Abstract: This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes using a medical fluid pump of a medical fluid pumping machine, such as a hemodialysis machine, to deliver medical fluid to a first portion of a cartridge that is positioned within a magnetic field, exciting atoms in the medical fluid in the first portion of the cartridge by applying radio frequency energy to the medical fluid in the first portion of the cartridge, receiving radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge, and determining a concentration of a substance in the medical fluid based on the received radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge.

Abstract: This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes using a medical fluid pump of a medical fluid pumping machine, such as a hemodialysis machine, to deliver medical fluid to a first portion of a cartridge that is positioned within a magnetic field, exciting atoms in the medical fluid in the first portion of the cartridge by applying radio frequency energy to the medical fluid in the first portion of the cartridge, receiving radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge, and determining a concentration of a substance in the medical fluid based on the received radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge.

Abstract: This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes using a medical fluid pump of a medical fluid pumping machine, such as a hemodialysis machine, to deliver medical fluid to a first portion of a cartridge that is positioned within a magnetic field, exciting atoms in the medical fluid in the first portion of the cartridge by applying radio frequency energy to the medical fluid in the first portion of the cartridge, receiving radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge, and determining a concentration of a substance in the medical fluid based on the received radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge.

Abstract: A medical fluid delivery cassette configured for use with a medical fluid pumping system. The cassette includes a base, a membrane attached to the base, and an adhesive disposed on a portion of the membrane overlying a fluid pump chamber of the cassette. The portion of the membrane overlying the fluid pump chamber is moveable such that the volume of the fluid pump chamber can be changed.

Abstract: A dialysis fluid cassette that includes a rigid body and a flexible backing covering a recessed portion of the rigid body to at least partially form a gas release chamber.

Abstract: This disclosure relates to medical fluid sensors and related systems and methods. In certain aspects, a method includes using a medical fluid pump of a medical fluid pumping machine, such as a hemodialysis machine, to deliver medical fluid to a first portion of a cartridge that is positioned within a magnetic field, exciting atoms in the medical fluid in the first portion of the cartridge by applying radio frequency energy to the medical fluid in the first portion of the cartridge, receiving radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge, and determining a concentration of a substance in the medical fluid based on the received radio frequency energy generated by the excited atoms in the medical fluid in the first portion of the cartridge.

Abstract: A peritoneal dialysis (PD) system that includes a disposable PD cassette including a base having a substantially planar portion and a dome-shaped protrusion extending from the substantially planar portion and a flexible membrane attached to the base and covering a recessed region of the dome-shaped protrusion to form a pumping chamber between the flexible membrane and the recessed region of the dome-shaped protrusion. The system also includes a PD machine including a deck and a door hinged from one side to the deck. The door and the deck can cooperate to form a cassette compartment, and the door has a cylindrical recess positioned to receive the dome-shaped protrusion of the base of the disposable PD cassette when the disposable PD cassette is disposed in the cassette compartment and the door is closed.

Abstract: A medical fluid delivery cassette configured for use with a medical fluid pumping system. The cassette includes a base, a membrane attached to the base, and an adhesive disposed on a portion of the membrane overlying a fluid pump chamber of the cassette. The portion of the membrane overlying the fluid pump chamber is moveable such that the volume of the fluid pump chamber can be changed.

Abstract: A medical fluid delivery cassette configured for use with a medical fluid pumping system. The cassette includes a base, a membrane attached to the base, and an adhesive disposed on a portion of the membrane overlying a fluid pump chamber of the cassette. The portion of the membrane overlying the fluid pump chamber is moveable such that the volume of the fluid pump chamber can be changed.

Abstract: In general, this disclosure relates to extracorporeal fluid circuits. In some aspects, an air-release device for allowing air to be released from a liquid in extracorporeal circuitry includes an elongate chamber having a bottom region and a top region and a fluid entry port and fluid exit port at or near the bottom region. The air release device also includes a vent structure at or near the top region of the elongate chamber that includes a porous material capable of swelling when moistened such that the vent structure can inhibit liquid from escaping the air-release device during use.

Abstract: A container for use with a hemodialysis apparatus having a vent structure is described. The vent structure is porous, and allows air in the container to vent when the container is being filled with fluid, but expands when the vent structure becomes wet, when filling is complete, thereby closing off the pores and inhibiting (e.g., preventing) fluid from flowing through the vent structure, and reentry of air into the container. The vent structure can also include a micro-porous membrane.

Abstract: In general, this disclosure relates to extracorporeal fluid circuits. In some aspects, an air-release device for allowing air to be released from a liquid in extracorporeal circuitry includes an elongate chamber having a bottom region and a top region and a fluid entry port and fluid exit port at or near the bottom region. The air release device also includes a vent structure at or near the top region of the elongate chamber that includes a porous material capable of swelling when moistened such that the vent structure can inhibit liquid from escaping the air-release device during use.

Abstract: A dialysis fluid cassette that includes a rigid body and a flexible backing covering a recessed portion of the rigid body to at least partially form a gas release chamber.

Abstract: A vent assembly is described for use in an extracorporeal fluid unit. A vent structure adjacent to a micro-porous membrane forms the assembly. The vent structure is porous, but expands when the vent structure becomes wet, thereby closing off the pores and inhibiting (e.g., preventing) fluid from flowing through the vent structure. The vent structure also protects the membrane from becoming wet, such as from condensation.

Abstract: A chamber is described for use in an extracorporeal fluid system. The chamber has a bottom entry port and a bottom exit port. A microporous filter at the top of the chamber allows air in the fluid to vent from the chamber. In use, the chamber is filled with saline. Blood is then introduced into the chamber. A layer of saline is above a layer of blood in the chamber. The saline stagnates as the blood flows through the chamber. The saline keeps the blood from contacting the filter and depositing protein on the filter.

Abstract: A medical fluid delivery cassette configured for use with a medical fluid pumping system. The cassette includes a base, a membrane attached to the base, and an adhesive disposed on a portion of the membrane overlying a fluid pump chamber of the cassette. The portion of the membrane overlying the fluid pump chamber is moveable such that the volume of the fluid pump chamber can be changed.

Abstract: This disclosure relates to blood treatment systems and related methods. The systems can include a blood pump arranged to move blood through a blood filter, a pressure sensor arranged to measure pressure of blood flowing through a fluid line between the blood pump and the blood filter, and a controller configured to activate a rinse pump to move rinse fluid through the blood filter based at least in part on the pressure of blood flowing through the fluid line as measured by the pressure sensor.

Abstract: A container for use with a hemodialysis apparatus having a vent structure is described. The vent structure is porous, and allows air in the container to vent when the container is being filled with fluid, but expands when the vent structure becomes wet, when filling is complete, thereby closing off the pores and inhibiting (e.g., preventing) fluid from flowing through the vent structure, and reentry of air into the container. The vent structure can also include a micro-porous membrane.

Abstract: A vent assembly is described for use in an extracorporeal fluid unit. A vent structure adjacent to a micro-porous membrane forms the assembly. The vent structure is porous, but expands when the vent structure becomes wet, thereby closing off the pores and inhibiting (e.g., preventing) fluid from flowing through the vent structure. The vent structure also protects the membrane from becoming wet, such as from condensation.