Best Practices in Drafting Patent Specifications

A patent specification is a written description of the invention and of the manner and process of making and using the invention that concludes with the claims to the invention.  The specification must be in clear, full, concise, and exact terms to enable any person skilled in the art or science to which the invention pertains to make and use the same.  Experienced patent attorneys and agents write patent specifications each day and may take for granted that they know how to write a proper patent specification; however, evolving case law and USPTO guidance must be considered and modifications to the preparation process to ensure precision to satisfy USPTO requirements to get a patent issued and to satisfy the court requirements to ensure that the patent remains valid and enforceable.

I.         Common Pitfalls in Patent Specification Preparation

When drafting a patent specification, it is important to fully describe the invention to provide support for the broadest claim construction possible and to comply with the written description and enablement requirements under 35 U.S.C. 112.  Various most common pitfalls can occur in preparation of patent specifications, which can affect patent registration.  The most common pitfalls include inconsistent use of terms through the specification, narrow examples without a more general description, emphasizing non-claimed features in embodiments of the invention, and the use of vague claim terms when the patent disclosure is otherwise narrow.  This is because even if the claims are broad, lack of precision in the patent specification can limit the claims.  See, e.g., Chef Am., Inc. v. Lamb-Weston, Inc., 358 F.3d 1371 (Fed. Cir. 2004) (finding that claim to process for baking dough “by heating the . . . dough to a temperature in the range of about 400 degrees F to 850 degrees F” referred to temperature of dough because patentee could have chosen “at a temperature” but did not).  Claim terms should be defined broadly and consistently to initially define functionally, if possible, and then provide ranges and examples as appropriate.  Further, while certain words or phrases such as “the present invention” may not be construed as limiting in all cases, care should be taken to avoid characterizations of the invention within the specification that could be construed as limiting.  See, e.g., Cont’l Circuits LLC v. Intel Corp., 915 F.3d 788, 798 (Fed. Cir. 2019) (citing Absolute Software, Inc. v. Stealth Signal, Inc., 659 F.3d 1121, 1136-37 (Fed. Cir. 2011) (“use of the phrase ‘present invention’ or ‘this invention’ is not always so limiting, such as where the references . . . are not uniform, or where other portions of the intrinsic evidence do not support applying the limitation to the entire patent.”)).

“[T]he specification may reveal a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess.”  Philips v. AWH Corp., 415 F.3d 1303, 1316 (Fed. Cir. 2005).  When the patentee acts as its own lexicographer, that definition governs. See id.  “To act as its own lexicographer, a patentee must ‘clearly set forth a definition of the disputed claim term’ other than its plain and ordinary meaning.”  Thorner v. Sony Comput. Entm't Am. LLC, 669 F.3d 1362, 1365 (Fed. Cir. 2012) (quoting CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366 (Fed. Cir. 2002)).   While patentees can be their own lexicographer, if the meaning of a claim is unclear or ambiguous, the scope of the claim becomes unclear.  See, e.g., E.I. Dupont de Nemours v. Unifrax I LLC, 17-2575 (Fed. Cir. Apr. 17, 2019) (evaluating the phrase “100% by weight” and concluding that the specification mentioning other embodiments that are not 100% platelets by weight counseled against using the traditional definition that “100% of the layer, when dry, must be platelets (and must weigh from 15-50 gsm”).

Another pitfall may be to describe the prior art (references that describe what has been done in the past) in a lot of detail in the specification, particularly including positive descriptive comments about the prior art.  These types of comments can often backfire when the USPTO later examines the non-provisional application because the applicant’s own admissions about the prior art may provide the examiner with the support needed to reject the claims, even without the examiner performing a search.  This is because a statement that something is prior art can be binding for determinations of anticipation and obviousness even if the characterizations are unclear.  A better approach is to keep the prior art (or background) section of the patent application to a minimum, while disclosing any relevant references through an Information Disclosure Statement.  A patent application should merely indicate what is lacking in the prior art and frame the discussion in the context of what the invention adds or improves upon when compared to the prior art.  This may make it less likely that an examiner reject the claims using statements from an inventor’s own patent application.

II.        USPTO Guidance on Claim Interpretation

In March 2019, the USPTO provided instruction on claim interpretation, particularly in view of the broadest reasonable interpretation (BRI), to the patent examiners.  See Claim Interpretation PowerPoint posted May 14, 2019, https://www.uspto.gov/patent/laws-and-regulations/examination-policy/examination-guidance-and-training-materials(“Claim Interpretation PP”).  The instruction focused on different aspects of claim interpretation including preambles, functional language, 

a.         Preambles

As noted in the instruction:

[t]here is no litmus test defining when a preamble limits a claim as every case will turn on its own facts (the words in the claim and entire disclosure).  Some instances where the preamble is limiting include words that limit the structure of the claimed invention, such as by positively adding a limitation, or words that are necessary to give meaning to the remainder of the claim, such as by further modifying a limitation recited in the body of the claim.  Some instances where the preamble is not limiting are words that only state an intended use or words that would have no effect on the body of the claim if removed.

See Claim Interpretation PP at 13.  The instruction further notes “word preference is not determinative of whether the preamble adds a limit to the claim.  If the words recite a purpose (. . . achieving a result), it would depend on whether those words result in a structural or manipulative difference in the invention recited in the body of the claim.”  Id.

b.         Wherein, Whereby, Thereby, Other Functional Language

“A functional limitation must be evaluated and considered, just like any other limitation of the claim, for what it fairly conveys to a person of ordinary skill in the pertinent art in the context in which it is used.  Functional limitations appear in § 112(f) limitations, but can also appear in limitations that recite a structure or a step followed by function to define a particular capability or purpose that is served by the recited element, ingredient or step.”  See Claim Interpretation PP at 17.  Examiners evaluate whether a phrase that describes a function, use or result adds a structural or manipulative difference.  For example, a phrase that states the environment in which the invention can be practiced – “a touchscreen for use in an airport” – with no further limitations relating to the how the touchscreen is used in the airport is merely a statement of intended use that would not be given patentable weight.  In contrast, a phrase that adds a capability to a claimed structural element – “a touchscreen for inputting text” – would be given weight to the extent the touchscreen must be capable of receiving textual input.  Id. at 18.  The instruction notes that “[a]ll language that limits structure or requires steps to be performed, regardless of where it appears in the claim, will impose a limit on the claim scope and serve as a patentable distinction.  Additionally, a clause that states a condition that is material to patentability cannot be ignored.”  See Claim Interpretation PP at 14. 

A clause that merely states the result of the limitations already recited in the claim would not limit the claim.  Clauses that give meaning and purpose to other claim limitations or add conditions material to patentability can add limits and should be given weight. . . it is important to consult the specification and not to view the clause in a vacuum to evaluate whether the clause recites an integral part of the invention or merely an intended result. Id.  The instruction also addresses non-functional descriptive material and its inclusion in claims.  Id. at 16.  

It often takes the form of written instructions (such as a label on a product) or instructional limitations (such as patient dosing instructions in a method of treatment).  The test for whether to give patentable weight to such material is whether it is functionally or structurally related to the product or method being claimed.  Relevant questions include whether the material performs a function and should be given weight, like ounce markings that indicate volume on a measuring cup, or whether the product merely serves as a support for information that should not be given weight, like images on a deck of playing cards. Id. (citing MPEP 2111.05).  

However, programming instructions are not considered to be non-functional descriptive material because “programming instructions that are executable, expressed as code, steps, or other known ways, have a relationship to the media substrate because the substrate allows a machine to read and execute the instructions.”  Id. at 17.  The instruction also makes a distinction between computer implemented elements that are “programmed” to perform a function compared to elements that are “programmable” to perform a function.  Id. at 19.  “In a claim that recites an element programmed to perform a function, the BRI of the claim must include the details of the recited programming limitation.  In a claim that recites that an element is programmable to perform a function, the BRI of the claim includes an element capable of being programmed to perform the function and does not require that the programming be present.”  Id.

The instruction also addressed phrases such as “configured to” that often appear in claims:

The phrase “configured to” is typically used to connect structure to a function, similar to the word “for”.  “Configured to” usually means the structure can perform the function with no additional modification.  However, it is important to look to the specification to understand how the applicant is using the term.  For example: a controller configured to generate a signal would be interpreted as a controller that can generate a signal, in a manner consistent with the specification as it would be understood by those of ordinary skill in the art. In this example, an analysis of whether § 112(f) is invoked should be made to determine whether the term “controller” as used in the application in the relevant field of art is recognized as known structure or whether it is serving as a generic placeholder for the term “means.”

Id. at 20.

c.         112(f) Interpretation

Whether and how a claim limitation is construed under 35 U.S.C. § 112(f) generally depends on the applicant’s disclosure of structure that performs the claimed function as opposed to plain meaning.  The instruction gives the example of a “means for fastening” and notes that it would be limited to particular fastener and its equivalents specifically disclosed in the specification.  Claim Interpretation PP at 22.  In contrast, “a fastener” would be defined by the ordinary and customary meaning of fasteners in view of the specification as it would be understood by one of ordinary skill in the art.”  Id.

As the instruction notes, there are some terms that may be used as generic placeholders for the word “means,” but there is not an exclusive list; accordingly, a word could be a generic placeholder in one patent but not in another.  Id. at 23.  Whether a word is a generic placeholder for “means” depends on “whether the words of the claim are understood by persons of ordinary skill in the art to have a sufficiently definite meaning as the name for structure. . . [I]s the word a known name for a structure in the art?  If so, § 112(f) is not invoked.  If one of ordinary skill in the art would not recognize the word as a definite structure, § 112(f) is invoked.”  Id.  “The term “processor” in many arts is typically recognized as a computer processor (a microprocessor) and in those cases would not be considered a generic placeholder as it is a known structure.”  Id. at 30.

The instruction provides even more specific guidance for claim interpretation under 112(f) when it comes to computer-implemented claim limitations.  “The specification must describe the corresponding structure as a programmed computer, which means the specification must identify a computer (or some type of microprocessor) along with the algorithm that causes the computer to perform the function.”  Id. at 29.  The instruction recognizes that the word “algorithm” is considered “a generic term for the programming/steps/procedure/process executed by a computer or microprocessor to perform a function.  The manner in which the algorithm is described is not important - applicant may express the algorithm in any understandable terms including mathematical formula, prose, flow chart, or any other manner that would be understood by those of ordinary skill in the art.”  Id.  “A general purpose computer is generally not sufficient [to support a computer implemented 112(f) limitation] unless the claimed function is so basic that it is performed by an off-the-shelf (OTS) general purpose computer without any special programming.  In that case, the specification would need to specify that the function is performed on a general purpose computer using well-known techniques or be readily apparent by those of ordinary skill in the art.”  Id. at 30.

d.         Examples from USPTO Guidance

The instruction provides several examples and explanations for how different phrases appearing in the claims may be interpreted.

For example, a claim may include the preamble “[a]n electronic device to be worn by a user comprising.”  “The preamble sets forth an intended use “worn by a user”, but is worded in functional terms “to be worn” that cannot be disregarded.  As such, the claim should be interpreted to cover an electronic device that is capable of being worn by a user, in any way that would be understood by those in the art.  See Claim Interpretation PP at 36.  See also MPEP 2111.02.  The instruction reflects that this phrase in the preamble may affect the examiner’s search because “it limits the structure of the electronic device to devices that are capable of being worn (i.e. not of exceedingly large size, shape, or weight that would prevent the electronic device from being worn).  If applicant wanted to limit the claim to a device capable of being worn in a particular manner (e.g. on the wrist), applicant would have to amend the claim to recite such a limitation.”  See Claim Interpretation PP at 37.

This same claim may include the limitation “a module for receiving a biometric input from a user.”  The instruction concludes that “module” is a generic placeholder because it is not the name of any recognized structure for receiving biometric input.  Id. at 38.  The word “module” is modified by functional language, but there is no structure recited in the limitation for performing the recited function.  Id.  Thus, the limitation would be interpreted under 112(f).  Id.; see also MPEP 2181.

Another claim limitation is “a processor configured to match the biometric input from the module with the at least one authorized biometric value stored in the memory to determine the corresponding user ID, wherein a match notification is generated and output to the display.”  The word “processor” is a recognized structural term and would not invoke 112(f).  Id. at 40.  However, if the word “processor” were substituted with “unit,” the instruction concludes that the limitation would be interpreted under 112(f).  Id.  This claim limitation includes “configured to” and “limits the processor to structures that perform the matching of biometric input in either pre-configured hardware or a combination of hardware programmed with software to perform the function.”  Id. at 41.  Further, the “wherein” clause in this claim limitation does add a limitation requiring that the processor generate a match notification and output it to the display.  Id.

In another example, the preamble of a claim recites “[a] molded container for encasing an automated external defibrillator (AED) comprising.”  “The recitation of “molded” limits the scope of the claim to the extent that it imparts structure to the container.  For example, the BRI of the claim would preclude a cardboard container folded from a cardboard blank.”  Id. at 51.  The phrase “for encasing an AED” limits the structure of “container” because it adds function and “imposes a structural limit on the container to the extent that it must be able to encase, i.e., surround and enclose, an object.”  Id.  The AED “serves as a reference point for establishing the reasonable interpretation of the term “encasing” by informing the structural limits – in this case the size - of the object that the container is able to encase (an AED or another object that is comparable in size).”  Id; see also MPEP 2111.02(II).  In contrast, if the phrase had been “for use with an AED,” this would impose “no structural limit on the container as it simply specifies an intended use.”  Id.at 51.  Another claim limitation is “a member for initiating severing, disposed at an end of the rib.”  The word “member” acts as a generic placeholder and is not modified by sufficient structure for performing the claimed function; thus, the limitation would be interpreted under 112(f).  Id. at 52.

In a further example, the preamble ([a] method for treating glaucoma in a patient), includes the phrase “for treating glaucoma” which “narrows the set of recipients who would be treated by the recited method by identifying the patient population as someone needing treatment for glaucoma.  It ties to the body of the claim, which recites a patient in need of treatment, and thus “for treating glaucoma” is not a mere intended use.”  Id. at 59; see also MPEP 2111.02(II).  The “thereby” clause in the claim limitation of “administering an effective amount of an ophthalmic composition of compound A to a patient in need thereof, thereby reducing ocular hypertension” does not further limit the scope of the claim.  Id. at 60.  The instruction notes that the “specification should be consulted to determine whether the clause is integral to the invention or merely states the result of the limitations already recited in the claim.”  Id.  Because the specification identified that administering the claimed composition in an effective amount results in reduced ocular hypertension, the instruction concludes that the reduction of ocular hypertension naturally flows from the administering of compound A in a method that treats glaucoma.  If the claim includes the limitation “wherein compound A is present in an amount effective for reducing ocular hypertension,” this phrase may further limit the claim to those amounts that would effectively reduce ocular hypertension.  Id. at 63.

III.      Recent Case Law Interpretations

In the past year, as in prior years, the Federal Circuit has decided several cases related to precision in patent specifications and how that affects patent protection.  What follows are examples of some of these recent cases and how they have touched on issues related to definiteness, enablement, and even anticipation/obviousness, particularly with respect to claim interpretation with an eye toward disclosure in the patent specification.

a.         “Consisting Essentially Of”

In the past, the phrase “consisting essentially of” has meant that the scope of a claim is limited to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention.  In re Herz, 537 F.2d 549, 551-52, 190 USPQ 461, 463 (CCPA 1976) (emphasis in original).  However, in HZNP Medicines LLC, Horizon Pharma USA, Inc., v. Actavis Laboratories UT, Inc., 940 F.3d 680 (Fed. Cir. 2019), the Federal Circuit concluded that claims using “consisting essentially of” to define an open-ended list of ingredients are indefinite, where the basic and novel property of the invention introduces an improper zone of uncertainty.  

In HZNP, the Federal Circuit found that although the language “consisting essentially of” requires listed components, it also permits inclusion of additional non-listed components that do not materially affect the basic and novel properties of the invention.  When the patentee chooses to use “consisting essentially of,” the underlying basic and novel properties of that invention must be sufficiently definite.  The Federal Circuit also found that the property of “better drying time,” recited in the specification (though not in the claims), was indefinite.  By using the claim term “consisting essentially of,” the inventor incorporated into the claim scope an evaluation of “better drying time.”  Because a POSITA would not know under what standard to evaluate drying times, the basic and novel property of “better drying time” was indefinite.  Id. at 696-697.  

In the dissent, Judge Newman argued that reciting “consisting essentially of” does not incorporate into the claim scope an evaluation of the basic and novel properties of an invention.  Id. at 705-708.  She believed that where the properties of a composition are sufficiently described in the specification, claiming a compound “consisting essentially of” certain ingredients does not render the claim indefinite.  Id. at 709.

Following the HZNP decision, pending applications and granted patents reciting “consisting essentially of” in the claims should be reevaluated.  It also may be helpful to reexamine whether the “basic and novel properties” are identified in the specification because they are often not easily found in the specification, if they are identified at all.  If these properties can be identified, the data supporting those properties should be assessed to evaluate if there are any inconsistencies.  See also Time to Rethink “Consisting Essentially Of” as a Claim Limitation, https://www.lexology.com/library/detail.aspx?g=0b1faa58-0e12-44a8-8804-816acaac382f.

b.         Means-Plus-Function Language – “Customization Module”

In the case of Grecia v. Samsung Electronics America, Inc., 2019-1019, 780 Fed. Appx. 912 (Fed. Cir. Aug. 20, 2019), the Federal Circuit found that the phrase “customization module” invoked means-plus-function considerations, but there was no example of the underlying mechanism for how the module would work disclosed in the specification.  Because the patent was focused on computer-implemented technology, disclosure of the associated computer algorithm would have been sufficient, but no algorithm appeared in the specification:

[T]he specification fails to explain how such customization is performed.  Instead, the specification only describes the results of customization. . . . We have held that describing “the results of the operation of an unspecified algorithm” is not sufficient to transform the disclosure of a general-purpose computer into the disclosure of sufficient structure to satisfy § 112, ¶ 6.  Aristocrat Techs.  Because the ’860 specification merely describes the results of customization without any algorithm for configuring the claimed module to obtain those results, we agree with the district court that the specification fails to disclose the “corresponding structure” required under § 112, ¶ 6, thus rendering claim 21 indefinite under § 112, ¶ 2.

Id. at 916-917.

c.         Teaching Which Embodiments Have Required Functionality

In Enzo Life Sciences, Inc. v. Roche Molecular Systems, Inc., 928 F.3d 1340 (Fed. Cir. 2019), the asserted claims were invalidated on enablement grounds.  The claims were directed to non-radioactive labeled polynucleotides and the use of non-radioactive labeled polynucleotides in nucleic acid hybridization and detection applications.  Id. at 1342.  Each of the asserted claims requires the functional limitation that the labeled polynucleotide is hybridizable and detectable upon hybridization and, in finding the claims not enabled, the Federal Circuit focused on this limitation.  Id. at 1345-48.

According to the decision, “the issue in this appeal is not simply whether the specification enables labeling; the question is whether it enables creation of a labeled probe that is both hybridizable and detectable upon hybridization.” Id. at 1345.  “[E]ven if we assume that the specification teaches one of skill in the art how to create the broad range of labeled polynucleotides covered by the claims, … the specification still fails to teach one of skill in the art which combinations will produce a polynucleotide that is hybridizable and detectable upon hybridization, as required by the claim language.”  Id. 

The Federal Circuit analyzed the claims using the factors set out in In re Wands, 858 F.2d 731, 737 (Fed. Cir. 1988) (“(1) the quantity of experimentation necessary, (2) the amount of direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims”).  Enzo, 928 F.3d at 1344.  The Federal Circuit concluded that the claims were broad, and the art was highly unpredictable.  Id. at 1346.  “[D]eficiencies in the description as to enablement cannot be cured in this case by looking to the knowledge of those skilled in the art at the time of the invention.” Id. at 1347.

Citing Genentech, Inc. v. Novo Nordisk A/S, 108 F.3d 1361, 1366 (Fed. Cir. 1997), the Federal Circuit stated “[a]lthough a specification need not disclose what is well known in the art, that rule is not a substitute for a basic enabling disclosure.” Id. (internal quotations omitted).  The Federal Circuit identified an example of a phosphate-labeled polynucleotide that was hybridizable and detectable in the patent but concluded that, regardless of whether the example was a working example or a “paper” example, it was “insufficient to enable the breadth of the claims here, especially in light of the unpredictability in the art.” Id.  “[E]ven if [the Example] describes one working embodiment with the claimed functionality, undue experimentation would still be required with regard to the many other embodiments of the claims based on the number of possible embodiments and the unpredictability in the art.”  Id. at 1348.  As the Federal Circuit pointed out, “[i]n cases involving unpredictable factors, such as most chemical reactions and physiological activity, the scope of enablement obviously varies inversely with the degree of unpredictability of the factors involved,” and here each individual labeled polynucleotide would have to be tested to determine whether it was hybridizable and detectable. Id. at 1347-48 (quoting In re Fisher, 427 F.2d 833, 839 (CCPA 1970)).  Thus, the claims were invalid for failing to satisfy the enablement requirement.

The decision in Enzo Life Sciences illustrates the requirements to provide an enabling disclosure for broad, functional claims.  “[B]road claims with many embodiments that recite a desired result, but only limited structure, require a specification that teaches a skilled artisan how to recognize which embodiments have the claimed function, and in areas where the art is unpredictable, such as chemical reactions and physiological activity, such an enabling disclosure will likely need to include more than a single example.”  See An Enabling Specification Must Teach Which Embodiments Have Required Functionality, https://www.haynesboone.com/Alerts/an-enabling-specification-must-teach-which-embodiments-have-required-functionality; see also Idenix Pharms, LLC. v. Gilead Scis. Inc., 941 F.3d 1149 (Fed. Cir. 2019) (finding that the Wands factors weighed toward invalidation for lack of enablement).

d.         Sample Formulations, Impossible Embodiments, and Prophetic Examples

In Nuvo Pharmaceuticals (Ireland) Designated Activity Co. v. Dr. Reddy’s Laboratories Inc., 923 F.3d 1368 (Fed. Cir. 2019), the Federal Circuit addressed prophetic examples and concluded that the specification must provide more than just a wish or hope that the invention might work.

In Nuvo, the patent at issue described a tablet that would coordinate the release of naproxen with an acid inhibitor to reduce gastrointestinal discomfort in the stomach and small intestine that is often experienced when taking NSAIDS, such as naproxen.  Id. at 1372-73.  Dr. Reddy’s alleged that the patent was invalid for failure to meet the written description requirements.  More specifically, Dr. Reddy’s alleged that the patent specification provided no experimental data to demonstrate the therapeutic effectiveness of any amount of an acid inhibitor.  Id. at 1376.  

The Federal Circuit affirmed the district court’s finding that the specification did not provide adequate support for the claims even though it disclosed sample formulations whose effectiveness were not at issue.  Although the specification included the claim language, the Federal Circuit noted that it has rejected the “argument that the written description requirement . . . is necessarily met as a matter of law because the claim language appears in ipsis verbis in the specification.”  Id. at 1381 (citing Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956, 968 (Fed. Cir. 2002)).  “‘The appearance of mere indistinct words in a specification or a claim, even an original claim, does not necessarily satisfy’ § 112, ¶ 1 because it may not both put others on notice of the scope of the claimed invention and demonstrate possession of that invention.”  Id. (citing Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956, 968-69 (Fed. Cir. 2002)).

The Federal Circuit confirmed that case law does not require experimental data demonstrating effectiveness.  Id. at 1380.  It also does not require theory or explanation of how or why a claimed composition will be effectiven.  Id.  However, the Federal Circuit concluded that “a person of ordinary skill in the art would not have known or understood that uncoated PPI [acid inhibitor] is effective.  And there is nothing in the specification . . . showing ‘that the inventor actually invented the invention claimed.’”  Id. at 1380 (emphasis in original).  Thus, the Federal Circuit found that the specification “does not demonstrate that the inventor possessed more than a mere wish or hope that uncoated PPI would work, and thus it does not demonstrate that he actually invented what he claimed: an amount of uncoated PPI that is effective to raise the gastric pH to at least 3.5.”  Id. 1381 (emphasis in original).

The Federal Circuit emphasized that the enablement requirement is separate and distinct from the written description requirement.  Id. at 1382.  “[T]he fact that an invention may be enabled does not mean it is adequately described, and vice versa.  Id.  “[U]nder a narrow set of circumstances, the written description requirement may be satisfied without an explicit disclosure if the claimed features are necessarily inherent in what is expressly described.”  Id.at 1382-83 (citing Yeda Research & Dev. Co. v. Abbott GmbH & Co. KG, 837 F.3d 1341, 1345 (Fed. Cir. 2016) (“Under the doctrine of inherent disclosure, when a specification describes an invention that has certain undisclosed yet inherent properties, that specification serves as adequate written description to support a subsequent patent application that explicitly recites the invention’s inherent properties.”); cf. Manual of Patent Examining Procedure § 2163 (9th ed. Rev. 3, Jan. 2018) (recognizing that inherency may satisfy the written description requirement)).  However, in Nuvo, whether uncoated PPI is inherently effective in raising the gastric pH to at least 3.5 was disputed, and the Federal Circuit found no written disclosure relating to efficacy of immediately released PPI or evidence that uncoated PPI is necessarily effective in a certain amount to raise the gastric pH to 3.5 or higher.  Accordingly, inherency could not be used.  Id. at 1383.

In the case of Trustees of Boston University v. Everlight Electronics Co., 896 F.3d 1357 (Fed. Cir. 2018), the Federal Circuit was asked to evaluate a claim construction that allegedly covered six permutations for the composition of a semiconductor device.  However, one of the permutations was indisputably impossible to make using the method disclosed in the patent.  The Federal Circuit found lack of enablement because the claim encompassed the unattainable permutation.  The Everlight case reflects the tension that may arise between how a claim is drafted to obtain allowance versus how a claim may later be interpreted in litigation.  In Everlight, the Federal Circuit noted that “to some extent, BU created its own enablement problem” with its proposed claim construction because “BU then needed to successfully defend against an enablement challenge as to the claim’s full scope.”  Id at 1365.

Questions have arisen out of the Everlight decision including whether an otherwise non-enabled claim could be enabled if one of ordinary skill would understand the claim to exclude impossible embodiments and whether a broad claim embracing a vast number of possible embodiments could be enabled while a narrower claim covering a finite set of permutations could lack enablement.  See Patent Coverage of Impossible Embodiments: A Cautionary Tale for Patent Owners, and Lingering Questions, July 19, 2019, https://www.wolfgreenfield.com/publications/articles/patent-coverage-of-impossivle-embodiments.  These questions remain open as the courts have not yet cited the Everlight decision for its implications as to enablement of claims covering impossible embodiments. 

The Nuvo and Everlight decisions raise questions about when and how to use examples and describe embodiments.  There can sometimes be a concern that examples written in the past tense suggest that the work was actually done, and thus, it is incumbent on the patent drafter to confirm whether examples were actually performed, especially if those examples may be used later in prosecution to establish patentability.  The examples should be written accurately to reflect work actually done.  If there are comparative examples, it is important to assess whether the examples are statistically significant.  Also, it is important to confirm whether there is undisclosed or inconsistent data.

IV.       Conclusion

This article touches on a small subset of the recent issues addressed through the USPTO Guidance as well as case law when it comes to precision in the drafting of patent specifications.  By staying on top of the USPTO guidance as well as case law, it is possible to “meet the specs” for patent specification drafting and avoid some of the pitfalls that may render patents indefinite, non-enabled, or even invalid over prior art.