Simultaneous Acquisition of EIT and ECG Signals on Active EIT Electrodes

• Published in: IEEE transactions on biomedical engineering Vol. 72; no. 4; pp. 1498 - 1507
• Main Authors: Abdelwahab, Ahmed, Barbosa da Rosa, Nilton, Wilcox, Christopher, Shishvan, Omid Rajabi, Isaacson, David, Newell, Jonathan, Mueller, Jennifer, Saulnier, Gary
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.04.2025; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive filters; Algorithms; Biomedical measurement; Current measurement; Current sources; Data acquisition; Dipole moments; EKG; Electric Impedance; Electrical impedance; Electrical impedance tomography; Electrocardiography; Electrocardiography - instrumentation; Electrocardiography - methods; Electrodes; Frequency measurement; Heart; Humans; Image Processing, Computer-Assisted - methods; Image reconstruction; Imaging; Impedance; Inverse problems; Noise; Noise reduction; Signal Processing, Computer-Assisted; Tomography - instrumentation; Tomography - methods; Voltage measurement; Waveforms
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2024.3509900

Objective: This paper introduces a new method of simultaneous acquisition of electrocardiogram (ECG) signals and electrical impedance tomography (EIT) measurements on active electrodes, i.e. electrodes that are applying current, in an EIT system. Methods: Howland noise reduction followed by an integrate-and-dump filter and adaptive filtering are used to extract the ECG signal without loss of amplitude. Results: Results of simultaneous ECG signals and EIT reconstructions on human subjects are shown. It is also demonstrated that the recovered ECG waveforms from 32 electrodes can be used to reconstruct the heart current source vectors during a cardiac cycle, yielding an approximate solution to the inverse problem of electrocardiography. Significance: Acquiring ECG signals from all electrodes attached to the body simultaneously with EIT data acquisition eliminates the need for a separate system to collect ECG signals. Time-aligned ECG signals are helpful in interpreting pulsatile perfusion images by providing exact timing of each image in relation to the cardiac cycle. Additionally, collecting ECG signals from many or all of the EIT electrodes enables reconstruction of the heart's moving dipole moment at the same time as the EIT images.