Abstract: A method of reducing the effects of Compton scattered photons detected in a gamma ray detection arrangement includes the steps of receiving data responsive to energy states of the detected photons and storing the data in memory locations corresponding to predetermined image grid points, grouping the stored data, whereby a coarser grid having fewer image grid points is produced, calibrating the gamma ray detection arrangement by utilizing a spectral shape corresponding to a calibration function which is expected to correspond to a first data set corresponding to unscattered ones of the detected photons, processing the stored data for at least selected ones of the predetermined grid points employing minimization of a function which includes a product of an energy regularization term times an energy regularization parameter, as well as a spatial regularization term times a spatial regularization parameter, for separating the stored data into the first data set corresponding to unscattered ones of the detected ph

Abstract: An image of an object embedded in a diffusing medium is formed by propagating a coherent or equivalent light pulse through the diffusing medium and applying a reference pulse so as to gate precisely the first emerging light transmitted through the diffusing medium. An ultra-short pulse, having a duration on the order of 150 fs, insures that only the first emerging light is used to form a hologram. Instability in the diffusing medium, which may be inherent therein, as is the case with living tissue, or artificially induced therein, such as by vibrating the specimen, ensures that a subsequent hologram has a different background noise and speckle pattern. Integration of such holograms causes the background noise to average out, but time-invariant features, such as the object being imaged, become increasingly more visible as more holograms are integrated.

Abstract: Synthetic biomaterials are provided with irreversibly bound amino diphosphonate, polyphosphonate, or other anticalcification agent to prevent in vivo calcification. Such biomaterials include biocompatible elastomers such as polyurethane and/or polydimethylsiloxane, and the like which are intended for invasive, or in-dwelling use in a human or animal body. Illustratively, reaction conditions utilizing bi- or polyfunctional epoxides result in epoxide bridge incorporation of the anticalcification agent to the biomaterial elastomer.

Abstract: Four-fold and higher order lasers pumped by multiphoton absorption, avalanche mechanisms, or other means of internal upconversion for continuous-wave and continuous-wave mode-locked lasers. A solid-state laser system is contained within an astigmatically compensated cavity containing first and second mirrors. The gain medium is formed of a crystal of lithium yttrium fluoride heavily doped (5%) with trivalent erbium, or another form of crystal, such as CaF.sub.2 where the dopant atoms are clustered in quartets. The crystal, in a lithium yttrium fluoride embodiment, is approximately 3 mm thick with both sides thereof being polished flat to a laser grade finish. A pumping source supplies a pumping energy having a wavelength of 1.5 .mu.m to the gain medium, which wavelength is considerable longer than the output wavelength (701.5 nm) of the laser system. The gain medium may additionally be an alkali vapor formed of Cesium or Rubidium.

Abstract: A laser source which operated under the principals of cooperative unconversion produces controllable optical pulses at wavelengths which are shorter than the wavelength of the laser energy which pumps the gain medium. The source is a solid-state laser which employs a five percent Er:LiYF.sub.4 crystal which is arranged in an astigmatically-compensated 3-mirror cavity. Pumping is achieved at 1.5 microns in the infrared, and the system operates in a continuous-wave, mode-locked fashion in the green spectral region at approximately 544 nm. The cooperative inversion mechanism involves energy pooling by trios of excited rare earth dopant ions in the laser medium. Q-switching is achieved with the use of intracavity amplitude modulation so as to achieve three-fold upconversion. A 3-mirror astigmatically-compensated cavity with the gain medium permits modulation of losses in a manner which cannot be achieved with known systems and achieves high stability.

Abstract: A photosensor arrangement produces an electrical signal responsive to the position of a source of light by employing a mask situated at a predetermined height above a plurality of photodetectors, such that as the sun moves with respect to the apparatus, a shadow is cast which is responsive to the location of the sun. An apparatus constructed in accordance with the invention has a plurality of photosensors, each having a respective substantially planar light-sensitive surface for receiving the input light from the sun over a predetermined range of positions. In a preferred embodiment where compactness is desired, the planar light-sensitive surfaces are arranged in a substantially coplanar relationship with respect to one another. The light mask, which has opaque and transparent portions, is arranged to overlie the substantially planar light-sensitive surfaces for determining the position-responsive sensitivity characteristic of the apparatus.

Abstract: Integral coupling of reaction with a single-bed rapid cycle pressure swing adsorber provides a hybrid device having improved performance characteristics including better separation and more efficient reactions. A single packed bed containing a mixture of catalyst and adsorbent is featured. Gaseous reactants are fed into the bed in a sequence including inflow, relax, and backflow, portions. The hybrid device, designated as a periodic separating reactor (PSR), enhances both the total conversion and selectivity of reactions. In an illustrative example with respect to CO oxidation, conversion 2.5 times that typically exhibited for the corresponding steady-state plug flow reactors was observed. The separation performance (selectivity) of the hybrid device/process can be enhanced, illustratively for irreversible reaction systems, up to 10.sup.4 times that possible in pressure swing adsorption processes without reaction.

Abstract: The amount of mercury released from amalgam restorations in the teeth of living beings is significantly reduced without changing the composition of the silver-tin-copper alloy or changing the mercury-alloy ratio. This is achieved by introducing a mercury-absorbing metal component which acts only during the final setting stage of the amalgam. In a process embodiment, this is achieved by introducing a mercury-absorbing metal component which is applied to the prepared tooth cavity walls where it absorbs excess mercury from the setting amalgam. In a composition embodiment, the composition of the amalgam restoration consists of three components: a finely divided silver-tin-copper alloy; mercury; and a mercury-absorbing metal powder containing at least 50% by weight of palladium and the remainder of the group consisting of gold, copper, platinum, indium, zinc, and silver, some of which may be present as a coating on the palladium base powder.

Abstract: A system for producing reliable navigation data for a mobile vehicle, such as a robot, combines multiple range samples to increase the "confidence" of the algorithm in the existence of an obstacle. At higher vehicle speed, it is crucial to sample each sensor quickly and repeatedly to gather multiple samples in time to avoid a collision. Erroneous data is rejected by delaying the issuance of an ultrasonic energy pulse by a predetermined wait-period, which may be different during alternate ultrasonic firing cycles. Consecutive readings are compared, and the corresponding data is rejected if the readings differ by more than a predetermined amount. The rejection rate for the data is monitored and the operating speed of the navigation system is reduced if the data rejection rate is increased. This is useful to distinguish and eliminate noise from the data which truly represents the existence of an article in the field of operation of the vehicle.

Abstract: An anion exchange membrane for ionic macromolecules, specifically heparin, which is formed of a polymeric matrix material, an anion exchange material suitable for heparin detection, and a plasticizer can be employed in an electrochemical sensor arrangement to directly measure the concentration of heparin ions in blood or blood fluid. Potentiometric response to heparin has been observed with membranes comprising 30-70 wt. % polymeric matrix material, such as polyvinyl chloride, 0.1-12 wt. % quaternary ammonium salt, such as tridodecyl methyl ammonium chloride, and 30-70 wt. % of a plasticizer, such as dioctyl sebacate.

Abstract: A twilight sensor for controlling the headlamps of vehicles employs a photodiode having a predetermined spectral response and a diffuser which also has a predetermined spectral response, the spectral responses being combined to achieve an overall spectral response which corresponds to that of the human eye. With this arrangement, the headlamps of a motor vehicle are turned on and off under different ambient light conditions, in a manner which corresponds to the perception of the driver. In addition, the invention employs a control system which turns the lights on rapidly after the vehicle enters a tunnel.

Abstract: A system for producing ultra-high peak power pulses employs a plurality of solid state amplifying materials, such as Nd:glass, alexandrite, and Ti:sapphire, to achieve stretching of a pulse prior to amplification by a factor of approximately between 100 and 10,000. The time-stretched pulse is amplified by many orders of magnitude, illustratively 10.sup.9. After time-stretching and amplification, the pulse is then recompressed to its original duration. Pumping of the multiple solid-state elements is performed simultaneously using an alexandrite laser which is tunable between approximately 700 and 800 nm. The pumping energy has a pulse duration which is less than the fluorescence lifetime of the excited solid-state media.

Abstract: A drug delivery system for administering a drug in controlled pulse doses to an aqueous environment in the body of a living being has one or more, and preferably less than ten, individual drug-containing subunits in a unitary drug depot, such as a tablet or capsule. The individual subunits are designed to dissolve at different sites and/or times in the gastrointestinal tract to release pulse doses of drug into the portal system in an analogous manner to the rate of release from an immediate release dosage form administered according to an appropriate dosing schedule. The dissolution time of the individual subunits can be controlled by several methods including the provision of pH-sensitive enteric coatings and permeability-controlled coatings. The drug delivery system has significant advantages for the oral administration of first-pass metabolized drugs which exhibit a non-linear relationship between input rate of the drug into the portal system and bioavailability.

Abstract: A range hood positioned above a cooking range employs a continuous heat sensor system which includes twisted wires which are separated from one another by an insulator which is formed of a material which melts at a predetermined temperature. The wires carry a supervisory current which is monitored continuously. When the magnitude of the current is increased, such as by the creation of a short-circuit condition as would be caused by the presence of a fire, an actuation signal is issued to an actuator, which may include an explosive squib. The explosive squib releases a tension wire which holds a discharge valve in a closed position, permitting a fire suppressant fluid to be discharged from a supply tank. Monitor circuitry ensures that open-circuit or short-circuit faults do not disable the functioning of the actuation system. Multi-condition fault indicators alert the user visually and audibly of system faults.

Abstract: A vacuum pickup arrangement, particularly for a pick and place system for automated testing of integrated circuits, employs a resilient, bellows-like retractable device for making a secure vacuum-tight engagement with the integrated circuit specimen. The creation of the vacuum-tight engagement causes axial collapse of the bellows-like arrangement whereby the specimen is brought into communication with one or more protuberances or edges which define a predetermined angular orientation of the integrated circuit specimen desired to be achieved. Laterally disposed alignment jaws are employed to align the integrated circuit specimen with a test socket at a remote location. However, when the specimen is returned, the resilient nature of the bellows automatically realigns the integrated circuit specimen with the location at which it was originally picked up.

Abstract: A system for scrambling and descrambling complex signals, such as video signals, employs a system for encoding the decoding information, in the form of two security keys, directly onto the scrambled signal being transmitted, without the need of a second communications link for delivering one of the keys. In a video embodiment, several of the video lines during the vertical scan period are encoded with identification information which identifies a specific one of multiple decoders at the receiving stations, and a scrambled security code. The security code can only be descrambled by the decoder which is specifically identified in the identification code. A security code descrambling algorithm which is specific to the respectively associated decoder is permantently installed in the decoder along with the identification information. The relationship between the security code descrambling algorithm and the identification code for each of the decoders is stored in a memory at the transmitting station.

Abstract: A range hood positioned above a cooking range employs a continuous heat sensor system which includes twisted wires which are separated from one another by an insulator which is formed of a material which melts at a predetermined temperature. The wires carry a supervisory current which also flows through an actuator, which may be an electrified system for cutting a tension wire. An indicator lamp, such as an LED, which may have a series resistor associated therewith, limits the current through the actuator to a level below the activation threshold of the actuator.

Abstract: A handler system for transferring circuit packages, such as integrated circuits, from a tray containing a batch of the integrated circuits to a testing socket at a test site enjoys the advantages of high precision placement of the integrated circuit in the testing socket to achieve greatly reduced lead bending and damage to the integrated circuit body. Such precision is achieved by a simple mechanism wherein the travel of the integrated circuit from the tray to the test site and back to a selectable one of the good tray and the reject tray is performed exclusively along a single axis of movement of a carrier. The linear bidirectional motion of the carrier is limited to the z-axis, and eliminates misalignment which might result from wear of a ball screw and nut. The system is controlled by a computer which contains in its memory information relating to the dimensions of the trays and the types of circuit packages which are to be tested.

Abstract: A system for measuring the forces which are applied by a limb of a living being, particularly the hand, wrist, and forearm of a human being, employs a plurality of cable members for conducting the forces exerted in a variety of directions to a single force transducer. In addition to permitting a significant reduction in cost for the apparatus of the invention, the use of a single transducer ensures that all forces are correlated in magnitude with respect to one another, thereby greatly reducing the problems associated with system calibration. The apparatus aspect of the invention permits readings of plural motions and forces to be taken, which readings can be delivered to a recording device, such as a computer for storage, analysis, and cross-correlation of the resulting data with itself and with extrinsic data.

Abstract: Very large dynamic RAM integrated circuits are rendered self-testing by using on-chip generation of data test patterns with very high fault coverage, and concurrent testing of storage cell subarrays to reduce overall testing time. A test generator, which may operate in combination with the refresh control and timing system of the RAM integrated circuit, supplies the initial data test pattern which is loaded into the storage arrays. The conventional sense amplifier array is modified, and coupled with a gate control system for shifting data in each column of each storage subarray to an adjacent column. Alternatively, a two-terminal bilateral storage cell may be used to effect the shifting function, which effectively converts the memory into a shift register. The use of complementary data test patterns will permit detection of symmetrical faults within storage arrays.