What options are available if an inventor refuses to sign a patent application?

For applications filed on or after September 16, 2012:

• An assignee or obligated assignee may file the application as the applicant
• A person who shows sufficient proprietary interest may file the application on behalf of and as agent for the inventor
• The applicant may file a substitute statement in lieu of an inventor’s oath or declaration if the inventor has refused to execute the oath or declaration

For applications filed before September 16, 2012, a petition under pre-AIA 37 CFR 1.47 could be filed.