This article discusses the importance of boundary spanning innovation, demonstrates the drawbacks of popular metadata based boundary spanning measures, and proposes a new full text semantic similarity measure of boundary spanning. It subsequently uses the semantic distance boundary spanning measure to demonstrate that boundary spanning innovation has become more common in recent decades, and show that these boundary spanning inventions pose challenges for the traditional specialized-examiner patent examination model. Examining the applications for inventions that span technical boundaries takes longer and requires more back-and-forth with the patent office than their comparatively simple peers. Finally, this article discusses potential reforms to the patent examination system to help address these challenges.