Towards Wearable High-Density MEG: A Compact, Low-Power, and Scalable OPM-MEG System with Automated Control.

OBJECTIVE/BACKGROUND: Optically pumped magnetometer-based magnetoencephalography (OPM-MEG) is advancing toward wearable and high-density sensor configurations, posing significant engineering challenges in miniaturization, thermal management, and scalable integration. Here, we present a high-performance wearable OPM-MEG system that addresses these challenges. METHODS: The system was developed through a system-level co-design of the sensor head and electronic control units (ECUs) with a fully automated control workflow. To reduce thermal dissipation and lower scalp temperature, we implemented a thermally optimized suspended vapor-cell module. RESULTS: This design achieves a miniaturized sensor head (12 × 16.5 × 22.5 mm3) and ECU footprint (34 × 28 mm2), with a total per-sensor power consumption of 3.5 W (0.7 W allocated to the sensor head). Crucially, the sensor maintains high sensitivity required for detecting ultraweak brain magnetic fields, exhibiting single-axis sensitivity < 7 fT/$\sqrt$ Hz and dual-axis sensitivity < 10 fT/$\sqrt$ Hz, with a bandwidth of 130 Hz. Inter-sensor crosstalk and intra-sensor cross-axis projection error (CAPE) are suppressed to lower than 2%, addressing the critical challenge of signal interference in high-density sensor arrays. Phantom experiments demonstrate accurate source localization with a mean error of 1 mm, while human recordings provide further validation of stable and high-fidelity performance in wearable OPM-MEG settings. CONCLUSION: Collectively, this work establishes a scalable, instrument-level framework for the design, automated operation, and quantitative end-to-end evaluation of high-density wearable OPM-MEG systems. SIGNIFICANCE: This work provides a scalable foundation for high-density wearable OPM-MEG, enabling mobile brain measurements for brain-computer interfaces, cognitive neuroscience, and future translational clinical neuroimaging applications.