Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210, USA.
Sensors (Basel). 2023 Jun 14;23(12):5567. doi: 10.3390/s23125567.
We demonstrate a magnetocardiography (MCG) sensor that operates in non-shielded environments, in real-time, and without the need for an accompanying device to identify the cardiac cycles for averaging. We further validate the sensor's performance on human subjects. Our approach integrates seven (7) coils, previously optimized for maximum sensitivity, into a coil array. Based on Faraday's law, magnetic flux from the heart is translated into voltage across the coils. By leveraging digital signal processing (DSP), namely, bandpass filtering and averaging across coils, MCG can be retrieved in real-time. Our coil array can monitor real-time human MCG with clear QRS complexes in non-shielded environments. Intra- and inter-subject variability tests confirm repeatability and accuracy comparable to gold-standard electrocardiography (ECG), viz., a cardiac cycle detection accuracy of >99.13% and averaged R-R interval accuracy of <5.8 ms. Our results confirm the feasibility of real-time R-peak detection using the MCG sensor, as well as the ability to retrieve the full MCG spectrum as based upon the averaging of cycles identified via the MCG sensor itself. This work provides new insights into the development of accessible, miniaturized, safe, and low-cost MCG tools.
我们展示了一种无需屏蔽环境、实时运行且无需配套设备即可识别心脏周期进行平均处理的磁心图 (MCG) 传感器。我们进一步在人体受试者上验证了该传感器的性能。我们的方法将七个（7）先前经过优化以获得最大灵敏度的线圈集成到一个线圈阵列中。根据法拉第定律，心脏的磁通量被转换为线圈之间的电压。通过利用数字信号处理 (DSP)，即带通滤波和线圈间平均，可以实时获取 MCG。我们的线圈阵列可以在非屏蔽环境中实时监测具有清晰 QRS 复合体的人体 MCG。同内和同间受试者变异性测试证实了与金标准心电图 (ECG) 相当的可重复性和准确性，即心脏周期检测准确率>99.13%，平均 R-R 间隔准确率<5.8ms。我们的结果证实了使用 MCG 传感器进行实时 R 波检测的可行性，以及基于 MCG 传感器本身识别的周期平均来获取完整 MCG 频谱的能力。这项工作为开发易于使用、小型化、安全且低成本的 MCG 工具提供了新的见解。
