Friday, 2 November 2012

T 2344/08 – Simplification

It is often difficult to obtain patent protection for a simplification of an existing device. Here is a case where a simplification was found not to be inventive.

The only claim of the sole request before the Board (corresponding to claim 1 as granted) read:
1. Use of a humidity augmenting apparatus consisting of a water source, a non-porous hydrophilic membrane, optionally at least one opening for filling the apparatus with the water source, and optionally a support material, wherein the non-porous hydrophilic membrane is coated or adhered onto the support material,
wherein said water source contains water and at least one of a suspended solid, a dissolved solid, a pollutant, a salt, and a biological material,
wherein said non-porous hydrophilic membrane allows the water to pass through the membrane and be emitted as water vapor into an airspace of an enclosed chamber, said non-porous hydrophilic membrane preventing the at least one suspended solid, dissolved solid, pollutant, salt, and biological material from passing through the non-porous hydrophilic membrane,
wherein said non-porous hydrophilic membrane comprises one or more layers of hydrophilic polymers, said hydrophilic polymer being selected from a copolyetherester elastomer, a polyether-block-polyamide, a polyether urethane, a homopolymer of polyvinyl alcohol, a copolymer of polyvinyl alcohol, and mixtures thereof,
further wherein the one or more layers of hydrophilic polymers have a water vapor transmission at a thickness of 25 microns of at least 400 g/m²/24hours according to ASTM E96-95 (procedure BW), said water vapor transmission rate being measured at an air temperature of 23º C, relative humidity of 50% and an air velocity of 3 m/s,
for providing moisture to an airspace of an enclosed chamber.
The Opposition Division (OD) had found this claim to lack inventive step.

[2.1] The patent in suit is concerned with the use of a humidity augmenting apparatus, comprising a non-porous hydrophilic membrane, for providing moisture to an airspace of an enclosed chamber.

[2.2] D4 is considered to represent the closest prior art.

Said document discloses a humidifier comprising a water supply reservoir (2) and a water-evaporation conduit (1) consisting of a water evaporation tubing (3) of a porous hydrophobic polymeric material and of a continuous non-porous hydrophilic water-vapour permeable membrane (4) coated onto or attached to the inner side of the tubing […]. The non-porous hydrophilic membrane (4) may consist of a polyurethane resin containing oxyethylene groups having a water vapour transmission of at least 1000 g/m²/day, preferably in the range of 5,000 to 90,000 g/m²/day […]. The humidifier device of D4 further comprises a fan (11) which blows air over the surface of the water-evaporation conduit which entrains the water vapour emanating from the conduit. The air and entrained water vapour are blown out of the humidifier equipment into the surrounding environment, thus humidifying it.

[2.3] Having regard to D4, the object of the patent in suit is to provide a simplified humidifying apparatus useful for providing moisture to an airspace of an enclosed chamber.

[2.4] As a solution to the above defined problem, the patent in suit proposes the use of a humidifying apparatus according to claim 1, characterized in that the apparatus consists only of a water source, a non-porous hydrophilic membrane and an optional support material for coating or adhering the membrane onto it, and in that the apparatus is used for providing moisture to an airspace of an enclosed chamber.

[2.5] As to the success of the solution, due to the term “consisting of”, the wording of the claims thus excludes the presence of further essential parts or equipment, such as a fan, for blowing air over the surface of the water-evaporation membrane.

The board is therefore satisfied that the object of the patent in suit of providing a simplified humidifying apparatus, having regard to the closest prior art of D4, has been successfully solved.

[2.6] It remains to be decided whether or not the claimed solution is obvious having regard to the prior art.

In the board’s judgment, it belongs to the common technical knowledge that the water transport across a membrane and the evaporation of water vapour from the membrane’s surface (the pervaporation process) is controlled by the difference in chemical activities on the feed and permeate sides, respectively […]. Document D2 […] sets out in detail that for separation across a semi-permeable membrane to occur, a driving force (a gradient in pressure, concentration, temperature, electric field) has to be applied and maintained across the membrane. It is also explained that the gradient in chemical potential needs to be maintained by continuous removal of the migrating components from the side of the lower chemical potential, or otherwise chemical equilibrium would be reached and no further separation would occur […].

The skilled person would immediately realize that a fan which blows fresh (dry) air over the surface of the water-evaporation conduit and thus entrains the water vapour emanating from the conduit exactly serves the above-mentioned purpose of continuous removal of the migrating component from the side of the lower chemical potential and thus maintaining the driving force across the membrane. It is also obvious that a forced ventilation can be dispensed with if natural convection and diffusion are sufficient to maintain a gradient in chemical potential which is strong enough to keep the process going at the desired speed. It cannot be disputed that the water-evaporation conduit of D4, consisting of the porous hydrophobic polymeric tubing and the non-porous hydrophilic polymeric membrane attached to it, in combination with a water reservoir, would be sufficient to provide a certain amount of moisture to an airspace, even without the fan proposed in D4. Therefore, the board cannot see any inventive idea in the concept of omitting the fan from the humidifier disclosed in D4, at the cost of a less efficient humidification process.

[2.7] Another matter of course is to realize that the humidifying equipment of D4 can be used for providing humidity not only to an open airspace, but also to an airspace of an enclosed chamber. In the latter case, it would be apparent to those of skill in the art that - depending on the relative size of the said enclosed airspace – at some point saturation and/or condensation of water vapour would occur. The board observes in this context – as did the OD – that claim 1 on file neither puts any limitation on the properties of the enclosed chamber in terms of its size and shape nor contains a feature concerning the degree of humidification to be achieved. Thus, this particular claim feature does not support the presence of an inventive step, either.

[2.8] The board cannot, thus, come to any other conclusion than the OD in the contested decision, namely that it is self-evident and does not involve an inventive step to use a humidifying equipment known in its essential features from D4, but without a fan, in an enclosed chamber for the purpose of providing moisture to an airspace of said enclosed chamber.

[2.9] According to an argument of the appellant, D4 taught the use of a hydrophilic coating to prevent contamination of the conduit tubing, but this hydrophilic coating was allegedly not the same as the non-porous hydrophilic membrane which was the essential feature of the simple humidity augmenting apparatus in accordance with the present invention.

The board disagrees with this argument. The polyether urethane - which is one of the preferred materials for the non-porous water-vapour permeable hydrophilic membrane in accordance with the patent in suit - falls under the definition of a polyurethane resin containing oxyethylene groups, specifically recited in D4 as a membrane material (see column 2, lines 50 to 58), the oxyethylene groups in the diol component of the polyurethane (usually polyoxyethylene glycols [PEG] or polyoxypropylene glycols [PPG]) containing polyether moieties. To the extent that the appellant’s argument suggests that D4 only disclosed a hydrophilic membrane coating, it is sufficient to point out that the patent in suit explicitly encompasses coatings of the non-porous water-vapour permeable hydrophilic membrane material on a support material (see claim 1).

[2.10] In conclusion, the subject-matter of claim 1 as granted does not fulfil the requirements of inventive step (A 56).

Regardless of whether the Board was right or not in the present case, I would think that inventions consisting in simplifications (i.e. omission of features present in the prior art product) are stepchildren of the patent system, which appears to be better suited for “complexifying inventions” (i.e. where features are added to the prior art product). Certainly the problem-solution approach of the EPO is better suited for the case where the invention adds features to the prior art rather than omitting features.

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.


Anonymous said...

I disagree. If it is surprising that the sinplified inevntion would provide the same (cf worse) technical effect then the p-s approach would find it inventive.

MaxDrei said...

I don't understand that comment. A cake-baking oven with its fan removed provides the "same" technical effect as the oven did before its fan was removed, just not quite as speedily.

Same with humidifiers, isn't it?

If you want to slow it down, remove its fan. That's obvious, isn't it?