Practice Tips:

The Use Of Extrinsic Evidence In Patent Prosecution – There Is More To Your Patent Application Than Meets The Eye

By Thomas A. Miller - September 30, 2014

As career patent practitioners, we are constantly and simultaneously working our ways through hundreds if not thousands of pending patent applications.

The prosecution histories of those cases often have similar and repeating themes, such as antecedent basis or indefiniteness issues in the claims, anticipatory references, and obviousness challenges. The vast majority of those can be addressed using the four corners of the patent application, and/or the four corners of the art being cited against a given case. Sometimes, however, we need to reach outside of that intrinsic evidence to prove our point and win the day. It is within the confines of that extrinsic evidence that this paper attempts to explore potential new avenues for successful prosecution.

One of the most straightforward, but now often forgotten, uses of extrinsic evidence is that needed to swear behind a reference. With the passage of the American Invents Act (AIA), the clock started ticking on the lifeline of swear behind declarations, but until that ultimate day arrives, we can still use so called Rule 1311 declarations where applicable. The AIA of course migrated the United States from a first-to-invent country to a first-to-file country. This was done largely to harmonize our patent laws in this regard with most other industrialized nations. However, the first-to-file provisions of the AIA only took effect on March 16, 2013, and thus only apply to patent applications having an earliest effective filing date of March 16, 2013 or later. Any other application filed before March 16, 2013, whether as an original filing, or one claiming priority by way of continuation, divisional, conversion, or foreign relation is still subject to the previous first-to-invent approach.

With such declarations, we are allowed to use extrinsic evidence to prove conception and diligent reduction to practice prior to the effective date of the cited art. That extrinsic evidence can include inventor notes, emails and sketches dated prior to the effective date of the cited art, correspondence with patent counsel asking for advice on, or prosecution of, a patent application on the given subject matter, requests for search or search reports generated on the viability of the invention and its proximity to the prior art, sales brochures or PowerPoints® displaying or describing the subject matter of the invention, websites doing same, or any other document disclosing conception or reduction to practice of the claimed subject matter. That evidence can then be filed with the Rule 131 declaration as exhibits to the declaration, with the declaration itself walking the Examiner through the timeline from conception to reduction to practice. As long as conception is proven by such extrinsic evidence to be prior to the effective date of the cited art, and its reduction to practice (either actual or constructive) is shown to be diligent, the cited art is sworn behind and must be removed.

While the use of Rule 131 declarations is well-known by experienced practitioners, we have seen an increase in art inaccurately being cited by Examiners since the passage of the AIA, and you or your patent counsel should be diligent in reviewing the effective date of the cited art relative to your application. If you have extrinsic evidence to antedate that effective date, continue to use swearing behind declarations until the March 16, 2013 date precludes it. This is particularly important as it would be easy for your existing patent counsel to innocuously assume all cases are now under a first-to-file protocol, when in fact we will be in a hybrid first-to-invent, first-to-file arrangement for many more years to come given the nature of extended patent families and protracted prosecution before the USPTO.

Another area in which extrinsic evidence can be used is with respect to Rule 132 declarations. Rule 1322 is much more open-ended than Rule 131 and simply reads:

“When any claim of an application or patent under reexamination is rejected or objected to, any evidence submitted to traverse the rejection or objection on a basis not otherwise provided for must be by way of an oath or declaration under this section.”

In other words, evidence outside of the four corners of the patent application can be submitted, but must be done so by way of such a declaration. Often times, we use such declarations to bring in the attestation of an expert in the given field. For example, if discussing what one of ordinary skill in the art of mechanical engineering would understand a certain claim or specification term to mean, we can have an expert in the field of mechanical engineering sign a Rule 132 Declaration stating same. Such a declaration necessarily carries much more weight than our voice as advocating patent counsel. Alternatively, the inventor or inventors themselves can sign the Declaration, but this often weakens the probative value of the declaration under the argument that the inventor is biased.

Aside from the meaning of claim terms, Rule 132 declarations can also be used to buttress arguments as to what a cited piece of prior art does or does not say, or in fact what the pending application does or does not say. Which brings us to another important avenue for the use of extrinsic evidence. It is not uncommon for Examiners at the USPTO to argue under Section 112 that a given application specification does not support the claim language of the application. This can occur with the first Office Action with the Examiner arguing that the original claim language is not supported by the original application, or more commonly with a first or subsequent response to Office Action amending the claim language. At such times, we can remind the Examiner that as patent practitioners we are entitled to be our own lexicographers3 and the standard to apply is not whether the claim language finds verbatim support in the specification, but rather whether one of ordinary skill in the art would understand the meaning of the claim language when read in light of the specification.

The above being said, there are of course times when it is arguable whether the specification does indeed support the claim language. In such situations, it may be necessary to rely on the drawings for the requisite support. This is particularly apropos in mechanical cases where the figures or “pictures” do indeed say a thousand words. In the cross-section of a complicated mechanical assembly, such as an engine or machine tool for example, hundreds of parts are often times being simultaneously depicted, when in fact only a handful or few dozen of those parts are actually discussed in the text of the specification. More specifically, those particular parts which are most germane to the technology at hand and readability of the application may be specifically enumerated on the drawings and described in the detailed description. That does not mean, however, that the other dozens or hundreds of parts shown but not described cannot be later relied upon to either support a claim element or otherwise distinguish over the cited art.

Again, this can be done through oral or written argument of your patent counsel, but for evident reasons may carry significantly more weight if extrinsic evidence in the form of an expert in the relevant art signing a Rule 132 declaration is submitted. Such a declaration can attest to what one of ordinary skill in the art would understand those non-enumerated parts to be or how those non-discussed parts would interact if not specifically shown or discussed. This is true not only with respect to the patent application being prosecuted, but the art being cited as well. If the non-enumerated parts shown in the drawing connote to one of ordinary skill in the art that the assembly will or will not work in a certain way, or are for a particular or peculiar purpose, extrinsic evidence by way of such a declaration can prove this point. We find this to be particularly the case when an Examiner cites a foreign language patent as prior art, but only has the drawings and perhaps abstract of such a patent from which to glean disclosure.

Yet another example of extrinsic evidence which can be used in prosecuting patent applications pertains to definitions. We strongly recommend setting forth the definitions of any unique or particularly important claim terms in the specifications we write starting from the beginning draft. Having a definition on which our client can rely and use to its advantage, and which can be taken directly from the patent specification provides the future litigator of our patent assurance of claim scope and removes significant uncertainty when entering a Markman hearing to determine claim construction. However, we often inherit applications where such definitions are not included, or despite our best efforts, did not include an exhaustive list of definitions of all claim terms in the specification upon filing. In those situations of potential ambiguity, the Examiner may take a stance on a particular claim term counter to our desired interpretation. If helpful, we can at that point again turn to extrinsic evidence to provide the needed support. Such a definition can come from a simple dictionary or thesaurus definition, a respected treatise in the relevant field of endeavor, an academic paper delving into such subject matter, an on-line or print encyclopedia, or any other trusted source. Moreover, rather than using a Rule 131 or 132 declaration as the vehicle for submission of such extrinsic evidence, we can simply site to the supporting text or source in bibliographic format and submit the relevant portions of same as an Exhibit to our response or amendment. If it helps carry the point of our clients, we use it.

With the foregoing examples in mind, the attorneys of Miller, Matthias & Hull LLP are well-versed in the use of extrinsic evidence in gaining the allowance of patent applications. If you would like to learn more, or think your application could benefit from such an approach, feel free to contact us (312)977-9902, We would be happy to help.

1 Rule 131 refers to that statute codified at 37 CFR §1.131 which states, in pertinent part: When any claim of an application or patent under reexamination is rejected, the inventor of the subject matter of the rejected claim…maysubmitanappropriateoathordeclarationtoestablishinventionofthesubjectmatter oftherejected claim prior to the effective date of the reference or acti vity on which the rejection is based.
2 See 37 CFR §1.132.
3 Itisawell-establishedprinciplethata“patentee isfreetobehisownlexicographer.” Markmanv.Westview,Inc., 34 USPQ2d 1321, 1330 (Fed. Cir. 1995) (in banc), aff’d, 38 USPQ2d 1461 (1996)