Unified Patent Court: First Ruling on Equivalent Infringement

The doctrine of equivalents is a staple patent law principle, addressing the tension between providing fair protection to innovative ideas and ensuring legal certainty for third parties.

Under this doctrine, an accused system/process may infringe a patent if, even in the absence of literal infringement, it is found to be "equivalent" to what is specified in the claims. This prevents the patent from being circumvented through minor changes.

Although Article 2 of the Protocol on the Interpretation of Article 69 of the European Patent Convention makes clear that equivalence must be considered when assessing the scope of protection, the UPCA contains no provision on the doctrine of equivalents—like most other European patent laws.

In a first decision on equivalence, issued on November 22, 2024, in a case opposing Plant-e Knowledge B.V. & Plant-e B.V. against Arkyne Technologies S.L. (Bioo) in relation to microbial fuel cell ("MFC") technology, the UPC's local division of The Hague has now provided its views on how to assess whether a patent is infringed by equivalent means.

Applying the Dutch four-prong test, this ruling achieves a certain balance between technical assessment and legal fairness and certainty.

The Case: Background and Technical Context

EP 2 137 782, owned by Plant-e, claimed an invention related to Plant-Microbial Fuel Cells, or P-MFCs, a technology leveraging living plants to generate electricity through photosynthesis and microbial oxidation.

The claimed process involves:

• A living plant in the reactor, whose photosynthesis produces organic material;
• An anode compartment with anodophilic microorganisms oxidizing this organic material;
• A cathode compartment, enabling electrons to flow and generate electricity.

Plant-e alleged that Bioo's products, including the Bioo Panel and Bioo Bench, infringed this patent either literally or by equivalence. Among other challenges, Bioo countered with arguments of non-infringement, arguing that their devices operated using soil and did not require a living plant for functionality, as required by the literal wording of the claim in suit.

The Hague local division found that while literal infringement was not established, Bioo's devices infringed the patent by equivalence.

The Hague local division adopted a systematic two-step approach to assess infringement:

1. Literal infringement: Does the accused device or method embody all claim elements as written?
2. Equivalence: If not, does the variation achieve the same result, in substantially the same way, fulfilling the invention's function as understood by a skilled person?

Four-Prong Test for Equivalence

The court's analysis goes beyond literal interpretation to examine equivalence, under four guiding principles:

1. Technical Equivalence: Does the variation perform the same function and solve the same problem?
   
   In this case, the court found that Bioo's devices, though described as Soil-MFCs, performed the same function as the patented P-MFC: generating electricity using microbial oxidation of organic matter. The plants, though deemed "optional" by Bioo, contributed to the process by replenishing organic matter, akin to the claimed invention.
    
2. Fair Protection for the Patentee: Is extending the patent's scope to cover the variation justified?
   
   The court's approach is that a fair balance must be struck between preventing patents from being designed-around through minor changes while the substance of the invention is reproduced, while safeguarding against an overly broad and generous interpretation.
   
   Here, the court held that interpreting the patent to include Bioo's implementation was warranted, given that: (i) Plant-e's invention was a significant contribution to the state of the art and (ii) the accused devices clearly relied on the principles of the patented invention.
    
3. Reasonable Certainty for Third Parties: Would a skilled person understand that the variation is within the patent's scope?
   
   In other terms, the skilled person must read into the literal wording of the patent claims that there is an additional room for equivalents, in particular when no reason can justify to limit the scope of protection of the claim.
   
   Here, the court noted that Bioo's communications about its technology, including grant applications, emphasized the role of plants, aligning closely with Plant-e's patented claims. A skilled person would thus reasonably infer that the accused technology fell under the scope of the patent.
    
4. Novelty and Inventiveness: Is the alleged equivalent novel and inventive over prior art?
   
   This fourth prong corresponds to the Formstein or Gillette defenses, which provide that there is no infringement if an accused product or process, while falling within the scope of a patent claim (the validity of which has been unsuccessfully challenged), were known or obvious from the prior art (aka "no infringement can result from merely practicing the prior art").
   
   Here, the court held that the accused devices' combination of plant photosynthesis and microbial fuel cells was novel and inventive, and thus did not merely amount to practicing the prior art.

Comparative Analysis With Case Law of National EU Jurisdictions 

The UPC's four-prong test for equivalence is identical to the test applied by the Hague Court of Appeal in its pemetrexed decision of October 27, 2020 (Eli Lily v. Fresenius Kabi). 

While—as the court itself remarked—it intends to borrow principles from the case law of several European jurisdictions, it does not yet provide clear harmonization between varying European equivalence tests:

• In Germany, a three-prong test known as Schneidmesser questions examines technical equivalence, obviousness, and interchangeability.
• In France, courts have historically taken a pragmatic view, emphasizing the function of the invention over strict wording, and disregarding any obviousness test: Two means are equivalent when, although different in form, they perform the same (new) function, with a view to achieving a result of the same nature, if not the same degree.
• In Italy, courts have often used either the so-called Triple Identity Test, or FWR Test (function, way, result), taken from U.S. case law, or in recent years an obviousness test, which correspond to the first and third prongs of the Dutch test.
• In the United Kingdom, the approach, particularly post-Actavis v. Eli Lilly, emphasizes the purposive construction of claims, focusing on the patentee's intent and the skilled person's understanding.

Technical Details: Why Bioo's Devices Were Equivalent

A deeper technical dive is needed to illustrate why the court found equivalence in this case:

• First, the defendant Bioo argued that the plants in its devices were purely decorative or optional. However, the court examined Bioo's grant documentation, promotional materials, and device setup, all of which emphasized the role of plants in generating organic material for microbial oxidation.
• Secondly, the court found that the accused devices had the same structure and function: While Bioo's devices incorporated a double-layered structure (with soil as a mediator), the functional setup mirrored the claimed P-MFC. Organic matter was still oxidized in the anode compartment, with the cathode enabling electron flow.
• Finally, Bioo's evidence, comparing devices with and without plants, was deemed insufficient. The court noted that short-term experiments could not capture the long-term role of plants in replenishing organic matter, reinforcing the technical equivalence.

The court's reasoning demonstrates the UPC's commitment to a rigorous, evidence-based evaluation of equivalence claims, considering both technical details and practical realities. This was in particular made possible owing to the involvement of the technically-qualified judge (Simon Walker in the case at hand, Ph.D. in Physics and who in particular performed research works in bio-electromagnetism).

Implications for Stakeholders

The Hague local division's ruling has several implications for the users: 

• For patentees: This decision underscores the importance of foresight in drafting patent claims. Clear articulation of the invention's function, scope, and potential equivalents is critical. Patentees should anticipate potential design-arounds and include sufficient descriptions to encompass foreseeable equivalents.
• For alleged infringers: The ruling serves as a cautionary tale. Companies must evaluate not only literal infringement risks but also whether their products could fall within a patent's equivalent scope. This includes thorough assessments of prior art, claim construction, and the technical role of each component in their products.
• For practitioners: The four-prong test provides a first structured framework for advising clients, offering more legal certainty on equivalence assessments.

All eyes are now on the UPC Court of Appeal and whether it will uphold or depart from this ruling.

Indeed, Mr. Grabinski, President of the Court of Appeal, has made abundantly clear that eventually the court will be decisive for defining—and harmonizing—how foundational legal concepts, like equivalence, are to be assessed at the UPC.