Abstract: A peritoneal dialysis system includes a chamber, a hydraulic pump including or operating with a hydraulic fluid storage area, an inflatable bladder located within the chamber and in hydraulic fluid communication with the hydraulic pump, and a control unit configured to cause known amounts of hydraulic fluid to be reuseably (i) pulled from the inflatable bladder into the hydraulic fluid storage area in a draw stroke in which fresh or used dialysis fluid is pulled into the flexible container, and (ii) pushed from the hydraulic fluid storage area into the inflatable bladder in a discharge stroke in which fresh or used dialysis fluid is pushed from the flexible container.

Abstract: A capacitive priming sensor for a medical fluid delivery system is disclosed. In an example embodiment, a priming sensor includes a housing including a recessed section configured to accept a portion of a patient tube. The housing includes a first electrode located adjacent to a portion of the patient tube when the portion of the patient tube is inserted into the housing and a second electrode located above the first electrode. The priming sensor also includes a capacitive sensor that measures a capacitance between the first electrode and the second electrode. A processor operates with the capacitive sensor and is configured to use the measured capacitance to determine a transition between a no-tube state and a dry tube state.

Abstract: A peritoneal dialysis system includes a cycler having a pumping actuator configured to move an incompressible fluid, a positive pressure actuator, and a control unit; and a disposable set including a chamber including an opening, and at least one plate (e.g., rigid plate) located within the chamber, wherein the control unit is programmed to cause (i) the pumping actuator to move the incompressible fluid to discharge fresh or used dialysis fluid from the chamber through the opening and (ii) the positive pressure actuator to expand the at least one plate to create negative pressure within the chamber to pull fresh or used dialysis fluid into the chamber through the opening.

Abstract: A peritoneal dialysis system includes a control unit is programmed to cause (i) a pressure sensor to take a first pressure reading of a reference chamber with a pneumatic valve closed, (ii) a pump actuator to pump fresh dialysis fluid through a fresh dialysis fluid pathway into a patient line expandable chamber, expanding the expandable chamber into a dome, (iii) the pneumatic valve to open, allowing the reference chamber to communicate pneumatically with any air in the dome, (iv) the pressure sensor to take a second pressure reading with the pneumatic valve open, (v) the first and second pressure readings to be used with the ideal gas law to determine an amount of air in the dome, and (vi) the amount of air in the dome and a known volume of the dome to be used to determine an amount of fresh dialysis fluid delivered into the expandable chamber.

Abstract: A peritoneal dialysis system is disclosed. In an example, a peritoneal dialysis system includes a mixing container configured to accept purified water and peritoneal dialysis fluid concentrate to form fresh peritoneal dialysis fluid. The peritoneal dialysis system also includes a distillation unit comprising an unpurified water/used peritoneal dialysis fluid storage tank for receiving unpurified water and used peritoneal dialysis fluid. The distillation unit further includes a heater in fluid communication with the unpurified water/used peritoneal dialysis fluid storage tank. The heater is configured to boil the unpurified water and the used peritoneal dialysis fluid to form water vapor.

Abstract: A peritoneal dialysis system includes a chamber; a hydraulic pump; an inflatable bladder located within the chamber and in hydraulic fluid communication with the hydraulic pump; and a control unit configured to cause a known amount of hydraulic fluid to be metered to the inflatable bladder and to determine (i) a first amount of air before a discharge stroke of the hydraulic pump via a first ideal gas law calculation, (ii) a second amount of air after the discharge stroke of the hydraulic pump via a second ideal gas law calculation, and (iii) a discharge volume of fresh or used dialysis fluid for the discharge stroke by subtracting a difference between the first amount of air and the second amount of air from the known amount of hydraulic fluid metered to the inflatable bladder for the discharge stroke.

Abstract: A capacitive priming sensor for a medical fluid delivery system is disclosed. In an example embodiment, a priming sensor includes a housing including a recessed section configured to accept a portion of a patient tube. The housing includes a first electrode located adjacent to a portion of the patient tube when the portion of the patient tube is inserted into the housing and a second electrode located above the first electrode. The priming sensor also includes a capacitive sensor that measures a capacitance between the first electrode and the second electrode. A processor operates with the capacitive sensor and is configured to use the measured capacitance to determine a transition between a dry tube state and a wet tube state. The processor then causes a pump to stop pumping dialysis fluid through the patient tube for the priming sequence after the wet tube state is determined.

Abstract: A fluid purification unit is disclosed. In an example, a fluid purification unit includes a heater configured to boil a fluid. The heater includes first and second electrodes positioned and arranged to contact the fluid. The first and second electrodes are configured to receive electrical power, heat resistively due to the electrical power, and transfer the heat to the fluid to boil the fluid to form water vapor. The fluid purification unit also includes a condenser including (i) a thermally conductive flowpath configured to conductively cool the water vapor, and (ii) a cooling source configured to direct a cooling medium past the thermally conductive flowpath to convectively cool the water vapor. The conductive and convective cooling combines to condense the water vapor into purified water.

Abstract: 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.

Abstract: A patient connector for dialysis is disclosed. In an example, a patient connector includes a housing including an inlet and an outlet and defining at least one aperture. The patient connector also includes a seal initially blocking the outlet and a hydrophobic filter covering the at least one aperture of the housing. The patient connector further includes a check valve positioned and arranged to prevent air from being vented from the housing via the at least one aperture and through the hydrophobic filter when the housing is under atmospheric pressure or negative pressure. The check valve is configured to allow air to be vented from the housing via the at least one aperture and through the hydrophobic filter when the housing is under positive pressure.

Abstract: 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.

Abstract: A patient connector for dialysis is disclosed. In an example, a patient connector includes a housing including an inlet and an outlet and defining at least one aperture. The patient connector also includes a seal initially blocking the outlet and a hydrophobic filter covering the at least one aperture of the housing. The patient connector further includes a check valve positioned and arranged to prevent air from being vented from the housing via the at least one aperture and through the hydrophobic filter when the housing is under atmospheric pressure or negative pressure. The check valve is configured to allow air to be vented from the housing via the at least one aperture and through the hydrophobic filter when the housing is under positive pressure.

Abstract: Systems and methods are disclosed for reducing valve noise and detecting a valve position in medical fluid systems. One method includes transmitting, by a microcontroller, a control signal for closing a valve via pulse width modulation (PWM) signals. The valve is configured to control a fluid flow in the medical fluid system. The valve may be open at least before the control signal is transmitted. The valve comprises a housing, a solenoid coil, and a plunger. The method further includes applying power to the valve to measure voltage across the valve and monitoring, based on a sense resistor, the voltage across the valve over a measurement interval. The measurement interval terminates when the voltage reaches a predetermined threshold voltage. The method also includes comparing the measurement interval to a reference interval for a normally functioning closed valve and generating, based on the comparison, an assessment of the valve position.

Abstract: A capacitive priming sensor for a medical fluid delivery system is disclosed. In an example embodiment, a priming sensor includes a housing including a recessed section configured to accept a portion of a patient tube. The housing includes a first electrode located adjacent to a portion of the patient tube when the portion of the patient tube is inserted into the housing and a second electrode located above the first electrode. The priming sensor also includes a capacitive sensor that measures a capacitance between the first electrode and the second electrode. A processor operates with the capacitive sensor and is configured to use the measured capacitance to determine a transition between a dry tube state and a wet tube state. The processor then causes a pump to stop pumping dialysis fluid through the patient tube for the priming sequence after the wet tube state is determined.

Abstract: A capacitive priming sensor for a medical fluid delivery system is disclosed. In an example embodiment, a priming sensor includes a housing including a recessed section configured to accept a portion of a tube. The recessed section of the housing includes a first side including a first conductive plate and a member including a second conductive plate. The member is moveably connected to a second side of the recessed section for detecting insertion of the portion of the tube into the housing of the priming sensor. The recessed section also includes a third side opposing the first side. The third side includes a third conductive plate disposed across from a top portion of the first conductive plate, and a fourth conductive plate disposed across from a bottom portion of the first conductive plate. The priming sensor also includes capacitive sensors or detectors for measuring capacitances between the conductive plates.

Abstract: A dialysis fluid apparatus includes a flexible dialysis fluid container, a holder structured such that the flexible dialysis fluid container is held vertically within the holder and conforms to a shape of the holder, a pressure sensor positioned and arranged to sense a pressure of a fluid held within the flexible dialysis fluid container, and a control unit configured to (i) store at least one cross-sectional area of the flexible dialysis fluid container, (ii) calculate a head height using the pressure of the fluid held within the flexible dialysis fluid container, and (iii) calculate a volume of the fluid held within the flexible dialysis fluid container using the cross-sectional area and the head height.

Abstract: A fluid purification unit is disclosed. In an example, a fluid purification unit includes a heater configured to boil a fluid. The heater includes first and second electrodes positioned and arranged to contact the fluid. The first and second electrodes are configured to receive electrical power, heat resistively due to the electrical power, and transfer the heat to the fluid to boil the fluid to form water vapor. The fluid purification unit also includes a condenser including (i) a thermally conductive flowpath configured to conductively cool the water vapor, and (ii) a cooling source configured to direct a cooling medium past the thermally conductive flowpath to convectively cool the water vapor. The conductive and convective cooling combines to condense the water vapor into purified water.

Abstract: An inductive inline dialysis fluid heater is disclosed. In an example, a dialysis fluid heater includes a cylindrical tube including an inner diameter that is between 4.00 millimeters (“mm”) and 12.7 mm. The dialysis fluid heater also includes a susceptor located within the cylindrical tube and an inductive coil extending around the cylindrical tube in a non-contacting arrangement. The dialysis fluid heater further includes power electronics in electrical communication with the inductive coil and configured to supply an electrical current to the inductive coil, causing the susceptor to heat.

Abstract: A peritoneal dialysis system includes a control unit is programmed to cause (i) a pressure sensor to take a first pressure reading of a reference chamber with a pneumatic valve closed, (ii) a pump actuator to pump fresh dialysis fluid through a fresh dialysis fluid pathway into a patient line expandable chamber, expanding the expandable chamber into a dome, (iii) the pneumatic valve to open, allowing the reference chamber to communicate pneumatically with any air in the dome, (iv) the pressure sensor to take a second pressure reading with the pneumatic valve open, (v) the first and second pressure readings to be used with the ideal gas law to determine an amount of air in the dome, and (vi) the amount of air in the dome and a known volume of the dome to be used to determine an amount of fresh dialysis fluid delivered into the expandable chamber.

Abstract: A peritoneal dialysis system includes a cycler having a pumping actuator configured to move an incompressible fluid, a positive pressure actuator, and a control unit; and a disposable set including a chamber including an opening, and at least one plate (e.g., rigid plate) located within the chamber, wherein the control unit is programmed to cause (i) the pumping actuator to move the incompressible fluid to discharge fresh or used dialysis fluid from the chamber through the opening and (ii) the positive pressure actuator to expand the at least one plate to create negative pressure within the chamber to pull fresh or used dialysis fluid into the chamber through the opening.