Monday, 12 March 2012

About the five six options for attacking claim 3

Claim 3(1) claims a patch for alleviating pain. Annex 4 (Analgesic dressing) clearly is the most promising starting point for an obviousness attack. It discloses the most similar function and has almost all features in common with the claimed patch. The only feature missing, an adhesive layer, is useful but unimportant for the overall function of the claimed patch. Until here, most candidates seem to agree.

Annex 1 discloses two types of adhesive layers, internal and external ones. The internal adhesive layer is for structural integrity. The external one is for sticking the patch to the skin. Claim 3(1) does not specify any type of adhesive layer. For successfully attacking the claim, it is sufficient to argue that just one of the possible types of adhesive layers is obvious.

For deciding what attack to perform, we now have to look for 54(2) documents lying in a technical field that is relevant for the objective technical problem. For improving structural integrity and skin attachment, the relevant field is skin patches. Unfortunately, all prior art documents (A2, A3, A5, A6) are about skin patches and could be relevant sources of information for the skilled person. Although I would already have a slight preference for A2 because it also deals with covering wounds, the missing effects are equally relevant for cosmetic or deodorizing patches.

Therefore, we have to go through all four 54(2) documents to find the missing feature and the missing effect. The result of this search is as follows:
A2: external adhesive layer (flaps) + to attach to the skin
A3: external adhesive layer (flaps) + to attach to the skin
A3: internal adhesive layer + attach depot layer to fabric carrier
A5: internal adhesive layer + tendency of the layers to separate is reduced
A6: external adhesive layer + to attach to the skin
A6: internal adhesive layer + laminated carrier structure does not fall apart

It looks like there are five six different ways of applying the problem-solution approach to attack the claim. All documents are, more or less, in a relevant field. All documents disclose the missing feature and related effects. Only for the internal adhesive layer of A3 it is not so clear that it solves the problems with the structural integrity.

For the internal adhesive layer, it might not be entirely clear whether the closest prior art actually has a problem to be solved. If no other options would have been available, I would not have had huge problems with accepting such attacks to be the expected ones. However, since we have better options, I'd like to focus on the external adhesive layer that is found in A2, A3 and A6.

Now we have to check what will happen when the skilled person would actually try to combine the features from the different documents with the closest prior art embodiment. And that is where the hydrogel layer comes into play. Any solution to be implemented should be compatible with the hydrogel layer. A skilled person would see the highest chances of success, if the prior art tells him that the adhesive layer can be combined with a hydrogel layer. A2 has such a hydrogel layer which, in my opinion, is a second argument for considering the A4+A2-attack to be a very good choice. However, also A6 [0010] mentions combining the external adhesive layer with a hydrogel layer.

The interesting question is now what the exam committee wanted you to do. Which attack do they prefer? Why? Do they expect multiple attacks? Are there points awarded for ‘incorrect’ attacks?
I do, e.g., see no good reason why adding the sticky flaps of A3 would not be possible and I would like to give almost full marks for A4+A3 (external adhesive) or A4+A6 (external adhesive).

UPDATE: Minor amendments made after reading the first comment. Further option added later.


  1. Hi Joeri,

    Please check A6, one of the last paragraphs. As I remember it, there is a statement there that a skin compatible adhesive layer can be used with other compatible layers, such as hydrogel (literal example).

    But maybe my memory is playing tricks on me.


    1. Hi Harm,

      I think you are right about the hydrogel. So compatibility is not a problem.
      That places A4+A6(external) in the same category as A4+A3. Good attack, but maybe not the strongest possible. Let's see what the exam committee has to say about this claim.

  2. I reasoned a bit further for selecting the 2nd document to combine with A4: the adhesive layer allows attachment to the skin and aims to "releases a sufficient amount of the active ingredient within the intended time of application" [0006] of A1, which then is OTP.

    And A3 states as the object: "to increase the contact time, thereby increasing the amount of active ingredient delivered" [0003] of A3

    So, A4 + A3 would be best in my opinion.

    1. This could be a relevant aspect. However, in both A1[006] and A3[003] this effect is not really related to the feature 'adhesive layer', but more to the feature 'patch with releasable compound'.
      Furthermore, I could imagine that pressing on the skin provides better delivery to the skin than the sticky flaps of A3, but that is pure speculation and not based on information from the documents.

  3. in addition: A3 discloses both an internal adhesive layer as an external adhesive layer. But I'm not sure whether I mentioned it in my answer...

    1. True, but it hardly mentions an effect for the internal adhesive. However, I'll add it to the list of possibilities. Just to show how many options there are.

  4. I'll present my case for A4 + A6.

    I picked an external adhesive layer as distinguishing feature, because I didn't see a clear path from A4 to an added internal adhesive layer. So far so good.

    Objective technical problem: how to overcome the inconvenience (this word is literally used) of having to hold the A4 patch while the ingredient is being administered.

    The skilled person will browse A6 - therein a number of ways for sticking patches to skin is disclosed, among which the adhesive layer is explicitly mentioned as the most convenient (again literally). So that is what the skilled person would want to apply to solve to OTP.

    There's no compatiblity issue with the hydrogel layer as already noted, since A6 [0010] discloses explicitly that it's compatible.

    These are the objective reasons.

    The subjective reason is:

    The inconvenience/inconvenient pair is just too perfect to be a coincidence, and the compatibility remark in par [0010] is just too neat. Therefor, in my opinion, this is at least one of the attacks (and perhaps the only one) that the exam committee wants to see.


  5. Agreed again (I'm the anonymous that just posted in reply to your comment re: Q5 of DI). This is precisely the attack I made, for exactly the reasons you suggest.

  6. Agreed again (I'm the anonymous that just posted in reply to your comment re: Q5 of DI). This is precisely the attack I made, for exactly the reasons you suggest.