CPAP, Bi-Pap and Volume Ventilators
Dr. Bruno’s Original Post: Polio survivors often ask about the differences between CPAP, Bi-Pap and Volume Ventilators. I hope this diagram and explanation help:
CPAP blows air into the lungs continuously at one pressure;
Bi-Pap blows air into the lungs in cycles (the cycles being the "Bi" part), for several seconds at a high pressure and then at a lower pressure so you can exhale;
Volume Ventilators inflate the lungs with a measured amount (volume) of air, like carefully blowing up a balloon, and then decreases the volume so you can exhale.