Abstract: A tubing occluder pump is provided that includes a structure for occluding flexible tubing that distributes a relatively low amount of force at the transverse center portion of the tubing during occlusion and a relatively large force at the distal transverse ends of the occluded tubing, utilizing a mechanical advantage. The occluding structure includes a recessed first occluding surface and a projecting occluding surface. The tubing occluding surface is configured so that one-half of a transverse section of occluded tubing generally conforms to its original shape and so that most of the strain energy stored within the occluded tubing is utilized to return the other half of the tubing to an open position. The occluding structure may form part of either a peristaltic pump or a linear pump.

Abstract: A monitor and control system for water purification apparatus includes first and second conductivity cells located in the input water path and the purified product water path of the apparatus, respectively. The conductivity cells produce output signals exhibiting amplitudes representative of the impurity concentrations in the respective water paths. These signals are detected and modified by circuitry which imposes logarithmic characteristics upon the two signals. The two logarithmically variable signals are differentially combined to produce a signal for display which is representative of the percent of impurity rejection of the water purification apparatus. The detected signal are also individually combined with signals representative of the temperature of the water being processed. The temperature-corrected signals are then displayed to provide an indication of the impurity concentrations of the input and purified water paths in parts per million.

Abstract: The present invention provides an accurate method and apparatus for monitoring the drop flow rate from a fluid source. The drops are indirectly sensed by piezoelectric means mounted on a drip chamber when the drops impinge on a fluid surface in the chamber. The chamber can include a second differential piezoelectric sensing element, which provides a noise reference signal which can be subtracted from the drop sensing signal. The volume of the fluid drops sensed can be determined. The sensing element can be incorporated in open and closed loop disposable chamber modules which can include both monitoring and occlusion valving functions integral therewith.

Abstract: A medical liquid administration set is disclosed for the sequential administration of two medical liquid sources which can be delivered at different liquid flow rates without readjustment of the administration set. The set includes first and second conduits for connection to first and second medical liquid sources, respectively. A cross-over branch places the second conduit in communication with the distal end of the first conduit. A common conduit extends downstream of the first conduit and cross-over branch. The common and second conduits are in communication at their downstream ends, just upstream of the set outlet. Separately adjustable liquid delivery rate control means are disposed on the common and second conduits to allow for separate delivery rates of the first and second liquid sources. One-way valves are disposed in the cross-over branch and the first conduit to permit liquid flow only in the downstream direction.

Abstract: A system is provided for increasing the control accuracy of a motor 12 which feeds back a signal to a motor control circuit 14. The motor control circuit output 20 provides a command voltage to the motor winding. The motor control circuit 14 has an input 18 for receiving an input command from a source external of the motor 12. The actual speed of the motor shaft 26 is sensed and data representative of this actual speed is transmitted through a frequency to voltage converter 36 and an analog to digital converter 40 to a microprocessor 46 which calculates an input command based upon the received actual motor speed data. The input command is transmitted from the microprocessor 46 through a digital to analog converter 58 to the motor control circuit input 18. The command voltage from the output 20 of the motor control circuit 14 is adjusted in response to variations in the input command transmitted from the microprocessor 46.

Abstract: A star coupler is described in which a plurality of optical fibers are embedded in a first rigid substrate. The fibers may be etched or polished to a core area to expose a first evanescent coupling zone. A second substrate has one or more optical fibers embedded in the second substrate. The optical fibers in the second substrate are similarly etched or polished to expose a second evanescent zone area. The two substrates are then placed in juxtaposition with each other so that the first and second evanescent zones are in close proximity to one another so that evanescent coupling may occur between the plurality of fibers in the first evanescent zone and one or more optical fibers in the second evanescent zone.

Abstract: An optical interferometer matrix is described which includes a reference waveguide for optically transmitting a reference signal. The optical interferometer matrix further includes a signal source waveguide for optically transmitting a source signal which has been modulated with respect to the reference signal in response to an applied physical effect. The physical effect may be, for example, thermal, acoustic, hydrodynamic, electrical, electromechanical or magnetic. The reference and signal waveguides are then optically coupled to one another at two different points so that interference between the light in the waveguides occurs under two different phase conditions, with a phase difference between these conditions which approaches .pi./2 radians. In the preferred embodiment, the two points of optical coupling are confined in a small space so that thermal- or pressure-induced differential phase changes of light between the first and second coupling points are negligible.

Abstract: A transistor switching circuit for switching a power transistor (28) from an on state to an off state at high speeds with minimal dissipation of power and without encountering secondary breakdown in the power transistor. The transistor switching circuit includes a transformer (36) having a secondary winding (35) connected to the base (30) of the power transistor (28) and a primary winding (49) connected to switching logic (38), the transformer (36) providing galvanic isolation between the power transistor (28) and the switching logic (38). The switching logic (38) includes a first switch (50) and a second switch (52). With the first switch (50) on and the second switch (52) off, the secondary winding (35) of the transformer (36) develops a positive base current applied to the power transistor (28) turning the transistor on.

Abstract: A photoluminescent indicator apparatus having automatic feedback means to maintain the sensitivity of the indicator apparatus with respect to variations in environmental conditions. The apparatus includes a sample of photoluminescent material having a photoluminescent decay rate which varies as a function of environmental conditions. The sample is positioned in a remote location having some unknown aspect of the environment desired to be measured. The sample is optically excited with a modulating signal to generate an excitation output signal functionally dependent on the modulating signal and indicative of the unknown environmental condition. A phase detection means is provided for comparing difference in phase between a phase reference signal and the excitation output signal to generate a phase differential signal functionally related to the photoluminescent decay rate of the sample.

Abstract: A transducer (14) including an optical fiber core (15) having a first refractive index profile, and an optical cladding (16) encircling the core and having a second refractive index profile different from that of the profile of the optical core. At least one of the core and cladding is formed of a photoresponsive material providing a variable difference between the refractive indices of the core and cladding as a function of a physical effect applied to the transducer. Light may be propagated through the core from a suitable light source (18) and the light which is lost from the core to the cladding may be detected by a suitable detector (22,23) providing an output signal corresponding to the force applied to the transducer. In one form, the detector receives light from the end (21) of the transducer, and in another form, the detector (23) receives light through the outer surface (24) of the transducer.

Abstract: A portable hose fitting crimping machine using an interchangeable cartridge die assembly in conjunction with a portable framework so as to provide for an efficient means for crimping hoses and couplings of different sizes without reliability and calibration problems.

Abstract: A dust cover for a quick disconnect coupling in which a clamping means is attached to the female half of the coupler and supports spring means which closes the cover and aligns the same on two mutually perpendicular axes.