A Continuous Positive Airway Pressure/Noninvasive Positive Pressure Ventilation (CPAP/NIPPV) apparatus for treatment of a patient with a sleeping disorder, the apparatus includes: a gas flow path (116) between a gas inlet (118) and a gas outlet (120), a motor (150), and an impeller assembly. The impeller assembly includes a shaft (152) in communication with said motor for rotational motion about a first axis, and first (114) and second (115) impellers coupled, e.g., fixedly secured to said shaft (152). Said first and second impellers are placed in fluid communication with one another by said gas flow path (116) such that both impellers (114,115) are disposed between said gas inlet (118) and said gas outlet (120) to cooperatively pressurize gas flowing from said gas inlet to said gas outlet.
