“Taking the time to carefully draft claims with an eye toward potential infringement scenarios, minimizing prosecution history, and ensuring clarity in claim language can save significant time, money, and effort in the long run.”
Patent prosecution plays a critical role in shaping the strength and enforceability of patents in court. The language and strategies used during prosecution can significantly impact the outcome of future litigation. This paper explores key strategies, drawing on litigation experience, to guide patent prosecutors in enhancing the defensibility of their patents.
Language Precision in Drafting
The careful use of language is a crucial aspect of patent drafting . A frequent pitfall is the use of the phrase “present invention” in patent specifications. This phrase can unintentionally limit the scope of claims, as defendants might argue that the claims should be confined to the described embodiments and nothing more. Instead, prosecutors should opt for phrases like “in certain embodiments” or “in various embodiments,” which provide greater flexibility and reduce the risk of limiting interpretations to specific embodiments during litigation.
Another area of concern is the unnecessary definition of common terms. Over-defining terms in the specification can lead to restrictive interpretations during litigation, potentially harming the patentee’s position. Definitions should be used sparingly and only when essential to clarify the invention.
Strategic Use of the Background Section
The Background of the Invention section can be a double-edged sword in patent applications. While it is important to provide context for the invention, this section often introduces risks that outweigh its benefits. A lengthy background can inadvertently admit prior art, which might be used against the patent during litigation. Therefore, keep this section brief and avoid discussing prior art unless absolutely necessary.
The detailed description often better highlights a problem that the invention solves. Emphasizing the solution or solutions to that problem in the detailed description minimizes potential issues during litigation.
Detailed and Consistent Specifications
A well-drafted specification is crucial for satisfying the written description requirement under 35 U.S.C. § 112. Detailed drawings are particularly valuable as they can serve as written description support, even if not explicitly described in the text. Vas-Cath Inc. v. Mahurkar,, 935 F.2d 1555 (Fed. Cir. 1991). Ensuring consistency in numbering features across figures showing different embodiments strengthens the specification. For example, consistently referring to a feature as “Widget 100” across embodiments clarifies that it applies equally throughout the specification.
Patent drawings play a fundamental role in explaining inventions to fact finders during litigation. Litigators often use color-coded drawings to vividly illustrate key aspects of the invention, making complex concepts more accessible to judges and juries. More detailed and numerous drawings provide greater flexibility in presenting the case and help maintain engagement during lengthy trials.
Consistency in the application can also be a game-changer during litigation. Linking different embodiments effectively within the specification can reinforce the claimed combination of features. For instance, express and intentional linking of embodiments has supported the claimed combination and to a favorable litigation outcome.
Minimizing Prosecution History and Its Long-Term Implications
A well-managed prosecution history helps avoid prosecution history estoppel. This estoppel can arise from narrowing claim amendments or arguments made during prosecution, potentially limiting the enforceability of the patent in litigation. Even if the narrowing amendment was not necessary to obtain allowance, it could still trigger estoppel.
In litigation, opposing counsel will scrutinize the prosecution history extensively. While the patent prosecuting attorney may spend only a few hours drafting an office action response, litigation teams may spend months analyzing the prosecution history for weaknesses. Therefore, taking a few extra minutes to carefully consider the language used in responses can pay off significantly in the long run.
A practical example of a clean prosecution history would be a case involving an examiner interview where the interview summary was minimal, and the subsequent office action response succinctly referenced the discussion at the interview, leading to allowance of the claims. The simplicity and clarity of the prosecution history in such a case makes it difficult for challengers to find limiting statements to use against the patent in litigation.
However, there are exceptions where minimizing prosecution history might not be the top priority. For instance, if the patent is being drafted with a specific competitor’s product in mind, and the claim scope needs to be narrowly tailored to capture that product, the benefits of obtaining a tailored claim might outweigh the risks of prosecution history estoppel.
Drafting Claims with Infringement in Mind
Before jumping into the drafting of claims, there are crucial preliminary steps that can significantly impact the prosecution process and the strength of the patent. One key consideration is understanding the significance of the invention from the client’s perspective. This understanding can save time and effort in overcoming prior art rejections and reduce the need for amendments. Fewer amendments not only streamline the prosecution process but also minimize the risk of prosecution history estoppel, which can limit the enforceability of the patent in litigation.
When drafting claims, it’s crucial to anticipate potential infringement scenarios. Claims should be drafted to avoid situations where multiple entities are required to infringe, as proving indirect or divided infringement can be significantly more challenging than proving direct infringement.
For apparatus or system claims, one key question is whether the device infringes as sold. For example, a claim directed to a smartwatch should ideally capture all the essential elements within the smartwatch itself, rather than requiring interaction with other devices like smartphones, which could lead to an indirect infringement scenario. In another example, a medical manufacturer could not be held liable for direct infringement for selling a medical device used in spinal surgery because the claim required that “an anchor seal means which has a lower bone interface operatively joined to said bone segment.” Cross Medical Products, Inc. v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1299 (Fed. Cir. 2005). The Federal Circuit held that “operatively joined” meant that the interface and the bone must be in contact, which had to be performed by the surgeon during the surgery, and Medtronic could not infringe because it did not sell such a device. Id. at 1305.
For method claims, one key inquiry is who will perform the steps of the claim. Claims generally should be written to ensure that a single entity performs all method steps to simplify enforcement and strengthen the patent. If the steps are performed by different entities, it may limit the patentee to asserting divided or indirect infringement, which are more difficult to prove.
Addressing Divided Infringement and Its Challenges
Divided infringement occurs when multiple parties are required to perform the steps of a patented method. Akamai Technologies, Inc. v. Limelight Networks, Inc., 797 F.3d 1020 (Fed. Cir. 2015) (en banc). This creates challenges in proving infringement, as it requires showing that the acts of one party are attributable to another, either through direction or control, or through a joint enterprise. This is a complex and often difficult standard to meet, making it less desirable from a litigation standpoint.
An illustrative example of divided infringement comes from a case involving the administration of a chemotherapy drug. The claim required three steps, with the first step (administering folic acid) being performed by the patient and the subsequent steps being performed by a physician. Eli Lilly & Co. v. Teva Parenteral Medicines, Inc, 845 F.3d 1357 (Fed. Cir. 2017). This division of responsibility created a divided infringement issue, complicating the enforcement of the patent.
To avoid such issues, claims can be drafted to ensure that a single entity performs all the steps. For instance, instead of claiming the administration of a drug, the claim in Eli Lilly could have been written to cover the physician’s actions in prescribing or directing the administration, thereby ensuring all steps were performed by a single actor.
The Importance of Clear and Precise Claim Drafting
Clear and precise claim drafting is essential to avoid unnecessary litigation over claim interpretation. Preambles, for instance, can be a source of contention if they are not clearly drafted. While preambles are generally not limiting, they may become limiting if they provide antecedent basis or are necessary to give meaning to the claim. Catalina Marketing Int’l v. Coolsavings.com, 289 F.3d 801, 808 (Fed. Cir. 2002).
To avoid disputes, it is advisable to place any essential limitations within the body of the claim rather than in the preamble. This approach reduces ambiguity and minimizes the risk of having to litigate whether the preamble should be considered limiting.
Moreover, attention to detail in claim grammar and structure can reduce the cost of litigation. Small oversights, such as misplaced commas or clauses, or ambiguous phrasing, can lead to extensive legal debates and delayed court decisions.
The ‘Configured To’ Dilemma
The phrase “configured to” is sometimes construed broadly to mean that a device is capable of or suitable for performing a function. See, e.g., TQ Delta LLC v. Adtran, Inc., No. 1:14-cv-954-RGA, 2021 WL 1200595 (D. Del. Mar. 30, 2021) (“configured to” means “includes the necessary hardware and software for performing the functionality recited in the claim without the need to rebuild, rewrite or recompile the code for, or redesign any of that hardware or software”). This interpretation is often favorable for patent holders, as it aligns with the idea that the device need be only capable of performing the claimed function, without necessarily being explicitly designed for that purpose or even enabled to perform the claimed function.
However, recent trends show a more restrictive interpretation, where “configured to” is read as implying intent by requiring that a device was specifically “adapted,” “designed,” or “programmed” to perform the claimed function. This narrow construction can introduce an intent requirement into the infringement analysis, which complicates proving infringement. Generally, patent infringement is a strict liability offense where intent should be irrelevant.
As one example, in a case involving a patent on a breathing tube connector, the claim required a condensation deflector “adapted to” direct condensation away from a sensor in the connector. The court construed “adapted to” to mean “made to,” “designed to,” or “configured to,” which the court further construed to mean that the manufacturer had to intend for the deflector to perform the claimed function. Since there was no evidence that the accused infringer had this intent, the infringement case for that patent was lost on summary judgment. Fisher & Paykel Healthcare Ltd. v. Flexicare Inc, 2021 WL 5990160 (C.D. Cal. July 7, 2021). This case underscores how the interpretation of “configured to” can derail an infringement analysis by implicating the accused infringer’s intent.
Alternatives and Strategies
Given the potential for “configured to” to introduce an unintended intent requirement, alternative phrases like “capable of” might be preferable in certain contexts. However, “capable of” presents its own challenges at the Patent Office, as it can be difficult to secure claims based on such language due to the broad interpretation that any processor might be “capable of” performing a function. A more precise alternative might be “programmed to,” though this too could encounter the same intent issues as “configured to.”
One strategy to mitigate these risks is to draft multiple independent claims with varying language. For example, one set of claims might use “configured to,” while another might avoid any language that could imply intended use, relying instead on structural components. This approach can provide flexibility during litigation, allowing for arguments that capture the appropriate breadth of the invention.
Avoiding Ambiguity and Indefiniteness
Having a degree of leeway in the meaning of claims sometimes can be strategically advantageous by allowing for broader interpretation during litigation. However, this must be balanced against the risk of indefiniteness, which can render a claim invalid. For instance, the term “about” is often used to provide flexibility, particularly in claims to numerical ranges. But when multiple definitions of “about” are offered in the specification, it can lead to indefiniteness arguments, potentially costing significant resources in litigation. A more prudent approach might be to use specific numerical ranges.
Strengthen and Defend
Taking the time to carefully draft claims with an eye toward potential infringement scenarios, minimizing prosecution history, and ensuring clarity in claim language can save significant time, money, and effort in the long run. These best practices not only strengthen a patent but also make it more enforceable and defensible in litigation. By anticipating potential issues and addressing them proactively, patent attorneys can provide their clients with more robust and valuable patent protection.
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