Abstract: A method and apparatus are disclosed for using an acceleration of a flow control system to determine the density of a fluid relative to the density of an in-line flow object.

Abstract: A fluid flow control system using flow rate changes to extract additional information from an in-line flow sensor. The system provides the ability to determine a position of a movable flow sensor element of a flow sensor by illuminating a photosensitive pixel array with a light source to create a first set of pixel intensity values, introducing an abrupt change to the fluid driving pressure, illuminating the photosensitive pixel array with a light source to create a second set of pixel intensity values, and calculating the difference between the first and second sets of pixel intensity values as a function of pixel position.

Abstract: A system for controlled delivery of medicinal fluid includes a fluid pathway assembly defining a fluid pathway and including means for calculating a first calculated fluid flow rate using gas laws. The fluid pathway assembly has an inline flow sensor element received within the fluid pathway movable in response to fluid flowing in the fluid pathway. A flow control device is removably attached to the fluid pathway assembly and has a sensor for sensing a position of the inline flow sensor element in the fluid pathway, the position of the inline flow sensor element being representative of a second calculated fluid flow rate. The fluid pathway assembly includes a variable flow resistor adjustable to regulate a rate of fluid flow in the fluid pathway assembly. A drive mechanism attached to the flow control device is operably coupled to the variable flow resistor when the flow control device is attached to the fluid pathway assembly.

Abstract: A fluid flow control system using flow rates to extract additional information from an in-line flow sensor. The system provides the ability to determine a position of a movable flow sensor element of a flow sensor by illuminating a photosensitive pixel array with a light source to create a first set of pixel intensity values introducing an abrupt change to the fluid driving pressure, illuminating the photosensitive pixel array with a light source to create a second set of pixel intensity values, and calculating the difference between the first and second sets of pixel intensity values as a function of pixel position.

Abstract: An infusion pump and method are provided which combine flow rate measurements calibrated by accurate volume measurements over time.

Abstract: An infusion pump and method are provided which control flow rates with variable fluid pressure and variable series flow resistance.

Abstract: A method and apparatus are disclosed for using an acceleration of a flow control system to determine the density of a fluid relative to the density of an in-line flow object.

Abstract: A method and apparatus are disclosed for using flow rate changes to extract additional information from an in-line flow sensor.

Abstract: A system and method for measuring fluid volume and changes in fluid volume over time, using a simple, low cost architecture is described.

Abstract: An infusion pump and method are provided which control flow rates with variable fluid pressure and variable series flow resistance.

Abstract: Methods and apparatus for air content and pressure measurement of sample fluid, especially sample fluid in association with an infusion pump. Volume change in a chamber as the chamber transitions between negative and positive pressure relates to the air content in the chamber. In particular, in an infusion pump, the volume change of infusion fluid as it transitions between being under negative pressure and positive pressure within a cassette central chamber, e.g., pumping chamber, relates to the air content in the infusion fluid. The outlet pressure of the cassette central chamber, e.g., blood pressure, can be monitored based on the cassette central chamber pressure.

Abstract: Methods and apparatus for air content and pressure measurement of sample fluid, especially sample fluid in association with an infusion pump. Volume change in a chamber as the chamber transitions between negative and positive pressure relates to the air content in the chamber. In particular, in an infusion pump, the volume change of infusion fluid as it transitions between being under negative pressure and positive pressure within a cassette central chamber, e.g., pumping chamber, relates to the air content in the infusion fluid. The outlet pressure of the cassette central chamber, e.g., blood pressure, can be monitored based on the cassette central chamber pressure.

Abstract: A device for control of fluid flow with closed loop quasi static adjustment of in-line pressure-based resistance. The disclosed device and methods of using the device provide for the ability to control a flow rate with a highly portable device; the ability for an operator to safely use the device with minimal training; the ability to automatically switch between a primary and secondary fluid; the ability to maintain a flow rate through a tubing set even when the control device is removed; and the ability to measure fluids introduced with a manual bolus injection.

Abstract: A controlled force fluid delivery system which provides fluid delivery with continuity over a wide range of flow rate. The system sets the force provided by an energy storage device, e.g. a spring and the opening of system outlet valve in response to a low volume due command. Specifically at a low flow rate, the controlled force is decreased and/or the outlet valve of the system closes before the fluid flow reaches stable velocity whereas at a high flow rate the controlled force is increased and/or the outlet valve does not close until the fluid stops flowing. The system also reduces fluid flow rate variation in part by adjusting the timing and the level of opening and closing the outlet valve, and the speed of pumping the fluid out of system central cassette chamber.

Abstract: A cassette for controlling fluid flow from a source to a sink, for example, a patient. The cassette comprises a housing, and a passive inlet valve for hydraulically controlling pressurized fluid flow from the inlet valve to a central chamber, and an actuatable outlet valve. The central chamber provides a fluid pathway between the inlet and outlet valves. The cassette further comprises a piston assembly for exerting pressure in the central chamber. The piston assembly comprises a movable member, a covering for the moveable member; and a flexible interface between the member and the housing for providing near frictionless movement between the member and the housing.

Abstract: Methods and apparatus for air content and pressure measurement of sample fluid, especially sample fluid in association with an infusion pump. Volume change in a chamber as the chamber transitions between negative and positive pressure relates to the air content in the chamber. In particular, in an infusion pump, the volume change of infusion fluid as it transitions between being under negative pressure and positive pressure within a cassette central chamber, e.g., pumping chamber, relates to the air content in the infusion fluid. The outlet pressure of the cassette central chamber, e.g., blood pressure, can be monitored based on the cassette central chamber pressure.

Abstract: An infusion regulation system for regulating, monitoring, and control of the intravenous infusion of fluids into an animate body. A delivery tube receives and diverges from a fluid supply inlet tube and converges to deliver fluid to an outlet tube to the cannula. A transverse, intermediately positioned volume control tube having a movable control member therein is ported to said divaricated delivery tube. Regulated valve members operate in diagonally paired tandem fashion to control and restrict the flow through the system in an alternating and traverse course. Means for monitoring instantaneous flow through the tubing network allow resistance/pressure changes to be noted and acted upon, either with clinical alarms or through servo mechanisms. Means for selectively increasing the infusate driving pressure allow servo controlled high pressure infusions as well as low pressure, gravity driven infusions.