Abstract: The handset of electrosurgery or welding apparatus has two spaced contacts which make connection with the shaft of an electrode that is insertable into the handset. A low power alternating signal generator is connected to the forward contact. When the electrode is fully inserted into the handset and contacts the rear contact, the alternating signal is supplied to a detector. The detector is connected to a power generator and rams it on when the alternating signal is detected so that electrosurgery power is supplied to the forward contact.

Abstract: A marine radar has a screen on which is displayed a radar image and several representations of the different control functions of the radar such as range, gain and sea clutter setting. The radar also has a key pad with three keys and a tracker ball that is connected to the radar control unit. The control unit generates a marker on the screen that is movable by the tracker ball. To change one of the control functions, the tracker ball is displaced until the marker moves into the region of the representation of the appropriate control function. The control unit then produces three boxes on the screen below the control function to indicate the different options available for that function. The user can select the desired option by pressing the appropriate one of the three keys.

Abstract: A safety needle device adaptable to fit over a tube holder includes a skirt that fittingly mates to the front end of the tube holder. A housing flexibly attached to the base of the safety device is pivotable to a position in alignment with the needle mated to the device so as to cover the same.

Abstract: A force detecting microsensor comprises a single crystal Si substrate, a single crystal cone formed on the substrate and a resilient electrode mounted above the tip of the Si cone. The space between the tip of the Si cone and the resilient electrode is maintained in a vacuum environment and the distance between the tip and the resilient anode is in the order of a few atomic diameters. The tunneling effect of electrons occurs between the tip of the Si cone and the resilient electrode when a potential is applied to the resilient electrode and the Si cone tip. The resilient electrode deflects as a result of the force acting on the microsensor. The deflection of the resilient electrode alters the electrical characteristics between the resilient electrode and the Si cone tip. The changes in the electrical characteristics can be measured to determine the level of force acting on the microsensor.

Abstract: An apparatus is provided for controlling the luminous output of a fluorescent lamp over a wide dimming range. The luminous output is controlled by controlling the lamp current, while the lamp is immersed in a lateral electrostatic field. The lamp and external electrostatic ionization electrodes are driven by a true analog voltage-to-current converter that has a dynamic range inherently wider than conventional PWM circuits. A modified, transformer coupled, push-pull converter with an analog-current-driven primary circuit is used in one embodiment of the apparatus. The lamp driver must be capable of providing a high compliance voltage consistent with the I-V profile of the lamp. A subordinate primary winding on the transformer may be used to reduce magnetization current and to supply sufficient energy for supporting the lateral electrostatic field that is generated by the ionization electrodes which may be printed on a PWB mounted behind the lamp.

Abstract: A medico-surgical suction system has a container with an outlet connected to a vacuum pump and an inlet connected to a suction catheter via a dual-lumen tube assembly one end of which is connected to the container and the other end of which is has a suction control and a coupling for the catheter. A valve located in the outlet of the container is connected to the suction control via a minor lumen of the tube. A side lumen enables the vacuum pump to apply reduced pressure to one end of the valve which holds the valve off against the action of a spring. Actuation of the suction control allows air to flow to the valve via the minor lumen so that the effect of the reduced pressure is overcome and the spring opens the valve.

Abstract: A catheter has a tubular plastics body and an insulated metal wire extending along the bore of the catheter through an aperture close to its patient end. The exposed end of the wire is covered by and connects with an electrically-conductive plastics material injection molded about the tubular body to form an electrode with a convex surface projecting from the surface of the catheter.

Abstract: Electrodes 11 and 12 in a cold-cathode discharge lamp have a row of holes 13 arranged side-by-side along their length. The holes are formed by laser machining and extend at an angle of between about 25.degree. and 35.degree. to the normal, the holes in the two electrodes being oppositely inclined.

Abstract: An intercranial pressure sensor assembly has a sensor at one end of an electrical cable. At its other end, the cable has a low profile coupling with annular contact members spaced axially along its length. A guide of a plastics material has an attachment with a tapering surface at one end from which extends a flexible lead. The guide is screwed to the coupling by means of an internal thread on the attachment and is used to pull the cable beneath tissue on the scalp. After the sensor is correctly positioned, the guide is removed and the coupling can be connected to a monitor.

Abstract: An optical rotation sensor comprises a light amplification stimulated emission ring laser formed in a solid medium is provided with phase modulator devices which produce push-pull phase modulation of counterpropagating optical waves in the ring thereby enhancing bidirectional lasing in single longitudinal modes in each direction. A frequency selective output coupler couples a predetermined portion of the optical energy at the lasing frequency from the ring to an output waveguide. A substantially U-shaped output waveguide having legs extending away from the ring in opposite directions and toward a common position. Clockwise and counterclockwise light waves are coupled from the ring to the two separate legs of the output waveguide and are directed to the common position to create an interfering light pattern on photodetector apparatus. The interfering light pattern is indicative of the rate of rotation, as defined by the Sagnac effect.

Abstract: An operating table used with electrosurgery equipment has a high impedance static discharge resistor connected between the table and ground. A monitor is connected across the resistor and is responsive to a change in resistance between the table and ground which is indicative of bypassing or failure of the resistor and which is independent of operation of the electrosurgery equipment. The monitor provides an output to an alarm and also disables the electrosurgery equipment in response to such a change in resistance.

Abstract: A tracheal tube assembly comprises an outer tube and an inner cannula that is insertable within and removable from the outer tube. The inner cannula has an inner surface of a flexible plastic material such as PVC to which respiratory secretions cling. The outer surface of the cannula is of a material having a lower friction than the inner surface and may be a helical filament or a continuous layer. The machine end of the inner cannula projects beyond the outer tube to form a flexible portion which is terminated with a coupling.

Abstract: An aircraft fire extinguisher system includes a fire extinguisher bottle and an attached explosive squib which has one side connected to ground and its other side connected alternately to two constant current sources in opposite senses. A differential amplifier subtracts the voltages in two sample-and-hold circuits caused by the opposite currents to eliminate the effect of the voltage at the point where the squib is grounded. A utilization circuit, coupled to the output of the differential amplifier, is used to indicate the presence of a fault in the squib or in associated circuitry.

Abstract: An electrical circuit has a substrate and a surface mount capacitor having a connector pad at each end. The substrate has two separate contact pads that are both soldered to the same connector pad on the capacitor. Two further contact pads on the substrate are soldered to the other connector pad on the capacitor. The contact pads on the substrate are connected to tracks that extend to plated-through holes and are electrically connected to one another at a point remote from the capacitor.

Abstract: A circuit for measuring current flowing along a line including a resistance has two transistors with their emitters connected to the line on opposite sides of the resistance and with their collectors connected to a zero voltage rail via respective resistors. The bases of the transistors are connected together so that one transistor controls current flow through the second. The voltage across the resistor connected to the second transistor is representative of current flow in the line.

Abstract: A spark plug printing machine has two silk screens with different color inks mounted side-by-side and facing down. Spark plug insulators are rotatably mounted in a vertical orientation on a turntable. A print transfer pad located beneath the screens is rotatable from a first position, where it is horizontal and contacts the screens, to a second vertical position. In the second position the pad contacts one of the insulators and is displaced along its length to roll the insulator along the pad through more than 360.degree. so that ink from both screens is transferred to the insulator one after the other.

Abstract: A display or other radiation-emitting device has an array of vertical ballistic transistors which produce electrons that flow into overlying phosphor regions. Light produced by the phosphors is focussed by an array of convex lenses above the phosphor regions to provide a high intensity display with limited viewing angle.

Abstract: A connector assembly has two rotatable parts both of which have external splines. An internally-splined locking ring is slidable along the assembly into a locking position where the splines on the ring engage the splines on both the rotatable parts so that relative rotation of the parts is prevented.

Abstract: A hydrostatic pressure release for releasing a life raft or the like when a ship sinks has a flexible diaphragm sealing a chamber on one side and exposed externally on its opposite side. A ceramic vent plug is mounted on the diaphragm so that it is protected within the casing of the device. The diaphragm has a resilient plate with an integral sleeve that projects through a collar in a rigid disc mounted on the plate. The plug is retained within the sleeve, in the collar. A rod projecting from the diaphragm extends into one end of an aperture in a slider and locks it in position. When the device is submerged, the diaphragm is deflected and pulls the rod out of the aperture allowing the slider to be released. A button on the slider extends into the other end of the aperture so that when is is depressed it pushes the rod out of the aperture and releases the slider.

Abstract: An interferometric fiber-optic gyro system includes a light source and a plurality of optical fiber rings employed to measure angular displacement along three axes. Optical circuit elements interposed between the source and the rings include an optical switch for periodically applying the optical signal to each of the rings individually along three separate optical transmission paths. Included in each of the optical transmission paths is a modal filter, including a polarizer, and a beam splitter which provides two separate beams to the optical ring for counter-propagation through the ring. Compensating birefringent devices are added in the optical circuits to compensate for a residual birefringence introduced by the various optical elements in the circuits. The characteristics of the compensating devices consist of predetermined lengths of polarization preserving, single-mode optical fiber. The birefringence of each of the optical devices is characterized in terms of a total number of beat lengths.