Abstract: Systems and methods for purposeful computing are disclosed that, among other things, include a user purpose class resource information computing environment. Such environment supports resource purpose classes, and further supports resource identification information sets that characterize their respective subject matter resources. The computing environment can be used to identify and evaluate one or more purpose class subject matter resource members.

Abstract: Ultrasonic bubble detection apparatus utilizes a typically one-piece, rigid housing having a channel defined therein for receiving flow tubing in which bubbles are to be detected. First and second ultrasonic sending and receiving transducers are positioned on opposite sides of the channel, with an aperture communicating between each of the transducers and the channel, the aperture being filled with an elastomeric material capable of transmitting ultrasound energy between the channel and each transducer means. An air-containing slot may be positioned at the bottom of the channel to hinder the propagation of ultrasound energy through the housing from the first to the second transducer by a route other than one passing through the elastomeric material. Also, a novel shape for the apertures, and the elastomeric material filling them, is disclosed.

Abstract: Metering apparatus for controlling the flow of fluid through a fluid infusion system at an operator-designated rate includes a single-use cassette having a syringe-type pump in the flow system. The cassette is removably mounted on actuator apparatus which drives the syringe plunger through alternate fill and pump modes to advance fluid through the system. To provide compensation for the lack of flow in the system during fill strokes, the plunger is advanced at a higher compensation rate for first and second portions of the pump stroke immediately preceding and immediately following each fill stroke, with the pump stroke advancing at the designated rate therebetween. This results in an average flow rate which corresponds to the designated rate. By making the first and second compensations of equal duration, the effect of the fill cycles on the regularity of the average flow rate is minimized.

Abstract: The photometer is adapted for sensing radiation emitted by a chemical sample held in a cuvette received in a first compartment and includes a highly sensitive photomultiplier in a second compartment adjacent the first compartment for detecting fluorescent radiation emitted by the chemical sample and passing through an opening between the compartments. A mechanical protector assembly is provided for protecting the photomultiplier from ambient light and includes a movable light shield movable between a first position blocking the opening and a second position not blocking the opening. A knob is provided for moving the light shield to the first position to protect the photomultiplier from light entering from the first compartment when the first compartment is opened for insertion or removal of a cuvette, and for moving the light shield to the second position not blocking the opening to permit radiation emitted by the chemical sample to impinge upon the photomultiplier in the second compartment.