Doctor Hans Ruden was a Human scientist.

In 2157, Ruden and Dr. Emily Jensen were living on Galorndon Core in order to study the planet's biological wonders when Captain Jonathan Archer of the Enterprise informed them they would have to evacuate the planet because of an iminent threat from the Romulans. Ruden and Jensen were initially hesitant to leave but were eventually escorted from the planet by a squad of MACOs, saving the scientists' lives. (ENT - The Romulan War novel: To Brave the Storm)