A medical aspirator is a suction machine used to remove mucus, blood, and other bodily fluids from a patient. They can be used during surgical procedures but an operating theater is generally equipped with a central system of vacuum tubes. Most aspirators are therefore portable, for use in ambulances and nursing homes, and can run on AC/DC or battery power. They consist of a vacuum pump, a vacuum regulator and gauge, a collection canister, and sometimes a bacterial filter. Plastic tubing is used to continuously draw fluid into the collection canister.