Figure 1.

(a) Sucking out the tiny fragments and dust during lithotripsy by V-UAS: (A) inserting a flexible endoscope into the sheath through the aperture of rubber cap to gain a closed system, (B) the oblique drainage tube was connected to a negative pressure aspirator, and (C) a stone collection bottle is connecting the UAS and the negative pressure suction. (b) Structure of V-UAS: (A) straight introduced tube with a red marker, (B) rubber cap, and (C) oblique drainage tube. (c) Structure of oblique drainage tube in V-UAS: (A) a longitudinal slit on this oblique drainage tube that is a pressure-regulating vent.