In affirming a decision by the U.S. Patent and Trademark Office’s Board of Patent Appeals and Interferences (Board) finding of obviousness, the U.S. Court of Appeals for the Federal Circuit agreed that there was substantial evidence to support a finding of a motivation to combine references.  In re Hyon et al., Case No. 11-1239 (Fed. Cir., May 24, 2012) (Bryson, J) (Newman, J., dissenting). 

Hyon submitted the reissue application at issue and included a claim for a method for producing an ultra-high molecular weight polyethylene (UHMWPE) block, as well as a claim that was substantially identical, except it also included a preamble that recited an UHMWPE artificial joint component for implantation in a human or other animal.  The method claims included the steps of crosslinking an UHMWPE block by irradiating it; heating the crosslinked block; subjecting the heated block to pressure; and then cooling the block. 

During prosecution, the examiner found that a prior art patent (Zachariades) met each limitation of the reissue claims except the step of crosslinking the UHMWPE prior to the step of compression deformation of UHMWPE.  However, the examiner found that another prior art patent (Kitamaru) disclosed the step of crosslinking the UHMWPE prior to compression.  The examiner then found that it would have been obvious to use the crosslinked UHMWPE in the method of Zachariades given Kitamaru’s teaching that crosslinking prior to compression deformation results in improved transparency, increased melting point and excellent dimensional stability. 

On appeal to the Board, the applicant did not challenge the examiner’s findings as to what the references disclosed. Instead, the applicant argued only that there would have been no motivation to combine the teaching of the two references.  The Board rejected that argument, finding that Kitamaru provided the reason for modifying Zachariades to crosslink before compressing.  The applicant appealed to the Federal Circuit.  

The issue on appeal was whether the Board’s determination on motivation to combine was in error because the references themselves teach fundamentally different material technologies;   Zachariades being directed to artificial joints and Kitamaru being directed to films and sheets.  

The Federal Circuit found that the Board’s determination regarding motivation to combine was supported by substantial evidence.  The Court also found the Board’s conclusion that the references both teach processes directed to making the same class of products is also supported by substantial evidence, stating that “differences in the UHMWPE products described by the embodiments do not negate the motivation to combine the references.”  The Court stated that Zachariades “does not disparage pre-compression crosslinking,” “does not state that UHMWPE product can be made only be crosslinking after compression deformation, nor does it state or suggest that faulty or inferior products will result from crosslinking prior to compression.” 

Judge Newman dissented from the Court’s “endorsement of the Board’s flawed analysis.”  She explained that the Board’s finding of obviousness was based on impermissible backward reasoning from the Hyon method:  “[i]t was only after Hyon demonstrated how to achieve this improved result that the Board was able to plug the prior art steps into the template of the Hyon method.”