The disclosed subject matter relates to extracorporeal blood processing or other processing of fluids. Volumetric fluid balance, a required element of many such processes, may be achieved with multiple pumps or other proportioning or balancing devices which are to some extent independent of each other. This need may arise in treatments that involve multiple fluids. Safe and secure mechanisms to ensure fluid balance in such systems are described.

An extracorporeal alarm suppression method is arranged to be carried out in a continuous renal replacement therapy and/or chronic hemodialysis device and includes the steps of monitoring vascular access pressure, including arterial and/or venous pressure, of a patient using a vascular access pressure monitoring means; detecting an access pressure alarm situation if the arterial or venous pressure is out of predetermined alarm limits; when a first access pressure alarm situation is detected, setting the device to an alarm suppression state reducing the blood flow and therapy flows using an alarm suppression state setting means; detecting that a predetermined alarm suppression state condition is met using a predetermined alarm suppression state condition detecting means, the predetermined alarm suppression state condition including at least a predetermined waiting time having passed or a parameter threshold having been reached after the first access pressure alarm situation has been detected; and when a further access pressure alarm situation is detected after the predetermined alarm suppression state condition has been met, setting the device to a safety state using a safety state setting means, the safety state being a state in which the blood pump is stopped.

A patient interface includes: a plenum chamber; a seal-forming structure; a positioning and stabilising structure; a plenum chamber insert configured to be positioned and retained within the plenum chamber; and a vent structure; wherein the plenum chamber insert has a plenum chamber insert port; wherein the plenum chamber insert has an exterior surface configured to be positioned adjacent to an interior surface of the plenum chamber; wherein when the plenum chamber insert is positioned and retained within the plenum chamber, a radial channel is formed by the interior surface of the plenum chamber and the exterior surface of the plenum chamber insert such that gas is able to pass between a patient-proximal side plenum chamber insert and a patient-distal side of the plenum chamber insert via the radial channel during use.

Improved systems and methods for extracorporeal blood temperature control and patient temperature control, e.g., for induced hypothermia and optional normothermia, may include or otherwise employ a heat exchanger for cooling/warming of a fluid, a thermal exchange module having fluidly isolated first and second volumes, and a fluid pump for circulating the fluid through the heat exchanger and the first volume of the thermal exchange module. A blood pump may be provided for the flow of blood through the second volume of the thermal exchange module, and a first controller may be provided for providing output signals for use in operation of the heat exchanger to selectively control thermal exchange between the fluid circulated through the first volume of the thermal exchange module and the blood flowed through the second volume of the thermal exchange module, thereby providing for selective cooling/warming of the blood. A multi lumen catheter may be utilized for the flow of blood from a patient vascular system to the second volume of the thermal exchange module, and for flow of blood from the second volume of the thermal exchange module back to the patient vascular system. The circulated fluid may be optionally circulated through a patient contact pad(s) for contact cooling/warming, wherein patient cooling/warming may be provided in a first mode via blood cooling/warming in the thermal exchange module, and patient cooling/warming may be provided in a second mode via thermal exchange by the contact pad(s).

A pressure switch for controlling application of negative pressure to dressing disposed adjacent a tissue site is disclosed. The pressure switch comprises a body having a base, sidewalls extending from the base to an open end, and an inlet coupled to the dressing and forming a passage through the body. The pressure switch further comprises a diaphragm closing the open end of the sidewalls and forming a vacuum chamber with the body, wherein the inlet fluidly couples the vacuum chamber and the dressing. The pressure switch further comprises a valve disposed in the passage and configured to restrict the flow of gas through the passage so that a switch pressure developed in the vacuum chamber as a result of the application of negative pressure to the dressing lags a wound pressure at the tissue site to delay, wherein the diaphragm is adapted to be operatively responsive to the switch pressure to move between a relaxed position and a compressed position as the negative pressure increases and decreases. This pressure switch further comprises a switching element coupled to the diaphragm to turn on the negative pressure in the relaxed position and turn off the negative pressure in the compressed position. In another example, a method for controlling application of negative pressure to dressing disposed adjacent a tissue site using a pressure switch is disclosed. In another example, a system for applying negative pressure to a tissue site using a pressure switch is disclosed.

A pump system is disclosed that comprises a control unit and one or more modular infusion devices removably docked to the primary control unit. Each modular infusion device comprises a pumping mechanism and a processor configured to control the pumping mechanism and communicate with the control unit. The modular infusion device is configured to manipulate a portion of a fluid delivery set to pump a fluid. The first processor and the second processor are configured to exchange one or more operating parameters when the modular infusion device is docked to the primary control unit. The modular infusion device is configured to pump the fluid after being undocked.

In a method for intermittently occluding the coronary sinus, in which the coronary sinus is occluded using an occlusion device, the fluid pressure in the occluded coronary sinus is continuously measured and stored, the fluid pressure curve is determined as a function of time, and the occlusion of the coronary sinus is triggered and/or released as a function of at least one characteristic value derived from the measured pressure values. The pressure increase and/or pressure decrease per time unit each occurring at a heart beat are used as characteristic values.

Disclosed is an infusion pump which may include a native pumping mechanism to drive fluids through a functionally associated conduit, at least one native sensor to sense a physical characteristic of the fluid within the conduit and computing circuitry having a decalibration test mode to determine whether the infusion pump is decalibrated. The computing circuitry may be adapted to receive output from at least one native sensor during the decalibration test mode.

An arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement including: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power to the solenoid such that the pump is driven at or near a resonant frequency of the pump.

Devices, systems and methods for controlling, regulating, altering, transforming or otherwise modulating the delivery of a substance to a delivery site. The devices, systems and methods optimize the delivery of the substance to an intended site, such as a vessel, vascular bed, organ and/or other corporeal structures, while reducing inadvertent introduction or reflux substance to other vessels, vascular beds, organs, and/or other structures, including systemic introduction.