Generalization of the one-dimensional cardiac-phase assumption to other echocardiographic views

Determine whether the one-dimensional cardiac-phase assumption underlying the single-parameter latent-orbit model extends to parasternal and subcostal echocardiographic views.

Background

The paper introduces a self-supervised cardiac-phase detector for apical four-chamber (A4C) echocardiographic videos. Its central inductive bias is that cardiac phase can be represented by a single scalar parameter traversing a one-dimensional latent orbit, enabling direct localization of end-diastole and end-systole without annotations.

The experiments are limited to A4C videos from the EchoNet-Dynamic dataset. The authors explicitly leave unresolved whether the same one-dimensional representation remains appropriate for parasternal or subcostal views, where imaging geometry and visible cardiac motion may differ. Establishing this would assess the model's generality across echocardiographic acquisition views.