Abstract: A hemapheresis system and method in accordance with the invention comprises a stationary closed housing concentric about a central axis and a feed system that moves blood upwardly from the housing lower end toward an outlet port adjacent a substantially closed upper end. Within the stationary housing is a double walled rotor concentric with the housing and rotatable by magnetic means within the housing on sealed end bearings. The space between the rotor walls defines a centrifugation gap into which whole blood is passed and within which centrifugal separation takes place as the rotor is spun at a relatively low rate. Whole blood also seeks to flow upwardly in the space between the rotor and housing, but this path is arranged to have a substantially higher flow impedance, so that the preferential path is within the centrifugation gap.

Abstract: Dynamic variation of the functional properties of a surface acoustic wave (SAW) device is achieved by using photoconductive material on a wave propagating substrate and illuminating the material with changing light patterns. Photoconductive materials, such as lead sulfide or cadmium sulfide, are used that are essentially dielectrics and have substantially no effect on SAW propagation when not illuminated, but under suitable levels of illumination become resistive and interact with the electric fields of the waves to dissipate energy as heat. Scanning control of the areas of illumination may be used to attenuate sidelobes and scattering in a wideband system, while intensity variations may be used to amplitude modulate the waves.

Abstract: A system for processing of multifrequency input signals to provide a Fourier transform output is provided which can, for example, partition a wide input frequency band into a number of narrow bands and concurrently detect the presence of one or more signals of different frequency in the input. An array of input wave energy transducers is energized with the broadband signal, and by virtue of progressive shifting of the transducers relative to the propagating medium (such as a surface acoustic wave substrate) generates one or more composite wavefronts dispersed at frequency dependent angles. An array of output transducers are disposed along a focal region, each responding to wave energy within a specific frequency range received at its location due to dispersion of the composite wavefront. Such systems preserve phase coherence while responding to multiple input frequencies, but are compact and mass producible at relatively low cost.

Abstract: A read amplifier generates pulses in response to the transitions of a phase encoded signal and selectively gates the pulses to an output and to a retriggerable one shot multivibrator under the control of inhibit pulses produced by the multivibrator. During a preamble of the data signal in which a known sequence of zeros is produced, a decade counter prevents generation of pulses in response to the polarity return transitions between the zeros and prevents the inhibit pulses from being applied to gate the pulses produced by the data signal until a predetermined number of zero pulses has been counted. During the preamble the inhibit pulses at the output of the multivibrator are averaged and compared with a reference so as to adjust the duty cycle of the multivibrator to produce inhibit pulses which are 70 percent of the duration of the bit intervals of the data signal.