A BiPAP machine is a device primarily used to treat sufferers of obstructive sleep apnea who have difficulty tolerating a traditional CPAP machine.
BiPAP stands for "Bi-level Positive Air Pressure," distinguishing it from a CPAP device, which delivers "Continuous Positive Air Pressure." BiPAP machines contain a more sophisticated compressor than CPAP machines, enabling them to provide two levels of air pressure to the patient while he or she is sleeping. Many patients find this to be more comfortable than the constant pressure provided by CPAP machines.
After a polysomnogram (or "sleep study") that is positive for sleep apnea, a patient is usually given a CPAP machine to take home and try for several weeks. If the patient is unable to sleep with the CPAP device, he or she may be provided with a BiPAP machine to see if it works any better for them. Like a CPAP machine, a BiPAP is essentially an electric device containing a compressor connected to a long tube and a nasal mask (or nasal pillows) which are worn by the patient while sleeping.
BiPAP machines provide one pressure (for example, 10 cm of oxygen) when the patient is inhaling, and, when the machine senses the patient is exhaling, a different pressure (for example, 2 cm of oxygen) is provided so the patient does not feel he or she is having to "struggle" or "push" to exhale.