Description:

A Bilevel positive airway pressure (or BiPAP) machine builds to a higher pressure when you inhale and decreases to a lower pressure when you exhale. This device is most appropriate for central sleep apnea, a condition where the brain loses its drive to breathe. A BiPAP device looks and fits very much like a CPAP device, but the functionality is different. 

Adaptive Servo Ventilation (ASV) - ASV is a respiratory assist device (RAD) designed specifically to treat central sleep apnea (CSA) in all its forms, including complex and mixed sleep apnea. This type of machine treats CSA by adapting breath-by-breath to the patient.
 Unlike conventional sleep apnea therapies such as CPAP, ASV normalizes breathing, completely suppressing CSA and/or Cheyne-Stokes Respiration (CSR)