Provided herein is a method for assisting breathing in a subject, the method including passing a pressurized airflow through a fluidic diverter, wherein the fluidic diverter converts the airflow into pulses of pressurized air that are diverted alternately to provide a first and a second train of pulses of pressurized air; and directing the first and second trains of pulses of pressurized air into a nasal passageway of a subject to assist breathing. Also provided herein is a device for assisting breathing, including an airflow source coupled to a fluidic diverter. The devices and methods provided herein generate positive airway pressure in the form of pulsatile vortex airflow for the treatment of obstructive sleep apnea in a subject, without the need for a sealed interface between the subject and the device.