T 0516/14 25-01-2019

1. The appeals are admissible.

2. The invention

The invention relates to a device for producing a three-dimensional tomographic mammography image, with the general objective of making possible an early detection of breast cancer.

The device is generally depicted in figure 2A, reproduced below.

FORMULA/TABLE/GRAPHIC

It comprises a gantry frame (206) movable by a motor and to which a source (210) of cone-beam radiation (C) and a flat panel detector (208) are attached, and a support comprising a table (202) on which a patient rests while projection images of a breast (B) are taken. The table has a through hole (204), through which the breast descends. The support further comprises a breast holder (205) configured to pull the breast out of the chest wall and form it into a cylindrical shape. According to an embodiment depicted in figure 7D reproduced below, the breast holder comprises two halves 205a and 205b which are pressed together to pull and form the breast as claimed. A piston (208) may be provided to push the nipple towards the chest wall (page 5, lines 23 and 24).

FORMULA/TABLE/GRAPHIC

In use, the breast is positioned between the source of radiation and the flat panel detector while the motor rotates the gantry frame around an axis passing through the breast so that the breast remains in the path of the radiation emitted by the source and projection images are taken by the flat panel detector. A reconstruction and processing module forms a three-dimensional tomographic mammography image from the projection images.

According to the patent, the three-dimensional tomographic mammography image obtained with the claimed invention makes it possible to better detect breast cancer (paragraphs [0025] to [0032] in particular).

3. Although having been duly summoned by communication dated 8 November 2018, opponent 1 was not present at the oral proceedings as announced by letter dated 22 January 2019. In accordance with Rule 115(2) EPC and Article 15(3) RPBA, the proceedings were continued without opponent 1, who is treated as relying only on its written case.

4. Interruption of appeal proceedings

The insolvency administrator of opponent 1 submitted that with the opening of insolvency proceedings over the assets of opponent 1, the appeal proceedings had to be interrupted according to § 240 S1 ZPO, German law.

In proceedings before the EPO, the applicable law is basically codified in the EPC. Interruption of proceedings is the subject of Rule 142 EPC.

Rule 142(1)(b) EPC stipulates that proceedings before the EPO are to be interrupted "in the event of the applicant for or proprietor of a patent, as a result of some action taken against his property, being prevented by legal reasons from continuing the proceedings".

Neither this nor any other provision mentions an opponent in opposition proceedings. The application of Rule 142(1)(b) EPC to an opponent by analogy is not justified either. Generally, in opposition proceedings, the legal situation for an opponent is different from that of a patent proprietor. While for a patent proprietor the irremediable loss of its patent is at stake, the opponent, if unsuccessful, could still bring an action for revocation before national courts.

According to German law (Schulte, Patentgesetz mit EPÜ, 9. Auflage, Einleitung, 190) when insolvency proceedings are opened, the insolvency administrator is entrusted with the administration of the insolvency assets which may include an opposition, as in the present case. As a consequence, for this appeal, the insolvency administrator became a party to the proceedings, acting for opponent 1 ex officio as of 14 July 2016. This provided the administrator with enough time to become acquainted with the case and prepare for the oral proceedings scheduled on 25 January 2019.

In conclusion, the Board sees no compelling reason for an interruption and, following also decision T 1533/07 (point 2 of the Reasons), decides to continue the appeal proceedings.

5. General objections

The opponents generally referred to all objections and arguments presented in the opposition proceedings.

In accordance with what was pointed out already in the communication accompanying the summons to oral proceedings, such objections lack substantiation. In particular, such general references do not deal clearly and concisely with the reasons in the impugned decision.

Hence, those objections do not meet the requirements of Article 12(2) RPBA and are disregarded under Article 12(4) RPBA.

6. Main request - Added subject-matter

6.1 The Opposition Division and the parties, when considering the requirements of Article 123(2) EPC concerning added subject-matter, partly referred to the content of the international application published under the PCT (WO-A-01/35829). The application as originally filed, however, was amended before publication by the filing of substitute sheets, which differ in substance from the original application documents. It is on the basis of the application as originally filed, to which the Board refers in the following, that the requirements of Article 123(2) EPC have to be assessed.

6.2 The opponents raised a number of objections against claim 1 of the main request.

The Board sees a general basis for the subject-matter of that claim on claims 16 and 31 to 33, page 11, line 4, to page 12, line 21, and figures 2A to 2C of the application as filed.

Both opponents objected to the feature "the breast holder (205) is configured to pull the breast out of the chest wall to assure proper imaging of the chest wall and to apply a light and reproducible compression to form the breast (B) into a cylindrical shape".

This feature finds a literal basis on page 12, lines 19 to 21, of the application as originally filed. Thus, the argument of opponent 2 that the feature as such was not originally disclosed is without merit.

Opponent 1 argued that the feature belonged to a combination of interacting features that formed an entire scanner, and had been picked out of context, thereby constituting a non-allowable intermediate generalisation. The Board does not share this view as the claimed feature of the breast holder specifically relates to the forming of the breast, whereas the other features of the scanner mentioned by opponent 1, i.e. the material of the breast holder and the motors for driving the gantry frame and the flat panel detector, have different technical purposes. For this reason, these latter features are not inextricably linked, from a technical point of view, with the claimed feature of the breast holder. It follows that the intermediate generalisation does not add any technical information that was not present in the application as originally filed.

As regards the objection of opponent 1 to the feature "the table (202) presents a through hole (204) so that the breast (B) to be scanned descends through the hole (204) in the table (202) into the breast holder (205) and the through hole (204) is disposed relative to the source (210) of radiation (C) and the flat panel detector (208) so that the breast (B) to be scanned only is disposed between the source (210) or radiation (C) and the flat panel detector (208)", the definition of the hole and its position with respect to the breast holder finds a basis in page 12, lines 4 to 6, of the application as originally filed. Furthermore, the Board does not see why claim 1 of the main request should require that the breast be held in position by the hole as argued by opponent 1. The claim merely specifies that the position of the hole is such that, in use, the breast descends into the breast holder. It is the latter that holds the breast in position, as its very name makes clear.

6.3 In summary, none of the objections as to added subject-matter raised by the opponents are convincing and Article 123(2) EPC is complied with.

7. Insufficiency of disclosure

7.1 The requirement of sufficiency of disclosure, prescribed in Article 83 EPC, is distinct from the requirements of clarity of the claims (Article 84 EPC). Sufficiency of disclosure has to be assessed taking into consideration the disclosure of the patent as a whole as well as the common general knowledge of the person skilled in the art (e.g. T 629/05, point 4 of the Reasons). This implies that the patent does not have to describe in detail every structural feature to be employed for achieving a certain function as long as the skilled person can reasonably be expected to figure out suitable arrangements based on common general knowledge.

7.2 The opponents submitted that the disclosure of the patent did not enable to skilled person to provide a breast holder configured to pull the breast out of the chest wall as defined in claim 1 of the main request.

The patent explains that the breast holder, in use, applies a compression to the breast to form it into a cylindrical shape (page 5, lines 21 to 23). The breast holder may comprise two halves, to be brought together around the breast to compress the breast into the cylindrical shape (paragraph [0051]). Due to the shape of the breast, the two halves of the breast holder will contact the base of the breast close to the chest wall first. As the proprietor argued, it is plausible that, by applying compression, the breast will deform towards the other extremity, out of the chest wall, where there is space left by the two halves. In any case, because of the compression acting on the periphery of the breast, the skilled person, wanting to make sure that the breast is pulled out from the chest wall by the breast holder as claimed, would simply have to provide some outward displacement of the breast holder, which, by friction, would pull the breast with it. Thus, the patent sufficiently discloses a breast holder configured to pull the breast out of the chest wall within the meaning of claim 1. An interpretation according to which the pulling out would only be the result of gravity is ruled out by the wording of the claim, which requires the breast holder to pull the breast out of the chest wall.

7.3 The opponents further objected that a breast holder configured to apply a light and reproducible compression to form the breast into a cylindrical shape was not sufficiently disclosed either.

While the Board agrees with the opponents that the compression between two halves of the breast holder is higher towards the chest wall and depends on the breast shape and dimensions, it is also true that the skilled person can set up the size of the two halves of the breast holder and the level of compression for the particular patient under examination and that, once the set-up has taken place, the compression would be reproducible for the specific patient. What is meant by the cylindrical shape and how it can be obtained is clear from paragraphs [0041], [0050] and [0051]: it is the shape that the breast will assume when squeezed between the two halves of the breast holder, possibly after the additional application of an axial load by a piston acting on the breast nipple (page 5, lines 23 and 24). Whether some figures of the patent, possibly because of their schematic nature, do not show a breast in the claimed cylindrical shape is of no relevance as long as that shape is sufficiently disclosed in the remainder of the patent.

7.4 Opponent 1 raised a further general insufficiency objection to the claimed flat panel detector. The Board shares the proprietor's view that the details of suitable flat panel detectors disclosed in paragraphs [0054] to [0056] - especially page 7, lines 24, 25 and 47 to 49 - together with table 2 provide sufficient disclosure of flat panel detectors within the meaning of the claim.

7.5 Opponent 2 argued that the feature that "the projection images of the breast taken by the flat panel detector are cone beam volume computed tomography breast projection images" and the claimed reconstruction and processing module were not sufficiently disclosed.

The expression "computed tomography" is well known in the art. Moreover, an interpretation according to which the flat panel detector should take "computed images" does not make technical sense as a detector takes images as such. How they are computed belongs to the data processing that takes place afterwards. The claim defines that the images taken by the flat panel detector will be processed to obtain a cone-beam volume computed tomography of the breast as explained, in particular, in paragraph [0025] of the patent. In this context, the expression "image signal" has to be interpreted as the signal comprising the image information taken by the flat panel detector.

7.6 A further objection as to lack of sufficiency raised by opponent 2 was directed at the expression that "the breast (B) to be scanned only is disposed between the source (210) of radiation (C) and the flat panel detector(208)".

The Board agrees with the interpretation provided by the proprietor that the term "only" must refer to the breast. In other words, the claim, read in context, requires that only the patient's breast - no other part of the body - is put between the source of radiation and the flat panel detector. An interpretation according to which the term "only" refers to the action of scanning is technically meaningless in the context of the patent, which clearly teaches that the breast undergoes several other manipulations during the examination (for example, the forming into a cylindrical shape and, optionally, the injection of a contrast medium).

The alleged contradiction to which opponent 2 pointed, i.e. that it would not be possible to obtain imaging of the chest wall as required by the claim, does not exist. Within the meaning of the claim, the chest wall, being adjacent to the breast, is imaged together with the breast.

7.7 In summary, the invention as defined in claim 1 of the main request is sufficiently disclosed. Hence, Article 83 EPC is complied with.

8. Lack of novelty

The opponents argued that the subject-matter of claim 1 of the main request was not novel over each of D1, D3 and Z17.

8.1 Z17 is a US patent derived from a division of D1. To a large extent, these documents provide the same technical disclosure. They concern a mammography machine for examination of a breast positioned in a water-filled container (figure 5, reproduced below).

FORMULA/TABLE/GRAPHIC

The inventions of D1 and Z17 stem from the observation that in conical structures of soft tissue such as a breast, a practical tomographic system is incapable of resolving tumours in the region of a tissue-air interface. Surrounding the breast with a medium, such as water, that has an x-ray absorption coefficient close to that of the soft tissue should improve that resolution (column 3, lines 4 to 17, of D1 and column 3, lines 8 to 21, of Z17).

Both D1 and Z17 disclose a device for producing tomographic mammography images of a breast, with a support including a table (12) on which a patient (10) rests, the table having a hole (18) and a breast holder (in the form of fluid-filled container 22), and means for rotating a source of radiation (40) and a detector array (42) about an axis (44) passing through the breast so that multiple images from different observation angles are acquired and the image information is transmitted to a computer for the reconstruction of tissue images (column 4, line 59, to column 5, line 1, of D1 and column 4, line 63, to column 5, line 5, of Z17).

Neither D1 nor Z17 disclose a breast holder configured to pull the breast out of the chest wall and apply compression to form the breast into a cylindrical shape. As the proprietor submitted, due to its high fat content, a breast would float in the medium (water or similar - column 3, lines 12 to 17 and 62 to 67, of D1, and column 3, lines 16 to 21, and column 3, line 66, to column 4, line 3, of Z17). Moreover, in column 3, lines 7 to 12, of D1 and column 3, lines 11 to 16, of Z17, it is even taught that the problem of the inventions of D1 and Z17, solved by the provision of water or a similar medium in a breast holder, would be unimportant in the case of substantially cylindrical structures. This points to the fact that the breast shape in the breast holder of D1 and Z17 is not cylindrical.

The argument of opponent 2, that a patient lying on the support table with her breast extending through the hole would have the breast pulled out of the chest wall by gravity at least when the breast was not in the container is not convincing since, according to claim 1 of the main request, the breast holder - not just gravity - has to be configured to pull the breast out of the chest wall.

It follows that the subject-matter of claim 1 is novel over each of D1 and Z17.

8.2 D3 concerns a device for aiming a puncturing device at an area of interest within a breast of a patient in order to sample, excise or treat suspicious breast lesions (page 1, lines 4 to 12).

With reference to figure 5 reproduced below, it discloses a device with an imaging system (supported by elongated arm 114) and a movable puncture element (supported by arms 116 and 117) which share a common isocentre. The imaging system comprises means for rotating a source of radiation and a detector array about an axis (Z) passing through the breast so that multiple x-ray images from different observation angles may be obtained.

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The images obtained are used to position the area of interest such that it overlies the isocentre. According to D3, this is done by ensuring that the area of interest overlies the isocentre in at least two views (page 5, lines 4 to 7, page 9, lines 14 to 17, and page 11, lines 6 to 8). The device further includes a support including a table on which a patient rests, the table being provided with a hole and a breast holder for applying compression to the breast (page 10, lines 1 to 7).

D3 does not disclose any reconstruction and processing module for forming a three-dimensional tomographic image of the breast from the projection images acquired by the detector array. On the contrary, on page 7, lines 22 to 26, it is stated that the device of D3 takes advantage of the isocentric geometry for correctly aiming the puncturing device at an area of interest "without the need for realignment, re-imaging of the patient or repeated calculations". The argument of opponent 1 that the mechanical arrangement of the device of D3 would make it possible to form the three-dimensional image is beside the point, since there is no direct and unambiguous teaching that the device as such comprises a reconstruction and processing module suitable for the formation of such an image.

It follows that the subject-matter of claim 1 is also novel over D3.

8.3 As a consequence, claim 1 of the main request is novel (Article 54(1) and (2) EPC).

9. Lack of inventive step

9.1 Opponent 2 raised an objection of lack of inventive step of the subject-matter of claim 1 of the main request starting from E2 for the first time in appeal during the oral proceedings.

Such an objection constitutes an amendment to the appellant's case filed after the statement of grounds of appeal and after oral proceedings had been arranged. Under Article 13(1) RPBA the admission of such an amendment into the appeal proceedings is at the Board's discretion, which is to be exercised in view of, inter alia, the complexity of the new subject-matter submitted, the current state of the proceedings and the need for procedural economy. Under Article 13(3) RPBA, such an amendment should not be admitted if it raises issues which the Board and the other parties cannot reasonably be expected to deal with without adjournment of the oral proceedings. A further relevant criterion, according to the established jurisprudence of the boards of appeal, may be the prima facie relevance of the amendment.

The objection of lack of inventive step starting from E2 was raised at the latest possible moment in the appeal proceedings without objective reasons. The argument of opponent 2 that the representative had been given and studied the case only shortly before the oral proceedings is without merit as it is a consequence of a free choice of opponent 2.

The new objection clearly raises new complex technical issues as it starts from a document which had not been considered before in the appeal proceedings. Moreover, the document is in a non-official language, and no official translation of it has been provided. D2, which does not belong to the state of the art because of its late filing date, cannot constitute a true translation as it comprises different figures and reference signs. Hence, not even the prima facie relevance of E2 could be established.

For these reasons, under Article 13(1) and (3) RPBA, the Board does not admit the objection starting from E2 into the proceedings.

9.2 According to the established jurisprudence of the boards of appeal, inventive step can be assessed following the problem and solution approach.

Accordingly, it has to be established which document or documents may qualify as the closest prior art. Such documents, which should constitute a promising starting point towards the invention, should be in a technical field and address a technical problem similar to that of the invention as defined in claim 1 of the main request (e.g. T 1841/11, points 2.1 to 2.7 of the Reasons).

In the appeal proceedings, there are objections raised by the opponents starting from D1, D3, D9, E3, E4 and E5.

D9 concerns a general-purpose X-ray apparatus. It is mainly directed to setting up proper X-ray conditions as regards the x-ray dose for achieving a certain image level for a particular application (column 5, lines 24 to 63). It is not specifically concerned with mammography and the forming and imaging of the breast only, by providing an x-ray source and a detector rotatable around an axis passing through the breast as defined in claim 1 of the main request. It is only with hindsight that the skilled person would figure out and try to solve problems specific to mammography starting from such a general-purpose document.

Similar considerations apply to E3 and E5, which are concerned with general-purpose cone beam CT systems, albeit providing three-dimensional volumetric images (abstract of E3 and page 1, first four lines of the section entitled "BACKGROUND OF THE INVENTION" in E5). The general reference to a breast in figure 5 of E3, pointed out by opponent 2, does not make the device in E3 a mammography device.

For these reasons, D9, E3 and E5 do not qualify as the closest prior art. Starting from those documents, the skilled person would not arrive at the subject-matter of claim 1 of the main request in an obvious way. Whether the skilled person, starting from a mammography device and faced with a specific problem in that field would possibly consult whole body CT scanners, as argued by opponent 1, is another question which may depend on the specific problem. There is no need for the Board to answer this question in the present case.

9.3 E4 relates to mammography. Figure 1 of this document is reproduced below.

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More specifically, E4 is concerned with the positioning and forming of a hanging breast (14) during X-ray image acquisition with a source (29) and a detector (30) to be rotated around an axis (32) passing through the breast. To improve image acquisition, it proposes to hold the breast in a container (10) filled with an X-ray transmitting medium (12), which can be water (page 5, first half of the third paragraph). An expandable support (18 and 22), which can be filled with the X-ray transmitting medium, is used to form the breast into a cylindrical shape by pressing it towards the chest wall (page 5, last paragraph).

E4 does not disclose a breast holder configured to pull the breast out of the chest wall.

As already explained with relation to D1 and Z17, the argument of opponent 2 that the breast would be pulled out of the chest wall by gravity, at least when the breast was not in the container, is not convincing. According to claim 1 of the main request, the breast holder - not just gravity - has to be configured to pull the breast out of the chest wall.

9.4 Starting from either D1 or E4 as the closest prior art, the technical effect of the distinguishing feature of the breast holder configured to pull the breast out of the chest is to have the breast spaced from the chest wall during imaging. According to the patent, that ensures proper imaging of the chest wall and solves the technical problem of better detecting breast cancer. As far as D1 is concerned, the distinguishing feature of the breast holder configured to apply compression to form the breast into a cylindrical shape permits improving the imaging of the breast and addresses the same technical problem.

D1 teaches away from providing a breast holder configured to apply compression to form the breast into a cylindrical shape. More particularly, it stresses the importance of having water or a similar medium in the breast holder to improve imaging of conical structures in contrast to cylindrical structures (column 3, lines 4 to 17). The skilled person would have no reason to provide a breast holder for forming the breast into a cylindrical shape as required by the claim based on that teaching.

E4 teaches away from providing a breast holder configured to pull the breast out of the chest wall. More particularly, it stresses the importance of compressing the breast towards the chest wall by providing an expandable support (page 5, last paragraph). The skilled person would have no reason to provide a breast holder for doing the opposite, i.e. pulling the breast out of the chest wall, as required by the claim.

The argument of opponent 2 that according to the patent the pulling out of the breast could not be important as a piston for pushing the breast up was optionally employed is without merit. As the proprietor argued, when used, the piston of the patent is not employed to push the breast towards the chest wall but only to push up the nipple (page 5, lines 23 to 27).

It follows that, irrespective of whether the distinguishing features as such may be disclosed in other documents cited in the appeal proceedings, the skilled person would not arrive at the subject-matter of claim 1 of the main request in an obvious way when starting from D1 or E4.

9.5 Starting from D3 as the closest prior art, a distinguishing feature of the subject-matter of claim 1 of the main request is the claimed reconstruction and processing module for forming a three-dimensional tomographic image of the breast from the projection images acquired by the detector array. The technical effect of the possibility of providing a three-dimensional image, easier to visually analyse than a two-dimensional image, addresses yet the same problem of better detecting breast cancer.

D3 teaches away from that distinguishing feature as it stresses the advantage of having a device for aiming a puncturing device at an area of interest within a breast of a patient "without the need for realignment, re-imaging of the patient or repeated calculations".

Hence, irrespective of whether that distinguishing feature as such may be disclosed in other documents cited in the appeal proceedings, the skilled person would not arrive at the subject-matter of claim 1 of the main request in an obvious way when starting from D3.

9.6 In summary, none of the objections of lack of inventive step in the appeal proceedings is successful. It follows that the subject-matter of claim 1 of the main request is inventive (Article 56 EPC).

10. As a consequence, the patent can be maintained on the basis of the main request. There is therefore no need for the Board to consider the lower-ranking requests of the proprietor.