On the boundaries of the exclusion from patentability of surgical treatment methods: the BrainLab case.
24 Aug 2026
Board of Appeal of the EPO, April 13th, 2026
In the medical technology field, Art. 53(c) EPC prohibits the patentability of surgical, therapeutic, and diagnostic methods practiced on the human or animal body and, unlike in the pharmaceutical field, Art. 54(4-5) EPC does not allow for the patenting of a “second medical use” for devices. MedTech companies must therefore limit themselves to patenting the device itself or a functional method devoid of any surgical, therapeutic, or diagnostic step. In this scenario, the decision of the Board of Appeal of the European Patent Office (EPO) of April 13th, 2026, in case T 0941/24 provides important strategic guidance.
The matter concerned a patent application filed by BrainLab for a medical tracking system based on the interaction between two devices, each of them with markers and detectors, and on a central unit that, by processing the combined data, ensured accurate tracking even in the presence of visual obstacles. In the first instance, the EPO Examining Division refused the patent, holding that the use of the sensors necessarily implied a bone-anchoring step – also raising objections under Art. 84 EPC regarding the clarity of the patent description, which did not explicitly disclose such a step – and that the movement of the patient’s leg by the doctor following inputs derived from the detection constituted a surgical act implicit in the description, meaning the patent application thus encompassed a surgical step. This approach aligned with the position expressed in decision G 1/07, which established the extension of the exclusion from patentability under Art. 53(c) EPC to inventions encompassing surgical steps.
The Board of Appeal set aside the decision, ordering the grant of the patent. The Board of Appeal clarified that a method falls under the exclusion of Art. 53(c) EPC only if the surgical steps are expressly claimed or necessarily implied as an essential feature of the invention, whereas the mere theoretical possibility of a surgical use is not sufficient to bring the invention within the exclusion. In this specific case, the tracking method functions regardless of the placement and anchoring object of the sensors, rendering attachment to the bone entirely optional and thus overcoming both the objections under Art. 53(c) EPC and those under Art. 84 EPC.
Furthermore, the Board of Appeal clearly distinguished the data processing phase from the clinical movement of the leg performed by the practitioner: the patent claim is limited to a passive detection of the position of the sensors, whereas the doctor’s movement constitutes a subsequent, optional step left to his discretion.
Finally, a decisive role was played by the inclusion of a disclaimer in the original text of the description excluding any surgical step. Applying decision G 1/24 – which requires interpreting the scope of the claims in light of the description – the Board confirmed that the inventor’s true intention was exclusively to protect the data processing method.
Camilla Allegra Rizzardini
