All-optical closed-loop control of human cardiomyocyte networks exploiting holographic optogenetics.

Heart diseases can trigger life-threatening arrhythmias by disrupting cardiac contraction wavefront propagation. In contrast to conventional treatments like electrical pacemakers, optogenetics offers high spatial and temporal resolution for non-invasive interrogation and modulation of cellular activity. However, combining sensing and actuation into a real-time control loop remains challenging. A major obstacle is the data load associated with dense sensor arrays typically required for spatially resolved wavefront monitoring. To overcome this, we present an all-optical, closed-loop control strategy using adaptive holographic stimulation and sparsely sampled, label-free imaging data, enabling robust classification and quantitative characterization of spatial wavefront properties in real time. We successfully demonstrate spatiotemporal optogenetic closed-loop control of wavefront dynamics in functional syncytia of human induced pluripotent stem cell-derived cardiomyocytes in at least 107 out of 109 evaluated cases across all experiments. This framework establishes a foundation for advanced feedback control strategies aimed at mimicking, detecting and terminating abnormal propagation patterns.