In a series of decisions, the boards have considered whether particular surgical steps form part of the claimed method or are simply preparatory measures which cannot be deemed such a part. They have arrived at some very different conclusions.
In T 992/03 of 4 November 2010, methods were claimed for MR imaging the pulmonary and/or cardiac vasculature of a subject, using dissolved-phase polarized 129Xe gas. The board stated that whilst a skilled person would know that a MR imaging method was a rather complex procedure requiring inter alia preparatory steps like positioning of a subject in the MR system, delivering polarised 129Xe gas to the subject and initialising the MR system, these preparatory steps did not form part of the contribution of the invention to the art. The method claims thus did not comprise "an invasive step representing a substantial physical intervention on the body which requires professional medical expertise to be carried out and which entails a substantial health risk even when carried out with the required professional care" (G 1/07).
In T 836/08, claim 1 concerned a method for tracking the position of the distal end of a bone guide wire, using a medical optical tracking and navigation system. The board found that, while this meant that the reference apparatus had to be attached to, and the wire introduced into, the bone, these steps were not part of the claimed method. The fact that the method was performed after, or even during, a surgical intervention on the body did not mean that the claimed position-tracking method as such was a method of treatment by surgery.
Although the decision in T 923/08 was concerned with circumstances similar to those in T 836/08, the board came to a very different result: where a method for determining measurements of the human or animal body necessarily entailed a surgical step consisting of fixing to the human or animal body a measuring device indispensable for performance of the method, that step had to be deemed an essential feature of the method which was covered by such a method, even if none of the claimed method features expressly related to this step. Such a method was excluded from patentability under Art. 53(c) EPC. Moreover, such a surgical step could not be removed from the scope of the claimed method by means of wording stating that the surgically placed measuring device was already fixed to the body before the start of the method, or by means of a disclaimer, as this would breach Art. 84 EPC (1973).