Zusammenfassung von EPC2000 Art 083 für die Entscheidung T0174/21 vom 05.12.2023

In T 174/21 the invention concerned a method of estimating an acoustic transfer quantity by employing a hearing instrument, and a hearing instrument therefor. The opposition was rejected. The opposition division considered the opposed patent to specify "at least one way" to carry out the method of claim 1. However, in the board's view this did not mean that the opposed patent disclosed the claimed invention, i.e. the subject-matter of claim 1, in a manner sufficiently clear and complete for it to be carried out by the skilled person. This would only be the case if the "at least one way" covered, possibly augmented with the skilled person's common general knowledge, the "whole range claimed" (T 867/21). With reference to T 2773/18, the respondent (patent proprietor) expressed some doubts as to the applicability of the "whole range claimed"-requirement in the field of audiology. However, the board considered that these doubts were unfounded. The board referred in this respect to the conclusions drawn in T 149/21. The board found that the claimed method of "estimating an acoustic transfer quantity representative of a sound pressure transfer to the eardrum of an ear" could not be carried out for all kinds of frequency-dependent and ear-independent reference characteristics encompassed by feature (c). In particular, a "microphone characteristic" constituted one example of a hearing-instrument characteristic that was frequency-dependent and ear-independent but for which the claimed method could not be carried out. This was because a microphone characteristic typically bears no information on how the ear canal actually impacts incident sound. Such information was however crucial when determining the "ear-canal impedance" in accordance with feature (c). As a result, a "microphone characteristic" could not be used to carry out the method defined in claim 1. The respondent contested that the skilled reader would consider a "microphone characteristic" to be a "frequency-dependent ear-independent characteristic" within the meaning of feature (c). In the respondent's view, the common patent-law practice of drafting claims as a generalisation of the description's disclosure inherently meant that some "non-working embodiments" could not be explicitly ruled out. The board noted, however, that the issue at hand was not whether certain embodiments "work" or not. Instead, it concerned whether the skilled person could carry out the claimed method over the "whole scope claimed". To establish whether that was the case, the "whole scope claimed" had to indeed be determined through the eyes of the skilled reader, i.e. based on objective criteria and closely following the wording of a claim. This practice avoided taking into account embodiments which were theoretically possible but not "technically meaningful". However, this did not mean that only those claim interpretations could be considered "technically meaningful" where the requirements of the EPC were met (cf. T 2210/16). The respondent could not persuade the board that feature (c) would be enabled even with a microphone characteristic as "frequency-dependent and ear-independent reference characteristics". This was because a "microphone characteristic", taken by itself, simply did not comprise the necessary information to determine the "ear-canal impedance" in accordance with feature (c). The board also dealt with the respondent's objection that the board had raised the issue applicability over the whole range ex officio (see point 2.2.2 of the Reasons). In conclusion the ground for opposition under Art. 100(b) EPC prejudiced the maintenance of the opposed patent in its granted form.