump chamber to deliver the fresh dialysis solution to the patient's peritoneal cavity.

A system for performing peritoneal dialysis comprising

• a pump including.a pump chamber having generally spaced ends including an upper non-critical gas-liquid extracorporeal circuit end and a lower critical liquid patient circuit end and a diaphragm on the pump chamber,
• conduit means for establishing flow communication among a patient's peritoneal cavity, a source of fresh dialysis solution, a reservoir for heating the fresh dialysis solution, and a drain through the pump chamber,
• an actuator holding the pump chamber generally vertically so that the upper non-critical gas-liquid extracorporeal circuit end is spaced generally above the lower critical liquid patient circuit end to form within the pump chamber an upper non-critical gas-liquid extracorporeal circuit region and a lower critical liquid patient circuit region while applying fluid pressure to the diaphragm to move liquid through the pump chamber, and
• paths to direct liquid flow through the pump chamber including
• a path to direct spent dialysis solution from the patient's peritoneal cavity into the lower critical liquid patient circuit region of the pump chamber,
• a path to direct. the spent dialysis solution from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber to the drain,
• a path to direct fresh dialysis solution from the source into the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber,
• a path to direct the fresh dialysis solution from the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber to the reservoir for heating,
• a path to direct the heated fresh dialysis solution from the reservoir into the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber, and
• a path to direct the heated fresh dialysis solution only from the lower critical liquid patient circuit region of the pump chamber to the patient's peritoneal cavity.

A peritoneal dialysis system comprising

• a liquid distribution set including a patient conduit in communication with a patient's peritoneal cavity for conveying liquid to and from the patient's peritoneal cavity and a second conduit,
• a liquid distribution cassette comprising,
• a cassette body,
• a pump chamber in the cassette body having spaced ends including an upper non-critical gas-liquid extracorporeal circuit end and a lower critical liquid patient circuit end, the pump chamber being oriented in use in a generally vertical plane so that the upper non-critical gas-liquid extracorporeal circuit end is spaced generally above the lower critical liquid patient circuit end to form within the pump chamber an upper non-critical gas-liquid extracorporeal circuit region and a lower critical liquid patient circuit region,
• a diaphragm on the pump chamber and responsive to fluid pressure for moving liquid through the pump chamber in an infusion direction and a reverse direction,
• a first liquid. distribution pathway in the cassette body connecting the patient conduit in flow communication with the lower critical liquid patient circuit region, and
• a second liquid distribution pathway in the cassette body connecting the second conduit in flow communication only with the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber to remove air from the upper non-critical gas-liquid extracorporeal circuit reregion of the pump chamber with liquid flow in the reverse direction, and
• an actuating station for the cassette including
• a support receiving the cassette body only when the upper non-critical gas-liquid extracorporeal circuit region is generally vertically oriented above the lower critical liquid patient circuit region so that the upper non-critical gas-liquid extracorporeal circuit region of the pump chamber is in a higher gravity position than the lower critical liquid patient circuit region, and
• a fluid pressure conveying element conveying fluid pressure to the diaphragm only when the cassette body is received by the support.