c) Surgical step part of claimed method or simply a preparatory measure? 

The boards have had to consider whether particular surgical steps form part of the claimed method or are simply preparatory measures which cannot be deemed such a part.

In T 992/03 of 4 November 2010 date: 2010-11-04, methods were claimed for MR imaging the pulmonary and/or cardiac vasculature of a subject, using dissolved-phase polarised ¹²⁹Xe gas. The board stated that delivering polarised ¹²⁹Xe gas to the subject and initialising the MR system were preparatory steps which, however, 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 2438/11 the claim was directed to a method for instrument alignment comprising steps whereby a surgical drill or mill was aligned with a target point. Said alignment was to take place in the patient's body, in direct physical contact with the bone. The board held that the very act of alignment, i.e. actively moving an instrument of this kind within the patient's body, was a substantial physical intervention on the body and thus a method step for treatment of the human body by surgery. The claimed method for instrument alignment, which explicitly included the (active) alignment step, also differed fundamentally from a mere (passive) position-tracking method of the kind at issue in T 836/08 (see below).