10.8.3 Determining effects that are crucial from those that are merely accidental?

In T 227/89 the board stated that in determining which effect was crucial and which was merely accidental (the so-called "bonus effect"), a realistic approach had to be taken, considering the relative technical and practical importance of those effects in the circumstances of a given case (see also T 732/89, T 729/90, T 1147/16). When assessing chemical substances for inventive step, it is often their surprising properties that are considered (see in this connection T 20/83, OJ 1983, 419).

In T 240/93 the application related to an apparatus for the surgical treatment of tissues by hyperthermia, equipped with heat protection means. The application was refused by the examining division, which considered the short treatment duration of one hour and further advantages resulting from the use of cooling means to be extra (bonus) effects. The board, however, stated that in the case in point the objective problem underlying the invention was to provide an apparatus for the effective therapeutic treatment of benign prostate hyperplasia in a short period of time. In view of the many considerable practical advantages of a single one-hour hyperthermia session for a patient, such a short treatment duration could not be dismissed as a mere "bonus" effect, but was crucial to the invention and the basis of the objective problem.

In T 2015/20 the application stated that it had been surprisingly found that for treatment of respiratory disorders, aclidinium was most effective upon administration by inhalation in a dosage of about 400 μg metered nominal dose. D1 described 1-2 formulations comprising 100 μg aclidinium bromide; it did not provide any suggestion towards an optimized dose of 400 μg. D2 presented a short summary of a trial in which patients suffering from COPD were administered a single dose of 100, 300 or 900 μg of aclidinium bromide, but which the board concluded seemed to teach away from an optimised dose of 400 μg for treatment of a chronic disease such as asthma. The board found that the defined subject-matter of claim 1 was not the obvious result of routine experimentation, but rather represented the unexpected outcome of a study and concluded that the subject-matter of claim 1 involved an inventive step.