Abstract: A medical pump with a closed loop stroke feedback system and method, for use with a pumping chamber, for example in a cassette, is disclosed. The pump includes a pumping element that intermittently pressurizes a pumping chamber during a pumping cycle. A pressure sensor detects the pressure exerted by the pumping element on the pumping chamber. A position sensor detects the position of the pumping element. A processing unit processes pressure data from the pressure sensor and position data from the position sensor to determine a calculated stroke volume of the pump for a pump cycle, and to adjust a stroke frequency of the pump to compensate for variation in the stroke volume.

Abstract: A medical pump with an improved continuity low flow delivery system and method for use with a pumping chamber, for example in a cassette, is disclosed. The pump includes a pump drive for exerting a force on the pumping chamber and a sensor for sensing the force/pressure exerted by the pump drive on the pumping chamber. The pump drive position sensor senses the position of the pump drive. The medical pump also includes a processing unit and a memory having a programming code adapted to calculate the rate of change of the sensed force/pressure values and determine whether the rate of change of the sensed force/pressure values meets a rate of change threshold. Once the rate of change threshold is met, the programming code is adapted to calculate a remaining pump drive travel value for determining how much farther the pump drive should travel before the end of an effective pump cycle.

Abstract: A formed, filled, and sealed flexible container is provided with an attached port assembly. The container is formed from film folded to define opposing sidewalls which are sealed to define a chamber for sterile fluid. A hollow, tubular port member is provided with a V-shaped saddle and is sealed to the bottom of the container. The film at the bottom of the container is received in the saddle. A unique shoulder is defined by the tubular port member. The film is sealed to the shoulder and to the saddle of the port member. A hollow penetrator element is slidably disposed within the port member and is movable between a retracted position and an advanced position to puncture the film whereby fluid can flow out of the container. Internal formations are provided to guide and to limit the movement of the penetrator element. The container film may be provided with a crease along the bottom of the container.

Abstract: A method and apparatus are provided for controlling the dispensing of a primary liquid from a pressurized source of primary liquid. Primary liquid is admitted through an inlet valve to a primary chamber having a primary element which is biased toward an initial position but is movable away from the initial position when subjected to the source pressure of the primary liquid. A sensor determines when the primary element has moved away from an initial position to a predetermined final position, and the inlet valve is closed in response thereto. The difference between the initial and final positions defines a predetermined dispensing volume. An outlet valve is opened to dispense the dispensing volume under the biasing force of the primary element which returns to the initial position. A sensor determines when the primary element has returned to the initial position, and the outlet valve is closed in response thereto.

Abstract: A solution pumping system including a disposable pump cassette is disclosed, with the system configured for efficient and accurate preparation of parenteral admixture solutions. The system includes a pump driver having a reciprocable pump plunger and a plurality of associated valve actuators. The disposable pump cassette of the system is configured for removable positioning in operative association with the pump driver, and includes a positive displacement pump configured for operation by the reciprocable pump plunger. The pump cassette further includes a plurality of liquid inlets, and at least one liquid outlet joined in fluid communication with the inlets. By selective operation of the valve actuators of the pump driver, one or more selected source solutions are drawn through the pump inlets by the positive displacement pump, and directed through the pump outlet to an admixture solution container.

Abstract: The present invention relates to a compression load cell used to monitor pressure in a diapragm cassette pumping system. A plunger is axially slidable in a linear bearing and has a first end in contact with the cassette and the second end in contact with the load cell. The force signals have a direct relationship with the pressure in the cassette.

Abstract: A solution pumping system includes a compressible pump cassette having front and rear body members, and an elastomeric diaphragm positioned therebetween. The front and rear body members are joined to each other for limited, relative movement, which movement effects compression of the diaphragm. The pump cassette is removably positionable in a pump driver of the system, which can be configured to effect compression of the cassette for use. In this way, the desired compression of the diaphragm during use can be achieved, while avoiding problems associated with compression set or load decay during storage of the cassette prior to use.