Think Carefully When Filing Continuation Applications

In Hakim v. Cannon Avent Grp., 479 F.3d. 1313 (Fed. Cir. 2007), the Federal Circuit affirmed a summary judgment of noninfringement for a patent covering a leak-resistant cup. The asserted continuation patent was based upon a continued prosecution application (“CPA”) that was filed after its parent application received a Notice of Allowance from the USPTO. The claims in the parent application included the claim term “slit,” while the continuation patent claims included the broader claim term, “opening.” Unfortunately for the patentee, the court interpreted the claimed “opening” in the continuation to be limited to a “slit” because of arguments in the parent application distinguishing prior art on that basis.

According to the court, while it is recognized that an applicant can broaden, as well as restrict claims during prosecution, and that continuing applications may present broader claims than were allowed in a parent, a disclaimer of scope (e.g., an argument distinguishing prior art over a particular claim term) must be properly rescinded to permit recapture. More specifically, “the prosecution history must be sufficiently clear to inform the examiner that the previous disclaimer, and the prior art that it was made to avoid, may need to be re-visited.”

In this case, the patent attorney actually did try to avoid the result that was ultimately reached. The patent attorney “informed the examiner that the new claims were broader than those previously allowed,” thus arguing that “when the examiner allowed the new claims without rejection, there is a presumption that the examiner had assured himself of the patentability of the new claims.” However, the accused infringer argued that the patentee still “did not specifically point out that he no longer intended to be limited to the specific mechanism that he had previously argued was the distinguishing feature of his invention.”

Consequently, it should now be a recommended prosecution practice to review the claims in every continuing application in view of statements made to the USPTO during prosecution of parent applications. If previous claim elements are being broadened in the continuing application and were previously distinguished over prior art, it would be advisable to include an explicit rescission of any previous claim scope disclaimers arising from those distinguishing statements. Likewise, if a patent in litigation is a continuation that does not include such a needed disclaimer, the patent may be subject to a narrower claim construction that results in noninfringement.

The written description, enablement, and best mode requirements flow from 35 U.S.C. ‘ 112(1), which is as follows:

The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.

In Liebel-Flarsheim v. Medrad, 481 F.3d 1371 (Fed. Cir. 2007), the Federal Circuit affirmed summary judgment findings of invalidity for lack of enablement (without needing to consider the additional lower court finding of invalidity for lack of written description) for patents directed to a front-loading fluid injector with a replaceable syringe capable of withstanding high pressures for delivering a contrast agent to a patient. The asserted patents were continuations that did not include a “pressure jacket” claim element that appeared in a parent patent.

The Federal Circuit observed that the patentee deleted the “pressure jacket” element from the continuation claims after learning of the defendant’s product, which did not include the pressure jacket. The court also stated that there was no suggestion in the specification of an embodiment that would not include a pressure jacket; the “Background” teaches pressure jackets are needed, thus teaching against removing them; and other evidence showed undue experimentation would have been needed to develop such a device. Because there was evidence of undue experimentation being needed in this case, the “full scope of the claimed invention,” which includes systems with and without a pressure jacket, was not enabled.

Consequently, in addition to the customary practice of disclosing embodiments with alternative elements in patent applications, practitioners should also evaluate disclosing that certain elements are not included in some embodiments. Furthermore, before deciding to accept a first patent and file a continuation seeking claims without a particular claim element, practitioners should review the specification to first determine if there is a statement in the specification that the claim element is not necessary or does not exist in some embodiments. If the specification does not include such a statement or teaches against embodiments without a particular claim element, it may be better to pursue the broader protection in the first patent application.

In ICU Medical v. Alaris Medical Systems, No. 2008-1077 (Fed. Cir. March 13, 2009), the Federal Circuit again affirmed a grant of summary judgment of invalidity of continuation patents based on ‘ 112(1), but for lack of written description. The continuation patents for medical valves failed to include a “spike,” despite that element being included in the initial claims and being in all embodiments. While the result is similar to that reached in Gentry Gallery, the Federal Circuit did not reference that case or rely upon common facts that were relied upon by the district court. For example, there were affirmative statements in the Summary about the “invention” including a “spike,” but the Federal Circuit did not rely on that statement. Thus, regardless of whether a patent specification suggests an element is “essential,” the broadest initial claim scope may be a barrier, absent specification statements that initial elements are optional.

Consequently, for each new patent application, care should be taken to make sure the original independent claims are as broad as possible, and if any elements could possibly be omitted or broadened in the future, the specification should state that those elements are not included in some embodiments. However, additional care should also be taken to make sure alternative embodiments are fully enabled in view of the recent cases of Sitrick v. Dreamworks, 516 F.3d 993 (Fed. Cir. 2008), and Auto. Tech v. BMW, 501 F.3d 1274 (Fed. Cir. 2007), since those cases require heightened enablement for alternative embodiments. In addition, if any elements of original independent claims are effectively deleted or broadened in continuing applications, it may be useful to notify the USPTO to bolster the presumption of validity under ‘ 112(1).

In PowerOasis, Inc. v. T-Mobile USA, Inc., 522 F.3d 1299 (Fed. Cir. 2008), the Federal Circuit affirmed summary judgment findings of invalidity under 35 U.S.C. ‘ 102(b) of continuing patents resulting from the patents losing their benefit to the filing date of an earlier patent under 35 U.S.C. ‘ 120. The filing date benefit was denied because of a continuation-in-part (“CIP”) filing in the continuity chain that the court used as evidence that the specification of the earliest patent did not support the asserted claims by providing the written description required by 35 U.S.C. ‘ 112.

The PowerOasis patents covered a vending machine for dispensing telecommunications channel access, and the asserted claims included a “customer interface” that the patentee unsuccessfully argued was supported by at least one embodiment in the earliest specification. Originally, the customer (or user) interface was disclosed (in all originally disclosed embodiments) as being located on the vending machine itself, but the CIP application disclosed that it could also be located as a software display on a customer laptop (which also corresponds to the accused system). Even though the claim did not explicitly reference the location of the customer display element, the court found that there was no written description support in the original specification for a customer interface located on a customer’s laptop.

By noting that there were no original embodiments that did not locate the customer interface on the vending machine, the court narrowly construed the “customer interface” claim element in a way that, by definition, could not have been supported by the original specification. This type of result may be possible in every patent having a CIP in its continuity chain. In other words, if any genus claim element in a CIP covers one species disclosed in a parent application and another species disclosed in a CIP application, the genus claim element may not have written description support in the parent application. Furthermore, this result is theoretically not limited to CIP continuity chains. For example, similar results may be reached when patents claim priority to provisional applications that disclose fewer embodiments or are less extensive than the resulting patent disclosures.

There are several practice tips to take from this decision. For CIPs, utility applications claiming priority to provisional applications, and continuations of both, claims intended to have original filing dates should be drafted to explicitly exclude all new matter. In other words, to be assured of earliest priority for a particular set of claims, it may be necessary to make sure that it is not possible for any new matter to fall within the scope of those claims in any way. In addition, the Federal Circuit also noted in this case that the USPTO did not make a priority determination during examination. While such determinations rarely occur unless intervening prior art happens to arise, practitioners may wish to prompt such determinations when possible, in view of this decision.

Recent decisions have assaulted continuations on several fronts. Because of a new requirement to rescind claim scope disclaimers, it will be easier to avoid infringement of continuations, and because of strengthening enablement and written description requirements, more continuations will be invalidated on those grounds and on prior art grounds when priority claims are more easily broken. Consequently, care should be taken in the preparation and prosecution of any patent application claiming priority to another application.

Jeffrey R. Kuester ([email protected]), a member of this newsletter’s Board of Editors, is a Founding Partner with the intellectual property law firm of Thomas