This is a machine looks the same as the conventional CPAP device. It still pumps air through a mask worn over the face. But this machine allow you to set different pressures for inhalation and exhalation. It means that if you required very high pressures to maintain the airway on inhalation you might not needed during exhalation. Reducing the Excitatory Pap pressure helps many patients to adjust to wearing such a device. (Note: normally when we exhale the air just flows effortlessly. As the pressures are increased, more effort is needed to clear our lungs of the air. The less pressure needed the more natural it will feel.)
