Detection of IM points in Seismocardiogram and possible application

The seismocardiogram (SCG) is the record of cardiac mechanical activity below 30 Hz. This paper proposes an algorithm for identifying IM points in the SCG, which are associated with isovolumetric ventricular contraction. This algorithm highlights for the exclusive use of the SCG signal in detecting points. With these points it is possible to obtain an equivalent time series to the RR series in the electrocardiogram (ECG), which can be a starting point for the analysis of heart rate variability (HRV). This paper compared the IM-IM and RR series from a group of healthy subjects. The results showed more than 96% similarity between them. In addition, SDNN, RMSDD and pNN50 indicators are evaluated in both series obtaining a correlation of 95.14%, 94.82% and 95.25% respectively. These results show that the IM-IM series can be an alternative for the analysis of HRV.