The Future of Brain Imaging: Diamond Quantum Magnetometers for Millimeter-Scale Magnetoencephalography
Magnetoencephalography (MEG) has long been a revolutionary biomedical imaging technique for mapping brain activity. By recording the magnetic fields produced by the electrical currents generated by neurons in the brain, MEG offers insights into brain function that are crucial for both clinical diagnosis and fundamental research. However, traditional MEG systems rely on highly sensitive magnetometers and require a magnetically shielded room for operation, limiting their practical applications.
Enter the innovative diamond quantum magnetometer utilizing nitrogen-vacancy centers. Researchers from Tokyo Tech have developed a novel magnetometer that promises millimeter-scale resolution for MEG, bringing the possibility of ambient condition brain imaging one step closer to reality. This breakthrough technology is based on continuous-wave optically detected magnetic resonance, offering a simpler and more efficient method for measuring magnetic fields compared to conventional techniques.
Utilizing diamond quantum sensors with nitrogen-vacancy (NV) centers, the newly developed magnetometer pushes the boundaries of MEG resolution. NV centers are defects in diamond crystals that exhibit unique magnetic properties, making them ideal candidates for highly sensitive magnetometers. By harnessing the power of continuous-wave optically detected magnetic resonance, the team of researchers in Japan, led by Associate Professor Naota Sekiguchi, has achieved record sensitivity levels of 9.4 pT Hz-1/2 in the frequency range of 5 to 100 Hz.
What sets this diamond quantum magnetometer apart is its design without the need for a magnetic flux concentrator, which typically reduces spatial resolution. By optimizing the experimental conditions and utilizing a high-pressure high-temperature method to fabricate single crystalline diamonds, the researchers have created a sensitive magnetometer capable of measuring magnetic fields as low as 0.3 pT. This level of sensitivity opens up new possibilities for practical applications, such as MEG studies in living animals.
Looking ahead, the team envisions a future where MEG can be performed without the need for magnetic shielding, paving the way for daily diagnosis, brain-machine interfaces, and groundbreaking research in brain function. With the successful development of the diamond quantum magnetometer, the dream of ambient condition MEG with millimeter-scale resolution is within reach.