Figure 4

Fiberscope images corresponding to each of the three classifications of breathing sounds. (A) Fiberscope image in normal breathing sound. The mucosa of the trachea and carina were well observed. (B) Fiberscope image in vibrant breathing sound. Some thick yellow-colored sputum was surrounded by the trachea ring. The surface of the sputum exhibited waves corresponding to breath. After only suction, the participant appealed for improved airway condition. (C) Fiberscope image in sharp breathing sound. Blood clots and crust were adhering together, filling the inside of the trachea. They were also filling the inside of the tracheostomy tube. After tube change and suction, the participant appealed comfortable breathing, and the breathing sound was also improved to normal breathing sound.