I. The Need for Precise Patent Drafting
Patent application drafting is complicated. As noted by Judge Newman, “there are few, if any, legal documents more difficult to craft, more fraught with pitfalls than patent applications[.]” See Energizer Holdings, Inc. v. International Trade Commission, 2008 WL 1791980, *10 (Fed. Cir. April 21, 2008) And with hundreds of thousands of patent applications filed with the USPTO each year, it is not surprising that many patents are issued with potentially serious patent drafting errors. For instance, the study relating patent drafting quality to patent validity found that “more than a quarter of the patents held invalid in the data set suffered from drafting problems, which generally reflect a failure to include a specification that adequately describes and enables an invention that is delineated with definiteness in the claims.” See Mann, Ronald J. & Marian Underweiser, A New Look at Patent Quality: Relating Patent Prosecution to Validity, 9 J. EMPIRICAL LEGAL STUD. 1 (2012).
If the drafting errors go undetected before the patent is issued, they become increasingly costly and difficult to fix, especially after a patent has been asserted in litigation. The courts’ power to correct even the smallest drafting errors is severely limited, as long as there is “reasonable debate to one of ordinary skill in the art” about the correction. See Ultimax Cement Mfg. Corp. v. CTS Cement Mfg. Corp., 587 F.3d 1339, 1353 (Fed. Cir. 2009). And one can be assured that there always will exist ” reasonable debate” between parties about the meaning of various claim terms during litigation.
With limited correction options, precise patent application drafting and proofreading is critical because the specification will be used to drive claim construction during litigation. See Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005)(en banc) (“The specification is always highly relevant to claim construction and is the single best guide to the meaning of a claim term in dispute.” ) And, as a patent drafter, you really are “in the best position to resolve the ambiguity in the patent claims.” Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244, 1255 (Fed.Cir.2008). Otherwise, if you leave errors and unintentional ambiguity in your application, you are opening the door for the opposing counsel to control the outcome of the claim construction.
However, manual patent proofreading is tedious and time-consuming. This is where automated patent proofreading tools, like ClaimMaster, can help. Automated proofreading can serve as a second set of eyes for supplementing manual review, resulting in stronger patents, faster patent prosecution, and satisfied clients. In fact, we recommend including automated patent proofreading into a multi-step patent review process to ensure that the drafted patent applications are in the best shape possible before filing.
II. Drafting Errors Leading To Ambiguity In Patent Claims
To satisfy the requirements of 35 U.S.C § 112(b), “[t]he specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.” The claims, viewed in light of the specification and prosecution history, must “inform those skilled in the art about the scope of the invention with reasonable certainty” Nautilus, Inc. v. Biosig Instruments, Inc., 134 S.Ct. 2120 (U.S. 2014) (emphasis added). While there are many drafting mistakes could create ambiguity in claims rendering them indefinite under 35 U.S.C § 112(b), here are some of the more common examples that reduce “reasonable certainty” of the precise claim scope:
i. Invalid claim numbering and amendments
Invalid claim structure is probably the most serious claim drafting error, as it makes the scope of the affected claims instantly ambiguous and renders the claims essentially impossible to enforce. How can you assert a dependent claim that doesn’t depend from a clear independent claim? It’s basically useless. In addition, when filing multiple dependent claims originally drafted by the foreign attorneys, U.S. practitioners need to watch out for improper multiple dependent claims that depend from other multiple dependent claims and are considered indefinite in the USPTO. See, e.g., Trs. of the Univ. of Pa. v. Eli Lilly & Co., 2:15-CV-06133 (E.D. Pa. May. 31, 2016) (finding nested multiple dependent claims invalid). The drafter also needs to verify that the claims are complete and are not inadvertently missing text portions. See Allen Engineering Corp. v. Bartell Indus., 299 F.3d 1336 (Fed. Cir. 2002) (claim ending in the middle of a limitation is indefinite because it is impossible to discern the scope of such a truncated limitation).
Notably, claim numbering issues can be created both by drafting mistakes in the original application and through incorrect amendments during prosecution (e.g., cancelling one of the claims but forgetting to update its dependents), so care must taken to review patent claims during all stages of patent drafting and prosecution. Not only that, but the attorneys also need to perform a final sanity check on the claims after the patent issues to make sure the USPTO publishes the allowed claims without errors, as it unfortunately happened in Smart Wearable v. Microsoft, 2017 WL448616 (W.D. VA Jan. 1, 2017), where the USPTO forgot to include a portion of the claim in the issued patent.
While catching such drafting mistakes is not always easy, attorneys can use ClaimMaster to quickly proofread their claims for these and many other numbering and amendment issues, as explained in more detail here.
ii. Lack of antecedent basis
Another common drafting mistake is lack of antecedent basis in claims. As explained in MPEP, the “lack of clarity could arise where a claim refers to ‘said lever’ or ‘the lever,’ where the claim contains no earlier recitation or limitation of a lever and where it would be unclear as to what element the limitation was making reference. Similarly, if two different levers are recited earlier in the claim, the recitation of ‘said lever’ in the same or subsequent claim would be unclear where it is uncertain which of the two levers was intended. A claim which refers to ‘said aluminum lever,’ but recites only ‘a lever’ earlier in the claim, is indefinite because it is uncertain as to the lever to which reference is made.” See MPEP 2173.05(e). Note that in most cases, failure to provide explicit antecedent basis for terms does not always render a claim indefinite. Ex parte Porter, 25 USPQ2d 1144, 1145 (Bd. Pat. App. & Inter. 1992). That said, clear antecedent basis issues in claims could protract litigation, at minimum increasing its costs and complexity. One also shouldn’t count on the USPTO to fix antecedent basis issues in claims. For example, take a look at some of the glaring problems in the issued U.S. Patent No. 6,819,858. Therefore, we recommend a thorough antecedent check with ClaimMaster, both during the initial claim preparation and also when making amendments.
iii. Use of ambiguous terms
Practitioners need to be extra careful when using poorly defined, relative, or unclear terms in claims, as these could render the claim indefinite to one of ordinary skill in the art – a defense commonly raised by the accused party in litigation. Below are some of the examples of common types of problematic claim language that led to findings of indefiniteness by the Federal Circuit.
- Relative terms – use of relative terms (e.g., “improved”, “enhanced”, “very high”, etc.) could render the claim indefinite to one of ordinary skill in the art. See Karsten Mfg. Corp. v. Cleveland Golf Co., 242 F.3d 1376 (Fed. Cir. 2001) (the user of the phrase “improved correlated ” when describing “a set of iron type golf-clubs, each club…” was held indefinite); ArcelorMittal France v. AK Steel Corp. , 700 F.3d 1314 (Fed. Cir. 2012) (use of term “very high mechanical resistance” was held indefinite)
- Words of degree and ranges without end points on both sides – using words of degree (e.g., “virtually”, “substantially”, “essentially”, etc.) can introduce ambiguity or unintentionally broaden the claim scope, especially when specifying open ranges, as seen in Valeo North America, Inc. v. Magna Electronics, Inc. , IPR2015-00251, Paper 18 (P.T.A.B. May 26, 2016), which found that the claim reciting “at least about 200 candelas/sq. meter” was obvious in view of the reference that taught using a max of 200 candelas/sq. meter)
- Functional language – See Halliburton Energy Services, Inc. v. M-I LLC, 514 F.3d 1244 (Fed. Cir. 2008) (the court holding that the claim term “fragile gel” was indefinite because of the insufficiently defined functionally, explaining that “[a] patent drafter could resolve the ambiguities of a functional limitation in a number of ways. For example, the ambiguity might be resolved by using a quantitative metric (e.g., numeric limitation as to a physical property) rather than a qualitative functional feature. The claim term might also be sufficiently definite if the specification provided a formula for calculating a property along with examples that meet the claim limitation and examples that do not”)
These and other issues would be flagged by ClaimMaster when performing the patent proofreading check.
III. Drafting Errors Causing Ambiguity In the Specification
Section 112(a) also requires that “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 or joint inventor of carrying out the invention.” The courts have held that the written description requirement of 35 U.S.C. 112(a) “is met if the specification shows that the stated inventor has in fact invented what is claimed, that he had possession of it.” AbbVie Deutschland GmbH & Co., KG v. Janssen Biotech, Inc., 759 F.3d 1285 (Fed. Cir. 2014). Applying a slightly different standard, the USPTO states that “the fundamental factual inquiry is whether the specification conveys with reasonable clarity to those skilled in the art that, as of the filing date sought, applicant was in possession of the invention as now claimed.” MPEP 2163.02. Therefore, to satisfy 35 U.S.C. 112(a), the specification must convey clearly to those skilled in the art the information that applicant has invented the specific subject matter later claimed. Like section (b), section (a) of 35 U.S.C.112 also provides practitioners with plenty of opportunities to make drafting mistakes that result in unintentional ambiguity and weaken the patent. Here are some of the examples:
i. Lack of specification support
It goes without saying that claims must be clearly supported by the specification to satisfy the written description requirement of section 112(a). A drafter could perform a quick sanity check for missing support by using ClaimMaster’s to find literal support for claim phrases and individual words in the specification. Aside from checking for literal support, the drafter also should make sure that claims are supported in specification with functionally described structure or representative number of species. In addition, one needs to make sure that claim amendments made during prosecution are still supported by the specification. These types of checks require a more thorough manual review of the claims and specification (e.g., side-by-side), but are vital to obtain strong and enforceable patents that are defensible against 35 U.S.C. 112(b) challenges. To speed up the process, one could use ClaimMaster’s Patent Reader to quickly review the existing draft of the specification, claims, and figures side-by-side to ensure adequate support for the claimed structure.
ii. Inconsistent use of parts in the specification and figures
To satisfy the “possession” and “enablement” requirements of 112(b), the drafter needs to provide sufficient description of the invention with the help of drawings and their related structural descriptions in the specification. The process of drafting and describing figures in the specification is prone to errors due to the sheer number of parts that need to be tracked by the writer. While a few mistakes in part names or numbers in the specification are unlikely to render the entire patent invalid, such inconsistencies could still introduce enough ambiguity to cause protracted battles during litigation, especially if these mistakes relate to the disputed claim terms. Thus, care must be taken to make sure that figures and their contents are precisely and accurately labeled and described in the specification. While checking part names and numbers in the specification and figures by hand is extremely tedious, luckily this is where the automated patent proofreading software shines. For example, you can use ClaimMaster to check both the specification and figures for a variety of inconsistencies in part naming and numbering, ensuring you have precise, well-tailored patent applications. In addition, ClaimMaster offers a number patent drafting tools that help with quickly entering part names and numbers while you are drafting the application.
iii. Patent profanities
“Patent profanities” are the so-called words and phrases of characterization in the specification or claims that can be used to narrow claim scope during claim construction. In general, a patent drafter needs to be careful to not unintentionally characterize the invention, but sadly many practitioners are still using those words based on the old habits. There are quite a few of such “bad” words, but here are some of the more popular ones:
- “the invention” or “present invention“- the courts often rely on characterization of the entire invention to limit claims during claim construction. See, e.g., C.R. Bard, Inc. v. U.S. Surgical Corp., 388 F.3d 858 (Fed. Cir. 2004) (“Statements that describe the invention as a whole, rather than statements that describe only preferred embodiments, are more likely to support a limiting definition of a claim term.”); see also Honeywell Int’l, Inc. v. ITT Industrials, Inc., 452 F.3d 1312 (Fed. Cir. 2006) (narrow construction because “on at least four occasions, the written description refers to the fuel filter as ‘this invention’ or ‘the present invention”) .
- “necessary” – same as the above. See Atofina v. Great Lakes Chemical Corp., 441 F.3d 991 (Fed. Cir. 2006) (narrow constructions because the specification stated that “it is necessary to have a catalyst containing solely chromium.”) (emphasis added).
- Other potentially limiting terms: chief, majority, vital, critical, essential, fundamental, important, main, principal, significant, and so on.
ClaimMaster can check for the presence of these and many other “patent profanities” in claims and specification using a specialized proofreading check.
iv. Other drafting inconsistencies
One difficulty with new application drafting is that it often involves a fair amount of guessing about what specific features of the invention will become important years later, when it is asserted against the currently non-existing infringing products. A seemingly small drafting error might blow up into a huge litigation issue 10 years later after the patent is granted. One way to reduce a number of such future surprises is to draft patent applications that are as internally consistent as possible. ClaimMaster provides a number of additional proofreading tools to help remove unintentional ambiguity in patent applications. For example, practitioners can use ClaimMaster to check for inconsistent acronyms and also for contextually incorrect terms. In addition, we have proofreading tools that an help with the procedural checks to ensure that your filings are compliant with the USPTO’s electronic filing system and use correct routing information to avoid processing delays.
We hope you’ll find this long post helpful for providing a more thorough discussion of various patent drafting issues that could affect the quality of the patent. In our next post, we’ll discuss some strategies and provide tips for drafting high-quality patent applications and Office Action responses.