Abstract: A system and a method for detecting the presence of air bubbles in an intravenous (IV) line supplying a medicinal liquid to a patient. An air bubble sensor includes an ultrasonic transmitter acoustically coupled to an ultrasonic receiver to detect the presence of a gas (e.g., air) in a portion of a tube comprising the IV line. The transmitter and receiver are mounted on pivoting transducers that are disposed on opposite sides of the tube. A spring biases the transducers inwardly toward each other so that the transmitter and receiver contact opposite sides of the tubing. This assembly automatically accommodates different sizes of tubing and tubing of a relatively wide range of stiffness. The tube is connected to a disposable pumping cassette that is engaged in a pump chassis on which the transducers are pivotally mounted.

Abstract: A system and a method for detecting the presence of an occlusion in an intravenous (IV) line supplying a medicinal liquid to a patient. Two pressure occlusion sensors are employed to produce a value for the proximal and distal pressures within an IV pumping cassette that is disposed in the fluid path of the IV line. Each pressure occlusion sensor includes a strain gauge connected to a leaf spring that is fixed at one end within a pump chassis and a rod that is disposed transverse to the leaf spring. Each rod has one end that responds to the force of a portion of an elastomeric membrane inside the pumping cassette and another end that contacts a free end of the leaf spring. When a leaf spring is flexed by the movement of a rod, the strain gauge mounted on the leaf spring produces a differential voltage that corresponds to a fluid pressure within the pumping cassette.

Abstract: A system and method for mounting a piezoelectric crystal and forming electrical connections to it in an air bubble sensor (10). Piezoelectric crystals (26, 54) are mounted against inner surfaces of two opposed cavities (16, 44) using a conductive epoxy. The conductive epoxy both adhesively secures the crystals in place and provides conductive paths to adjacent conductive pins (28, 30, 46, and 48). To mount one of the piezoelectric crystals, a drop of the conductive epoxy is placed on an inner planar surface of the cavity and the crystal is pushed into the conductive epoxy, forcing the conductive epoxy to flow from under the crystal and into contact with one of the conductive pins. The inner end of another conductive pin is bent over the crystal and a drop of the conductive epoxy is then placed on the outwardly facing surface of the piezoelectric crystal, electrically and mechanically coupling the end of the conductive pin that was bent over, to the outwardly facing surface of the crystal.

Abstract: A magnetic head assembly including a slider (15) for supporting a magnetic transducer (12) adjacent the surface of a recording media (14) on an air film, said slider including an air bearing member (26) having a peripheral wall (38) extending toward said media and presenting a substantially equal cross sectional area to the air film moving with the media as the head is skewed slightly relative to the oncoming air film.

Abstract: A slider for flying along a recording surface and carrying a recording head (19,20) for recording data, comprising an air bearing region (12,14) to create a positive pressure region tending to support the slider, and a negative pressure region (21) tending to hold the slider close to the recording surface, with buffer pads (27,28) and grooves (25,26) between the positive and negative pressure regions to create a neutral pressure zone separation.

Abstract: A helical wrap tape transport system having a plurality of components cooperating to provide a low friction and highly accurate transport of magnetic tape for video broadcasting. The transport system has a helical scanner assembly with a rotating scanning drum having helical surface V-grooves which create an air bearing for magnetic tape wrapped across the drum and oppositely mounted recording transducers which permit continuous recording on a 180.degree. tape wrap around the drum, and a stationary drum on a common axis with the rotating drum having a fixed control track transducer for synchronizing tape transport at the scanning assembly. The transport system has further, air bearing guide posts and a pair of vacuum columns which continuously monitor a tape supply loop which in combination with the guide posts provide a section of low inertia recording tape, the transport of which can be controlled by a single high friction drive capstan.