Abstract: A biomagnetic sensor that incorporates an integrated active noise cancellation unit that uses a gradiometer to remove ambient magnetic noise from a detection signal obtained from a tunnelling magnetoresistive (TMR) sensor unit that is indicative of a magnetic field adjacent to biological tissue. The ambient magnetic noise can thus be removed in real time at a front end of the sensor (e.g. as part of circuitry in the sensor body itself). The active noise cancellation technique proposed herein may be effective enough to enable the biomagnetic sensor to be used in an unshielded environment (i.e. an environment that is subject to the Earth's magnetic field, for example), which widens significantly the potential uses for the sensor.

Abstract: A biomagnetic sensor that incorporates an integrated active noise cancellation unit that uses a gradiometer to remove ambient magnetic noise from a detection signal obtained from a tunnelling magnetoresistive (TMR) sensor unit that is indicative of a magnetic field adjacent to biological tissue. The ambient magnetic noise can thus be removed in real time at a front end of the sensor (e.g. as part of circuitry in the sensor body itself). The active noise cancellation technique proposed herein may be effective enough to enable the biomagnetic sensor to be used in an unshielded environment (i.e. an environment that is subject to the Earth's magnetic field, for example), which widens significantly the potential uses for the sensor.

Abstract: A readout integrated circuit (IC) architecture for a tunnelling magnetoresistive (TMR) sensor which uses common mode feedback to achieve a performance level suitable for accurate detection of biomagnetic signals. The architecture uses a three-operational amplifier configuration with chopper stabilization. The architecture may form part of a fully integrated biomagnetic sensor electronics package that includes an array of TMR sensors together with modules for signal amplification and conditioning, data conversion and communication.

Abstract: A readout integrated circuit (IC) architecture for a tunnelling magnetoresistive (TMR) sensor which uses common mode feedback to achieve a performance level suitable for accurate detection of biomagnetic signals. The architecture uses a three-operational amplifier configuration with chopper stabilization. The architecture may form part of a fully integrated biomagnetic sensor electronics package that includes an array of TMR sensors together with modules for signal amplification and conditioning, data conversion and communication.