T 0054/14 () of 20.4.2018

Summary of Facts and Submissions

I. The appellant-opponent lodged an appeal, received 23 December 2013, against the decision of the opposition division posted on 7 November 2013 rejecting the opposition filed against European patent No. 1797925 pursuant to Article 101(2) EPC. The appeal fee was paid at the same time. Their statement setting out the grounds of appeal was filed on 14 March 2014.

II. Opposition was filed against the patent as a whole and based inter alia on Article 100(c) with Article 123(2) EPC, added subject matter and 100(a) EPC with Article 52(1) and 56 EPC, lack of inventive step.

The opposition division held, inter alia, that neither of the the above grounds for opposition prejudice the maintenance of the granted patent. With regard to inventive step, the opposition division considered the following documents, amongst others:

D1: US 3,189,027

D2: EP 1 170 026A2

D3: WO98/26830

D4: US 5,730,122

D5: US 4,506,667

D6: Leaflets "CPAP Systems" and "Pre-hospital CPAP Systems", published by Vital Signs Inc., 2001

D18: EP 1 018 348.

III. Oral proceedings before the Board were duly held on 20 April 2018.

IV. The appellant-opponent requests that the decision under appeal be set aside and that the patent No. 1797925 be revoked.

The respondent-proprietor requests that the appeal be dismissed and that the patent be maintained as granted (main request) or, alternatively, that the patent be maintained on the basis of one of the 1st to 4th auxiliary requests, all filed with letter dated 19 March 2018.

V. Claim 1 as granted reads as follows:

"A helmet for artificial respiration without the aid of masks, comprising a containment body (1) with at least one optically transparent portion (2), which can accommodate hermetically the head of a patient, said containment body (1) having an air intake port (8) that can be connected to a ventilation apparatus, an outlet port (9), an anti-suffocation valve (30) being connected to said containment body (1), characterized in that said antisuffocation valve (30) comprises a flat body (31) that forms a plurality of through holes or slots (32) that lead outside and are affected, inside said containment body (1), by a floating disk (33) that is held in position by a cage or crosspiece (35) and is adapted to be disengaged from said holes (32), due the action of a pre-adjusted spring (34) that acts on said floating disk, at a pressure value, inside said helmet, that is lower than a preset value, thereby allowing said floating disk (33) to free said holes (32) when an accidental drop in air flow and/or pressure occurs".

VI. The appellant-opponent argued as follows:

The subject matter of claim 1 as granted adds subject matter beyond the application as filed because it incorporates the feature of a spring from paragraph [0017] of the published application, but not the feature of the valve being manually closed from the same paragraph. Thus the claim constitutes an intermediate generalisation that has no basis in the application as filed.

The subject matter of claim 1 lacks inventive step starting from D2 in combination with the skilled person's general knowledge or with D1, D3, D4, D5, D6 or D18.

VII. The respondent-proprietor argued as follows:

Claim 1 does not represent an intermediate generalisation. There is no structural or functional relationship between the features of the valve being opened by a spring, as now claimed and that it is manually closed in paragraph [0017] of the published application. Therefore no subject matter is added by adding the spring feature to claim 1 without the manual closing feature.

The subject matter of claim 1 involves an inventive step when starting from D2 and in the light of the skilled person's general knowledge or the teachings of D1, D3, D4, D5, D6 or D18.

Reasons for the Decision

1. The appeal is admissible.

2. Background

The patent relates to a helmet for artificial respiration without masks (see published patent specification, paragraph [0001] and claim 1). Such a helmet, with an anti-suffocation valve that opens the helmet to the atmosphere if the air supply fails, is known (see specification, paragraph [0002]). An aim of the patent is to optimise the anti-suffocation valve to increase safety (specification, paragraph [0004]). The valve is shown in figure 3. An accidental drop in airflow and/or pressure allows the immediate opening of the valve by way of the fact that the floating disk 33 (valve closure member), due to the action of a pre-adjusted spring 34, frees the holes 32, allowing the free circulation of air and of the respiratory flow (see specification, paragraph [0019] and claim 1).

3. Added subject matter

3.1 According to established jurisprudence of the Boards of Appeal (see the Case Law of the Boards of Appeal, 8th edition, 2016 (CLBA), II.E.1.7, and the decisions cited therein), if a claim is to be restricted to a preferred embodiment, it is normally not admissible under Article 123(2) EPC to extract isolated features from a set of features which have originally been disclosed in combination in that embodiment. Such an amendment results in an "intermediate generalisation", i.e. an undisclosed combination of selected features lying somewhere between an originally broad disclosure and a more limited specific disclosure. An intermediate generalisation is justified only in the absence of any clearly recognisable functional or structural relationship among the features of the specific combination, or if the extracted feature is not inextricably linked with those features.

3.2 Claim 1 as granted largely corresponds to claim 1 as originally filed but is amended, inter alia, by defining that the floating disc of the anti-suffocation valve is "adapted to be disengaged from said holes, due the action of a pre-adjusted spring that acts on said floating disk".

The impugned decision found that this amendment did not add subject matter (reasons point 2.3).

3.3 The appellant-opponent argues that this feature, taken from the description as filed (see published application, paragraph [0017]), is only originally disclosed inextricably linked with the further feature: "Moreover, when the flow and/or pressure are restored, the floating disk must be repositioned manually against the holes...", which has not been incorporated into the claim. Thus, they reason, claim 1 is an intermediate generalisation which adds subject matter extending beyond the application as filed.

3.4 In the Board's opinion, there is no functional or structural link between the feature added to claim 1 (spring acting on disc to open the valve) and the feature not added (disc manually repositioned when pressure restored), nor are they inextricably linked. Therefore, applying the approach explained above, incorporating the spring feature into claim 1 without the manual closing feature does not add subject matter extending beyond the application as filed.

3.5 Although both features concern the disc of the same valve and appear in the same paragraph, the mechanisms of opening and closing are different and work independently of one another. As explained in the application as filed (see published application, paragraph [0017]), in case of an accidental drop in air flow and or pressure, the action of the pre-adjusted spring immediately frees the holes of the valve. Thus the spring opens the valve without any manual intervention. On the other hand, when the airflow and or pressure are restored, the floating disc must be manually repositioned against the holes. In other words valve closure is achieved manually, by manipulating the disc, not the spring, nor does it involve any action from the spring. Thus the mechanisms for changing valve state (opening with a spring and manual closing) are structurally and functionally independent of each other.

Nor, in the Board's opinion, does the wording chosen in paragraph [0017] imply anything different. Separating the two ideas (in separate sentences) by the connector "moreover" (column 3, line 20) merely indicates that the manual closure aspect is an additional piece of information about the valve, not that the two ideas are structurally or functionally related or inextricably linked, as the appellant-opponent has argued.

3.6 Nor does the Board agree with the appellant-opponent's argument that by incorporating only the spring feature into the claim, the claim covers theoretical embodiments of valves with a spring but not manually closed, which constitute new subject matter vis-à-vis the application as filed.

As explained above, an intermediate generalisation always represents a narrowing of an original broad disclosure. In this case original claim 1 defined a valve specifying neither a spring nor manual closing. Thus, contrary to the argument of the appellant-opponent, original claim 1 already defined the invention to cover all those theoretical embodiments (with spring but closed by other than manual means).

3.7 From the above, the Board confirms the finding of the opposition division that the amendment to claim 1 as granted, inter alia adding the feature of a spring, but without including the manual repositioning feature mentioned above, does not add subject matter that extends beyond the application as filed.

4. Inventive step of granted claim 1 starting from D2

4.1 Interpretation of the claim

According to the characterising portion of claim 1, the "anti-suffocation valve comprises a flat body that forms a plurality of through holes or slots that lead outside and are affected, inside said containment body, by a floating disk that is held in position by a cage or crosspiece and is adapted to be disengaged from said holes, due the action of a pre-adjusted spring that acts on said floating disk, at a pressure value, inside said helmet, that is lower than a preset value, thereby allowing said floating disk to free said holes when an accidental drop in air flow and/or pressure occurs".

Thus the claim defines the spring to act on the disc to disengage it from the holes below a preset pressure value. In other words the spring is not forcing the disc to close the holes but exerting a force acting to separate it from the holes, actively trying to disengage it, so the preset pressure value must be some positive pressure value that is higher than ambient pressure. The spring works against the force exerted on the valve disc by this positive pressure and overcomes it when the pressure in the helmet falls below it.

4.2 D2 discloses a helmet for artificial respiration without the aid of masks (see D2, title, abstract and figures 3 and 4). The helmet comprises a containment body 1 with an optically transparent portion 6, which can accommodate hermetically the head of a patient. The containment body 1 has an air intake port 10 that can be connected to a ventilation apparatus, an outlet port 11 and an anti-suffocation valve 30, connected to the containment body 1. Thus D2 discloses all the features of the preamble of claim 1.

4.2.1 The Board is not convinced that D2 discloses, or even hints at, a valve opening when a pressure above zero (relative to ambient) occurs in the helmet. For D2 to disclose this feature, it must be directly and unambiguously derivable by the skilled person using normal reading skills and, where necessary, taking account of their general knowledge.

4.2.2 According to the abstract, paragraph [0012] and claim 1, the anti-suffocation valve connects the inside to the outside, in other words opens, when a pressure in the helmet is "below a presettable value". From this wording in isolation, the value could be either a positive or negative pressure (relative to ambient), thus ambiguous in this respect.

Faced with this ambiguity, the skilled person will delve further into the document, in particular the description of the single detailed embodiment, to understand how the valve works. The anti-suffocation valve is described in paragraphs [0020] and [0021] with figure 4. There it is explained that the anti-suffocation valve is a one-way valve that connects the containment body to the outside when a "pressure value below zero" occurs inside the helmet. The skilled person understands this to refer to differential pressure and thus to mean a pressure within the helmet below ambient pressure outside.

4.2.3 Thus D2 discloses an anti-suffocation valve that opens when the pressure in the helmet falls below a preset pressure that is lower than the ambient (outside) pressure, i.e. upon falling below a preset under-pressure. Figure 4 shows how this is achieved. A membrane 21 seals the inner side of a hole 22 when the valve is shut. However this under-pressure value may be "preset" (D2 does not explain this, nor does figure 4 appear to show any biasing means), the membrane 21 would only be able to move out of its blocking position if the pressure in the helmet is negative with respect to ambient pressure.

4.2.4 Nor, in applying their general knowledge would the skilled person arrive at any other interpretation. In a positive pressure respiration system (cf. D2, paragraph [0008]), a one-way anti-suffocation valve can but work by (only) admitting air - when the air supply fails - rather than (only) allowing it to exit should supply fail. Opening a one-way valve arranged to admit air when pressure in the mask was at some predetermined above ambient pressure would however make no sense, since the pressure differential would prevent such a one-way valve from admitting air until pressure in the mask was below ambient pressure.

4.2.5 From the above, D2 does not disclose an anti-suffocation valve that opens when air in the mask falls below some preset positive pressure with respect to ambient as claimed (cf. point 4.1 above). Furthermore, the valve 20 of D2 does not comprise a spring. Rather the anti-suffocation valve of D2 opens at a preset negative pressure, that is one below ambient pressure, as stated in paragraph [0020], and the valve has no perceivable biasing means, let alone a spring.

4.3 Therefore, whether or not the membrane closing member of the valve of D2 is a floating disc, and leaving aside the fact that the valve of D2 has a single hole 22 rather than a plurality of holes, the subject matter of claim 1 differs from D2, at least by the feature of the anti-suffocation valve closing member (disc) being adapted to be disengaged from valve hole[s] due the action of a pre-adjusted spring that acts on said [closing member], at a pressure value, inside said helmet, that is lower than a preset value, thereby allowing [the closing member] to free said hole[s] when an accidental drop in air flow and/or pressure occurs.

Put succinctly, the differing feature amounts to the claimed anti-suffocation valve opening, due to a biasing spring acting on the closing means, at a preset positive pressure with respect to ambient pressure. In contrast, the anti-suffocation valve of D2 has no spring biasing means and opens at a preset negative pressure with respect to ambient pressure.

4.4 In the Board's view, the technical effect of the anti-suffocation valve of the invention opening at a positive pressure is that it opens faster than the valve of D2, which only opens once the supply pressure has been completely exhausted and a negative pressure prevails. In the Board's view, this rapid response of the anti-suffocation valve makes the helmet safer (cf. published patent specification, paragraphs [0002], [0004] and column 3, lines 14 to 20).

4.5 Thus, in the Board's opinion, the objective technical problem associated with this difference can be formulated as: how to modify the anti-suffocation valve of the helmet of D2 to make the helmet safer.

4.6 D2 with the skilled person's general knowledge

In the Board's opinion, faced with the above problem (safety) it would not be obvious for the skilled person to arrive at the above differing feature (valve opening by means of a spring at a preset positive pressure with respect to ambient).

4.6.1 According to D2, providing an anti-suffocation valve makes the helmet particularly safe (D2, paragraph [0002]). D2 itself offers no hint as to how this valve could be modified to further improve safety. D2 only suggests to improve helmet safety by providing a maximum-safety pressure valve (see paragraphs [0022] and [0025]). Nor, in the Board's opinion, would the skilled person, by applying their general knowledge but without knowledge of the present invention, introduce a spring into the anti-suffocation valve of D2 as claimed.

4.6.2 The appellant-opponent has provided no evidence showing that an anti-suffocation valve that opens when pressure in an artificial respiration helmet falls below a certain positive pressure with respect to ambient pressure belongs to the skilled person's general knowledge, nor does the Board have any reason to believe this to be so.

4.6.3 As explained above, D2 discloses an anti-suffocation valve that opens if a pressure inside the helmet falls below a presettable a negative pressure with respect to ambient pressure (cf. point 4.2.3 above, and D2, paragraphs [0020] and [0021]).

Therefore, applying their general knowledge, at best the skilled person might add a biasing (compression) spring to the valve of D2 that urged it shut until a predetermined negative pressure occurred in the helmet (e.g. one mounted to the left of the closure member 21 shown in figure 4), but they would not, as a matter of obviousness, provide such a spring that biased the valve in the opposite direction, that is one positioned to the right of the closure member 21 of figure 4 and designed to urge it into an open position.

4.6.4 Therefore the skilled person would not, as a matter of obviousness, arrive at the claimed invention from D2 with their general knowledge.

4.7 D2 with D1

4.7.1 D1 (see column 1, lines 13 to 20, lines 36 to 41, column 2, line 45 to column 4, line 17 with figures 1 and 2) discloses an anti-suffocation valve 14.

The Board notes that the anti-suffocation valve 14 is not for a breathing helmet but for an oxygen supplying mask such as used by flight personnel, col.1, 2nd paragraph. In D1 the user breaths using a mask 1 (column 1, line 17 and figure 1). Furthermore, the valve 14 is attached to the breathing tube section of the face mask, not to the face mask itself. Moreover, it is opened, inter alia, by the user developing a negative pressure as they gasp for air, that is breath in deeply (column 3, lines 71 to column 4, first line).

4.7.2 As the appellant-opponent has argued, the breathing helmet of D2 (see paragraph [0024]) is made of elastically flexible material and is unlike a mask in that it has a large air volume compared to the volume a user breaths in and out. Consequently, they argue, the wearer's breathing efforts have practically no influence on the pressure conditions prevailing in the helmet. For this reason, the Board considers that the the skilled person would not look to a solution to the objective technical problem (improving helmet safety by modifying the anti-suffocation valve) in a document disclosing a face mask with an anti-suffocation valve that is triggered to open by the user's breathing efforts (gasping). Therefore they would not, as a matter of obviousness, combine the teachings of D2 and D1.

4.7.3 Furthermore, starting from D2, even if the skilled person were to think that D1 might offer a solution to the problem (the Board holds this not to be so), the Board considers that the skilled person would still not arrive at the claimed solution as a matter of obviousness.

4.7.4 D1 discloses (see column 2, line 45 to column 4, line 17 with figures 1 and 2) an anti-suffocation valve 14. The valve is formed by a disc (piston 28) closure member, and the seat of the valve is formed by flexible bellows 29 (column 2, lines 69 to 71). A biasing spring 30 between the spring cap 21 and disc 28 biases the disc towards the valve-open position (column 2, line 71 to column 3, line 2). A snap-acting mechanism (column 3, lines 33 to 36 with figures 1 and 2) positively displaces, that is biases, the disc 28 into either the valve open or closed position. Only once a lever 32 passes a horizontal position does it snap from the one to the other.

Thus, the disc (piston 28) is acted on by a complex arrangement of biasing means comprising the spring 30, the expanding bellows 29, which constitute the seat of the valve and can move with the disc 28 (column 3, lines 10 to 15), and the snap acting mechanism (see column 3, lines 33 to 36), with its springs 37 and lever 32, which biases the valve shut by pushing on the disc 28 in opposition to the biasing spring 30.

4.7.5 As already mentioned, the net effect of this arrangement is to keep the valve shut until the user's gasping for breath creates a negative pressure in the mask (column 4, lines 1 to 17). Thus the anti-suffocation valve does not appear intrinsically safer than that of D2, which also first opens when a negative pressure condition in the breathing air supply exists, let alone does D1 suggest that the spring 30, arranged to bias the disc 28 open, plays any special role in improving safety.

4.7.6 In particular, the spring 30 has insufficient force by itself to move piston 23 downwardly to unseat it from bellows 29 whenever a positive pressure exists within housing 16 exists (see column 3, lines 2 to 6). Although it assists this action, (see column 4, lines 1 to 17) the valve remains shut until it is snapped open by the snap mechanism, under the influence of a negative pressure within the housing.

Moreover, the spring 30 is but one part of a complex arrangement of tightly integrated components (inter alia spring 30, snap mechanism 32, 37 and expanding bellows 29) that cooperate to control opening and closing of the valve 14. Therefore, the Board considers that abstracting the spring 30 in isolation from this original context and incorporating it into a different anti-suffocation valve (of D2) goes beyond the routine skills of the skilled person.

4.7.7 For all these reasons, the Board does not think that D2 with D1 takes away inventive step of claim 1.

4.8 D2 with D3

4.8.1 D3 discloses an anti-suffocation valve for use with the air supply to a patient breathing mask (abstract). The anti-suffocation valve of D3 (see abstract and page 2, lines 20 to 24 and page 3, lines 6 to 9 and claim 3 with claims 1 and 2) is disposed between the patient and source of breathing gas, thus in the air supply line. It has a slider element 24 that slides between a position where it blocks ports 30 to the atmosphere (figure 3A) and a position where it opens these ports (figure 4A). A biasing means 36, 38 - shown as magnets but which can be a spring (page 7, lines 11 to 14) - biases the slider towards the ports-open position by acting on a base plate 39 positioned in the path of the airflow (figure 4A).

4.8.2 Under normal air supply conditions, the airflow exerts a force on the base plate 39 of the sliding element which overcomes the force exerted by the biasing means. When airflow diminishes to a critical level, the biasing means exerts the stronger force on the base plate 39 so the slider slides to the left, thus opening the ports 30 and blocking airflow from the breathing gas supply (page 7, lines 3 to 11).

Although this critical airflow may be equated to a critical air pressure delivered to the patient (see for example claims 2 and 3), the force exerted on the base plate 39 which keeps the slider in its right hand position so that the ports are blocked (figure 3A), is first and foremost due to the flow of air in the supply tube and not due to a pressure differential between the two major surfaces of the base plate 39. Put differently, considering a starting condition in which the slider is in the right hand position (figure 3A) but without airflow, whatever the pressure is in the whole volume of valve 14, the biasing means will always pull the slider into its left hand position (as shown in figure 4A).

4.8.3 Faced with the objective technical problem (modifying the anti-suffocation valve of D2 to improving mask safety), in the Board's view, it would not be obvious for the skilled person to arrive at the biasing spring features of claim 1 in the light of D3.

4.8.4 The skilled person might well recognise that D3 offers a particularly safe anti-suffocation valve in that it opens quickly, before airflow to the patient is completely stopped, in other words even under airflow conditions reduced to an unsafe level.

4.8.5 However, the skilled person would also see that the valve of D3, even if positioned close or even on the mask (see D3, figure 14), functions because it is in the air supply line. As explained above the valve opens in response to a reduction in airflow in the air supply tube, not a pressure differential. On the other hand, the valve of D2, positioned as it is on the surface of the helmet, is not subjected to significant airflow. Rather it functions due to pressure differential (D2, paragraph [0020] and [0021]).

4.8.6 The physical structures of the valves are also very different (figures 3A and 4A). The anti-suffocation valve 14 of D3 is tubular, with a cylindrical slider 24 for opening and closing radial openings 30, consistent with the fact that the valve only works when it is part of the air supply tube. On the other hand, the anti-suffocation valve 20 of D2 (figures 3 and 4) has a flat body with an opening 22 on its cap, because it is arranged on the surface of the helmet.

4.8.7 In the Board's view, due to the disparate functional and structure concepts of the valves of D2 and D3, the skilled person would consider them incompatible for combination into some hybrid anti-suffocation valve.

It might be obvious for the skilled person to modify the arrangement of D2 by adding the valve of D3 into the air intake 10 to the helmet. If they did so, at most, they might completely remove the redundant anti-suffocation valve 20 of D2. However they would not modify it in the light of D3, let alone abstract only the idea of a spring from its original context in the supply tube valve of D3 where it counters a force generated by airflow, and incorporate it into the helmet mounted anti-suffocation valve of D2, operating on pressure difference not airflow. In the Board's opinion, making such a hybrid valve goes far beyond the routine skills of the skilled person.

4.8.8 Therefore the combination of D2 with D3 would not lead the skilled person to the anti-suffocation valve with a spring as claimed in an obvious manner.

4.9 The remaining documents (D4, D5, D6 and D18) suggested by the appellant-opponent for combination with D2 are less relevant than D1 and D3. In particular none of them discloses the differing feature of a spring biasing a valve open. Therefore, in the Board's opinion, the combination of D2 with any of these would not lead the skilled person to the claimed invention as a matter of obviousness. In particular, D4 disclose a valve with a spring that biases the valve closed until a negative pressure in a breathing mask overcomes the closing force of the spring (see column 5, lines 35 to 41 with figure 4). D5 discloses an anti-suffocation valve 28 but does not describe it, and a positive expiration pressure (PEEP) valve 118 which is biased to block flow by a spring (see column 3, line 24, column 5, lines 13 to 22 with figures 1 and 2). D6 (see whole document) discloses a PEEP valves but does not disclose how they are biased, let alone disclose a spring. Finally, D18 discloses an exhalation valve 10 with springs 38 that bias the valve disc 44 shut (see paragraph [0009] and [0016] with figure 3).

4.10 Starting from D2, as explained above, none of the appellant-opponent's arguments convincingly demonstrate that it would be obvious for the skilled person to arrive at the differing claim feature of a pre-adjusted spring as claimed. Therefore the Board agrees with the Opposition Division's finding (see impugned decision, section 2.5) that the subject matter of claim 1 involves an inventive step starting from D2 in combination with common general knowledge, D1, D3, D4, D5, D6 or D18.

Whether or not it would be obvious for the skilled person to modify the arrangement of D2 to arrive at any remaining differing claim features can therefore remain unanswered.

5. In summary, the arguments presented by the appellant-opponent fail to demonstrate that granted claim 1 adds subject matter extending beyond the application as filed, nor that the subject matter of granted claim 1 lacks inventive step. The Board therefore confirms the decision's positive finding in respect of the opposition grounds of added subject matter, Article 100(c) with Article 123(2) EPC and inventive step, Article 100(a) with Articles 52(1) and 56 EPC. Thus there is no need for the Board to consider the respondent's auxiliary requests.

Order

For these reasons it is decided that:

The appeal is dismissed.