Abstract: A pressure catheter for monitoring changes in pressure within the body is comprised of an outer tube containing a fluid channel and a closed air column having a pressure-compliant member which is deformable upon an increase in pressure. A change in pressure deforms the pressure-compliant member, which modifies the pressure in the air column, and is translated to a pressure sensor, which converts the pressure change data to an electrical signal recognizable by a fetal monitor. The outer tube employs a window extending along at least a portion of the side thereof for viewing of bodily fluids moving through the fluid channel from the body in which the catheter is inserted toward the proximal catheter end. The pressure catheter of the present invention is particularly suitable for intrauterine pressure monitoring during labor. Viewing of amniotic fluid through the window facilitates verification of proper catheter tip placement within the amniotic fluid space.

Abstract: Novel methods and apparatuses for terminating busses are disclosed based upon the number of devices secured to the bus. The impedance of the bus lines varies with the number of devices coupled to the bus. The number of devices coupled to the bus line is determined and a precision resistor is selected based upon the number of devices coupled to the bus matching the expected impedance of the bus. A voltage is generated across the precision resistor with a known current and that voltage is compared with the voltage generated across a controllable resistances such as a FET biased in the linear mode with a like current passing through the fed. A feedback network provides a control voltage to the control electrode of the FET to control the resistance of the FET so that the resistance of the FET equals the selected precision resistance.

Abstract: An electronic calculator is disclosed for calculating important obstetrical dates based on the entry of certain variables or information. The electronic calculator is structured to accept input relating to the last menstrual period, conception date, estimated date of confinement and estimated gestational age. The entry of any one of these variables of information, along with the entry of a reference date, allows the calculator to calculate the other, remaining variables. The electronic calculator provides information similar to that conventionally obtained from an obstetric wheel or birth wheel, but additionally provides for the capability of recalculating and updating the obstetric dates based on new or additional information input into the calculator. The dates calculated using the invention are, therefore, more accurate and can be stored in memory for recall at each subsequent obstetrical visit.

Abstract: A controllable active terminator for a computer bus providing low power, small size, switchable termination of a computer bus having a plurality of conductors. The active terminator includes a voltage reference circuit, an enable circuit, a buffer amplifier, and a plurality of output cells. The voltage reference circuit includes a power down circuit which turns the voltage reference circuit off, using the same control signal which also disconnects the termination resistors and output transistors of the output cells. The terminator uses FET technology to produce a low-power, small size, controllable terminator having stable and reliable operating characteristics. The amplifiers used in the active terminator comprise CMOS devices and thus are relatively small and consume relatively low power. When enabled, the voltage reference circuit is used to establish a reference voltage for the linear operation of the output transistors in the output cell. The output current is supplied by terminator power.

Abstract: A voltage regulator for use in controllable bus terminators providing a source and a sink to a regulated output without clamping circuitry is disclosed. The regulator maintains a voltage at a node by sourcing current into the node when a cable line sinks current from the node and sinking current from the node when a cable line sources current into the node. By avoiding the use of clamping circuitry, a voltage deadband between the regulator output voltage and the clamp circuit voltage is avoided.

Abstract: A non-linear transmission line terminator (10) is provided in which voltages appearing on a transmission line are sensed. If the voltage level sensed is equal to a predetermined voltage, the non-linear transmission line terminator (10) couples a reference voltage to the transmission line. If the sensed voltage is less than the predetermined voltage, the non-linear transmission line terminator (10) delivers current to the transmission line having a magnitude related non-linearly to the sensed voltage.

Abstract: A process and an apparatus are described for separation of water and solids from oil sands froth in which heated froth is fed into a gravity settling vessel at a level below a bitumen-water interface established between a bitumen froth layer floating on a quiescent body of water whereby water and solids contained in the froth separate from the froth stream, the oil rises to accumulate in the bitumen froth layer, and the solids fall by gravity to the bottom of the gravity settling vessel. The apparatus comprises an injector manifold suspended horizontally within the vessel below the bitumen-water interface, said injector manifold having a plurality of equispaced, inwardly facing openings for the inward discharge of oil sands froth into the body of water. The injector ring manifold may also have a plurality of outwardly facing openings for both inward and outward discharge of froth.

Abstract: A system and method for muliplexing two lumens of a catheter to a single pressure transducer and monitor setup such that the pressure found in either of the two lumens may be alternately monitored. Included in the present invention is a pressure mulitplexing valve provided with a four-port body and a rotor which may be selectively rotated to either of two monitoring positions. The rotor is privided with passageways that interconnect the ports. In one embodiment both catheter lumens are always connected to a medical infusion device regardless of which lumen is connected to the transducer. In another embodiment, one lumen is shut off when not connected to the transducer. The present invention provides a compact system removably mounted on a single carrier.

Abstract: A method of accurately mixing gases in desired proportions which comprises establishing the gases to be mixed at a uniform pressure; sequentially feeding the gases through a common restrictor for proportionate time periods to give the gas mix desired. The apparatus used includes a pressurizing gas reservoir unit which adjusts all gases to be mixed to have a common pressure; electronically actuated rapid response fluidic interface valves; a common restrictor through which the gases are passed to a receiving and mixing chamber; and timing means controlling the valves to allow gases to be sequentially passed therethrough for pre-set time periods.

Abstract: A method of accurately mixing gases in desired proportions which comprises establishing the gases to be mixed at a uniform pressure; sequentially feeding the gases through a common restrictor for proportionate time periods to give the gas mix desired.