Singularity scalpel

The Singularity Scalpel was an alien medical device, believed to be used for operating on a body without surgery. It was discovered by Torchwood 3, but they were unable to use it properly at first. After practice, Owen Harper managed to use it to kill a Mayfly which had been implanted into Martha Jones. Prior to this, he killed a man when attempting to eradicate a Mayfly, but blew open his stomach instead. (TW: Reset)

It was used again to remove a Nostrovite egg from Gwen Cooper by Rhys on their wedding day, although it had been modified by Owen. (TW: Something Borrowed)