What evidence is required to establish long-felt need in 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.

To establish long-felt need in a patent application, specific types of evidence are required. The MPEP 716.04 outlines the following key requirements:

• Objective evidence: The long-felt need must be supported by evidence, not just assertions.
• Persistent need: Show that the need has been recognized and persistent for a significant time.
• Unsuccessful attempts: Demonstrate that others have tried and failed to solve the problem.
• Satisfaction of the need: Prove that the invention actually satisfies the long-felt need.

The MPEP states: “Establishing long-felt need requires objective evidence that an art recognized problem existed in the art for a long period of time without solution.” This evidence can include industry reports, expert testimonies, or documented failed attempts by others in the field.