What is the function-way-result test in the doctrine of equivalents?

The function-way-result test is a key aspect of determining equivalence under the doctrine of equivalents. MPEP 2186 references this test as follows:

“[A]n analysis of the role played by each element in the context of the specific patent claim will thus inform the inquiry as to whether a substitute element matches the function, way, and result of the claimed element, or whether the substitute plays a role substantially different from the claimed element.”

This test evaluates whether a substitute element in an accused product performs substantially the same function, in substantially the same way, to achieve substantially the same result as the claimed element in the patented invention.

To learn more:

• function-way-result test
• doctrine of equivalents
• patent infringement
• MPEP 2186