An axiom of patent law is that the patent claims are read in light of the patent specification but are not limited by the specification which may describe preferred embodiments. In Synthes v. Spinal Kinetics, the Federal Circuit found otherwise — but in the context of satisfying the written description requirement.

The patent-in-suit was for an intervertebral implant - a prosthetic device to replace a degenerated disc between vertebrae of the human spine. The implant had a "plurality of openings" according to the claims.

The infringing device sused slots or openings, but not grooves. The parties agreed that "grooves" were a species of "openings." The parties disagreed over whether "grooves" were sufficient to disclose all types of "openings." The jury found that the patent failed to meet the written description requirement of the term "plate including a plurality of openings."

The written description requirement, according to the Federal Circuit, "allows a person of skill in the art to recognize that the patentee invented what is claimed." "[T]he test for sufficiency is whether the disclosure of the application relied upon reasonably conveys to those skilled in the art that the inventor ha[d] possession of the claimed subject matter as of the filing date."

The Federal Circuit pointed out that the concept of "openings" was added to the claims after the patent application was filed and after the infringing devices were on the market. The application, when filed, described and claimed a plurality of "grooves" and "channels."

According to the Federal Circuit, the specification included examples of how a person's fiber system is anchored to cover plates of the implant. Those examples, according to the Federal Circuit employed "grooves" but not "slots" or "openings." Thus, the "written description . . . never [disclosed] anything broader than using "grooves" to anchor the fiber system to the cover plates."

The Federal Circuit further found that there was expert testimony that "grooves" would not disclose to persons skilled in the art that "slots" would serve the same function. Thus, the jury was free to conclude that the patent only disclosed "grooves" and that the use of "slots" was not predictable. Accordingly, a court had to defer to the jury finding.

PRACTICE POINTER: A patentee cannot rely on the axiom that the claims define the scope of the invention. Claims may be read in light of and be limited by the examples. Having examples of varying scope will enable a broader claim interpretation. Describing alternative embodiments, rather than just a single preferred embodiment can also enable a broader claim interpretation.

© Michael A. Shimokaji 2014

The contents of this article represent the opinions of the author and not those of the author's law firm or clients.

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