Methods and apparatus for concentration determination using polarized light. The apparatus includes a first polarized light source having a first light source polarization axis and a second polarized light source having a second light source polarization axis generally perpendicular to the first light source polarization axis. Also, a first polarized light receiver having a first polarized light receiver polarization axis and configured to measure an intensity of light transmitted from the first light receiver polarizer and a second polarized light receiver having a second polarized light receiver polarization axis substantially perpendicular to the first light receiver polarization axis and configured to measure an intensity of light transmitted from the second light receiver polarizer, wherein the first and second light receiver polarization axes are generally +/45 degrees relative to the first and second light source polarization axes.

A housing-free first dialyzer element has a hollow-fiber bundle, a fluid-permeable sheath wrapped around the periphery of the hollow-fiber bundle, cast elements at the axial ends of the hollow-fiber bundle, and end caps fastened to the cast elements for connection to an extracorporeal blood circulation. A second dialyzer element has a housing and can be closed, opened and reused. A dialyzer includes the housing-free first dialyzer element and the second dialyzer element that has a housing. A blood treatment device includes the second dialyzer element that has the housing, the second dialyzer element being rigidly fastened to a machine front. A method for reprocessing the second dialyzer element that has the housing can be used after blood treatment therapy.

A medical fluid or dialysis system includes an auto-connection mechanism that connects connectors from the supply bags to dialysis cassette ports or cassette supply lines. The system provides for multiple, e.g., four, supply bags, which can be connected to a manifold of the auto-connection mechanism. Tip protecting caps that protect the supply line ends and cassette ports or cassette supply line ends are made to be compatible with the auto-connection mechanism. The auto-connection mechanism removes all the caps and connects the supply lines to the cassette. At least one roller occluder is provided that occludes the supply tubing prior to the tip protecting caps being removed. The roller occludes prevent medical dialysis fluid from spilling out of the supply lines between the time that the caps are removed and connection to the cassette is made.

A balancing unit for medical fluids includes at least one balancing chamber and at least one conveying unit for filling the balancing chamber, in which the conveying unit is a pressure controlled conveying unit and/or is designed and provided for being operated in at least one operating state as a constant-pressure source. An external medical functional unit, a treatment apparatus and methods are also described.

A cassette module (32, 46) for a differential flowmeter (305, 415) is disclosed, wherein the cassette module (32, 46) forms a first channel (30, 45) and a second channel (31, 44), which channels carry fluid during operation of the differential flowmeter and are permeated by a magnetic field (33, 43) during operation of the differential flowmeter (305, 415), each having an electrode pair (301, 302, 403, 405) arranged on the first channel (30, 45) and on the second channel (31, 44). A flow difference between the first fluid-carrying channel (30, 44) and the second fluid-carrying channel (31, 45) can be determined by comparing the signals on the first electrode pair (301, 403) and on the second electrode pair (302, 405). The first channel (30, 45) forms an additional section (34, 41) that is permeated by the magnetic field during operation. Another electrode pair (303, 402) is arranged in the additional section (34, 41), so that a change in the measurement conditions can be detected by comparing the signal on the first electrode pair (301, 403) and on the additional electrode pair (303, 402).

A peritoneal dialysis (PD) system includes a cycler including an actuation surface having a peristaltic pump actuator; a manifold assembly including a rigid manifold having first and second chambers, the rigid manifold configured and arranged to be abutted against the actuation surface for operation, a peristaltic pump tube extending from the first chamber to the second chamber of the rigid manifold, a dialysis fluid container line extending from the first chamber, and a branch line extending between the dialysis fluid container line and the second chamber; and a control unit configured to cause the peristaltic pump actuator to actuate the peristaltic pump tube to pump dialysis fluid from the branch line into the second chamber and from the second chamber into the first chamber.

An occluder, and methods for occlusion, that employs first and second opposed occluding members associated with each other, a tube contacting member connected to, or comprising at least a portion of, at least one of the first and second occluding members, and a force actuator constructed and positioned to apply a force to at least one of the first and second occluding members. The application of the force by the force actuator may cause the tube contacting member to move between a tube occluding position and an open position. A release member may be configured and positioned to enable an operator to manually move the tube contacting member from the tube occluding position to the open position even with no force applied to the at least one of the first and second occluding members by the force actuator. In one embodiment, the force actuator may apply the force sufficient to bend both the first and second occluding members, so that upon the application of the force by the force actuator (such as an air bladder), the first and second occluding members (e.g., spring plates pivotally connected at opposite ends) bend and the tube contacting member may move between the tube occluding position and the open position.

Components for a medical infusion fluid handling system, such as an APD system, in which one or more lines (such as solution lines), spikes or other connection ports may be automatically capped and/or de-capped. This feature may provide advantages, such as a reduced likelihood of contamination since no human interaction is required to de-cap and connect the one or more lines, the spikes or the other connection ports. For example, a fluid handling cassette may include one or more caps that cover a corresponding spike and include a raised and/or recessed feature to assist in removal of the one or more caps from the cassette. A solution line cap may include a hole and a recess, a groove or other feature to engage with a spike cap and enable removal of the spike cap.

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.

Methods and apparatus for concentration determination using polarized light. The apparatus includes a first polarized light source having a first light source polarization axis and a second polarized light source having a second light source polarization axis generally perpendicular to the first light source polarization axis. Also, a first polarized light receiver having a first polarized light receiver polarization axis and configured to measure an intensity of light transmitted from the first light receiver polarizer and a second polarized light receiver having a second polarized light receiver polarization axis substantially perpendicular to the first light receiver polarization axis and configured to measure an intensity of light transmitted from the second light receiver polarizer, wherein the first and second light receiver polarization axes are generally +/45 degrees relative to the first and second light source polarization axes.