Patent ID: 8669770
Filing Date: 2014-03-11
Classification: A61B

Abstract:
1. A wireless sensor, comprising: a primary passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy and that comprises a first inductor and a first capacitor; a secondary passive electrical resonant circuit further comprising a second inductor and a second capacitor, wherein the secondary passive electrical resonant circuit is responsive to the electromagnetic coupling of a predetermined frequency produced by the ex-vivo source of RF energy; and a switch operatively coupled to the primary passive electrical resonant circuit and the secondary passive electrical resonant circuit, wherein the switch is selectable between an off position, in which the primary passive electrical resonant circuit is de-tuned, and an on position, in which the primary passive electrical resonant circuit is tuned; wherein, when the switch is positioned in the on position, the primary passive electrical resonant circuit has an intrinsic electrical property that is variable in response to a characteristic of a patient, and wherein the primary passive electrical resonant circuit, in response to an energizing signal produced by the ex-vivo source of RF energy, is configured to generate a sensor signal characterized by a resonant frequency that is indicative of the characteristic.