Most positive pressure ventilators have an airway pressure monitor to assess the pressure in the circuit. They have a volume measure to assess the volume of the patient��s breaths. These also monitor if the patient is properly connected to the ventilator.
 
Many positive pressure ventilators have sophisticated pressure, volume and flow sensors. These sensors control the ventilator's output and monitor the interaction between the patient and the ventilator. These monitors allow the caregiver to follow the patient's condition.