What are the key factors in establishing long-felt need for a patent application?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Establishing long-felt need for a patent application requires consideration of three key factors:

• Persistent and recognized problem: There must be objective evidence that a recognized problem existed in the art for a long time without a solution. As stated in the MPEP, Establishing long-felt need requires objective evidence that an art recognized problem existed in the art for a long period of time without solution. (MPEP 716.04)
• Unsatisfied need: The long-felt need must not have been satisfied by another before the invention. The MPEP cites the case Newell Companies v. Kenney Mfg. Co., where it was determined that [O]nce another supplied the key element, there was no long-felt need or, indeed, a problem to be solved.
• Invention satisfies the need: The invention must actually satisfy the long-felt need. This is supported by the case In re Cavanagh, as mentioned in the MPEP.

These factors are crucial in demonstrating that the claimed invention addresses a significant, unresolved problem in the field.