Magnetometer Array Calibration for Inter-Sensor Coupling

The patent applies preliminary action by performing calibration measurements before actual medical measurements. The coupling matrix is determined in advance through a calibration phase where reference magnetic fields are generated and measured by each magnetometer. This pre-determined coupling matrix is then used to correct measurements taken during subsequent medical imaging procedures, eliminating the need to physically separate the magnetometers while maintaining measurement accuracy.

The patent applies feedback by using the measured coupling matrix to correct the output signals from the magnetometer array. During medical measurements, the system continuously applies the pre-determined coupling matrix to the raw measurements to compensate for inter-magnetometer coupling effects. This feedback mechanism allows the magnetometers to operate in stable closed-loop mode while maintaining accurate field value measurements through mathematical correction.

The patent applies this principle by replacing expensive, complex SQUID sensors with optically pumped magnetometers that operate at room temperature. While individual optically pumped magnetometers have higher intrinsic noise than SQUIDs, the elimination of cryogenic cooling systems and large magnetic shielding enclosures results in a more practical, cost-effective, and democratisable system for clinical deployment.

The patent applies preliminary action by performing the complex coupling calibration once during the initial setup phase, before patient-specific adaptations. The coupling matrix determined during this preliminary calibration remains valid even when the magnetometer array is repositioned to accommodate different patient morphologies, eliminating the need to repeat calibration for each patient while maintaining measurement accuracy.