Broadest Reasonable Interpretation

During examination of a patent, the claims are “given their broadest reasonable interpretation consistent with the specification.”1 Generally, the BRI indicates that claims should be given the “broadest reasonable interpretation in light of the specification, from the perspective of one skilled in the relevant art.”2 Furthermore, under the BRI, words of the claim must be given their plain meaning, unless such meaning is inconsistent with the specification.3 The plain meaning of a term means the “ordinary and customary meaning given to the term by those of ordinary skill in the art at the time of the invention.”4

The U.S. Patent and Trademark Office (“USPTO”) uses the BRI to interpret claims during examination, while the federal courts utilize a different—more narrow—standard for claim construction.5 “Patented claims are not given the BRI during court proceedings involving infringement and validity, and can be interpreted based on a fully developed prosecution record.”6 A broader construction during prosecution is justified on the ground that patent applicants have the opportunity to amend the claims of a pending application, whereas, during an enforcement action, the patentee’s hands are tied by the claims as allowed.7

Despite this guidance, accurately identifying the BRI continues to be a challenging issue for practitioners and the USPTO alike. The struggle often appears with whether a particular broad interpretation remains “reasonable.” As seen in recent cases, there oftentimes is an overemphasizing of the BRI in a lexemic sense rather than interpreting the claims consistent with the specification. For example, while specific limitations of the specification cannot be imported into the claims,8 contextual consideration of the specification is required, which creates opportunities for claim construction to go astray.

Broadest Possible Interpretation

In Re Smith International, Inc. was an appeal from the Patent Trial and Appeal Board (“PTAB”) that came before the U.S. Court of Appeals for the Federal Circuit (“CAFC”) regarding the validity of U.S. Patent 6,732,817 (the “’817 patent”).9 In the decision, the CAFC reversed the PTAB’s conclusion of unpatentability (via an ex parte reexamination) for failing to conform the “reasonableness” determination with the scope of the patent specification.10 Specifically, the CAFC determined the ’817 patent was valid based on the proper definition of the claim term “body” as used therein.11

The ’817 patent relates to a downhole drilling tool (See Fig. 5 included herein) which alternates between collapsed and expanded positions in response to differential fluid pressure between the flowbore and the wellbore annulus, such that the tool can fit through a small borehole and subsequently expand to fill a larger borehole.12

By way of example, claim 28 illustrates that the invention includes two main elements: a body and an arm, without any further limitations on the body term.13 The specification, however, provides detail and refers to “a generally cylindrical tool body 510 with a flowbore 508 extending therethrough” and “one or more moveable, non-pivotable tool arms 520.”14 The Examiner interpreted “body” broadly as capable of encompassing additional components such as a “mandrel” and a “cam-sleeve,” which were taught by the cited art.15 The Examiner also noted that the specification does not provide an explicit definition.16 In affirming the examiner, the PTAB stated that the term “body” is a “generic term equivalent to terms such as ‘member’ or ‘element’ that by itself provides no structural specificity.”17 The PTAB reasoned that despite the fact that “the specification describes the body as a discrete element separate from other elements, the specification does not define[] the term body or preclude the Examiner’s interpretation.”18</18>

On appeal, the CAFC reversed, holding that that the PTAB’s construction was “unreasonably broad” even given the proper usage of the BRI.19 The Court explained that the ’817 patent does not use the term “body” in a generic manner, but specifically discusses the term consistently as being distinct from other components, and, as such, should be more narrowly construed. Specifically, the Court stated, “[e]ven when giving claim terms their broadest reasonable interpretation, the Board cannot construe the claims ‘so broadly that its constructions are unreasonable under general claim construction principles.’”20 Thus, the Court determined that the PTAB’s interpretation was erroneous, because it based its broad interpretation on the fact that the specification did not “in and of itself proscribe the Examiner’s construction.”21 The Court further outlined the proper inquiry in light of the BRI and further noted that the BRI does not extend to cover all those definitions not expressly prohibited by the specification:

"The correct inquiry in giving a claim term its broadest reasonable interpretation in light of the specification is not whether the specification proscribes or precludes some broad reading of the claim term adopted by the examiner. And it is not simply an interpretation that is not inconsistent with the specification. In re Morris, 127 F.3d 1048, 1054 (Fed. Cir. 1997) (citation and internal quotation marks omitted); see also In re Suitco Surface, 603 F.3d 1255, 1259–60 (Fed. Cir. 2010). It is an interpretation that corresponds with what and how the inventor describes his invention in the specification, i.e., an interpretation that is “consistent with the specification.”

The Board emphasized that the patentee here did not act as a lexicographer, and that the specification neither defines nor precludes the examiner’s reading of the term “body.” Accordingly, the Board found that nothing in the specification would disallow the examiner’s interpretation, rendering it “reasonable.” However, following such logic, any description short of an express definition or disclaimer in the specification would result in an adoption of a broadest possible interpretation of a claim term, irrespective of repeated and consistent descriptions in the specification that indicate otherwise. That is not properly giving the claim term its broadest reasonable interpretation in light of the specification.22"

Ultimately, the CAFC reversed the PTAB to conclude that the claims were, in fact, patentable in light of a proper claim construction. It is not an obligation of the applicant to disprove any and all unreasonably broad constructions as it would be nearly impossible to determine and preclude all interpretations and readings for various terms. Overall, Smith illustrates that the BRI is an ongoing issue, but provides additional guidance to alleviate some of the challenges with respect to claim construction. Moreover, this decision demonstrates how the BRI can be stretched too far, such that it becomes unreasonable.