Objective To study the techniqiue of cleaning residual biliary tract stones with the net basket catheter by "T" type duct and it's effect.

Physical properties: a single scattering holes, including gum sediments, tylosis rich, catheter and ray pits between small, axial parenchyma as paratracheal type, main poly of, ribbon is also common.

This paper introduces a new type of fiber optic catheter tip pressure transducer, describes its design, construction and clinical application.