Abstract: The present invention provides devices and systems for detecting shunt malfunction. The detection devices employ ultrasound instrumentations to evaluate shunt malfunction. The detection devices can be coupled with pumps to provide consistent shunt valve and/or reservoir actuation for reliable readings. The devices can output a determination of a degree of shunt blockage and relative location of shunt blockage.

Abstract: Antennas developed for electromagnetic field energy harvesting, typically referred to as rectennas, provide an alternative electromagnetic field energy harvesting means to photovoltaic cells if designed for operation in the visible frequency spectrum. Rectennas also provide energy harvesting ability or power transfer mechanism at microwave, millimeter and terahertz frequencies. However, the power harvesting efficiency of available rectennas is low because rectennas employ traditional antennas whose dimensions is typically proportional or close to the wavelength of operation. This invention provides a device for electromagnetic field energy harvesting that employs a plurality of electrically-small resonators such as split-ring resonators that provide significantly enhanced energy harvesting or energy collection efficiency while occupying smaller footprint. The invention is applicable to electromagnetic energy harvesting and to wireless power transfer.