A portable magnetocardiography system: Using a magneto-impedance sensor

A portable magnetocardiography (MCG) system is introduced and validated. The MCG system is based on a commercially available magnetoimpedance (MI) sensor that has nano tesla sensitivity. The output signals from the sensor were digitized at 1 ksps and 16-bit resolution. The signals were displayed on a computer through a custom-made graphical user interface and stored for off-line analysis. The system was validated on a human subject while MCG, electrocardiography and finger pulse oximetry were carried out simultaneously. The results showed a good correlation between the MCG and the other two signals in both time and frequency domain. The system can potentially complement wearable ECG devices in the future, since they do not require any electrode to be in contact with the skin.