Medegen MMS, Inc. v. ICU Medical, Inc. (Fed. Cir. 2008)

    By Kevin E. Noonan —

The Federal Circuit recently had the opportunity to appreciate firsthand the frustrations of district court judges with its review of claim construction under Markman v. Westview Instruments, Inc.  This teaching came in a dissenting opinion from the Honorable Vaughn R. Walker, Chief Judge, U.S. District Court for the Northern District of California, sitting by designation in Medegen MMS, Inc. v. ICU Medical, Inc. decided November 20, 2008.

The case involves "needle-free valve[s] for intravenous (I.V.) therapy used to administer fluids to a medical patient."  The claimed devices are used to connect a syringe to a catheter, without suffering from "retrograde flow."  The opinion characterizes retrograde flow as being "the reverse flow of fluid out of the patient's body and back into the catheter tubing, the connector, and the syringe, caused by the negative pressure suction that occurs as the syringe is withdrawn from the connector."  Such retrograde flow can result in blood fouling the catheter, with clotted blood necessitating flushing or replacement of the catheter.  Positive pressure produced using a plug counteracts the negative pressure that produces retrograde flow.

After a Markman hearing construing several claim terms, including "plug," ICU filed and the District Court granted a motion for summary judgment of non-infringement.  The basis for this judgment was that the ICU product embodied a rigid, inflexible plug, while the District Court's construction of plug required a flexible, elastomeric plug.

According to the majority opinion, written by Judge Dyk and joined by Judge Rader, this construction of the term "plug" was error.  The opinion characterized the construction as "relying heavily" on the fact that the specification consistently described the plug as having an elastomeric character, and that the specification "nowhere describe[d] a non-elastomeric or rigid plug."  The CAFC agreed with Medegen, that the term "plug" should be given "its ordinary meaning" as "a moveable member between an open and closed position."  The bases of the Court's opinion included that the term "plug" was claimed "broadly"; that the term was "not expressly limited by the language of the claims"; that there was "no contention that the ordinary meaning of the term 'plug' does not include a rigid plug or that it has a special meaning in the medical field that requires elastomericity"; and that there was no "clear disclaimer of non-elastomeric plugs in the specification."

The opinion expressly disagreed with ICU's contention that the skilled worker "would read the specification as limited to elastomeric plugs," and characterized elastomeric plugs as being "merely an example" of how to practice the invention.  The Court reached its determination even though the Detailed Description section of the patent disclosed elastomeric or "rubber" plugs twenty-one times (and never discussed non-elastomeric or rigid plugs).  This disclosure merely reflects "preferred embodiments," and limiting the claims to preferred embodiments is improper.  According to the opinion, ICU's construction "relies on a single embodiment theory," a construction "specifically rejected" in Phillips v. AWH Corp.  In view of this disagreement on the proper construction of the term "plug," the Federal Circuit vacated and remanded to the District Court for trial using this more expansive construction of plug.

Judge Walker (at left) dissented.  He asserted that the issues before the CAFC presented "a conundrum often faced by district courts when construing" claim terms.  He cited the "twin axioms" of claim construction that produced the conundrum:  "[o]n the one hand, claims 'must be read in view of the specification'," citing Markman, while "[o]n the other hand, it is improper to read a limitation from the specification into the claims," citing Arlington Indus. Inc. v.  Bridgeport Fittings, Inc.  The problem with these axioms, according to Judge Walker, is that "the axioms themselves seldom provide an answer, but instead merely frame the question to be resolved."  Here, Judge Walker contended that the majority based its decision to overrule the District Court's construction on the second axiom without properly assessing the term by taking both axioms into consideration.  While recognizing the sound policy reasons for a patent drafter to be required to include "all claim limitations in the claims of a patent," he also admonished that "patents must be read as well as written."  Citing Phillips, this analysis must be performed with due consideration of a term's "ordinary and customary meaning" informed by the "context of the entire patent, including the specification."  The majority's construction gave too little weight to the specification, in Judge Walker's view, in favor of "broad dictionary definitions."

In contrast, the "very able district court . . . looked first to the patent" in performing its construction of the term "plug," basing its decision on the "repeated" description of the plug as having "elastomeric, pivoting and buckling limitations" that the District Court included in its construction.  Moreover, the claimed invention would not work using a rigid, non-elastomeric plug, and for this reason alone, Judge Walker contended that the District Court's construction of the term was more consistent with an elastomeric plug being "an essential element" of the invention.  In addition to the intrinsic evidence, the District Court also relied on extrinsic evidence from expert witnesses, including evidence that Medegen's expert could not explain how a rigid plug would be operable in the claimed invention.

Judge Walker raises the essential paradox of the Federal Circuit's practice under Cybor Corp. v. FAS Technologies, Inc. of giving no deference to claim construction by district courts:  "[a]s a jurist more accustomed to working on the front lines of patent litigation than reviewing decisions from above, it is my experience that claim construction — determining how one of ordinary skill in the art would understand the patent at the time of invention — often requires making fact-like determinations not well suited to appellate review."  The "uniformity and predictability" desired by the CAFC as a general, guiding principle is not always best served in the individual determinations necessary to construe claim terms.  In this he cites with approval Judge Lourie's point in Phillips, that while there is (and perhaps cannot be) formal deference by the CAFC to a district court's claim construction, it is better policy for the Federal Circuit to affirm "in the absence of a strong conviction of error."  Despite the fact that current academic research suggests that Federal Circuit affirmance rates of district court claim construction has "improved" to from 60-70%, these broad statistics do not inform how each Federal Circuit panel addresses, and resolves, specific claim construction issues in any particular case.  And so long as a majority of the Federal Circuit judges continue to resist en banc reconsideration of Cybor, and the Supreme Court appears singularly disinterested in the issue, the inconsistencies resulting from the Federal Circuit's "no deference" standard of review will continue to produce the type of results decried by Judge Walker in Medegen.

Medegen MMS, Inc. v. ICU Medical, Inc. (Fed. Cir. 2008)
Panel: Circuit Judges Rader and Dyk and Chief District Judge Walker
Opinion by Circuit Judge Dyk