I. A blood manipulation process involving the continuous removal of blood from a patient, its subsequent flowing through a circulating line of an extracorporeal circuit and its re-delivery to the patient is a method of treatment of the human body by surgery excepted from patentability under Article 53(c) EPC. It does not belong to the kind of methods which should not be covered by the exception clause according to the "narrower understanding" suggested by the Enlarged Board of Appeal in decision G 1/07, because the process is not performed in a "non-medical, commercial environment" and cannot be considered as a "minor intervention" being performed on "uncritical parts of the body" (Reasons, 8 to 10).

II. Such an in vivo process requires "professional medical expertise" and belongs to the kind of interventions representing the "core of the medical profession's activities", even when performed by paramedical support staff (Reasons, 11).

III. Even when the process is carried out with the required medical professional care and expertise, it involves "substantial health risks" for the patient. A health risk is considered to qualify as "substantial" whenever it goes beyond the side effects associated with treatments such as tattooing, piercing, hair removal by optical radiation, micro abrasion of the skin as mentioned in G 1/07. A factual analysis of absolute or relative risks and their likelihood of occurrence based on objective evidence is hardly feasible and should therefore not be required (Reasons, 12).