Abstract: A "pulse to zero" modulation scheme is taught to transmit binary information by modulating a bit mark onto a carrier at the start of each "0" in the bit stream. The "pulse to zero" decoder produces an output that switches to "0" at the occurrence of the detected bit mark and resets to "1" if a second bit mark has not occurred within a preset time lapse from the previously detected bit mark.

Abstract: A signal processing technique is described which suppresses interference in spread-spectrum communications receive systems by optimizing the detection process dynamically against the current interference. This is accomplished by estimating the statistics of the interference and then using this information to derive the locally-optimum mapping to apply to the signal of interest plus interference. As the statistics of the interference change, the measured distributions and the resulting transformations also change. The adaptation is open loop so convergence problems do not arise.

Abstract: The present invention is a universal interface allowing a main implant to supply power and receive data from remotely implanted sensor modules through a minimum number of interconnecting lines. The main module can supply a single DC voltage, two sequentially applied DC voltages or an AC voltage to the sensor module. A capacitor means in the sensor module supplies power while the sensor module is transmitting data.

Abstract: A process for fabricating a sheathed-helix circular overmoded waveguide bend comprised of an inner helical wound insulated wire, a dielectric lining, and an outer conductor layer surrounding the dielectric lining. The inner winding is wound on a removable hollow rigid core, the dielectric liner or sheath is then molded onto the outer surface of the winding, and outer conductor is then attached to the outer surface of the dielectric liner. The core is made removable (from the helix winding) by coating it with a low melt temperature alloy which is melted by passing hot water through the hollow core.

Abstract: An apparatus and method is disclosed for generating a bit reversed sequence. The apparatus includes a reverse addition means for adding binary words in most significant to least significant bit order with the overflow or carry bit propagated to the left. The invention is used to generate a bit reversed address and/or an address sequence that is mapped into a "closed" space.

Abstract: The present invention provides an apparatus and method for laser direct writing of materials onto a receiving substrate using a high power pulsed laser. The invention includes a pulsed laser light source, a receiving substrate, disposed opposite the pulsed laser light source, and an optically transparent source support substrate positioned between the receiving substrate and the pulsed laser light source, wherein a surface of the optically transparent source support substrate facing the receiving substrate has coated thereon a thin film of material to be deposited on the receiving substrate. Laser direct writing using the invention is accomplished by impinging the thin film of material with a pulsed laser light from the pulsed laser light source causing material to be selectively "blown off" the optically transparent source support substrate and deposited onto the surface of the receiving substrate.

Abstract: Vanadium dioxide thin films have been prepared from tetrravalent vanadium organic compounds via the sol gel process. The vanadium dioxide was deposited from an alcoholic solution. Films were annealed between 200.degree.-700.degree. C. under nitrogen to achieve complete dehydration and crystallization.

Abstract: A capacitive chemical sensor is disclosed that uses an ion exchange layer to detect analyte ions in a liquid medium. An exchange mechanism occurs on the surface of the ion exchange layer, wherein a portion of the counter-ions are removed from the surface in favor of analyte ions. The resulting movement of counter-ions from the surface of the ion exchange layer alters the dielectric constant of the liquid medium along the surface of the ion exchange layer. This change in dielectric constant produces a change in capacitance of the capacitive chemical sensor.

Abstract: A method for performing computations with an asynchronous linear array of multiple processing stages is disclsoed. The linear array comprises multiple processing stages interspersed with flow control flag mechanisms and with dual port linking memories. The method utilizes the flow control flag mechanisms between processing stages to control the flow of computations through the array.

Abstract: An apparatus and method for the passive, non-invasive magnetoencephalographic (MEG) localization and tracking of sources of magnetic signals in the brain is disclosed. The apparatus and method uses a multi-axis magnetic gradiometer to detect the magnetic field, field gradient, and polarization emanating from neuronal sources in the brain under either normal or pathological conditions.

Abstract: A differential polarimeter is disclosed for detecting changes in optical rotation between a test cell and reference cell. The test cell contains a fluid sample exposed to an analyte specific enzyme; the reference cell contains a fluid sample not exposed to the enzyme. To enhance the sensitivity of the system a phase sensitive differential polarimetric technique is taught. In this technique, the phase difference between two resulting sinewave voltages is a measure of analyte concentration.

Abstract: Weak links in electrically continuous superconductors are detected by observing the effect of magnetic field modulation on the dc resistance of superconductors. The phase detected response to the magnetic modulation shows a peak at T.sub.c. The presence of a second peak at temperatures below T.sub.c, and concomitantly the appearance of a tail on the low temperature end of the dc resistance vs temperature curve indicates the presence of weak links in the superconductor.

Abstract: The invention concerns an implantable, inflatable helical cuff which is wrapped about a tubular body member such as a nerve cord, esophagus, colon, intestine, or blood vessel in a pressure transferring relationship. The cuff may be completely inflated to function as an occluder, or partially inflated to function as a pressure sensor or transducer in an appropriate system.

Abstract: An apparatus for generating pseudo-random codes is disclosed. The apparatus uniquely stores a set of codes in a memory and uniquely retrieves a particular code sequence. The apparatus has particular application to Global Position Satellite (GPS) earth receivers.

Abstract: An apparatus and method of intercomputer communications based on message broadcast with receiver selection is taught. A distributed computer system is described in which each computing element includes a hardware message filter which provides content tag recognition and selection. The overall system architecture allows software modularity and both hardware and software extensibility. The message filter can be preset or dynamically programmed, and can be operated in conjunction with a serial or parallel broadcast bus.

Abstract: An RF circuit to generate a stable carrier signal using a Voltage Controlled Saw Oscillator (VCSO) is disclosed. The invention teaches the use of a phase lock loop circuit employing a temperature compensated crystal oscillator (TCXO), or similar stable oscillator, to stabilize the output of the VCSO.

Abstract: An apparatus and method for non-invasive sensing of bone healing is disclosed. The apparatus and method uses an electromagnetic field to measure impedance changes at and about the bone fracture site during the healing process. The impedance change at the fracture site is a direct indication of the mechanical strength of the fracture site. A multi-coil sensor array is taught, which may be sutured to the patient's skin or mounted onto a plug that is inserted through a window in the cast.

Abstract: The invention relates to a method and apparatus to detect the superconductive state by measuring the change in the resistance of a sample. A dc magnetic field is imposed on the sample while the temperature is swept. The strength of the magnetic field is held below the critical value and is frequency modulated by the application of an ac field in such a way that total magnetic field is always positive. The resistance of the sample is measured incrementally as the temperature is swept and is phase detected at the modulation frequency. According to this embodiment, only magnetic field dependent changes demonstrating a precipitous drop in resistance identify a composition as superconductive.

Abstract: A method for noninvasively sensing bone mass loss associated with osteoporosis is disclosed. The method uses an electromagnetic field to measure impedance (or conductivity) changes in the bone. A decrease in conductivity is indicative of osteoporosis.

Abstract: A temperature responsive transmitter is disclosed. The transmitter utilizes a unique circuit design that allows encapsulation in an ingestible size capsule. The inventive circuit design uses a one transistor inverting amplifier with a tank circuit forming the link between the transistor's collector and the battery. The tank circuit is tuned to provide a lagging capacitive load which causes the inverting amplifier to oscillate. The tank circuit contains a coil inductor that emits a near field magnetic communications field containing temperature information. The ingestible size temperature pill can be configured in a rechargeable embodiment. In this embodiment the pill uses the inductive coil in the tank circuit as the magnetic pickup to charge a rechargeable nickel cadmium battery.