Abstract: A sensing means attachable to a blade (41) of a laryngoscope (40) comprising a transducer (10) and an indicator means (11). The transducer comprises at least a layer of a polymeric material (12) that undergoes a change in resistivity in response to incident pressure thereon. The change in resistivity is useable by the indicator means (11) to provide an output at least indicative of the incident pressure. A laryngoscope (40) having a LED-type light source (46) is also described. A laryngoscope having a transducer mounted to or incorporated on the handle is also described.

Abstract: A sensing means attachable to a blade (41) of a laryngoscope (40) comprising a transducer (10) and an indicator means (11). The transducer comprises at least a layer of a polymeric material (12) that undergoes a change in resistivity in response to incident pressure thereon. The change in resistivity is useable by the indicator means (11) to provide an output at least indicative of the incident pressure. A laryngoscope (40) having a LED-type light source (46) is also described. A laryngoscope having a transducer mounted to or incorporated on the handle is also described.

Abstract: In an overhead electric transmission system in which an overhead conductor includes at least one optical fibre constituting part of an optical communication system, there is provided, at a tower along the system, an electrically conductive rod supported by and electrically insulated by an insulator from the cross-arm of the tower but electrically connected to earth through the primary winding of a step-down voltage transformer. The rod is substantially horizontal and substantially parallel to a group of overhead electric conductors suspended from the cross-arm by an insulator. The surface area of the metal rod and its position with respect to the group of current-carrying conductors of the system are such that electrical power for regenerators or other ancillary equipment of the optical communication system is provided across the secondary winding of the transformer, thereby affording simple and inexpensive means of providing such power.

Abstract: In an overhead electric transmission system in which the phase conductors incorporate optical fibres, a joint between optical fibres of two phase conductors or between optical fibres of a phase conductor and an optical cable extending to a sub-station is enclosed within a fluid-tight metal housing. The housing is electrically connected to each phase conductor, is electrically insulated from earth, and has an external shape of such a form as to provide effective control of electrical stress. Preferably the metal housing is of hemi-spherical shape and is mounted on top of a porcelain insulator containing oil under pressure. Where an optical fibre connected at the joint is that of an optical cable, it passes into the metal housing through the oil filled porcelain insulator.

Abstract: An overhead electric conductor with optical fibres loosely housed in the bore of a central core, which bore also contains a greasy water-impermeable medium 4, is manufactured by causing a preformed elongate metal member of U-shaped transverse cross-section and the optical fibres to advance in the direction of their lengths, the rate of advance of the fibres being restrained. As the U-shaped elongate member is transversely folded around the optical fibres greasy water-impermeable medium is injected into the bore of the elongate metal member under a controlled pressure. The consistency of the greasy water-impermeable medium the pressure and rate at which it is injected into the bore and the degree of restraint imparted to the optical fibres 3 is such that, in a predetermined length of the conductor, the length of the optical fibres exceeds the length of the bore by a controlled extent, preferably 1 to 3%.