Abstract: A continuous fluid injection pump delivers a constant flow of fluid under variable loads.

Abstract: The present invention is a closed loop system for transfer of a fluid through a line between a reservoir and a vessel in a manner to provide a flow-related parameter at a selected value. The system will have major use as a non-gravity-dependent infusion device. The system comprises a pressurizable reservoir containing a quantity of the fluid; means to control the flow of the fluid being transferred in a conduit between the reservoir and the vessel, including means to pressurize the reservoir; reference means with an output related to a selectable value of the flow-related parameter; means to measure the flow-related parameter; means to compare the outputs of the reference means and the measuring means; and means responsive to the output of the comparator means to adjust the fluid flow control means to provide the selected value of the flow-related parameter. Normally, the flow-related parameter will be the fluid flow rate in the conduit or the change of fluid volume in the reservoir.

Abstract: The invention is a system for inflating and deflating an intra-aortic balloon through an isolating safety chamber, which utilizes a flexible element to separate the balloon actuating gas from the driving air in a closed balloon circuit. Pressure and vacuum are supplied by separate pressure and vacuum stages, which are driven by the same shaft. The shaft speed is varied to control one of the pressures at a selected value, whereby the other pressure is maintained at a constant value within an allowable band.

Abstract: The invention is a constant flow pump control system that compensates for a change in gas flow rate that is caused by a change in the load resistance, by making the speed change inversely with the change in load resistance, desirably by sensing the change in pressure and changing speed by an amount related to the pump performance characteristic that is required to restore the flow rate to its selected value. In a preferred embodiment the system includes a closed loop pump speed control in which a selected flow rate reference is combined with a pressure feedback to provide an inverse change in the pump speed reference function or a direct change in the motor speed feedback function to compensate for the change in flow rate caused by a change in flow resistance.

Abstract: Pumping action is performed by a unitary, sealed, easily replaceable pumping element, comprising a housing with a longitudinal axis, a pumping chamber at one end of the housing, an outlet in a wall of the pumping chamber, an inlet in the housing, axially spaced from the pumping chamber, and a circulator in the pumping chamber, mounted on a support which is free of the rotating elements, and which provides freedom of motion for the circulator to revolve in an orbital path about the longitudinal axis. Magnetic means external to the housing drive the circulator in its orbital path by magnetic action through the walls of the housing. The orbital circulator contains a magnetic element and is driven in a circular path by an external rotating magnetic field.

Abstract: An oscillating centrifugal pump is disclosed which has a housing, an impeller and a magnetic drive. The housing has a longitudinal axis, having a front end and a rear end that are spaced apart on the longitudinal axis. The housing includes a pumping chamber within and at the front end of the housing. The pumping chamber is created by a continuous transverse front wall that closes the pumping chamber at the front end of the housing, a transverse rear wall axially-spaced from said transverse front wall and has a central opening, and a longitudinal closed side wall which is between the front and rear transverse walls. The housing is closed except for an inlet in the housing that is outside of and is axially spaced from the pumping chamber. An outlet is provided in the longitudinal side wall of the pumping chamber, and the housing is free of mechanical bearings, flexing or external seals or apertures that lead to the exterior of the housing except for said inlet and outlet.

Abstract: The present invention is concerned with a controlled sampler device which draws a gas through a contaminant collection device. The controlled sampler comprises an inlet to the sampler; a pump adapted to draw a gas through the inlet; a reference element that provides a reference signal; a feedback element with an output; a differential pressure transducer to compare the reference signal with the feedback signal to provide an error signal that is linearly related to selected and measured values; an integrator with an input connected to the output of the differential pressure transducer and to a summer; and means between the differential pressure transducer and the summer to provide a signal to the summer which is proportional to the error signal, which is passed to a driver which regulates the speed of an electric motor to change the flow rate to reduce the error signal to a null.

Abstract: The present invention provides a system that provides a gas delivery system which is capable of cyclically delivering a selectable volume of gas at a predetermined rate for a predetermined interval. This system is useful as a miniature respirator or as a wearable driver for a pneumatic total artificial heart. The system comprises compressor means; valve means to direct gas from the compressor to the line; control means to drive the compressor motor and actuate the valve means; means to measure flow rate and determine delivery volume; and means to adjust the compressor speed.

Abstract: A dynamic type of mass flowmeter is disclosed in which an S-shaped conduit with supported ends is vibrated in a direction transverse to the plane of the conduit, and the force couple about an axis orthogonal to the longitudinal axis of the S-shaped conduit and also to the direction of vibration is sensed as a measure of the mass flow rate through the conduit.

Abstract: Constant selected speed running of an electric motor, with a varying mechanical load, is achieved by intermittently pulsing the motor at full power and comparing the back EMF of the motor, between power pulses, with a selected speed voltage, to accordingly control application of the power pulses. A particular control circuit is disclosed which permits operation of a pocket-sized system, powered by a three cell battery, to achieve substantially constant speed, at normally varying loads, throughout a ten hour period, with back EMFs at selected values between 0.01 volt (motor barely turning) and 2.0 volts (high speed). The system is useful in a personal air sampler, used to monitor a workman's exposure to noxious ingredients of breathing air.

Abstract: A system for the linear control and calibration of the flow of fluid through a pump in which the pump has a linear flow rate-to-fluid propeller speed relationship over a range of flow rates. A DC motor driving the fluid propeller has a linear drive speed-to-armature voltage relationship over a corresponding range of drive speeds. The voltage applied to the armature is regulated DC, the value of which provides an indication of the fluid flow rate. The system has particular utility in portable air pollutant measuring applications where a measured volume of air is pumped through a filter tube filled with a porous solid sorbent which is later subjected to chemical analysis.