A gas elimination apparatus and a method for use in an intravenous delivery system are provided. The apparatus includes in a fluid inlet coupling a fluid flow into a liquid chamber, a fluid outlet protruding into the liquid chamber, and a flow diversion member proximal to the fluid outlet. The flow diversion member configured to block a direct flow between the fluid inlet and the fluid outlet. The apparatus includes a membrane separating a portion of the liquid chamber from an outer chamber and a gas venting valve fluidically coupling the outer chamber with the atmosphere. The flow diversion member may be mechanically supported by at least one strut or elongate member extending along a flow direction into the liquid chamber.

An infusion pump including a fluid chamber having an outlet valve and a piezo-stack actuator including a stack of piezo-electric layers. The infusion pump also includes a linear actuator to measure displacement of the piezo-stack actuator during operation. An electronic processor is programmed to operate the outlet valve and the piezo-stack actuator to pump fluid through the fluid chamber at a programmed flow rate.

A system and method are provided for detecting air embolisms in lines for hemodynamic monitoring. In use, using a first sensor, one or more gas bubbles are detected within a first line for hemodynamic monitoring. In response to the detecting, a first clamp attached to the first line for hemodynamic monitoring is contracted.

A fluid sensing apparatus and a method for detecting pressure and a presence of bubbles within a fluid tube. The fluid sensing apparatus comprises a housing configured to receive a portion of the tube and to house a pressure sensor and an ultrasonic transmitter. The pressure sensor is positioned adjacent the tube and is configured to receive a pressure sensor signal, which correlates to a detected pressure differential within the tube. A controller transmits a drive signal to the ultrasonic transmitter, which emits ultrasonic waves through the portion of the tube and to the pressure sensor. The pressure sensor receives both the ultrasonic waves and the pressure sensor signal, and subsequently transmits an output signal to the controller. In a presence of a pressure differential or a bubble within the tube, the output signal will exhibit a DC shift or a distortion of signal characteristics of the output signal, respectively.

Various systems and methods for detecting air in a chamber of an infusion system are disclosed. In one embodiment, a determination is made that air is contained in the chamber on the basis of a change in the average force exerted against the plunger utilizing a derivative spike for event detection and a systematic reduction in the average force to confirm the nature of the change. In another embodiment, a determination is made that the chamber contains air when a difference between the current force profile and a baseline force profile crosses a threshold. In an additional embodiment, a force profile is classified as being an air force profile or a liquid force profile based on extracted features of the force profile.

An infusion device includes an infusion pump and an infusion tube assembly. The infusion tube assembly includes a first tube body connected to the infusion pump, a tube joint structure having first, second and third tube joints, a second tube body, and a clamping device on the second tube body. The clamping device is to clamp the second tube body. An infusion method includes instructing the infusion pump to perform an infusion operation. When bubbles are detected in a liquid in the infusion tube assembly, the infusion pump is instructed to stop the infusion operation and a bubble alarm is generated. After the infusion pump stops the infusion operation, it is determined whether a pressure of the liquid first drops to a first pressure value and then rises to a second pressure value. If yes, a rinsing operation is performed.

An infusion pump (10) includes a fluid chamber (28) having an outlet valve (34) and a piezo-stack actuator (36) comprising a stack of piezo-electric layers (38). An electronic processor (18) is programmed to operate the outlet valve and the piezo-stack actuator to pump fluid through the fluid chamber at a programmed flow rate.

A gas elimination apparatus and a method for use in an intravenous delivery system are provided. The apparatus includes a fluid inlet coupling a fluid flow into a liquid chamber, a fluid outlet protruding into the liquid chamber, and a flow diversion member proximal to the fluid outlet. The flow diversion member configured to block a direct flow between the fluid inlet and the fluid outlet. The apparatus includes a membrane separating a portion of the liquid chamber from an outer chamber and a gas venting valve fluidically coupling the outer chamber with the atmosphere. The flow diversion member may be mechanically supported by at least one strut or elongate member extending along a flow direction into the liquid chamber.

A method of dispensing fluid includes three processes. A first one of these processes includes pumping fluid into a resilient variable-volume dispensing chamber. The dispensing chamber is in series with a normally present finite fluid impedance and an output. The impedance is sufficient so as to cause expansion of the dispensing chamber as it receives pumped fluid even while some fluid flows through the output. Another one of these processes includes repeatedly measuring a parameter related to volume of the dispensing chamber over time. A third one of these processes includes controlling the pumping of fluid based on repeated measurements of the parameter to produce a desired fluid flow through the output. A corresponding system for dispensing fluid implements these processes.

To detect air in a fluid delivery line of an infusion system, infusion fluid is pumped through a fluid delivery line adjacent to at least one sensor. A signal is transmitted and received using the at least one sensor into and from the fluid delivery line. The at least one sensor is operated, using at least one processor, at a modified frequency which is different than a resonant frequency of the at least one sensor to reduce an amplitude of an output of the signal transmitted from the at least one sensor to a level which is lower than a saturation level of the analog-to-digital converter to avoid over-saturating the analog-to-digital converter. The signal received by the at least one sensor is converted from analog to digital using an analog-to-digital converter. The at least one processor determines whether air is in the fluid delivery line based on the converted digital signal.