In some embodiments, a method may include inhibiting contamination of a medical device. The method may include positioning a first shield on a torso of a subject. The first shield may inhibit transmission of solid and fluid contaminants. The method may include positioning a wearable harness of a medical device on a torso of a first subject. The method may include positioning a second shield on a torso of a subject such that the wearable harness is positioned between the first shield and the second shield. The second shield may inhibit transmission of solid and fluid contaminants. The method may include applying an oscillation force to at least one of the treatment areas using at least some of a plurality of engines coupled to the wearable harness. The method may include mobilizing at least some secretions in an airway within the subject substantially adjacent to the treatment areas.