Hemodialysis machines balance ultrafiltration fluid removal, anticoagulant heparin infusion, blood pump tachometers, and venous air bubble optical sensors. Missing an air detector deadline by 5 milliseconds can cause fatal air embolisms. This engineering study verifies concurrent RTOS scheduling under IEC 60601-2-16.
The air bubble detection task runs as an uninterruptible highest-priority interrupt, directly commanding electromechanical venous line clamps within 1.2 milliseconds of acoustic boundary detection.
Ultrafiltration pumps and conductivity sensors operate on fixed time slices, mathematically proven against race conditions using formal Petri net verification models.