Event recap: EPO Webinar Series “Technical Character at the EPO—Latest Guidelines & Case Law for Patenting AI & Software”

Speaker: Gerry Van Dooren, Director, Healthcare Technology, EPO
Moderator: Linda Huber, Partner, Nixon Peabody
By Aidan Persinger, Student Reporter

Gerry Van Dooren’s core message was both straightforward and stringent: success or failure of an application at the EPO hinges upon clarity, technical effect, and adherence to added-matter principles. He elucidated the foundational rules governing examination, highlighted points of divergence between U.S. and EP practices, and concluded by providing practical checklists for immediate application by drafters.

Clarity is not merely a courtesy; it serves as the mechanism by which the EPO safeguards third-party interests and empowers examiners to establish definitive claim boundaries. Mr. Van Dooren underscored the Art. 84 triad—clarity, conciseness, and support by the description—as an active benchmark throughout the search and examination phases. In practical terms, this necessitates the elimination of vague or relative terminology, the restriction to a single independent claim per category (with narrowly defined exceptions), and the inclusion of essential features within the independent claims. He further emphasized that clarity obviates ambiguity, enhances readability, and prevents applicants from claiming subject matter beyond what was initially disclosed—points reiterated in his presentation slides concerning the “purpose of Art. 84” and associated drafting checklist.

The EPO’s added-matter test evaluates whether a skilled person, utilizing common general knowledge, can directly and unambiguously derive a proposed amendment from the application as filed. The presentation systematically cataloged common pitfalls—including intermediate generalization, multiple selections from lists, undisclosed sub-ranges, undisclosed disclaimers, and features added solely from common general knowledge—and offered corresponding avoidance strategies (e.g., drafting explicit combinations, defining overlapping ranges, and explicitly articulating what the invention does not encompass). The practical implication is to engineer modular disclosure at the time of filing, ensuring that prospective amendments are inherently present within the original text and examples.

Mr. Van Dooren drew attention to the two-part directive of G 1/24: (1) claims serve as the initial reference point, and (2) the description and drawings must invariably be consulted for interpretation when assessing patentability. The Enlarged Board further affirmed that the appropriate response to unclarity is amendment, and that inconsistencies between claims and description will continue to trigger the Guidelines’ adaptation practice, always with due consideration of Art. 123(2). A presented example illustrated how narrowing to “nails” resolved patentability but subsequently necessitated alignment of the description, serving as a reminder that amendments may affect either claims or the description.

For computer-implemented inventions (including AI/ML), the EPO seeks a technical purpose and a technical solution demonstrating a causal link to a technical effect. If this causal chain is articulated at the time of filing, even steps such as generating training data or training a model can contribute to technical character; conversely, its introduction at a later stage proves considerably more challenging (cf. G 1/19). A pedestrian-detection example demonstrated how drafting the mechanism of effect—connecting low-light data selection to training and then to improved detection—transforms boilerplate language into patentable substance.

When claims define a result (“cabin for radioactive environments”) without specifying the means by which it is achieved, a series of objections typically arises—including missing essential features (Art. 84), the absence of a solved problem (Art. 56), potential sufficiency issues, and broad “desiderata” language. The remedy extends beyond mere narrowing; it necessitates the specification of the underlying architecture that enables the protection.U.S.→EP Friction Points (and Avoidance Strategies)

Mr. Van Dooren cautioned against the “direct conversion” of U.S. filings, recommending the following:

• Utilize a single independent claim per category, avoiding U.S.-style claim stacks.
• Detail embodiments comprehensively and purge claim-like phrasing from the description to preclude inconsistency.
• Refrain from assembling new embodiments by combining features across existing embodiments at a later stage, as this poses an Art. 123(2) risk.
• Eliminate U.S.-specific boilerplate (e.g., inclusion-by-reference, “spirit of the invention,” enablement remarks); instead, employ the two-part form and cite the closest prior art.
• Replace “may/could” with definitive technical statements, particularly in dependent claims, and avoid combining disparate “mays/coulds” in amendments.
• Prepare fallbacks that articulate features and their effects; in Preliminary Search and Examination (PSA), examiners evaluate the effect of the difference over the prior art.

A Drafting Playbook:

• Rule 42 Discipline: Clearly state the technical field, background art, the (implicit) problem/solution, advantages, and at least one enabled method for carrying out the invention.
• Rule 43 Hygiene: Adhere to one independent claim per category; utilize the two-part form; maintain a reasonable claim count; avoid drawing references; use reference signs solely for intelligibility.
• Front-load Fallbacks: Disclose alternative ranges, explicit feature combinations, and negative boundaries to mitigate the risk of undisclosed disclaimers.
• Police Consistency: Ensure alignment of terminology across claims and description; adapt the description when claims are modified (post-G 1/24) without introducing new matter.
• Make the Effect Causal (AI/CII): Establish a clear connection between data characteristics and training choices with operational behavior and measurable technical effects.
• Functional Claiming: Permissible if the means are enabled and essential features reside in the independent claims; otherwise, anticipate Art. 84/83 objections.
• Defensible Sub-range: Justified when the application explicitly refers to it—through examples, overlapping ranges, or articulated advantages—thereby rendering a subsequent amendment genuinely derivable.
• Reconciling U.S./EP Styles: Adopt an EP-first approach: embed clarity and derivability within the foundational text, then incorporate U.S.-specific material. Reversing this order risks added-matter issues and inconsistency.

To satisfy the EPO, drafting must ensure that every potential amendment is inherently present within the original filing—clearly, technically, and directly, unambiguously derivable from the outset. This approach transforms novelty, inventive step, and post-G 1/24 adaptation into procedural executions rather than existential threats.