A fluid separation device includes a centrifuge in which a fluid is separated into at least two components, with an interface therebetween. At least a portion of one of the separated fluid components is removed from the centrifuge and flows through a vessel. Light is reflected off of the separated fluid component in the vessel and received and analyzed to determine its main wavelength. If the main wavelength is higher than a maximum value, a target location of the interface is changed. If the main wavelength is less than the maximum value, then the location of the interface is compared to the target location. When the interface is sufficiently close to the target location, the optical density of the separated fluid component in the vessel is compared to a minimum value. If the optical density is less than the minimum value, the target location of the interface is changed.

A computer-implemented method comprises providing a fluid circuit comprising fluid pathways configured to mount and associate with a durable processing device comprising a pressure sensor in communication with a controller and a fluid pathway. A container is connected to the pressure sensor and may receive a volume of fluid. A change in pressure values between a first and second time is measured from when the volume of fluid is not in communication with the pressure sensor to when the volume of fluid is in communication with the pressure sensor, the volume of fluid within the container or a presence or absence of a fluid connection to the fluid pathway based on the change in pressure values is determined, and a response action is executed if the volume of fluid within the container is not within an authorized volume range for the time period, or if a fluid connection is unauthorized.

Dialysis systems comprising actuators that cooperate to perform dialysis functions and sensors that cooperate to monitor dialysis functions are disclosed. According to one aspect, such a hemodialysis system comprises a user interface model layer, a therapy layer, below the user interface model layer, and a machine layer below the therapy layer. The user interface model layer is configured to manage the state of a graphical user interface and receive inputs from a graphical user interface. The therapy layer is configured to run state machines that generate therapy commands based at least in part on the inputs from the graphical user interface. The machine layer is configured to provide commands for the actuators based on the therapy commands.

A method for measuring pressure includes securing a flow channel to a chassis of a measurement device, the flow channel having a flexible wall with a first mechanical engagement feature presented from an external surface thereof. The method also includes engaging the mechanical engagement feature with a complementary engagement member connected to a force transducer, the securing being effective to immobilize the flow channel relative to the force transducer, and detecting at least one of the position and orientation of the of the flow channel relative to transducer and comparing to at least one of a predefined position and orientation. Further, the method includes generating a signal responsive to the detecting, flowing a fluid through the flow channel, and transmitting forces caused by displacement of the flexible wall through the complementary engagement member to the force transducer. Further, electrical signals are generated responsively to a state of the force transducer.

Systems and methods are provided for separating blood into two or more components. A blood separation system includes a blood separation device and a fluid flow circuit configured to be mounted to the blood separation device. The blood separation device includes a centrifugal separator and a spinning membrane separator drive unit incorporated into a common case, which allows for fluid separation by two different methods. Depending on the separation procedure to be carried out, the fluid flow circuit paired with the blood separation device may include only one separation chamber configured to be mounted to the centrifugal separator or spinning membrane separator drive unit or two separation chambers, with one being mounted to the centrifugal separator and the other to the spinning membrane separator drive unit. The system may be used to separate and collect any combination of red blood cells, plasma, and platelets.

A method is provided for removing red blood cells from a suspension comprising red blood cells, white blood cells, platelets and plasma using a spinning membrane separator. The method comprises: a) flowing whole blood into the gap of the spinning membrane separator; b) collecting red blood cells and white blood cells in the gap and passing plasma and platelets through the membrane; c) introducing a first quantity of lysing buffer into the gap; d) incubating the red blood cells, white blood cells and lysing buffer in the gap for a period of time to cause a lysis reaction with the red blood cells; e) introducing a second quantity of lysing buffer into the gap to displace the first quantity of lysing buffer and a first quantity of red blood cell debris out of the gap; f) introducing a first quantity of wash buffer into the gap to quench the lysis reaction and displace the second quantity of lysing buffer and a second quantity of red blood cell debris out of the gap; and g) introducing a second quantity of wash buffer into the gap to flow washed white blood cells out of the housing.

Systems and methods are provided for depleting platelets from blood. The system includes a multi-stage blood separation chamber in which blood is separated into red blood cells and platelet-rich plasma. The platelet-rich plasma is conveyed from a first stage of the chamber to a second stage, where it is separated into platelets and platelet-poor plasma. The platelet-poor plasma is conveyed out of the chamber while the platelets are allowed to accumulate in the second stage of the chamber. When a controller of the system has determined that the maximum chamber capacity of platelets has been accumulated in the second stage of the chamber, the platelets are conveyed out of the chamber to a waste container. The cycle of separating blood into its components, accumulating platelets in the chamber, and then flushing the platelets from the chamber is repeated until a target platelet concentration of the blood is achieved.

Methods and systems for sampling blood components in a photopheresis procedure are disclosed. The methods include collecting samples at selected times during a photopheresis procedure.

A renal therapy machine includes a blood filter including a plurality of porous fibers; a blood circuit in communication with the blood filter; and a dialysate circuit in communication with the blood filter and operable with at least one pump, wherein the renal therapy machine is configured to perform a priming sequence in which a physiologically compatible solution, other than dialysate, primes the blood circuit and is flowed within the fibers and through pores in the fibers of the blood filter, and the pump of the dialysate circuit vents air from the blood filter into the dialysate circuit.

Dialysis systems comprising actuators that cooperate to perform dialysis functions and sensors that cooperate to monitor dialysis functions are disclosed. According to one aspect, such a hemodialysis system comprises a user interface model layer, a therapy layer, below the user interface model layer, and a machine layer below the therapy layer. The user interface model layer is configured to manage the state of a graphical user interface and receive inputs from a graphical user interface. The therapy layer is configured to run state machines that generate therapy commands based at least in part on the inputs from the graphical user interface. The machine layer is configured to provide commands for the actuators based on the therapy commands.