| Patent application number | Description | Published |
|---|
| 20090030291 | Implantable Wireless Sensor - A wireless sensor for indicating a physical state within an environment includes a unitary housing defining a cavity. A structure located within the cavity of the housing has elements providing capacitance, the elements being arranged such that the distance and thereby the capacitance of the structure changes when a physical state of the environment changes. The structure has a resonant frequency based at least in part on the capacitance of the structure when in the presence of a fluctuating electromagnetic field. When the sensor is positioned within an environment and is subjected to a fluctuating electromagnetic field, the resonant frequency indicates the physical state of the environment. | 01-29-2009 |
| 20090115396 | Communicating with an Implanted Wireless Sensor - The present invention determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency or set of frequencies and a predetermined amplitude. The energizing signal is coupled to the sensor via magnetic coupling and induces a current in the sensor which oscillates at the resonant frequency of the sensor. The system receives the ring down response of the sensor via magnetic coupling and determines the resonant frequency of the sensor, which is used to calculate the measured physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal. | 05-07-2009 |
| 20090115397 | Preventing False Locks in a System That Communicates With an Implanted Wireless Sensor - The present invention determines the resonant frequency of a wireless sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. The system energizes the sensor with a low duty cycle, gated burst of RF energy having a predetermined frequency. The system receives the ring down response of the sensor and determines the resonant frequency of the sensor, which is used to calculate a physical parameter. The system uses a pair of phase locked loops to adjust the phase and the frequency of the energizing signal. The system identifies false locks by detecting an unwanted beat frequency in the coupled signal, as well as determining whether the coupled signal exhibits pulsatile characteristics that correspond to a periodic physiological characteristic, such as blood pressure. | 05-07-2009 |
| 20090273353 | STRAIN MONITORING SYSTEM AND APPARATUS - This application relates to an apparatus and system for sensing strain on a portion of an implant positioned in a living being. In one aspect, the apparatus has at least one sensor assembly that can be mountable thereon a portion of the implant and that has a passive electrical resonant circuit that can be configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy. Each sensor assembly, in response to the electromagnetic coupling, can be configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of strain applied thereon a portion of the respective sensor assembly. | 11-05-2009 |
| 20090278553 | SYSTEM AND APPARATUS FOR IN-VIVO ASSESSMENT OF RELATIVE POSITION OF AN IMPLANT - A system and apparatus for providing an in-vivo assessment of relative movement of an implant that is positioned in a living being is provided that comprises a first assembly and a second assembly that are positioned within the living being. The first assembly comprises a passive electrical resonant circuit that is configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy and, in response to the electromagnetic coupling, generates an output signal characterized by a frequency that is dependent upon a distance between the first assembly and the second assembly at the time of the electromagnetic coupling. | 11-12-2009 |
| 20100026318 | Coupling Loop - A coupling loop or antenna is provided that can be used with a system that determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. In one embodiment multiple energizing loops energize an implanted sensor and a sensor coupling loop connected to an input impedance that is at least two times greater than the inductance of the sensor coupling loop receives the sensor signal. | 02-04-2010 |
| 20110105863 | Coupling Loop and Method of Positioning Coupling Loop - A coupling loop or antenna is provided that can be used with a system that determines the resonant frequency of a sensor by adjusting the phase and frequency of an energizing signal until the frequency of the energizing signal matches the resonant frequency of the sensor. In one embodiment orientation features are provided for positioning the coupling loop relative to the sensor to maximize the coupling between the sensor and the coupling loop. | 05-05-2011 |
