RTOS
An operating system that promises *when*, not just *what* — the software heart of infusion pumps, monitors and ventilators.
In one line
A real-time operating system schedules tasks with guaranteed timing: the alarm task runs within its deadline every time, no matter what else the device is doing — determinism over throughput.
How it works
Priority-based pre-emptive scheduling: the highest-priority ready task runs now, within a bounded, measured latency. Hard real-time systems (a pacemaker, a ventilator control loop) treat a missed deadline as failure; soft real-time (a display refresh) tolerates jitter. Common players: FreeRTOS, Zephyr, VxWorks, QNX. In medical devices the RTOS sits under software developed to IEC 62304 lifecycle rigor — the timing guarantee is part of the safety case.
Where it shows up in digital health
Inside nearly every active medical device: infusion pumps metering doses, patient monitors sampling waveforms at fixed rates, ventilators closing control loops. For the health-IT engineer the boundary matters: the RTOS world ends at the device's comms port — where BLE/IEEE 11073/MQTT take over and our integration story begins. Knowing what's on the other side makes you better at that boundary.