A cauterizing seal patch was a piece of medical equipment available to Federation medical personnel in the 24th century. Doctor Julian Bashir always kept a cauterizing seal patch in his medkit, which was most fortunate when he was attacked by the Jem'Hadar Kitana'klan in April 2376. Bashir received severe wounds and was losing a lot of blood, he passed out before he could apply the patch himself and would have died. Fortunately Taran'atar was able to apply the patch before he continued on in pursuit of Kitana'klan. (DS9 novel: Avatar, Book Two)