  The topology method is an algorithm for accurate estimation of instantaneous
heartbeat intervals using millimeter-wave radar signals. In this model, feature
points are extracted from the skin displacement waveforms generated by
heartbeats and a complex number is assigned to each feature point. However,
these numbers have been assigned empirically and without solid justification.
This study used a simplified model of displacement waveforms to predict the
optimal choice of the complex number assignments to feature points
corresponding to inflection points, and the validity of these numbers was
confirmed using analysis of a publicly available dataset.
