Modeling and Removal of Physiological Motion Artifacts in Capacitive ECG (PMA-cECG)

由于非接触测量，电容式心电具有优势，特别是在对心脏活动的监测必须尽可能不引人注意的情况下。然而，肢体或头部的运动产生的较强的运动伪影在更长的时间内监测心脏的电活动和心率表现出严重的缺陷。这种干扰可以通过减少运动伪影的特殊技术(如自适应滤波器)或通过cECG与其他生物医学信号融合而产生的冗余测量来部分补偿。然而，这些以前的方法主要是为了监测心率，而实际的心电波形对此并不感兴趣。然而，我们作为申请者，相信cECG在信号形态方面也具有很高的临床相关性，这应该通过对cECG信号波形变形的理解和补偿来发展。根据我们的理解，生理运动伪影(内部器官运动)应该与身体的经典运动伪影区分开来，在经典运动伪影中，相对较高的干扰幅度会显著降低信号覆盖范围。生理性运动伪影(PMAS)产生于心脏的心脏机械活动和由此引起的电极-组织界面的阻抗变化等。为了更好地理解运动伪影的时变耦合阻抗模型，将运动伪影的时变耦合阻抗模型扩展为源-滤波模型，表示心脏机械活动对心电测量的干扰。在一项针对志愿者的研究中，将开发一种多模式传感器来捕获这些信号，该传感器可以捕获心电、心电图仪和时变耦合阻抗测量。然后，将在数值模拟和模拟其行为的专用物理测试台中分析生理运动伪像。最后，对结果进行了解释，得出了在心电形态分析中处理PMAS的标准化程序。

Due to the non-contact measurement, the capacitive ECG (cECG) has advantages, especially where the monitoring of the heart activity has to be carried out as unobtrusively as possible. However, the stronger motion artifacts generated by the movement of the limbs or the head exhibit a severe drawback for monitoring the electrical activity of the heart and the heart rate over more extended periods. This interference can be partially compensated for by special techniques to reduce motion artifacts (such as adaptive filters) or by redundant measurements that result from the fusion of cECG with other biomedical signals. However, these previous approaches primarily aim to monitor the heart rate, where the actual ECG waveform is of little interest. However, we, the applicants, are convinced that the cECG also has high clinical relevance concerning the signal morphology, which should be developed through the understanding and compensation of the waveform deformation of the cECG signal.According to our understanding, physiological motion artifacts (internal organ movements) should be differentiated from the body's classical motion artifacts, where relatively high interference amplitudes can significantly reduce signal coverage. Physiological movement artifacts (PMAs) arise, among other things, from the cardiomechanical activity of the heart and the resulting impedance change at the electrode-tissue interface. With smaller amplitudes and synchronized nature with the ECG, PMAs can be misinterpreted as part of the signal, resulting in a faulty ECG analysis.In order to better understand the inherent waveform deformations, the time-variant coupling impedance model of the motion artifacts will be extended to a source-filter model, which represents the interference of the heart's mechanical activity on the measurement of the cECG. A multimodal sensor capturing cECG, ballistocardiography, and time-variant coupling impedance measurements will be developed to capture these signals in a study on volunteers. Physiological motion artifacts will then be analyzed in numerical simulations and a dedicated physical test bench that mimics their behavior. Finally, the results are interpreted to derive standardized procedures to handle PMAs in the cECG morphology analysis.