The Design of the Biomagnetic Field Sensor without Magnetic Shielding

Abstract

Due to the extremely weak intensity of the biomagnetic field and the serious interference from the environmental magnetic field, the detection of the biomagnetic field becomes such challenging work. After analyzing the deficiencies in the current biomagnetic field sensors, this paper proposes and realizes a high-sensitivity magnetic field sensor, based on the giant magneto-impedance (GMI) effect. Taking advantage of the miniaturized magnetic probe, the multistage multiple amplification and the multiband interference suppression, our sensor mainly makes three achievements: the pT level magnetic resolution, the ability to detect the muscle magnetic field without the magnetic shielding and the resistibility to a small-range wobbling in the state of working, which makes it possible to detect the biomagnetic field by wearable sensors under natural conditions.