ATRAUMATIC NEEDLE AND METHOD OF ITS MANUFACTURE Russian patent published in 1998 - IPC

FIELD: medical engineering. SUBSTANCE: atraumatic needle has arc-shaped sharpened rod 1 with eye and ligature 4 positioned on dull end 3. Ligature is secured in eye cavity through walls deformed in counter direction. Needle has rod 1 bent completely or partially. Its central axis is oriented over helical line, and cross-sections of opposite ends 2 and 3 of rod 1 are shifted about its central axis by at least 30 deg. relative to each other. Sharpened part 2 is made in the form of at least one inclined plane and one surface of revolution of not lower than second order or in the form of at least one surface of revolution . Method of atraumatic needle manufacture includes preliminary formation of pack of interconnected needle bodies, formation of bed grooves for ligature on bodies, pack separation, sharpening of bodies and coupling of bodies with threads by force action of surfaces of revolution on walls of bed grooves. It also includes formation of pack from wire by winding the latter on mandrel with radial-screw interference. This done, pack is removed from mandrel and formed again with interference and fixation on threaded mandrel-satellite of machining device. Bed grooves are formed by backing-off. Pack is separated by cutting with due regard for dimensions of bodies corresponding to angles of 90-270 deg., and sharpening is performed by machining and electrochemical treatment. Force action on walls of bed grooves is rendered by at least one surface of revolution of not lower than second order. EFFECT: improved interaction of atraumatic needle with tissues. 6 cl, 6 dwg