Patent ID: 8591427
Filing Date: 2013-11-26
Classification: A61B

Abstract:
1. A system comprising: at least one first magnetic field sensor configured to measure first and second magnetic fields; at least one second magnetic field sensor configured to measure the second magnetic field substantially without measuring the first magnetic field; wherein the first and second magnetic field sensors comprise magneto-electric sensors, each magneto-electric sensor comprising alternating layers of magnetostrictive material and piezo-electric material; wherein each magneto-electric sensor further comprises: wherein the electromagnet in each magneto-electric configured sensor is configured to receive a carrier signal; the at least one first magnetic field sensor is configured such that the carrier signal modulates the biasing magnetic field thereby emulating an up-converting heterodyne mixer, wherein the low frequency magnetic field signal is outputted from the sensor as coherent sidebands near the carrier frequency; the at least one second magnetic field sensor is configured such that the carrier signal modulates the biasing magnetic field thereby emulating an up-converting heterodyne mixer, wherein the low frequency magnetic field signal is outputted from the sensor as coherent sidebands near the carrier frequency; thereby repeatedly sensitizing and at least substantially desensitizing the at least one first and second magnetic field sensors; and processing circuitry configured to perform signal cancellation to generate measurements of the first magnetic field and to generate an output based on the measurements of the first magnetic field.