Dual mandrin for human body probe, has external mandrin in form of flexible tube, and internal mandrin movable in external mandarin, where wall of external mandrin has spring that includes sections with preset curving in tip area

摘要

The mandrin has an external mandrin (1) in the form of a flexible tube, and an internal mandrin (2) movable in the external mandarin. A wall of the external mandrin has a spring that includes sections of different elasticity with preset curving in a tip area, where the curving is beyond 360 degrees. The material of the spring is in the form of layers, and the spring is made of a plastic material. A wall of the spring is permeable to fluid, where the distance of individual spring windings is expanded for passing the fluid.