A CANNULA OF CHANGEABLE LENGTH AND SHAPE

摘要

A cannula (1) of changing length and shape, built up of spirally wound one or more bands (2), in which the free unlimited parts of the bands in the cannula wall pass into the interior of the cannula end are freely located along its entire length in guiding channels (5) of the endoscope (3) or in the exterior rotating part of the endoscope, while the interior part, to which the endoscope head (4) is attached, does not rotate. The lengthening or shortening of the cannula (1) as well as the change in its shape under the conditions of its elongation, are affected by co-ordinated linear movement in the desired direction and rotation of the endoscope (3) or only of its rotating external part in the direction of the spiral winding during elongation, or in the direction of the spiral unwinding during the shortening of the cannula (1).