Objective To observe the relationship between blood pressure instant variability( BPIV),heart rate variability( HRV) and respiration in rabbits separately before and after hibateral vagus nerves cutting and respiratory arrest under respiratory rate regulation. Methods Ten standard experiment rabbits were selected and rabbit model of mechanical ventilation was established. The rabbits were conducted with mechanical ventilation under anesthesia by ventilator,with a constant tide volume of 10 mL/kg and respira...