Abstract: A self-expanding stent for a medical device to be introduced into a cavity of a human body, is disclosed and includes a radially expandable and axially retractable tubular body (1), characterized in that the tubular body comprises first flexible rigid filaments (2, 3) which are arranged side by side in a number at least equal to two, wound along a first helicoid direction around a longitudinal axis (4) of the tubular body, and second flexible rigid filaments (5, 6) which are arranged side by side in a number at least equal to two, wound along a second helicoid direction opposite to the first, each multiple filament wound in one of the said directions crossing multiple filaments wound in the other direction according to a plaited arrangement. Methods for reproducibly forming the stent of the invention are disclosed.

Abstract: A balanced strand includes a fibrous core about which load bearing fibers are twisted. The fibrous core has an elongation factor of at least 10% and comprises approximately up to 30% of the material volume of the strand. The load bearing fibers have an elongation factor less than the fibrous core and a strength of at least 15 g denier. The load bearing fibers comprise the remaining strand material volume.

Abstract: During the production of a yarn, and independently of fiber feeding into the spinning element, the air circling together with the opener roller during spinning is removed from the area of the housing which does not convey fibers by an auxiliary air stream which is so strong that it removes fibers and fiber fragments that have become detached from the opener roller and are circling with the opener roller. The auxiliary air stream removed from the housing is introduced into the spinning rotor in such manner that the fibers which are conveyed with it are deposited on the fiber collection surface. To remove the auxiliary air stream, an auxiliary channel is provided which is connected to the source of negative pressure independently of the fiber feeding channel and at the same time may let out into the spinning element.