Abstract on Article 053 EPC for the decision T0941/24 of 13.04.2026

In T 941/24 the invention concerned a medical device relating to medical tracking. Typically, a medical tracking device is used to detect the position of markers which are attached to targets, such as objects or anatomical points to be tracked. The application proposed making use of two sensor devices, with each sensor device being able to determine sensor data representing the position of a marker device located on the other sensor device. A control unit can then combine the sensor data of both sensor devices to determine the relative position between them.

The examining division found that the method claim had an embodiment in which a step of attaching a sensor device to a bone was implicit, which constituted a surgical step (G 1/07). The claim at issue read:

"A method of determining a relative position between two sensor devices of a medical tracking system, wherein the sensor devices are independently manoeuvrable and can be positioned in a fixed position relative to targets, comprising the steps of determining, with the two sensor devices, respective sensor data comprising the position of a marker device of another sensor device and transferring the sensor data to a control unit, characterized by determining the relative position between the two sensor devices by the control unit by combining the sensor data."

The board held that for almost any method claim, it is possible to conceive of a more specific claim (i.e. a dependent claim) comprising an additional step that is surgical. This more specific claim would fall under the scope of the initial method claim which did not recite this additional surgical step. Therefore, if "encompass" were used with the above meaning, virtually all method claims would encompass a surgical step and not be allowable under Art. 53(c) EPC. It is therefore clear that "encompass" in G 1/07 is not used with the same meaning as discussed above.

In the case on which referral G 1/07 was based, a method claim comprised a step of "delivering polarized **(129)Xe gas" to a subject, in that it explicitly recited that step. This step was considered to encompass the specific embodiment described in the patent application whereby the delivery was performed via injection into the heart.

Consequently, G 1/07 uses the term "comprise" in relation to a step that is explicitly recited in a method claim. By contrast, G 1/07 uses the term "encompass" with regard to an embodiment or step that the patent application mentions as a specific implementation of a more generic claimed method step (see the second and third paragraphs of point 3.2 of the Reasons of G 1/07, as well as the remark in point 4.3.1 of the Reasons on "whether or not a step being or encompassing a surgical step excluded from patentability can be omitted ... by simply leaving it out from the claim").

The board accepted that a step of (directly) attaching a sensor device to a bone is to be regarded as a surgical step. However, the claim in question did not explicitly comprise any step of attaching a sensor device to a target, nor any other step encompassing – within the meaning of G 1/07 – attachment of a sensor device to a bone. In addition, the description, which always has to be consulted to interpret the claims when assessing the patentability of an invention under Art. 52 to 57 EPC (G 1/24), does not suggest that the step of attaching the sensor device to a bone is part of the claimed method. Rather, the last paragraph states that the invention "solely relates to the step of navigating, tracking and verifying by acquiring and analyzing data" (see also the second paragraph of each of pages 9 and 10 of the description, which indicate methods that do not form part of the invention).

The board further held that the claim in question concerned a method of determining a relative position between two sensor devices. In contrast to the situation in T 1526/17 or T 318/21, the sensor devices need not be moved in order for their relative positions to be determined. Instead, the method concerned a passive, one-time determination which does not rely on any motion or acceleration by the sensor devices or the targets. It was thus a situation comparable, in respect of the movement of a bone, with determining the position of the distal end of a bone guide wire in the case on which T 836/08 was based. It followed that the method did not comprise a step of moving the sensor devices, either implicitly or explicitly. Therefore, the claimed method did not comprise or encompass movement of an exposed bone. In conclusion, the board held that the claim did not comprise or encompass any surgical steps. Consequently, it did not constitute a method for treatment by surgery within the meaning of Art. 53(c) EPC.