Self-Supervised Representation Learning from Ventilator Waveforms: A Pilot Feasibility Study

Rationale: Modern ventilators generate high-frequency pressure and flow waveforms that contain respiratory mechanics, patient respiratory effort, and patient-ventilator interactions. However, these waveform data remain underutilized for representation learning. Objective: We conducted a pilot feasibility study to evaluate whether self-supervised representation learning can extract clinically relevant respiratory information from ventilator waveforms. Methods: We developed a self-supervised representation learning framework for mechanical ventilation waveforms using airway pressure and flow signals. The model was pretrained on unlabeled waveform segments over 255,355 breaths spanning 197.1 hours of mechanical ventilation across 115 patients and learned latent respiratory representations. Frozen embeddings were subsequently evaluated on held-out patients using downstream tasks, including ventilator mode classification, prediction of respiratory physiological variables, and reconstruction of waveforms. Measurements and Main results: Pretrained embeddings enabled recovery of ventilator modes, achieving a bootstrap-derived median balanced accuracy of 0.791 (95% CI: 0.715, 0.858) and macro-F1 score of 0.765 (95% CI: 0.682, 0.839). The learned representations also supported the prediction of respiratory physiological variables, including respiratory rate and positive end-expiratory pressure. Reconstruction of unseen waveforms achieved a median Pearson correlation of 0.801 (95% CI: 0.727, 0.870) for pressure waveforms and 0.783 (95% CI: 0.709, 0.838) for flow waveforms between the reconstructed and original waveforms. Conclusions: This pilot study demonstrates the feasibility of self-supervised representation learning from ventilator waveforms. Our framework introduces ventilator waveforms as a potentially useful data modality in critical care and establishes a foundation for future investigations of patient-ventilator asynchrony, respiratory state monitoring, and optimization of liberation from mechanical ventilation.