1. A catheter comprising: a flexible tube and a control handle located proximally relative to the flexible tube, and the control handle has: a cylindrical body and a piston in a telescopic configuration, the piston having a thumb control, and the piston is longitudinally movable relative to the body by the user Using the thumb control to tilt the handset a tension control unit, comprising: a power element configured to apply force to the piston； a handle rotationally connected to the power element, the handle being rotatable by the user to adjust the force applied to the piston by the power element. 2. The catheter according to claim 1, wherein the tension control unit further includes at least one rotation guide provided on the cylindrical body, and wherein the handle has at least one pin engaging the guide, the guide being configured to limit the rotation of the handle. . The catheter according to claim 1, wherein the force member includes a set screw. The catheter according to claim 3, wherein the set screw passes through an axial hole formed in the handle. The catheter according to claim 3, wherein the distal end of the set screw passes through a threaded hole formed in the cylindrical body, the distal end being in adjustable contact with the piston. The catheter according to claim 3, wherein the set screw has a non-slip distal end for contact with the cylindrical body. The catheter according to claim 1, further comprising a1. Катетер, содержащий:гибкую трубку ирукоятку управления, расположенную проксимально относительно гибкой трубки, причем рукоятка управления имеет:цилиндрический корпус и поршень в телескопической конфигурации, причем поршень имеет элемент управления большим пальцем, и поршень выполнен с возможностью продольного перемещения относительно корпуса, осуществляемого пользователем с помощью элемента управления большим пальцем для отклонения трубки； иузел регулирования натяжения, включающий:силовой элемент, выполненный с возможностью приложения усил
