The Unified Patent Court (UPC) recently issued its decision in UPC_CFI_376/2023, concerning mandibular advancement devices (MADs) for the treatment of obstructive sleep apnea (OSA). While the case's technical merits are complex, the decision’s significant focus on the doctrine of equivalents stands out.
In UPC_CFI_376/2023, the court analyzed equivalence using two frameworks: the Function-Way-Result (FWR) test and the Insubstantial Differences test. Interestingly, these tests - more often associated with U.S. jurisprudence - are applied in a European context here, making this decision highly interesting for global patent litigation.
The doctrine of equivalents is grounded in Article 69 of the European Patent Convention (EPC) and its accompanying Protocol, which guide courts to balance a fair scope of protection for patent holders with legal certainty for third parties. Traditionally, European courts (e.g., in Germany and the UK) have applied jurisdiction-specific methods to assess equivalence. However, the UPC’s decision in this case signals an openness to integrating analytical tools resembling U.S. legal constructs.
The Brussel Division explicitly refers to the first decision of the UPC dealing with equivalent patent infringement delivered by the Local Division in The Hague, as discussed HERE.
The Brussels Local Division used the terminology “Function-Way-Result (FWR)” test and “Insubstantial Differences” test, traditionally used in U.S. patent law.
The FWR test, a familiar framework in U.S. patent law, asks whether the accused product:
In this case, the court applied a version of the FWR test to assess whether the coupling elements of the accused NOA device performed the same technical function as those in the patent. The patent's claimed invention used coupling elements located in the vestibulum oris to prevent further closure of the mouth. The court held that the NOA’s coupling elements, positioned differently and functioning via a distinct mechanism, failed to meet the "way" criterion. This led to the conclusion that the NOA device was not equivalent under the FWR test.
The Insubstantial Differences test, used in U.S. jurisprudence, considers whether the differences between the claimed invention and the accused product are minor enough that they would be perceived as insignificant by a person skilled in the art. This test emphasizes the practical impact of the differences rather than their technical details.
Here, the court found that the design of the NOA device—in which the forces at play were centralized in the occlusal plane rather than redirected to coupling elements in the vestibulum oris—constituted a substantial difference. The court concluded that these differences were significant enough to preclude a finding of equivalence, given the distinct force dynamics and overall design philosophy of the NOA compared to the claimed invention.
The FWR and Insubstantial Differences tests have deep roots in U.S. patent law, particularly in cases like Graver Tank & Mfg. Co. v. Linde Air Products Co. (1950) and subsequent Federal Circuit decisions. These frameworks are critical in evaluating whether an accused product "departs insubstantially" from a patented invention.
In U.S. practice, the FWR test often applies to mechanical inventions, where the relationship between components is pivotal, while the Insubstantial Differences test tends to dominate in chemical and pharmaceutical cases. Notably, in Graver Tank, the Supreme Court emphasized the "function, way, result" of a welding composition and upheld equivalence despite non-literal differences.
More recently, the Federal Circuit reaffirmed these principles in cases like Warsaw Orthopedic v. NuVasive, where equivalence was assessed in the context of spinal implant technology. The court’s reasoning in these cases - particularly its insistence on clear functional equivalence - echoes the approach taken by the UPC in UPC_CFI_376/2023.
While the UPC’s reliance on FWR and Insubstantial Differences tests may seem influenced by U.S. precedent, European jurisprudence has long applied analogous principles. For example:
