What is the definition of an inventor on a patent, and who determines this?

An inventor is someone who has made an intellectual contribution to the claimed invention. Under U.S. law, an inventor is a person who takes part in the conception of the ideas in the patent claims of a patent application. Thus, inventorship of a patent application may change as the patent claims are changed during prosecution of the application. An employer or person who furnishes money to build or practice an invention is not an inventor. Inventorship is not something that can be negotiated.

Inventorship may require an intricate legal determination by the patent attorney prosecuting the application. Inventorship is often more restricted than authorship, thus it is important to note that authorship on an academic publication does not necessarily equate to inventorship on a patent application.