A new contactless magneto-LC resonance technology for real-time respiratory motion monitoring

Abstract

Monitoring the rate of respiration and its pattern is crucial to assessing an individual’s health or progression of an illness, creating a pressing need for fast, reliable and cost-effective monitors. We present here a novel respiratory monitoring technology based on a magnetic microwire coil (MMC) magneto-LC resonance sensor. The 3mm diameter coil is wound from a melt-extracted amorphous Co69.25Fe4.25Si13B12.5Nb1 microwire. Unlike typical solenoids, the MMC is sensitive to small magnetic fields due to a significant change in an impedance attributed to the high-frequency giant magneto-impedance (GMI) effect. We propose an application of the MMC sensor to detect a position-varying source of a small magnetic field (∼0.01–10Oe) for real-time respiratory monitoring of a human patient. We simulate this application by mounting a small permanent magnet to a mechanical vibrator and vibrating the magnet at different frequencies, amplitudes, and waveforms ∼3–15cm above the MMC. This newly developed MMC magneto-LC resonance technology is highly promising for active respiratory motion monitoring and other biomedical field sensing applications.