A priming sensor for a medical fluid delivery device is disclosed. In an example, the priming sensor includes light emitters and a detector. The detector is configured to detect light emitted by the emitters that interacts with a patient tube connected to the priming sensor. A processor of a medical fluid delivery device causes the emitters to operate in a sweep pattern during a sweep period. The processor receives output data from the detector that is indicative of light detected during the sweep period. The processor creates an output waveform corresponding to the sweep period based on the output data and compares the output waveform to at least one reference waveform to determine one of (a) a no-tube state, (b) a dry tube state, or (c) a wet tube state. The processor provides an output indicative of the comparison for operation of the medical fluid delivery device.

Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of the apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of a diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber. Improved heater control circuitry is also disclosed, to provide added or redundant safety measures, or to reduce current leakage from a heater element during pulse width modulation control of the heater. Improvements are also disclosed in the application of negative pressure during a drain phase in peritoneal dialysis therapy, and to control the amount of intraperitoneal fluid accumulation during a therapy. Improvements in efficiency are also disclosed in the movement of fluid into and out of a two-pump cassette and heater bag of a peritoneal dialysis cycler, and in the synchronization of the operation of two or more pumps in a peritoneal dialysis cycler or other fluid handling devices using a multi-pump arrangement.

An injection device comprises: a drug storer having a first space for storing a drug; a unidirectional switch having a second space in fluid communication with the first space; and an injection body having a third space in fluid communication with the second space, wherein the third space is provided with a piston adapted to move along the injection body, and to pump the drug stored in the first space into the third space. The drug storer comprises a base and a head cover, and at least one of the base and the head cover is formed by a flexible film, thereby forming the first space for storing a drug.

Blood treatment apparatus and methods of using the same are described herein that include two or more intermediate containers located between a treatment solution source and a port through which the treatment solution is to be delivered with the blood treatment apparatus. The weight of the intermediate containers is measured and used to control the refilling and emptying of treatment solution in the intermediate containers.

Disclosed is a valve clutch that has a central member extending along a central axis and includes a drive coupler that receives a driving torque. A coupling member is provided that includes coupling pins extending parallel to the central axis. A valve is rotatably disposed around the central axis between inlet and outlet positions. A sleeve is configured to rotationally engage the valve, the sleeve including at least one clamping member. The valve clutch is reversibly changeable between (1) an unengaged configuration wherein a driving torque received by the central member is not transmitted to the sleeve member, and (2) an engaged configuration wherein the at least one coupling pin is clamped between the central member and the at least one clamping member, thereby transmitting the driving torque that is received by the central member via the sleeve member to the valve member.

A control unit (30) is arranged to control a dialysis fluid distribution system (12) comprising first and second volumetric pumps (PI, P2) arranged upstream and downstream of a dialyzer (13). The control unit (30) is operable in a calibration mode, to establish a bypass flow path that bypasses the dialyzer (13) and extends from the first pump (P1) to the second pump (P2) in fluid communication with a calibration chamber (26) and to operate the pumps (P1, P2) at different combinations of speeds that cause first and second changes in fluid level in the chamber (26). The first and second changes correspond to first and second known volumes in the chamber (26). The control unit (30) measures, by a level detector (28) in the chamber (26), first and second time periods for the first and second changes, and computes the stroke volumes of the pumps (P1, P2) as a function of the speeds of the pumps (PI, P2), the first and second time periods, and the first and second known volumes. By computing the stroke volumes, the control unit (30) is operable to achieve an accurate ultrafiltration (UF) rate in the dialyzer (13) by controlling the relative speeds of the pumps (P1, P2).

A system including a pumping cassette having a first side including number of valve wells and second side having a fluid bus. Each side may be covered by a flexible membrane. A control surface having a number of valve well control stations actuatable with respect to the flexible membrane covering the first side of the cassette to open and close the valve wells when the cassette is mated against the control surface may be included. A pressure distribution assembly having a positive and negative pressure source and a number of pneumatic valves may be included. A controller configured to selectively actuate the number of pneumatic valves to apply pressure against the valve well control stations in a valve pumping sequence until a volume displaced through the fluid bus of the pumping cassette from a source to a destination is within a range of a target volume may be included.

Blood treatment apparatus and methods of using the same are described herein that include two or more intermediate containers located between a treatment solution source and a port through which the treatment solution is to be delivered with the blood treatment apparatus. The weight of the intermediate containers is measured and used to control the refilling and emptying of treatment solution in the intermediate containers.

A priming sensor for a medical fluid delivery device is disclosed. In an example, the priming sensor includes light emitters and a detector. The detector is configured to detect light emitted by the emitters that interacts with a patient tube connected to the priming sensor. A processor of a medical fluid delivery device causes the emitters to operate in a sweep pattern during a sweep period. The processor receives output data from the detector that is indicative of light detected during the sweep period. The processor creates an output waveform corresponding to the sweep period based on the output data and compares the output waveform to at least one reference waveform to determine one of (a) a no-tube state, (b) a dry tube state, or (c) a wet tube state. The processor provides an output indicative of the comparison for operation of the medical fluid delivery device.

A system including a pumping cassette having a first side including number of valve wells and second side having a fluid bus. Each side may be covered by a flexible membrane. A control surface having a number of valve well control stations actuatable with respect to the flexible membrane covering the first side of the cassette to open and close the valve wells when the cassette is mated against the control surface may be included. A pressure distribution assembly having a positive and negative pressure source and a number of pneumatic valves may be included. A controller configured to selectively actuate the number of pneumatic valves to apply pressure against the valve well control stations in a valve pumping sequence until a volume displaced through the fluid bus of the pumping cassette from a source to a destination is within a range of a target volume may be included.