BILEVEL THERAPY Many of the components of a BiPAP machine are the same as the standard CPAP machine. For example, it still requires a face mask and tubing connected to the device. BiPAP’s key distinguishing feature delivers pressurized air at two alternating levels. The inspiratory positive airway pressure (IPAP) is higher and supports a breath as it is taken in. Conversely, the expiratory positive airway pressure (EPAP) is a lower pressure that allows you to comfortably breathe out. Your sleep doctor provides a prescription that presets these pressures based on your needs, and they alternate just like your breathing pattern.
Beyond these standard settings, there are a few other variations that are available. Bilevel ST includes the timed delivery of a breath if breathing pauses occur. These pauses are often present in central sleep apnea.
In addition, auto or adaptive servo-ventilation (ASV) includes more sophisticated settings that vary the timing, length, and volume of the breaths that are delivered.