A wearable respiratory isolation system is configured as an open collar to be worn loosely around the neck of the user, with an articulating arm positioning a mouthpiece in front of the mouth and nasal region of the user. The system provides filtered and sterilized air through a inhalation vent on the mouthpiece which creates a curtain of sterilized air in front of the users face, which protects the users face from air bourne pathogens provides sterile air for the user to inhale. Exhaled air is extracted through an exhalation vent on the mouthpiece, is decontaminated and exhausted to the rear of the user. A modified, background oriented Schlieren imaging technique is used to determine whether the user is inhaling or exhaling, and this information is used to control the flow of sterilized air and the capture of exhaled gases.