In medical apparatus, for example a dialysis machine, a pump is used to move fluid such as purified water or dialysate. The pump performance is monitored by determining the weight or mass of the fluid being pumped. A less expensive pump may be used whilst maintaining an accurate determination of the volume pumped.

A method of detecting a fault condition in an infusion process, the method includes receiving a programmed flow rate pertaining to a fluid infusion provided by an infusion device; determining, a first weight of an infusion container associated with the fluid infusion provided by the infusion device at a first time; determining a second weight of the infusion container at a second time; determining based on the first weight and the second weight, a determined flow rate of the fluid infusion provided by the infusion device between the first time and the second time. The method includes determining a difference between the determined flow rate and the programmed flow rate. When a magnitude of the difference between the determined flow rate and the programmed flow rate satisfies a predetermined threshold, by the processor: causing an output of the infusion device or the weight sensor to indicate the fault condition.

A dialysis machine (e.g., a peritoneal dialysis (PD) machine) can include a control unit configured to operate in a hybrid automated mode during a PD treatment. A processor in the control unit is configured to engage a pump during a fill phase of the PD cycle. The volume of fluid (e.g., dialysate) transferred to a patient line during the fill phase is monitored. After a dwell period, the pump is disengaged at the start of a drain phase of the PD cycle. Disengaging the pump can include: configuring valves of a disposable cassette to bypass the pump chambers of a disposable cassette; activating a bypass valve to shunt the patient line to a drain line; or moving a roller assembly of a peristaltic pump. The fluid transferred from the patient line to the drain line is monitored during the drain phase of the PD cycle.

A method for operating a fluid management system includes automatically detecting an unstable condition in the system, which may include detecting a large change in the supply fluid amount (indicative of a bag change), detecting a large change in the waste fluid amount (indicative of a bag change), or detecting a large difference between the amount of fluid dispensed as measured by the weight data and the amount of fluid dispensed as measured by the flow data (indicative of a blockage in the supply tubing). The method further includes adjusting the operating mode of the system during the unstable condition, which may include switching to using flow data rather than weight data to track the fluid deficit during a supply bag exchange, halting operation of an outflow pump during a waste container exchange, and/or halting operation of the system during a blockage in the supply tubing.

A vacuum regulator device having a vacuum regulator and a vacuum gauge on a housing line that is configured to be in fluid communication with a patient include an electronic valve that selectively opens and closes the housing line. The vacuum gauge is located between the vacuum regulator and the patient and includes an electronic flow sensor upstream. The electronic flow sensor provides feedback to the vacuum regulator.

The specification discloses a portable dialysis machine having a detachable controller unit and base unit with an improved reservoir heating system. The controller unit includes a door having an interior face, a housing with a panel, where the housing and panel define a recessed region configured to receive the interior face of the door, and a manifold receiver fixedly attached to the panel. The base unit has a reservoir with an internal pan and external pan, separated by a space that holds a heating element. The heating element is electrically coupled to electrical contacts attached to the external surface of the external pan.

A device and method for measuring an IV pump infusion system flow comprises a fluid source configured to store medicinal fluid and a weight sensing mechanism comprising a weight sensor and microprocessor. The weight sensing mechanism is configured to detect the weight of the fluid source as the medicinal fluid leaves the fluid source. The device in the infusion system administers medicinal fluid using a set flow rate for the IV pump input into the control unit prior to infusion, measures the change in mass of the fluid source containing medicinal fluid as fluid exits the source, calculates the flow rate based on the change in mass over time, compares the calculations with a set flow rate, and adjusts the IV pump and flow rate based on the compared deviations, for improved delivery accuracy. This configuration may also prevent patient harm and medicine waste.

A computer-implemented method for quantifying fluid includes estimating a first volume of a first fluid contained in an item based on a difference between a dry weight and a wet weight of the item, and displaying a graphical representation of a container containing a volume of a second fluid and a second volume of the first fluid, wherein the graphical representation includes a first display element for receiving a first user input indicating the volume of the second fluid in the container, and a second display element for receiving a second user input indicating a total fluid volume in the container, estimating the second volume of the first fluid based on at least one of the first and second user inputs, and estimating a quantity of the first fluid based on the first and second volumes of the first fluid.

Extracorporeal blood treatment systems and methods to display graphical user interfaces displaying a plurality of fluids areas, each including a flow rate, and displaying adjustment notifications proximate one or more fluid areas. For example, when a user adjusts a flow rate to a limit, one or more notifications may be displayed proximate other flow rates that may be adjusted to modify the limit.

A plasmapheresis system and a method for operating a plasmapheresis system are provided by which the volume/weight of anticoagulated plasma that is collected is optimized. In one example, a nomogram is provided that utilizes the donor's hematocrit to calculate the volume/weight of raw plasma within a plasma product having the maximum volume permitted by the FDA nomogram. In a plasmapheresis procedure having multiple collection phases followed by a reinfusion cycle in which concentrated red blood cells are returned to the donor, the volume of plasma product to be collected is calculated prior to the start of each collection cycle to account for the donor's increasing hematocrit, thus resulting in a greater total volume of plasma product to be collected during the plasmapheresis procedure.