Investigation of Converse Magnetoelectric Thin-Film Sensors for Magnetocardiography

In principle, electrode-based bioelectrical signal acquisition can be complemented by biomagnetic sensing and therefore requires a more detailed assessment, especially because of the availability of novel noncryogenic sensor technologies. The current development of thin-film magnetoelectric (ME) sensors ensures that ME technology is becoming a prospective candidate for biomagnetometry. The main obstacle for large-scale usage is the lack of extremely low noise floors at the final sensor system output. This article highlights the current state of ME sensor development based on a magnetocardiography (MCG) pilot study involving a healthy volunteer in a magnetically shielded chamber. For assessment, an ME prototype (converse ME thin-film sensors) will be applied for the first time. This sensor type ensures a noise amplitude spectral density below 20 pT/root Hz at 10 Hz by using a sophisticated magnetic layer system. The main aim of this pilot study is to evaluate the applicability of this promising sensor for the detection of a human heart signal and to evaluate the sensor output with competitive optical magnetometry technology. A magnetic equivalent of a human R wave could be successfully detected within a 1-min measurement period with the sensor presented here. Finally, the article will provide an outlook on future ME perspectives and challenges, especially for cardiovascular applications.

Automated summary

Electrode-based bioelectrical signal acquisition can be complemented by biomagnetic sensing, and the development of thin-film magnetoelectric (ME) sensors shows promise for biomagnetometry. However, the lack of extremely low noise floors remains a challenge for large-scale usage. This article presents the current state of ME sensor development and evaluates its applicability for detecting human heart signals, comparing it to optical magnetometry technology. The results show successful detection of a magnetic equivalent of a human R wave, demonstrating the potential of ME sensors for cardiovascular applications.