Miniaturized Magnetic Sensors for Implantable Magnetomyography

Magnetism-based systems are widely utilized for sensing and imaging biological phenomena, for example, the activity of the brain and the heart. Magnetomyography (MMG) is the study of muscle function through the inquiry of the magnetic signal that a muscle generates when contracted. Within the last few decades, extensive effort has been invested to identify, characterize and quantify the magnetomyogram signals. However, it is still far from a miniaturized, sensitive, inexpensive and low-power MMG sensor. Herein, the state-of-the-art magnetic sensing technologies that have the potential to realize a low-profile implantable MMG sensor are described. The technical challenges associated with the detection of the MMG signals, including the magnetic field of the Earth and movement artifacts are also discussed. Then, the development of efficient magnetic technologies, which enable sensing pico-Tesla signals, is advocated to revitalize the MMG technique. To conclude, spintronic-based magnetoresistive sensing can be an appropriate technology for miniaturized wearable and implantable MMG systems.