On the elimination of pulse wave velocity in stroke volume determination from the ultralow-frequency displacement ballistocardiogram

A hydrodynamic model of the systemic circulatory system was mounted on an ultralow-frequency ballistocardiograph (ULF-BCG). The relationship between stroke volume and ballistocardiographic amplitude was investigated for different pulse wave velocities. It was found that the amplitude of the displacement ballistocardiogram, as used by Klensch (“J”M minus “I”J), is strongly correlated to stroke volume; however, the relationship is highly dependent on pulse wave velocity. Closer evaluation of the data showed that there is a combination of amplitude measurements that also gives a strong correlation between amplitude and stroke volume but is now independent of pulse wave velocity.