Abstract: A one-piece steering wheel is formed as a unitary casting from an alloy that includes 11.5% to 14% by weight silicon, and 350 to 450 parts per million strontium. Preferably the steering wheel mold is rotated during casting at relatively high rotational speeds exerting 100 g to 250 g force on the wheel. An optimum rotational speed is disclosed. A one-piece steering wheel formed according to the invention exhibits minimal length ferro-silicon hair-like strands, and thus exhibits reduced brittleness.

Abstract: Minority carrier bulk lifetime maps are accomplished using in-situ .mu.-PCD measurement techniques on a non-oxidized Si specimen of either polarity. Surface passivation of the specimen is accomplished chemically, preferably using a solution of iodine in ethanol with a concentration in the range of about 0.02 mol.multidot.dm.sup.-3 to about 0.2 mol.multidot.dm.sup.-3. For n-type specimens, a solution of concentrated alkaline such as ammonia, sodium- and potassium-hydroxide is especially effective. For either type specimens, a solution of HF at about 40% m/m is also effective. Surface passivation according to the present invention reduces surface recombination velocities to 10 cm/second or less. The specimen to be measured is placed in a container of passivation solution such that the specimen surfaces are covered with a solution film of about 1 mm or less. The container preferably is transparent to microwave and laser optical energy, and passivation and measurement can occur simultaneously.

Abstract: Geographical positional data is obtained for an underground object by locating the object using a device that locates underground objects. An apparatus that receives data from a global position system ("GPS") provides data identifying global position of the device, and thus also of the located underground object. A data storage unit stores such positional data, which may be used in the future to re-locate the underground object. The GPS-data receiving apparatus can preferably receive data from at least one overhead GPS satellite and from a secondary stationary receiver. Data from the secondary stationary receiver may be modulated on to a signal transmitted along a detected underground cable object.

Abstract: A latch-up pulse generator system includes a latch-up pulse generator coupled to first and second power supplies, for outputting JEDEC-standardized first and second output pulse trains. The generator includes a master clock, digital frequency dividers, and digitally controlled delay circuitry for outputting the two pulse trains. The first pulse train is a square-wave signal with a repetition rate of about two seconds. The second pulse train has a pulse width that is digitally controllable between about 0.2 .mu.s and 5 .mu.s. The delay between the fall-time of the second pulse train and the fall-time of the first pulse train is variably controlled between about 1 .mu.s and one second in 1 .mu.s steps. The amplitude and current output of each pulse train may range from 0 to perhaps 15 VDC at a current level of about 5 A. For power pin latch-up testing, the two pulse trains are combined to produce a composite pulse train. Signal and/or power pins of a CMOS device under test may be analyzed.

Abstract: An apparatus is provided for removing a small area of epidermis from the skin to expose an intact area of dermis and subsequently deliver a liquid in contact with the exposed dermis. This method of delivery allows the rate of absorption of substances into the body to be enhanced by removal of the epidermis. A preferred embodiment removes the epidermis by forming a suction blister, the apparatus having a housing attached to the skin adhesively to define a chamber in which suction is applied. Suction is applied to the chamber without connection to an external source of suction by means of an evacuated cell separated from the chamber by a disruptable membrane. A tubular member is actuated to rupture the membrane, disrupt the blister and deliver liquid to the chamber in successive stages of operation of the apparatus.

Abstract: A jewelry chain holder includes two tube-like structures joined together by a common partition wall in a side-by-side disposition, each tube defining a channel-like cavity and a longitudinal slit running the full tube length and preferably located on a portion of the tube somewhat opposite from the partition wall. The length of each tube approximates half the total chain length, and the cross-section of each cavity is sufficiently large to contain a cross-section of the chain within. Preferably the tube-like structures are transparent and made of a slightly resilient material that permits a user to force approximately half the chain length into each cavity through the longitudinal slit. The result is that substantially the entire chain is maintained in a stretched out disposition within the two cavities, the partition wall separating the two chain halves. So held, the chain is visible from 360.degree. and is protected by the exterior of the tube-like structures from dust, scratching and other damage.

Abstract: An all metal and ceramic high vacuum rotary anode x-ray tube adapted for mounting on a gantry of a rotational type CT scanner. The evacuated region where x-rays are generated is maintained at about 10.sup.-7 Torr. Vacuum sealing about the rotating shaft of the anode is provided by a magnetic fluid. No bearings are utilized within the evacuated region. Large, long wearing ball bearings that transmit rotation through the vacuum seal are provided about the shaft outside of the high vacuum region where conventional lubricants may be applied. Circulating coolant is applied internally through the anode assuring continual operation of the tube without the need for frequent cool-down waits. A preferred embodiment discloses a modified path in the rotor for the coolant designed to disturb the conventional laminar type of flow which is heat transfer inefficient to one characterized by high turbulence resulting in approximately an order of magnitude improvement in the coefficient of heat transfer.

Abstract: A network for use in a fourth generation CT scanner for noise reduction. The network comprises an active low pass filter whose cutoff frequency is controlled by a scaled signal responsive to the angular velocity of the rotating radiation source of the scanner. In a preferred embodiment a raw signal is generated by an encoder that detects movement of the source. As the source speed changes either in response to an operator's selection of a different scan speed or to systemic variations in the scanner relative to expected performance, the filter's cutoff frequency will automatically change thereby assuring optimum performance regardless of scan speed.

Abstract: Real time acquisition of cardiac or other gated cyclical data using a scintillation camera with image formulation utilizing only such data that satisfied a preselected time frame for each cycle. The technique provides real time processing of gated data without the need for specialized hardware equipment or for post processing of the data. Unwanted information corresponding to cycles falling outside a preselected time frame are deleted in real time and hence do not contribute to the cumulative cardiac image.

Abstract: A method for correcting predictable errors in the location of detected scintillation events acquired during emission computed tomography by a rotational scintillation gamma camera system. The method includes calibrating the rotational scintillation camera system and generating a look-up table comprising a set of pairs of x and y offset values, one pair for each viewing angle. The calibration reflects systemic deviations in the location of the rotating camera head detector measured in terms of x and y coordinates in the frame of reference of the detector for a plurality of view angles relative to the geometric ideal expected path. Once a look-up table is generated for a camera system, the detected location of each gamma event is altered in real time by adjusting in the camera head the x,y coordinate location of each event by the x,y offset values previously generated for the corresponding viewing angle associated with the detected event.

Abstract: The patient's ECG signal is employed in a traverse-and-rotate type CT scanner as a time base for triggering the beginning of a traverse such that the traveling beam reaches the heart at a desired phase of the cardiac cycle. For a purely-rotational-type CT scanner, continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves can be controlled by the ECG signal. The use of a pacemaker to stabilize the cardiac period is described along with a system for recognizing unacceptable variations in the cardiac period. In a traverse-and-rotate-type fan-beam CT scanner, the effective beam width is narrowed to hasten the traverse of the heart.

Abstract: Method and apparatus for increasing the effective data storage transfer rate in a system to permit the recording of a rapid sequence of high resolution images by eliminating and hence not transferring designated portions of each image in the sequence.

Abstract: A beam deflecting assembly in a laser device for precision manual control of the point of impact of a laser beam on a selected target site. The assembly includes a pivotable joy-stick universally coupled to an angled manipulator arm which in turn is pivotably connected to a mirror mount in which a beam deflecting mirror is mounted. The mount is rotatable about a vertical axis and includes a yoke for pivoting the mirror about a horizontal axis. Deflection of the joy-stick in the horizontal direction results in rotation of the mount and, independently, deflection in the vertical axis results in pivoting the mirror mount about the horizontal axis. The components of the assembly are dimensioned such that a movement in the free end of the joy-stick is reflected in a corresponding displacement in angle and distance in the point of impact of the delivered laser beam on a selected target plane to give the operator of the laser device a sense of direct control of the beam.

Abstract: A hybrid collimator for tomographic imaging with a scintillation camera comprising a coded aperture plate and a parallel plate collimator. The code plate includes a plurality of lateral slits each of which is radiopaque or radiotransparent pursuant to a time modulated code. The parallel plates define a plurality of radiotransparent channels whose lengthwise orientation is orthogonal to the lateral slits of the code plate. In a preferred embodiment, the code plate is advanced across the channels of the collimator in a direction parallel to their lengthwise orientation rendering a time coded pattern that is identical for each channel.

Abstract: A method of vacuum assembling a rotating anode X-ray tube of the type having a rotor and a shaft extending therefrom with a magnetic fluid for vacuum sealing about the shaft. The tube is subjected to a high temperature bake-out whereby gases are sufficiently evolved from exposed metal parts that a stable low pressure region is created. A static seal is used to temporarily seal the region during bake-out with the anode temporarily rendered non-rotatable and the permanent magnetic vacuum seal protected from the high temperature. The system is then allowed to cool off before the permanent magnetic vacuum seal is moved into its operational position within the high vacuum. Assembly tooling is provided ensuring that the high vacuum is maintained throughout the installation. Bearings are installed external to the region of high vacuum to transmit rotary motion of the shaft through the permanent seal. Finally, the tube is rendered operational by displacing the static seal thereby permitting the anode to be rotated.

Abstract: A transducer assembly is provided which performs simultaneous imaging and flow measurement. Separate imaging and Doppler transducers are mounted on one face of the assembly. Each transducer type is backed by backing material which provides damping in accordance with the performance criteria of the different transducer types. The transducer types may be mechanically focused in the same direction so that flow measurements are made in the center of the area being imaged.

Abstract: A waveguide gas laser of improved stability and efficiency resulting from novel improvements. Such improvements, including longitudinal RF excitation, unique ballasting techniques, a novel drive circuit design that is immediately responsive to defeat unstable hot spot problems, and a controlled power excitation function, result in an RF excited waveguide gas laser that substantially overcomes disadvantages of prior art devices.In one embodiment the invention consists of a longitudinally excited RF waveguide laser in which the spacing geometry of the electrodes is variable independently of the waveguide chamber geometry resulting in increased performance efficiency. In addition, hot spot problems are eliminated or substantially reduced by capacitive ballasting achieved through novel structural configurations including electrodes that are isolated from the waveguide chamber by means of a suitable dielectric spacing medium such as ceramic or aluminum oxide.

Abstract: A microsurgical laser device for guiding a laser beam to a desired target. The device includes a laser head that is vertically oriented and which is supported by a base that contains the required electronics for the system. This laser head can be tilted in all directions so as to position the device for use. The laser head is coupled to an articulated delivery system that allows for the delivery system, including a colposcope or an operating microscope, to be raised, lowered, tilted, rotated, and focused onto the target.The articulated connection from the laser head to the colposcope or operating microscope makes use of a minimum number of mirrors to redirect the laser beam at 90 degree angles along a direction perpendicular to the axis of the incident path. Each mirror is mounted on precision mounts that obviate the need for adjustments.In one embodiment of the device the articulated system makes use of three mirrors to redirect the beam and one lens to provide a fixed laser spot size at the target.

Abstract: Microsurgical laser device for guiding a laser beam to a desired target. The device includes a laser head supported in a relatively horizontal orientation by a counterbalanced articulated support arm which provides for elevational positioning of the laser head as well as rotation of the laser head about two parallel spaced apart vertical axes. The support arm, in turn, is rotatably supported by a vertical post defining a third vertical axis.Threadably connected to one end of the laser head is an articulated laser guide arm having a precision telescopic first section followed by four rotatable mirror sections each of which is adapted to redirect a beam 90.degree. along a plane perpendicular to the axis of the incident path. Each section is precision made to obviate the need to adjust the mirror or align the arm.

Abstract: In a rotating fan beam tomographic scanner there is included a variable detector aperture housed within a radiation scatter shield. The scanner includes a diverging source of penetrating radiation which is directed toward a patient receiving section for passing a fan shaped beam of radiation through a planar section of the patient. The incident radition beam is attenuated during its passage through the patient receiving section and the transmitted beam passes from the patient receiving section until it impinges on a plurality of detectors for eventual reconstruction into a visible image. The variable detector aperture controls the thickness of the fan shaped beam and hence limits the amount of radiation impinging on the detectors. The aperture includes a pair of elongated beam thickness defining members having an opening therebetween and rotatable relative to the scanning plane.