Bilevel positive airway pressure (BiPAP) provides different pressures for inhale and exhale

https://andrewjiw470.cavandoragh.org/sleep-apnea-weight-loss-can-bariatric-surgery-help-resolve-apnea

Bilevel positive airway pressure (BiPAP) provides different pressures for inhale and exhale, helpful for high-pressure needs or concurrent hypoventilation.