Signal processing methods and systems for biomagnetic field imaging

A computer system for determining magnetic fields from an organ of a human subject, comprising:

• one or more processors;
• and
• memory;
• and
• one or more programs stored in the memory for execution by the one or more processors, the one or more programs including instructions for:
• receiving a plurality of signals corresponding to first time-series magnetic data generated from a plurality of unshielded magnetometers proximate to the human subject, the first time-series magnetic data corresponding to magnetic fields generated from the human subject, wherein:
• the plurality of unshielded magnetometers comprises an m×n array of magnetometers arranged in a stack of p planes, wherein m is a number of magnetometers in a length direction of the array, n is a number of magnetometers in a width direction of the array, and p is a number of planes, in the stack of planes, arranged in a height direction of the array, the stack of p planes including a first plane and a second plane that is adjacent to the first plane;
• and
• the plurality of signals include contributions from a biomagnetic field from at least a portion of the human subject's organ and a background magnetic field;
• synchronizing the first time-series magnetic data to a common clock to generate synchronized time-series magnetic data;
• applying one or more filters to the synchronized time-series magnetic data to obtain filtered data;
• and
• applying one or more noise reduction techniques to the filtered data to generate updated time-series magnetic data, including:
• obtaining positional information corresponding to each magnetometer in the array of magnetometers;
• and
• for a respective pair of magnetometers, in the array of magnetometers, consisting of a respective first magnetometer positioned in the first plane and a respective second magnetometer positioned in the second plane, wherein the respective first magnetometer and the second respective magnetometer are aligned with respect to each other in the length direction and the width direction:
• calculating a difference between a first filtered signal corresponding to the respective first magnetometer and a second filtered signal corresponding to the second respective magnetometer.

A non-transitory computer readable storage medium storing computer-executable instructions that, when executed by one or more processors of a computer system, cause the computer system to perform operations comprising:

• receiving a plurality of signals corresponding to first time-series magnetic data generated from a plurality of unshielded magnetometers proximate to a human subject, the first time-series magnetic data corresponding to magnetic fields generated from the human subject, wherein:
• the plurality of unshielded magnetometers comprises an m×n array of magnetometers arranged in a stack of p planes, wherein m is a number of magnetometers in a length direction of the array, n is a number of magnetometers in a width direction of the array, and p is a number of planes, in the stack of planes, arranged in a height direction of the array, the stack of p planes including a first plane and a second plane that is adjacent to the first plane;
• and
• the plurality of signals include contributions from a biomagnetic field from at least a portion of an organ of the human subject and a background magnetic field;
• synchronizing the first time-series magnetic data to a common clock to generate synchronized time-series magnetic data;
• applying one or more filters to the synchronized time-series magnetic data to obtain filtered data;
• and
• applying one or more noise reduction techniques to the filtered data to generate updated time-series magnetic data, including:
• obtaining positional information corresponding to each magnetometer in the array of magnetometers;
• and
• for a respective pair of magnetometers, in the array of magnetometers, consisting of a respective first magnetometer positioned in the first plane and a respective second magnetometer positioned in the second plane, wherein the respective first magnetometer and the second respective magnetometer are aligned with respect to each other in the length direction and the width direction:
• calculating a difference between a first filtered signal corresponding to the respective first magnetometer and a second filtered signal corresponding to the second respective magnetometer.