Abstract: A system comprising: a sensor configured to be introduced into a clearance hole of a surgical implant, wherein the sensor is configured to be introduced in proximity to a generated magnetic field and cause distortion of the magnetic field; and one or more field measuring coils configured to: measure a characteristic of the magnetic field when the sensor is in proximity to the magnetic field; and provide, to a computing device, a signal representative of the measured characteristic of the magnetic field, wherein the computing device is configured to determine one or both of a position and an orientation of the sensor and the clearance hole based on the measured characteristic of the magnetic field.

Abstract: A system comprising: a transmitter that includes at least three coils, the transmitter configured to generate magnetic fields; a sensor that includes at least three coils, the sensor configured to provide sensor signals that correspond to the magnetic fields generated by the transmitter; and a computing device in communication with the transmitter and the sensor, the computing device configured to compare a first sensor signal and a second sensor signal, and based on the comparison, determine whether any of the sensor coils are locked to a corresponding frequency out-of-phase.

Abstract: A system comprising: a sensor configured to be introduced into a clearance hole of a surgical implant, wherein the sensor is configured to be introduced in proximity to a generated magnetic field and cause distortion of the magnetic field; and one or more field measuring coils configured to: measure a characteristic of the magnetic field when the sensor is in proximity to the magnetic field; and provide, to a computing device, a signal representative of the measured characteristic of the magnetic field, wherein the computing device is configured to determine one or both of a position and an orientation of the sensor and the clearance hole based on the measured characteristic of the magnetic field.

Abstract: A system comprising: a transmitter that includes at least three coils, the transmitter configured to generate magnetic fields; a sensor that includes at least three coils, the sensor configured to provide sensor signals that correspond to the magnetic fields generated by the transmitter; and a computing device in communication with the transmitter and the sensor, the computing device configured to compare a first sensor signal and a second sensor signal, and based on the comparison, determine whether any of the sensor coils are locked to a corresponding frequency out-of-phase.

Abstract: A safety and security device is housed on either an unmanned aerial vehicle or its land-based docking station and is combined with a cellular telephone for self-defense purposes. The phone broadcasts both recorded audio and video warnings on the device. A flashing light may be activated on the aerial platform or the docking station. The device may be integrated into a modular unit that combines numerous defensive mechanisms. These defensive mechanisms operate autonomously and respond to perceived threats.