Obviousness is almost invariably invoked as a defense in medical device patent litigation. To optimize the likelihood of success in court, we set out to analyze judicial treatment of obviousness in medical device patent cases over the six-year period following the U.S. Supreme Court’s seminal decision in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007).

Based on our analysis of obviousness challenges in nearly 40 cases, this article calculates the frequency of the most successful counters to obviousness and provides three issues patentees and accused infringers alike should consider in litigating the obviousness of medical device patents in a post-KSR world. For example, Federal Circuit decisions finding medical device patent claims non-obvious relied upon the absence of one or more claim limitations in asserted prior art references 64.7 percent of the time. And the numbers for district courts were similar.

Through an understanding of these and other related trends in the case law, medical device companies can gain a leg up on the competition when litigating patent obviousness in court.

Obviousness Background

The standard for obviousness is well settled. A party challenging a patent based on obviousness must show:

  1. The disclosure of each and every claim limitation in the prior art.
  2. A rationale for modifying or combining the prior art to arrive at the claimed subject matter.
  3. A reasonable expectation of success.
  4. The absence of secondary considerations.