Abstract: A device for use in pressure sensing has a housing enclosing a chamber and having at least one port that communicates with the chamber. A pressure sensor receives fluid pressure from the chamber. The chamber has a compliance that exhibits a marked change in volumetric stiffness repeatably at a fixed pressure.

Abstract: A device for use in pressure sensing such as hydrocephalus shunts, having a housing enclosing a chamber with at least one port communicating with the chamber. A wall of the chamber includes a flexible portion or thin diaphragm that deflects with transitions in pressure to contact an upstand structure of the housing. A pressure sensor is contained within an enclosure sealed from the chamber by a flexible membrane and which receives fluid pressure from the chamber. This arrangement allows for calibration of the device by identifying a knee feature in pressure data associated with the diaphragm making contact with the upstand.

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: A device for use in pressure sensing such as hydrocephalus shunts, having a housing enclosing a chamber with at least one port communicating with the chamber. A wall of the chamber includes a flexible portion or thin diaphragm that deflects with transitions in pressure to contact an upstand structure of the housing. A pressure sensor is contained within an enclosure sealed from the chamber by a flexible membrane and which receives fluid pressure from the chamber. This arrangement allows for calibration of the device by identifying a knee feature in pressure data associated with the diaphragm making contact with the upstand.