What are closed-loop systems in healthcare?

Closed-loop systems represent the most mature form of clinical autonomy, where sensor data directly drives therapeutic adjustments without requiring human intervention for each decision. The most established example is hybrid closed-loop insulin delivery, which has demonstrated superiority over sensor-augmented pump therapy in time-in-range outcomes across multiple RCTs. Analogous approaches are emerging in haemodynamic management, ventilator control, and anaesthesia.