Abstract: An electronic circuit breaker including a two stage detection mechanism; an instantaneous trip operating at a first threshold and a delayed trip such operating at a second lower threshold. This is advantageous in maintaining operation during very short transient load peaks, which do not warrant isolation from the supply. The breaker can be line powered, can be reset remotely by controlling the line power, and can be implemented entirely in solid state electronics. As such it requires little or no service or maintenance.

Abstract: Apparatus for the wireless transmission of data, and preferably also of power, across a space between a length of production tubing and a surrounding casing in a petrochemical well, includes a pair of inductively-coupled coils, a first of which is located on the exterior of the production tubing generally coaxially therewith, and the second of which is located on the interior of the casing generally coaxially therewith. This may be used in particular as part of a system for transmitting power and data to/from a sensor monitoring the pressure and/or other environmental conditions within the “B” annulus B of a sub-sea well.

Abstract: Apparatus for the wireless transmission of data, and preferably also of power, across a space between a length of production tubing and a surrounding casing in a petrochemical well, includes a pair of inductively-coupled coils, a first of which is located on the exterior of the production tubing generally coaxially therewith, and the second of which is located on the interior of the casing generally coaxially therewith. This may be used in particular as part of a system for transmitting power and data to/from a sensor monitoring the pressure and/or other environmental conditions within the “B” annulus B of a sub-sea well.

Abstract: An electronic circuit breaker including a two stage detection mechanism; an instantaneous trip operating at a first threshold and a delayed trip such operating at a second lower threshold. This is advantageous in maintaining operation during very short transient load peaks, which do not warrant isolation from the supply. The breaker can be line powered, can be reset remotely by controlling the line power, and can be implemented entirely in solid state electronics. As such it requires little or no service or maintenance.

Abstract: Apparatus for detecting failure of a protective barrier between a first object and a second object is provided. The apparatus includes a transmitter assembly for transmitting an alternating electrical signal through the first object and a receiver assembly, wherein the receiver assembly is configured to receive the alternating electrical signal through the second object upon breach of the protective barrier. In a preferred embodiment, the first object is a patient undergoing surgery and/or medical treatment, the second object is a healthcare worker such as a surgeon and the protective barrier is a glove such as a surgical glove. The transmitter and/or receiver assemblies typically include transmitter or receiver electronics and signal connections, and optionally, the electronics and connections can together form integral transmitter and/or receiver assemblies. A return path can be provided for the transmitted signal.

Abstract: Reader apparatus for receiving data from a transponder in the body of a patient, for example a femoral nail. The apparatus includes an antenna which can be varied in size and shape to fit patients, the size and shape of whose bodies vary significantly. A variable impedance unit is included to maximise power matching between the antenna and a reader unit for a given antenna configuration.