In re Suong-Hyu Hyon and Masanori Oka (Fed. Cir., 2012) 

“One point twenty-one gigawatts!  Great scott! . . . The only power source capable of generating 1.21 gigawatts of electricity is a bolt of lightning!”

Doc Brown, Back to the Future

 Hindsight reconstruction at the hands of a well-meaning patent examiner has victimized many a patent applicant.  The examiner has a daunting task.  He or she must review a new disclosure and claims, quickly grasp the nature of the invention, search for related prior art, and then (metaphorically) hop into the nearest flux capacitor-modified DeLorean, punch in the time, and accelerate to 88 mph.  The examiner must retreat to a time just before the application was filed to decide whether or not the invention would have been obvious to the person of ordinary skill based only on what the prior art teaches.  Unfortunately, the examiner’s judgment is naturally poisoned by having seen the applicant’s disclosure.  In considering the patentability of claims, is it possible to ignore what the inventor just taught us?

In re Hyon, decided May 24, 2012, is a recent example of hindsight reconstruction by the examiner, this time affirmed by the Board and further affirmed by the majority of a Federal Circuit panel.  (Interestingly, district court judge Hon. Jeremy Fogel, California, N.D., casts the tie-breaking vote.)

Hyon and Oka’s invention, originally granted as U.S. Pat. No. 6,168,626, relates to molded articles of ultra-high-molecular-weight polyethylene (UHMWPE) used for artificial joint replacement.  The inventors needed a low-friction material having improved abrasion resistance that could be used for the socket portion of an artificial joint.  Known UHMWPE materials had the desirable low-friction quality but tended to deform and degrade, often triggering a need for more surgery.  The inventors discovered that by irradiating the polyethylene with a low dose of gamma radiation, they could introduce a very small amount of crosslinking into the polymer.  The mildly crosslinked polymer could then be compression molded and cooled to give parts with superior abrasion resistance.

When Hyon and Oka sought to reissue the patent (based on claiming less than they were entitled to claim in the ‘626 patent), the examiner concluded the claims were obvious from the combined teachings of U.S. Pat. Nos. 5,030,402 (Zachariades) and 3,886,056 (Kitamaru et al.).  Zachariades teaches a process for compression molding UHMWPE to modify the polymer’s morphology and properties.  The reference mentions the option of using radiation to crosslink the polymer after it has been compression molded.  Outside the context of joint replacement, Kitamaru teaches to use radiation to crosslink a polyethylene film or fiber, which is subsequently melted or stretched.  Molded articles are not discussed.  The crosslinked polyethylene needs to have a minimum gel content of at least 1 wt.%.

The Federal Circuit majority held that “substantial evidence” supported the PTO Board’s findings of obviousness.  According to the Board, the claimed method was “nothing more than the predictable use of a prior art element . . . according to its established function.”  The majority rejected Hyon’s argument that the skilled person had insufficient motivation to combine the references.  Hyon argued that only Zachariades related to artificial joints; the technologies described by Kitamaru and Zachariades were “fundamentally different.”  The majority concluded, however, that the skilled person would have been “motivated to combine the early crosslinking step of Kitamaru with the process of Zachariades to obtain the enhanced properties disclosed by Kitamaru that result from crosslinking prior to deformation.”

In dissent, Judge Newman hits the bull’s-eye.  She calls the Board’s analysis “flawed” and based on hindsight.  “The Hyon procedure and its effects are not shown or suggested in any reference, despite the long history and extensive scientific studies of all forms of polyethylene.”  Judge Newman’s remarks reflect a careful reading and analysis of Hyon and the references:

Kitmaru is directed to cross-linking and extending polyethylene fibers and films, and does not relate to producing a polyethylene mass suitable an artificial joint having advantageous mechanical properties and dimensional stability.  It is noteworthy that Zachariades, seeking mechanical strength and dimensional stability, did not follow the known Kitamaru processing sequence, but instead crosslinked the polyethylene after deformation, not before.  Nonetheless, the examiner held that a person of ordinary skill . . . would have known to do what neither Kitmaru nor Zachariades did, and would have known or expected that this departure would produce “low friction and remarkably improved abrasion resistance.”

Judge Newman notes Hyon’s teaching that a high dose of radiation (as used in Kitmaru) did not improve abrasion resistance.  “Nothing in the record suggests that a person of ordinary skill would have foreseen that Hyon’s method of slight radiation cross-linking followed by heating and compression deformation would produce the described benefits . . . .  It is 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.”

Judge Newman calls the Board’s analysis “contrary to the [Supreme] Court’s guidance” in KSR v. Teleflex (550 U.S. at 421), which cautioned factfinders to be aware of the “distortion caused by hindsight bias” and not to rely on ex post reasoning.  Quoting from In re Fritch (972 F.2d 1260, 1266, Fed. Cir. 1992), she reminds us that it is “impermissible to use the claimed invention as an instruction manual or ‘template’ to piece together the teachings of the prior art so that the claimed invention is obvious.”

Hyon and Oka were not the first to fall prey to hindsight reconstruction; nor will they be the last.  Because no examiner, administrative patent judge, or district court judge (at least not yet) has, like Doc Brown, a DeLorean equipped with the latest beer-guzzling Mr. FusionTM time machine, practitioners should be alert for this natural bias of factfinders.  Only the wary agent/attorney will prevent his or her inventors from becoming victims of their own creativity.


-Jon Schuchardt


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