When Design Data Was Not Enough: Inventive Step and Article 123(3) EPC in a Maxillofacial Implant Case (T 0847/24)

1. Introduction

A recent Board of Appeal decision concerning computer-assisted design of patient-specific implants raises two separate but related questions. First, can the generation of implant design data contribute to inventive step? Second, does adding a manufacturing step to such a claim extend protection under Article 123(3) EPC?

2. The Inventive-Step Analysis

The patent concerned a computer-implemented method for configuring a surgical guide and an associated implant for maxillofacial osteosynthesis. Starting from patient anatomy data, the method generated virtual three-dimensional models, simulated osteotomies, repositioned bone segments into a desired post-operative configuration and ultimately determined a three-dimensional implant structure adapted to that configuration.

The Board considered that D2 disclosed virtually all aspects of the claimed workflow. The only distinguishing feature was the determination of a monolithic three-dimensional implant structure on the basis of attachment points defined in the modified post-operative model.

The decisive question was whether this feature contributed to the technical character of the invention.

According to the Board, it did not. Although the claimed method concerned the design of a patient-specific implant, the method itself merely generated data defining such an implant.

The Board stated:

“the outcome of the claimed method is not a physical implant but merely abstract data defining a 3D structure for such an implant”.

The proprietor argued that the generated implant structure would ultimately be manufactured and used in surgery and therefore produced technical effects. Referring to G 1/19, the Board accepted that manufacture of the implant could be regarded as a possible, and perhaps even probable, use of the generated data. However, it held that:

“a possible, or even probable, technical use is not sufficient”.

Instead,

“the technical use must be at least implicitly specified in the claim”.

The Board found no such limitation in claim 1. The claim neither required manufacture of the implant nor otherwise specified a technical use of the generated data. The fact that the method started from data representing the anatomy of a real patient did not alter that conclusion. According to the Board, the claim was directed to determining data defining an implant that did not yet physically exist, rather than determining a physical property of an existing object.

The Board therefore concluded that the distinguishing feature did not contribute to the technical character of the claimed method and could not support inventive step.

3. The Manufacturing Amendment

Auxiliary request 1 attempted to address the inventive-step objection by adding a final step requiring production of the surgical guide and the implant.

The Board accepted that this amendment narrowed the claimed process. A method comprising all steps of the granted claim together with an additional manufacturing step would already have fallen within the scope of the granted claim.

The issue arose instead from Article 64(2) EPC. According to the Board, the amended claim conferred protection not only on the process itself but also on the implant directly obtained by that process.

The Board stated:

“The physical implant … was not protected by claim 1 as granted.”

In the Board’s view, carrying out the granted method merely resulted in data defining an implant structure. By contrast, the amended claim resulted in a physical implant and therefore attracted product protection under Article 64(2) EPC. Since such protection did not exist under the patent as granted, the amendment extended the protection conferred by the patent and infringed Article 123(3) EPC.

4. Concluding Remarks

The decision provides a useful illustration of how the principles developed in G 1/19 may apply where the claimed method ultimately produces design data rather than a physical product. The Board considered that the generation of implant design data did not contribute to the technical character of the invention because no technical use of that data was specified, either explicitly or implicitly, in the claim.

The decision also illustrates the role of Article 64(2) EPC in the assessment of compliance with Article 123(3) EPC. Although the addition of a manufacturing step narrowed the claimed process, it also extended protection to the physical implant directly obtained by that process. According to the Board, that product protection was not available under the patent as granted.