Yu.K. Gruzevich1, V.M. Achildiev2, Yu.N. Evseeva3, N.A. Bedro4

1,2 Bauman Moscow State Technical University (Moscow, Russia)

1ؘ–4 “Scientific Production Unity Geofizika-NV” Stock Company (Moscow, Russia)

The paper is devoted to the research of different cardiac signals fiducial points features and their relationships. There are a lot of tested methods of information analysis of different cardiac signals which allows non-invasive screening and diagnostics of human internal organs diseases. One of them is based on a heart information function and designed by V.M. Uspenskiy. During the research of the possibility of application of this method to seismocardiography (SCG) and gyrocardiography (GCG) signals, we have run into a problem of their fiducial points identification and their relationships. Two series of measurements of simultaneously registered ECG, SCG, and GCG signals of healthy subjects made by designed electroseismogyrocardiography (ESGCG) system were used. The first one contains 21 periodical measurements during one month to estimate the signal shape and fiducial point individual variability. The second one contains measurements of 10 healthy young people. The fiducial points were identified and validated by operators. Features of the shape and fiducial points in multiple measurements on a single subject are preserved but differ markedly for a group of healthy subjects. Cardiac cycle duration that can be determined as R-R peak interval of ECG signal can be also determined based on SCG or GCG fiducial points such as IM, AO, GX1, GY1. Tn mean values are close that is shown in Bland-Altman plots but differs for some milliseconds in each cardiac cycle. Fiducial point IM lags behind the corresponding ECG R peak by an average of 45.0394 ± 6.2326 ms, AO - 65.8974 ± 6.7569 ms. Fiducial points GX1 and GY1 are registered with a difference of a few milliseconds and lag behind the R peak by 50.6109 ± 7.2232 ms и 53.5877 ± 7.5735 ms respectively. The obtained values of the fiducial points delays of SCG and GCG signals allow their automating identification relative to the reference ECG signal during data processing. In addition, the time delays from the R peak have individual variability for the subject which can also be used as information parameter in the information analysis method.

Gruzevich Yu.K., Achildiev V.M., Evseeva Yu.N., Bedro N.A. Research of fiducial points of cardiac signals of different nature. Biomedicine Radioengineering. 2021. V. 24. № 6. Р. 5−16. DOI: https://doi.org/10.18127/j15604136-202106-01 (In Russian)

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