T 1114/22 08-04-2025

1. Subject-matter of the application

The application relates, in an example described in detail, to a method and apparatus for measuring (predicting) the level of cortisol in the body of a person from electroencephalogram (EEG) data of that person.

The purpose of this method is to provide a non-invasive measurement technique for measuring the level of cortisol in the body.

The method comprises the steps of analysing an EEG with regard to various frequency bands to obtain an average power for each of a plurality of predetermined frequency bands (selected from the bands delta, theta, alpha, beta, SMR, high beta and gamma). In the example, the predetermined frequency bands are the theta, alpha, delta and SMR bands, which have a correlation with increasing or decreasing levels of cortisol (page 5, lines 18 to 19, and page 3, lines 31 to 33, of the description as originally filed). The average powers for these frequency bands are then combined by dividing or multiplying according to a predetermined order, to calculate a value X from which an estimate Y of the cortisol level is obtained from the equation Y=bX+C. The constants b and C have been determined on the basis of data obtained in a study which was conducted on 23 healthy participants and a regression line plotted to the data. In the embodiment described in the application, the constants are b = 227.51 and C = 1.1899 (page 15, lines 28 to 31).

2. Main request and auxiliary request 1 - sufficiency of disclosure

2.1 The wording of claim 1 of the main request and auxiliary request 1 is identical. According to claim 1 (and the corresponding apparatus claim 14), the level of any hormone, neurotransmitter or biomarker in the body of a person can be predicted from an analysis of EEG data of that person.

2.2 In order to perform the claimed method in a reproducible way, the person skilled in the art needs to know, for each hormone, neurotransmitter or biomarker of which the level is to be determined, which predetermined frequency bands are to be considered, the order in which the average powers for each frequency band are combined by dividing and/or multiplying, and which values for the constants b and C are to be chosen.

To determine these parameters, the person skilled in the art would first have to perform EEG measurements on a plurality of subjects (for instance at least 100 subjects, see page 9, lines 25 to 27, of the description). As mentioned on page 18, lines 20 to 27, of the description, one factor influencing the measurements is the location of acquiring EEG activity (a single location or multiple locations). Hence, the appropriate location would have to be chosen by trial and error.

Shortly before and after the EEG measurements, the actual level of the substance would have to be measured a number of times from saliva or other bodily fluids of each of the subjects (page 9, lines 31 to 35; page 12, lines 10 to 14).

Then, a fast Fourier transform would have to be conducted on each of the EEG measurements to provide average power values for each frequency band (delta, theta, alpha, SMR, beta, high beta and gamma) (page 6, lines 1 to 8; page 12, lines 31 to 35).

For each subject and for each measurement time, the average power for each frequency band would have to be plotted against the corresponding substance levels. The person skilled in the art would then have to establish by trial and error whether the average power of any of the frequency bands changed with the substance levels at any measurement time, and select those (page 10, lines 7 to 19; page 13, lines 1 to 6) as the predetermined frequency bands.

The average powers of the identified frequency bands would have to be divided and multiplied in a large number of possible different ways to provide a plurality of ratios or single values (page 10, lines 21 to 31). Each of these ratios would have to be plotted against the measured substance levels and, again by trial and error, the ratio giving the best fit to a straight line would have to be selected. The constants b and C could then be calculated as the slope and the Y-intercept of this line.

It is mentioned in the description that the boundaries of the frequency bands may vary and that by varying the boundaries a better correlation may be achievable (page 3, lines 25 to 29; page 11, lines 6 to 9). Hence, selection of the appropriate boundaries of the frequency bands already involves a considerable amount of trial and error.

Thus, to find the parameters needed for predicting the level of a substance from EEG data, the person skilled in the art would have to perform extensive experimentation resembling a research programme. This is unduly burdensome.

2.3 Only in respect of the hormone cortisol does the application as filed disclose which frequency bands should be selected as predetermined frequency bands (theta, alpha, SMR and delta), the order in which they should be divided (page 5, lines 18 to 22, of the description), and how the constants b and C should be derived for establishing the regression line equation (page 15, lines 28 to 31). The parameters had been determined from a study conducted on 27 subjects (page 5, lines 18-22, and page 11, line 11, to page 15, line 14).

2.4 The appellant argues that the experiments that would have to be conducted require only routine steps and that the number of frequency bands that would have to be taken into consideration is limited; that this does not impose an undue burden on the person skilled in the art; and furthermore that the frequency bands which correlate with the level of a particular substance can be retrieved from a database.

However, an undue burden is placed on the person skilled in the art by the, in total, excessive number of experiments that have to be performed and the amount of trial and error involved. For each individual hormone, neurotransmitter or biomarker of which the level is to be predicted, the person skilled in the art would have to perform the above-mentioned research programme to determine the necessary parameters.

2.5 Moreover, the appellant did not provide any evidence that databases for retrieving information on the suitable frequency bands were a matter of common general knowledge of the person skilled in the art. Documents A1 to A13 merely disclose that some substances or medical conditions significantly affect the EEG. However, the knowledge that there is a relationship between EEG activity and a substance or condition does not relieve the person skilled in the art of the large number of experiments to find the parameters of claim 1.

2.6 It is correct that the mere fact that a claim is broad is not in itself a ground for considering an application as not complying with the requirement for sufficient disclosure. However, in the present case, the issue to be considered is not merely the breadth of the claim. In the main request and auxiliary request 1, the method is to be carried out for a large number of different substances, while the description provides a concrete teaching of how to carry out the invention for only one of said substances, namely cortisol. In fact, as can be concluded from page 18, lines 20 to 27 of the description, the disclosed experimental settings and the parameters that are obtained to predict the level of cortisol cannot be transferred to other substances. On the contrary, as set out above, for every other substance the person skilled in the art would have to choose the experimental settings for obtaining the parameters by trial and error.

2.7 In view of the lack of disclosure in the application concerning a number of substances that are included in claim 1, there is no need, and indeed there is no way, to provide further verifiable facts to throw said disclosure into doubt. The finding of insufficient disclosure is thus justified.

2.8 Therefore, claim 1 of the main request and of auxiliary request 1 does not disclose the claimed invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (Article 83 EPC).

3. Auxiliary requests 2 and 3 - sufficiency of disclosure

3.1 Claim 1 is identical in auxiliary requests 2 and 3, and differs from that of the main request in that the biomarkers have been deleted from the list of possible substances.

3.2 While the deletion of biomarkers narrows down the scope of the claim, the remaining alternatives "hormones and neurotransmitters" still cover a very large number of possible substances for which, even taking into account the common general knowledge of the person skilled in the art, the application does not provide an enabling disclosure, contrary to the requirements of Article 83 EPC.

3.3 As mentioned above, the knowledge that there is a relationship between certain EEG frequency bands and a substance, which is exemplified by documents A1 to 13, does not relieve the person skilled in the art of the unreasonable number of experiments to find the parameters of claim 1 for each of the hormones and neurotransmitters included in the claimed method.

3.4 Hence, claim 1 of auxiliary requests 2 and 3 does not disclose the claimed invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (Article 83 EPC).

4. Auxiliary request 4a - admittance

4.1 The appellant filed auxiliary request 4a during the oral proceedings before the Board.

Pursuant to Article 13(2) RPBA, any amendment to a party's appeal case made at this stage of proceedings will, in principle, not be taken into account unless there are exceptional circumstances, which have been justified with cogent reasons by the party concerned.

The appellant did not put forward any cogent reasons justifying exceptional circumstances. Moreover, the Board disagrees with the appellant's argument that the amended auxiliary request was clearly allowable and thus conducive to procedural economy.

4.2 Claim 1 of auxiliary request 4a differs from that of the main request in that the substance of which the level is predicted is selected from any one of cortisol, testosterone, progesterone and oestrogen.

4.3 The amendments made in this request do not prima facie overcome the objection to sufficiency of disclosure, since the application does not prima facie contain an enabling disclosure for the substances testosterone, progesterone and oestrogen. For each of these hormones, the above-mentioned research programme involving a considerable amount of trial and error would have to be conducted.

4.4 The appellant referred to documents A3, A6, A8 and A10 and pointed out that A6, which discussed the effect of testosterone on the beta-delta frequency bands, was mentioned on page 2, lines 10 to 15, of the description of the application. However, none of these documents includes sufficient information to prima facie relieve the person skilled in the art of the unreasonable number of experiments which must be conducted to find the required parameters.

4.5 Furthermore, the appellant did not demonstrate that there were exceptional circumstances justifying the filing of this request at such a late stage of the proceedings.

4.6 Consequently, the Board exercises its discretion under Article 13(2) RPBA not to admit auxiliary request 4a into the appeal proceedings.

5. Auxiliary request 4b

5.1 In claim 1 of this request, also filed during the oral proceedings before the Board, the substance has been limited to cortisol. Claim 1 is thus limited to a specific substance which was already considered in the decision under appeal and in the Board's communication of 10 May 2024. The amendment does not therefore introduce any new issues following said communication. Moreover, it prima facie meets the requirements of Articles 83 and 53(c) EPC. Hence, taking into account the ex parte nature of the present appeal proceedings, the Board decides to admit it into the proceedings.

5.2 The method to predict the level of cortisol from EEG data according to claim 1 has been sufficiently disclosed in the description of the application, which explains the frequency bands that can be used and how they can be combined (page 12 and table 1), together with a procedure to obtain the constants b and C (page 15). Thus, the requirements of Article 83 EPC are met.

5.3 Due to the deletion of claims 7 and 8, auxiliary request 4b also overcomes the objection pursuant to Article 53(c) EPC raised by the Examining Division. Moreover, the claims of auxiliary request 4b meet the requirements of Article 84 EPC because they are clear and supported by the description.

6. Remittal to the Examining Division

There are no further grounds for refusal left for the Board to review on appeal.

The Examining Division did not assess novelty and inventive step in its decision.

In view of the primary object of the appeal proceedings to review the decision under appeal in a judicial manner (Article 12(2) RPBA), there are special reasons within the meaning of Article 11 RPBA for remitting the case to the Examining Division for further prosecution under Article 111(1) EPC.

7. Request for reimbursement of the appeal fee

7.1 According to Rule 103(1)(a) EPC the reimbursement of the appeal fee is ordered if such reimbursement is equitable by reason of a substantial procedural violation. A substantial procedural violation is an objective deficiency in the procedure before the department of first instance, not in the application of substantive law by that department.

7.2 The appellant's request for reimbursement of the appeal fee is based on the allegation that the Examining Division had misinterpreted (and misquoted) the application and had taken the decision under appeal without considering all the evidence on file. However, the alleged misinterpretation of the application concerns a (possible) error of judgment rather than a deficiency in the conduct of the procedure and therefore does not constitute a "procedural" violation, let alone a substantial one. The same is true for the alleged deviation from the guidelines in regard to whether a surgical step was part of the method claimed in dependent claims 7 and 8, and the allegedly inappropriate use of the phrase "doubtful expectation of success" in the context of sufficiency of disclosure. As to the alleged failure to consider all the information on file, the Board notes that the decision under appeal addresses in detail the arguments made by the appellant, together with the evidence provided in support of said arguments (pages 8 to 10) and the information in the application in table 1 and in relation to testosterone (page 7, first full paragraph). The correctness of the conclusions drawn by the Examining Division on the basis of said evidence is again a matter of judgement in the application of substantive law, which cannot constitute a procedural violation.

Hence, the issues raised by the appellant do not justify reimbursement of the appeal fee.