Seven years follow‐up of ballistocardiogaphy
Keywords:EMFi, BCG, follow-up, blood pressure
This work serves as a method description, where ballistocardiography (BCG) and pulse waves were used to study longer term alterations of heart-vasculature system. BCG and pulse signals were recorded from one person in sitting position by using Electromechanical Film (EMFi) sensors during 7 years time interval. ECG, BCG, carotid pulse (CP) signal from the right side of the neck near the carotid artery and the left ankle pulse wave (in five recordings) were recorded from one person. Duration of the signal components according to R wave from the ECG, amplitudes and spectral components of the signals were studied. Pulse wave velocity (PWV) values were calculated in order to compare aortic blood pressure (BP) to values obtained with commercial Omron BP measurement device.
The time domain properties of CP and BCG signals during seven years time remained fairly stable within the same person. Also when the signals were estimated visually in spectral domain from the seat BCG and especially from the CP, no major differences were found. Minor alterations in the frequency of the spectral spikes may be due to heart rate changes between measurements or due to slight changes in the arterial elasticity having an influence to the spectral traces. Obtained PWV values followed closely BP changes measured with Omron BP measurement device.