Abstract: According to an aspect of the present invention, there is provided an apparatus for ultrasonic welding of a removal thread (1) of an intrauterine system (2). The apparatus comprises a welding jig (3) comprising a welding groove (4), the welding groove having a length Lg, a width Wg and a depth Dg and a bottom (5) with concave shape. The apparatus further comprises a sonotrode (6) having a length Ls that is 150-220% of Lg, a width Ws of a welding tip (7) of the sonotrode that is 80-98% of Wg and a depth Ds. Further, the welding tip of the sonotrode has a concave shape.

Abstract: Disclosed is an intrauterine system (100, 300, 400, 500, 600) comprising a frame (102, 302, 402, 502, 602), a removal thread (218, 326, 436, 626) and at least one pharmaceutically active agent. The frame has a first end (104, 304, 404, 504, 604), a second end (106, 306, 406, 506, 606) and a length L. The first end of the frame comprises a first locking part (108, 308, 408, 508, 608) and the second end of the frame comprises a second locking part (110, 310, 410, 510, 610), the first locking part and the second locking part being arranged to form a lock (202, 312, 432). The removal thread is attached to the first end of the frame. The removal thread is configured to guide the first locking part to the second locking part. Further, disclosed is a kit comprising the aforementioned intrauterine system and an inserter.

Abstract: Disclosed is an inserter (1100, 1300, 1400, 1500) for an intrauterine system (1102, 1336, 1402, 1502), comprising a handle body (1104, 1306, 1416, 1504), a measurement tube (1110, 1328, 1406, 1510), a plunger (1132, 1202, 1362, 1450, 1532), a flange (1122, 1404, 1522), a finger holder (1124, 1314, 1446, 1524), and a means (1126, 1526) for reversibly locking removal thread (1128, 1358, 1414) of the intrauterine system. A proximal end (1106, 1440, 1506) of the measurement tube is movably attached to a distal end (1108, 1330, 1454, 1508) of the handle body, and the measurement tube is arranged to remain outside a cervix channel during insertion. The plunger is movably arranged inside the handle body and the measurement tube. The present disclosure also provides a kit comprising the inserter and the intrauterine system.