Abstract: A fractionally spaced adaptive equalizer is disclosed wherein the coefficients (C.sub.-2 to C.sub.+2) are updated synchronously by an integral -T error circuit (40) and alternately by a fractional =T error circuit (48). This arrangement features a single unique minimum for the adaptive structure thereby preventing the coefficient drift to very large values so coefficient tap leakage is not required to minimize coefficient values. The adaptive characteristic is well suited for linearly dispersive channels, such as exhibited during terrestrial radio transmission during tropospheric multipath propagation. The inventive principles are broadly applicable to any of the well known algorithms for adapting digital filters. A configuration of fractionally spaced equalizers (70.sub.1 -70.sub.4) provides the benefits of Nyquist-rate coefficient updating for a dual rail quadrature amplitude modulated (QAM) signal application.

Abstract: From a heart sound signal input the occurrence of a first occurring heart sound is detected. Thereupon a predetermined heart sound enable window time is established, which for a first detection cycle is set to approximately the diastolic interval for the maximum heart rate to be detected. If a second heart sound occurs within this heart sound enable window time, this second heart sound is detected as a systole heart sound. The first heart sound may be detected as a diastole heart sound. If a second heart sound does not occur within the heart sound enable window time the procedure is repeated with increasing heart sound enable time as long as a second heart sound occurs within an increased heart sound enable window time. Cardiac cycle data provided by diagnostic equipment is gated from discriminated heart sound signals and also ECG signals to provide more meaningful diagnostic analysis.

Abstract: From a heart sound signal input the occurrence of a first occurring heart sound is detected. Thereupon a predetermined heart sound enable window time is established, which for a first detection cycle is set to approximately the diastolic interval for the maximum heart rate to be detected. If a second heart sound occurs within this heart sound enable window time, this second heart sound is detected as a systole heart sound. The first heart sound may be detected as a diastole heart sound. If a second heart sound does not occur within the heart sound enable window time the procedure is repeated with increasing heart sound enable time as long as a second heart sound occurs within an increased heart sound enable window time. For monitoring remotely or by a using recording, an ECG signal is modulated and combined with the associated heart sound signal for use as a single combined signal.

Abstract: This invention is a two-dimensional pressure sensor which can be used to determine a pressure distribution across a two-dimensional object which comes in contact with the sensor. The sensor includes a light source, a matrix of light transmitting fiber endings which includes an alternate pattern of transmitting and receiving light fibers, a transmitting fiber sub-array located a distance from the matrix and composed of transmitting fibers, a receiving fiber sub-array located a distance from the matrix and composed of receiving fibers, a semi-transparent deformable medium located above the matrix, a retro-reflective material located on top of the deformable medium, a flexible membrane located adjacent said retro-reflective material and positioned to contact an object, and apparatus such as a photodetector array, for detecting light which is reflected by the retro-reflective material and transmitted to the receiving fiber sub-array.

Abstract: Apparatus is disclosed which is capable of determining the two-dimensional connectivity profile of a prescribed binary variable associated with a surface. This apparatus comprises a "connectivity-matrix" of switch cells and a two-dimensional sensory array of sensor cells. The sensor cells are responsive to the presence or absence of the binary variable and control corresponding ones of the switch cells in the connectivity matrix.

Abstract: A method for laser soldering of soldered connections of flexible wiring, which are provided at their contact points with a flux. The parts to be joined are held together by a clamp made of translucent material. The transmission of heat for the soldering process is provided by a non-contact laser beam. When the laser beam is applied the solder on both strip conductors melts. Upon removing the heat source the connection hardens to a solid solder joint.

Abstract: From a heart sound signal input the occurrence of a first occurring heart sound is detected. Thereupon a predetermined heart sound enable window time is established, which for a first detection cycle is set to approximately the diastolic interval for the maximum heart rate to be detected. If a second heart sound occurs within this heart sound enable window time, this second heart sound is detected as a systole heart sound. The first heart sound may be detected as a diastole heart sound. If a second heart sound does not occur within the heart sound enable window time the procedure is repeated with increasing heart sound enable time as long as a second heart sound occurs within an increased heart sound enable window time. For diagnostics synchronization signals developed exclusively from the heart sound signals are used to validate data from diagnostic equipment such as a gamma camera.

Abstract: An echo suppressor (21, 22) monitors signal levels associated with the working environment of an echo canceler (16, 17) to prevent spurious transient responses from the canceler. These spurious responses typically occur before the echo canceler has had sufficient time to appropriately adapt which is also the time when a call is first established. At such times, signaling and maintenance testing are performed in a telecommunications network and the echo canceler tends to produce an output when there is no actual transmit input signal. The echo suppressor includes a comparator (26, 27) which detects the presence of this output and the absence of an actual transmit input signal and operates a switch. The switch prevents the transient echo from propagating on the transmit path.

Abstract: A digital processor (16) is disclosed for improving the statistical characteristics of nondeterministic random-like binary sequence. The basic elements of the digital processor are a feedback loop comprising a delay (17) and a signal combiner (18) and a subsampler (19). Maximum performance of the digital processor is achieved when a relatively prime relationship exists between number of cells in the delay (17) and ratio of the original signaling rate to the output signaling rate of the subsampler (19). Mathematical analysis is presented for showing that the digital processor improves both the equidistribution of the binary variable and autocorrelation statistic of output signal over the nondeterministic random-like binary signal. A further improvement in statistical properties is obtained by using two digital processors (116 and 121) in serial fashion.

Abstract: Contact arrangement for vacuum switch in which one of two contacts is movable relative to the other in the axial direction of the contacts and is designed as a recessed contact. According to the invention, a condensation plate with a diameter greater than the inside diameter at the rim of the recessed contact is provided between the other contact and its current lead. The sidewall of the recessed contact forms a guide ring for the metal vapor, a substantial part of which condenses on the condensation plate.

Abstract: Optical wand for automatic character recognition including a scanner unit designed to be a manually movable along a line of print of a data carrier in order to recognize optical characters and incorporating a light source for illuminating a scanning window and a sensing device. A second scanner unit includes a second sensing device and is designed for recognizing bar code marks. A gun shaped housing forms a common case for both scanner units.

Abstract: An automatic locking device (402) is disclosed that can be utilized to secure a first member (40) to a second member (10). The device includes a latching member (12) with an integral spring member (18), the latching member being attached to a bolt member (11). The bolt member (11) is inserted into the first member (40) and then is inserted in an opening (15) in the latching member (12). Thereafter, an E-shaped retaining ring (13) is attached to a shank end of the bolt member (11) to secure the bolt member (11) to the latching member (12). The spring member (18) is continuously biased via a projecting portion (410) in the first member (40). When the first and second members are properly engaged with one another, the latch member (12) enters a detent (116) in the second member (10) and retains the first member (40) securely in place. Thereafter, the bolt member (11) can be rotated to release the latching member (12) from the detent (116) facilitating detachment of the first member (40) from the second (10).

Abstract: A stripline features high symmetry and promotes uniform current densities to lower losses. The channel (11) of the outer conductor of the stripline has a generally circular cross-section. Opposing lateral grooves (13,14) securely positions a substrate (16) which includes a center conductor. The center conductor features dual metalized strips (17,18) connected together by spaced through-plated holes (19). The stripline is readily formed in a single block of metal and hence eliminates the losses associated with the joint of conventional split-block striplines.

Abstract: A carrier and timing recovery technique is disclosed for combating the phase effects of multipath fading occurring during radio transmission. The technique is based on a known mathematical model of multipath fading. A test variable generator (26) develops a number of test variables whose relationship characterizes the multipath distortion. A processor (27) derives a plurality of coefficients of weighting measures from the test variables. The coefficients serve to adjust a matched filter (28) to provide greater use of those portions of the received radio signal yielding higher signal-to-noise ratios than those portions with lesser yields, as well as to compensate for multipath phase perturbations. The technique is also compatible with maximum-likelihood sequence detection techniques to provide further compensation for multipath fading effects.

Abstract: A fused station protector is disclosed wherein the fuse links have precisely controlled fusing characteristics. A shrink away foam element (28) encloses a portion of the fuse link (26) to provide a potential hot spot for slight current excesses. The remainder of the fuse link is in contact with arc quenching material (27) for extinguishing potential power arcs. Thus, the protector provides a precise fusing characteristic for slight current excesses and arc quenching capability for severe current excesses.

Abstract: A single adjustment phase resolver uses common voltage control in a dual inversely tracking bridged-Tee attenuator circuit (21) to provide a variable relative phase displacement between two output signals whose amplitude levels are maintained equal and constant throughout the range of the phase adjustment. The dual bridged-Tee attenuator is implemented using two variolossers wherein the PIN diodes are serially connected in two pairs (51 and 52, 53 and 54) and the pairs are oppositely poled from one another. An automatic gain control circuit (16, 24 and 26) adjusts the input signal level to compensate for a latitude of discrepancy between the inverse tracking variolossers.

Abstract: An insertion filter is described for existing waveguide without modification. The filter includes a resilient bifurcated dielectric member (11) which conforms to the internal geometry of the waveguide (21). The dielectric member secures the position of a dielectric resonator (15) and a tuning screw (17) and retains their relative positions. A stud (18) is mounted on one of the bifurcations of the dielectric member to compensate electrically for the presence of the member in the waveguide while the dielectric resonator attenuates waveguide energy in a prescribed frequency band.

Abstract: A wideband amplifier utilizes predistortion components developed by an amplifying device (14) similar to the power amplifying device (15) to provide effective linearization for substantially reducing all of the intermodulation distortion products. Since the compensation is provided at the input to the power amplifier, the need for an output signal combiner is obviated so that the total power is available at the output. The efficiency is also enhanced since the predistortion amplifier (14) which operates from the input signal ony need be a voltage amplifier. An optional feedback circuit is disclosed which may be employed to reduce nonlinearities further if necessary.

Abstract: Various implementations of a technique are presented for capitalizing on signal correlation in a manner for providing usable frequency information. In a specific embodiment, a filter (51) is adapted to a signal component of an input signal using a variable generated by an adapter (58). The variable has a prescribed relationship to the frequency of the signal component. The variable is used to weight a combination of signal values derived from past signal history to form a prediction of a future signal. An adder (56) combines the new signal value with the prediction to form an error signal which is used by the filter (51) and the adapter (58). When the filter converges, a frequency indicator (59) using the variable provides an output signal indicative of the frequency of the signal component.

Abstract: To obtain optimal operational sensitivity from an amplifier connected to a source of electrical signals, a technique utilizes multiple amplifiers connected together. The technique determines the number, N, of amplifiers (31 or 51) to be used and whether they should be connected in parallel (FIG. 3) or series (FIG. 5) in order to optimize the sensitivity of a given type of amplifier. Accordingly, multiple interconnection of amplifiers may be used in lieu of noise matching with transformers to minimize the excess-noise figure of the multiple amplifier circuit. The technique capitalizes on the advances in integrated circuit amplifier design, such as compactness and wideband performance, while providing lower loss and higher reliability through redundancy.