Abstract: A wireless power transfer secondary or pick-up has a resonant circuit and a switch connected to the resonant circuit operable to produce a phase shift in an oscillating voltage or current in the resonant circuit. A controller is configured to operate the switch to introduce one or more controlled phase shifts in the oscillating voltage or current in the resonant circuit which encode data for detection by a coupled circuit.

Abstract: An inductively powered sensor system includes a primary conductive path 100 capable of being energised to provide an electromagnetic field in a defined space 1. An inductive power pick-up 120 is associated with a sensor 124 and is capable of receiving power from the field to supply the sensor 124. The system includes a first sensing means to sense the power available to the pick-up 120 and control means to increase or decrease the power available to the sensor dependant on the sensed power available. A method of inductively powering a sensor, an inductively powered sensor and an animal enclosure including one or more primary conductive path of an inductive power supply are also disclosed.

Abstract: An inductively powered sensor system includes a primary conductive path 100 capable of being energized to provide an electromagnetic field in a defined space 1. An inductive power pick-up 120 is associated with a sensor 124 and is capable of receiving power from the field to supply the sensor 124. The system includes a first sensing means to sense the power available to the pick-up 120 and control means to increase or decrease the power available to the sensor dependant on the sensed power available. A method of inductively powering a sensor, an inductively powered sensor and an animal enclosure including one or more primary conductive path of an inductive power supply are also disclosed.

Abstract: In one embodiment of the invention a catheter (203) comprises a body having at least one inlet aperture (21, 24), at least one outlet aperture (22, 25), and at least one passage (20, 23) between the at least one inlet aperture (21, 24) and the at least one outlet aperture (22, 25). The catheter (203) is provided with pumping means (32) for selectively pumping fluid from one of said apertures (21, 22, 24, 25) to another of said apertures (21, 22, 24, 25). Methods of operating such a catheter are also disclosed.

Abstract: An inductively powered sensor system includes a primary conductive path 100 capable of being energised to provide an electromagnetic field in a defined space 1. An inductive power pick-up 120 is associated with a sensor 124 and is capable of receiving power from the field to supply the sensor 124. The system includes a first sensing means to sense the power available to the pick-up 120 and control means to increase or decrease the power available to the sensor dependant on the sensed power available. A method of inductively powering a sensor, an inductively powered sensor and an animal enclosure including one or more primary conductive path of an inductive power supply are also disclosed.

Abstract: An inductively powered sensor system includes a primary conductive path 100 capable of being energised to provide an electromagnetic field in a defined space 1. An inductive power pick-up 120 is associated with a sensor 124 and is capable of receiving power from the field to supply the sensor 124. The system includes a first sensing means to sense the power available to the pick-up 120 and control means to increase or decrease the power available to the sensor dependant on the sensed power available. A method of inductively powering a sensor, an inductively powered sensor and an animal enclosure including one or more primary conductive path of an inductive power supply are also disclosed.

Abstract: A method for determining a flow rate of a substance in an environment includes positioning a device having a balanced circuit in or on an object or within a particular environment, wherein the balanced circuit comprises elements which are operationally sensitive to changes in a parameter of the object or the environment. The method further includes measuring a common mode signal of the balanced circuit and determining, from the common mode signal, a value of the flow rate. An exemplary implementation of the method includes determining temperature using a resistive sensor having a Wheatstone bridge circuit with two variable resistors and two fixed resistors. Embodiments of systems and devices configured to employ such methods are provided, particularly medical probes, electronic signal monitoring devices, and systems employing such devices.

Abstract: The present invention provides an inductively powered sensor system having a primary conductive path capable of being energized to provide an electromagnetic field in a defined space. An inductive power pick-up is associated with a sensor and is capable of receiving power from the field to supply the sensor. The system includes a first sensing unit to sense the power available to the pick-up and a control unit to increase or decrease the power available to the sensor dependant on the sensed power available. A method of inductively powering a sensor, an inductively powered sensor and an animal enclosure including one or more primary conductive path of an inductive power supply are also disclosed.

Abstract: In one embodiment of the invention a catheter (203) comprises a body having at least one inlet aperture (21, 24), at least one outlet aperture (22, 25), and at least one passage (20, 23) between the at least one inlet aperture (21, 24) and the at least one outlet aperture (22, 25). The catheter (203) is provided with pumping means (32) for selectively pumping fluid from one of said apertures (21, 22, 24, 25) to another of said apertures (21, 22, 24, 25). Methods of operating such a catheter are also disclosed.

Abstract: A method of determining the location in time of maxima and/or minima of an oscillatory signal. The method may have application to measurement of biological signals, in particular measurement of heart rate from a pulsatile blood signal. The method includes a first stage including the steps of observation over a measurement period, identifying large local maxima or minima and computing an average interval between the identified local maxima or minima. One or more exclusion periods are located in time in the oscillatory signal, having a duration dependent on the average interval, the exclusion periods used to reject false maxima or minima. Maxima or minima may also be detected as an absolute maximum or minimum between crossing points of a fast and a slow moving average of the oscillatory signal. An exclusion period may also be used to reject false maxima or minima when crossing points are used. Apparatus for performing the method is also claimed.

Abstract: A method of determining the location in time of maxima and/or minima of an oscillatory signal. The method may have application to measurement of biological signals, in particular measurement of heart rate from a pulsatile blood signal. The method includes a first stage including the steps of observation over a measurement period, identifying large local maxima or minima and computing an average interval between the identified local maxima or minima. One or more exclusion periods are located in time in the oscillatory signal, having a duration dependent on the average interval, the exclusion periods used to reject false maxima or minima. Maxima or minima may also be detected as an absolute maximum or minimum between crossing points of a fast and a slow moving average of the oscillatory signal. An exclusion period may also be used to reject false maxima or minima when crossing points are used. Apparatus for performing the method is also claimed.