Federal Circuit Clarifies Substantial Evidence Standard on Appeal for Questions of Motivation to Combine

May 24, 2012

Jessamine N. Lee PhD

What This Means To You

  • In an appeal to the Board of Patent Appeals and Interferences (“BPAI”), raise an argument directed to a question of law (provoking de novo review) instead of only a question of fact (provoking substantial evidence review).
  • Carefully consider how you raise an issue with respect to motivation to combine which is a question of fact, even though its determination results in a legal conclusion of obviousness.


In In Re Hyon, the US Court of Appeals for the Federal Circuit (Federal Circuit) upheld a decision by the BPAI that claims sought in a reissue application were obvious due to the presence of motivation to combine two prior art references. Since the only question brought forth by the Appellant was motivation to combine, a question of fact, the Federal Circuit could only overturn the Board’s decision if that decision was not supported by substantial evidence, a relatively low standard.

Case Background

Hyon’s patent includes claims directed to a method for producing ultra high molecular weight polyethylene which can be used to form artificial joints. In an effort to broaden the claims, Hyon sought a broadening reissue application in which several claims were added. Those claims were rejected as being obvious by the US Patent and Trademark Office (USPTO) because there was motivation to combine two prior art references that taught all the elements of the claims. The Federal Circuit affirmed the BPAI’s decision.

Decision Analysis

The question before the Federal Circuit was whether the USPTO properly combined two prior art references in an obviousness rejection and, specifically, whether the BPAI’s decision that there was motivation to combine the prior art references was supported by substantial evidence. Because Hyon’s arguments before the BPAI only related to lack of motivation to combine, a factual question, the Federal Circuit could only overturn the BPAI’s decision if the decision was not supported by substantial evidence. The substantial evidence standard is relatively low and the Federal Circuit determined that the BPAI met this standard.


This case highlights the importance of carefully thinking about your strategy for raising arguments in an appeal to the BPAI. In an appeal, it is important to consider raising arguments with respect to a legal question, rather than only a factual question.

Challenging a legal question will provoke de novo review if appealed to the Federal Circuit--review as if the court were considering the question for the first time--rather than substantial evidence review when challenging a question of fact, in which the court must defer to the BPAI’s decision unless the decision is not supported by substantial evidence. For issues involving obviousness in particular, one should consider challenging the underlying legal question of obviousness, and not just certain elements of obviousness such as motivation to combine, a question of fact.