Abstract: An electrode for a cold cathode discharge lamp, has several parallel recesses extending across the width of the electrode and at an angle of about 35 degrees away from the normal to its surface. The electrode may be formed by folding a strip of metal so that the recesses are formed between adjacent folds of the strip. Alternatively, the electrode may be a block of metal in which the recesses are slots formed in a surface of the block. The electrode may be included in a tubular lamp or in a planar lamp.

Abstract: To be used with a double-ended needle assembly and to prevent the accidental pricking of user, or others, in a first embodiment of the present invention, a container holder mated with the needle assembly has a protective housing integrally and flexibly connected thereto. To prevent a contaminated needle from posing a risk to the user and others, the housing connected to the container holder is pivoted into alignment with the contaminated needle such that the needle is retained by at least one locking mechanism integral of the housing. The container holder, along with the contaminated needle assembly, can then be disposed of. If the container holder were to be reused, a second embodiment of the present invention provides for the connection of a protective housing to the hub of a double-ended needle assembly. For this embodiment, after use, the contaminated needle assembly, after having been properly retained in the protective housing, is removed from the reusable container housing and disposed of.

Abstract: Opposite ends of a fibre-optic cable have terminations including a metal diaphragm which is welded or brazed at its outer edge to the termination. The diaphragm has a central aperture into which extends the ends of a bundle of optical fibres, the fibres being hermetically sealed together at their end and sealed in the aperture by a glass seal. The diaphragm tapers in thickness from its outer edge to its central aperture where it is thinner and is flexible to accommodate relative displacement between the fibre bundle and the sheath of the cable.

Abstract: A vent cycle indicator for a suction catheter formed by a sleeve connected between a collar having a wiper seal and a crosspiece. The suction catheter includes a vacuum connection member having a normally closed valve. A catheter tube is connected to the vacuum connection member and extends through the collar and crosspiece. The crosspiece is for connection to a ventilator such that during ventilation the indicator sleeve expands and contracts during the inspiration and expiration cycles. The protective sleeve may be provided between the collar and the vacuum connection member to keep the catheter tube enclosed.

Abstract: An accelerometer includes a compliant cylinder supported midway along its length and having equal masses at opposite ends. Two birefringent optical fibers with elliptical cores are wound around the cylinder in opposite senses on opposite sides of the support. Radiation from a source is supplied to one end of both fibers and emerges from the opposite end where it is supplied to respective photodiodes via respective polarizers. Acceleration axially of the cylinder causes extensive strain in one fiber and compressive strain in the other which causes equal and opposite changes in birefringence. A processor subtracts the change in outputs of the photodiodes to provide an acceleration output that is independent of temperature.

Abstract: A valve for a urine collection bag has a base plate with a valve housing within which a valve member is displaceable. The valve member is hollow and has an aperture that aligns with an aperture in the base plate and bag when the valve member is in its lower position. The valve is opened by squeezing a finger plate on the valve member down towards a lower finger grip on the base plate. In the open position, the valve member can engage a coupling which slots between the arms of a fork projection on the base plate. The valve is closed by squeezing the finger plate up towards an upper finger grip on the base plate.

Abstract: An electrical assembly including a digital logic circuit, an analogue processing circuit and an analogue power circuit is connected to test equipment. Test data from the equipment is supplied to the circuits via a shift register divided into three serial portions. One portion is connected between the digital circuit and the processing circuit, another portion is connected between the processing circuit and the power circuit, the final portion being connected at the output of the power circuit. The portions can isolate the circuits from each other and supply test data to the circuit under test. The test data output from the circuit is clocked along the register to its output.

Abstract: A syringe tip cap and a method for purging air from a syringe-like container containing air and hazardous liquid. The cap contains a hydrophilic filter which, when dry, allows air to pass through the filter. When the air is purged from the syringe, liquid from the container is pushed or drawn to the filter. The filter expands when wetted, seals the cap, and prevents further fluid flow. A flow restrictor may be included within the cap to concentrate the flow to only a portion of the filter to prevent premature sealing of the filter.

Abstract: A probe has an inlet and outlet by which a fluid flows over an optical sensing element in the sensing probe. Broad band optical radiation is supplied to the element and radiation transmitted through the optical sensing element is supplied to three photodiodes responsive respectively to radiation at different wavelengths. The transmission characteristic of the optical sensing element varies in different ways with change in temperature and pressure respectively. A store of temperature and pressure against amplitude of radiation at different wavelengths is addressed by the outputs of the photodiodes to give an indication of pressure and temperature at the sensing element.

Abstract: An aircraft threat monitoring system has several sensors responsive to a potential threat external to the aircraft such as a radar warning receiver, a radar sensor, a missile approach warning receiver, a forward-looking infrared detector and an electro-optic sensor. Each sensor has a respective inference processor the outputs of which are supplied to a groundspace map manager and an airspace map manager. The map managers collate the processor outputs to derive a threat output signal which is supplied to a planner programmed with tactical route information. The map managers also control operation of the sensors such as by modifying their sensitivity, scan or frequency in accordance with the output from other sensors.

Abstract: A required time of arrival (RTA) control system (200, 220, 240) is disclosed for use with an aircraft on-board computer system (100). The control system (200, 220, 240) is adapted to provide data for controlling aircraft flight in a manner so as to meet time of arrival constraints at selected waypoints. The control system (200, 220, 240) includes means (212) for determining a time error between an estimated time of arrival and a designated RTA. A cost index predictor (216) is utilized to determine an estimated cost index parameter for meeting time of arrival constraints, while maintaining relative minimum fuel consumption. A flight profile predictor (202) is adapted to generate requisite target air speed data based on the estimated cost index parameter. In one embodiment, the system (240) includes determination of a time window based on maximum and minimum permissible cost index and speed limiting parameters.

Abstract: A tracheal tube assembly has an outer tube and an inner cannula with a patient end that is flared outwardly to a diameter greater than the internal diameter of the outer tube. When inserted in the outer tube, the patient end of the inner cannula is deformed inwardly and forms a wiping seal. The remainder of the inner cannula has an external diameter less than the internal diameter of the outer tube so that it is readily inserted. The inner cannula may be coextruded with an outer layer of a low friction material such as a polyolefine.

Abstract: An operating table or the like has a platform supported by a hydraulically adjustable column. Castors contact the floor through apertures in a base plate that supports a guide wheel. Application of hydraulic fluid to raise the platform causes the base plate to be lowered first to an intermediate position in which the guide wheel contacts the floor. Additional hydraulic pressure brings the base plate into contact with the floor so that the table is braked before the platform rises.

Abstract: A fibre-optic cable has a silica optical fibre within a fluoropolymer sleeve. The optical fibre extends between two couplings and is protected by a sheath that is fixed at each end to the couplings. The sheath comprises parallel silica filaments that extend between two braided aramid sleeves. The sheath is completed by an outer tube of a fluoropolymer resin extruded onto the braided sleeves so that its material flows through them and the filaments. The filaments restrain thermal expansion of the sheath to an expansion closely matched to that of the optical fibre.

Abstract: An optical multiplexing system has a source of depolarized radiation at one end of a non-birefringent optical fiber that extends to a decoding interferometer. Sensors in series along the fiber induce birefringence so that the radiation is superimposed onto two polarization modes producing two output wave trains from each sensor with different time separations. The interferometer measures the time separations of the wave trains to identify the sensor and its output.

Abstract: An optical fibre connector or similar entry for an optical fibre cable to an aperture in a enclosure has a metal shell supporting a resilient insert made of an elastomeric polymer loaded with up to about 30% of a material such as carbon particles so that the insert is absorptive of microwave energy at wavelengths similar to the size of the aperture. The faces of the insert have electrically-conductive layers thereon. The optical fibres of the cable are terminated in metal ferrules supported in apertures in the insert.

Abstract: An autoclave or other equipment has a counter provided by an EEPROM for counting the number of times the autoclave has been used. The EEPROM has a first set of ten registers which contain the unit value of the count together with a fault code associated with the last use of the autoclave. Two further registers contain the hundreds and tens, and the ten thousands and thousands value of the count. The tens value in one of the further registers is used to determine in which of the registers of the first set the units value is stored, so that each of the registers in the first set is only written into ten times for every hundred counts, thereby extending the life of the EEPROM. Another register in the EEPROM contains information about the nature of the autoclave.

Abstract: An electrical connector assembly has several sockets mounted in apertures in a ground plane. Each socket has a metal tube supporting wires that engage the surface of a pin inserted in the socket. Each socket is filtered by means a tubular capacitor one electrode of which is soldered in the aperture and the other electrode of which is electrically connected to the wires. An annular, ferrite inductor embraces the tube within the capacitor. Protection from a transient at any one of the sockets is provided by a transient protector device on a flexible circuit board joined to each socket.

Abstract: An aircraft navigation system has a digital map store of terrain features or man-made features in the region over which the aircraft is flying. Infra-red television cameras view the surrounding of the aircraft. Their outputs are supplied to processors in which the camera outputs are compared with a library of features transformed according to the camera viewing angle. Information about those features identified is supplied to a correlator which correlates the features against the map store to identify their location in the map and estimates the aircraft position as an output to a navigation computer. The system also indicates aircraft attitude which may be independent of known-features, from observation of the horizon. Position information can also be provided by dead reckoning from a known initial position by monitoring the change in positional relationship of a feature from the initial position to that at a later position.