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Friday, 7 June 2013

Doctrine of Equivalents and Prosecution History Estoppel in Sweden, Who Knew?

Peter Kenamets
The IPKat was fascinated to hear a report of a decision of the Swedish Appeal court about the doctrine of equivalents and prosecution history estoppel as it applies in that country.  He asked his Katfriends at Awapatent AB to write a note for his dear readers, and Peter Kenamets (pictured right), Attorney-at-law, kindly obliged.  Here is his report.

The IPKat is most grateful for this interesting piece, noting that in the UK we don't seem to have either a doctrine of equivalents (whatever the Protocol to Article 69 EPC may say) or prosecution history estoppel.

Swedish Appeal Court applies prosecution history estoppel in the Swedish part of a multinational dispute

In a judgment issued this spring, a Swedish Appeal Court confirmed that a (type of) prosecution history estoppel can bar a finding of infringement under the doctrine of equivalents.

The background to this case was that AGA Medical had the European patent EP 0 808 138, directed to an intravascular occlusion device and a method for manufacturing the same. Occlutech sold a product – the "Figulla Occluder" – used for sealing (occluding) e.g. holes in the walls separating the chambers of the heart.

Occlutech sued AGA for a declaration that the Figulla Occluder did not infringe AGA’s patent, and AGA sued Occlutech for an injunction against the Figulla Occluder.

The District Court sided with Occlutech and found that the Figulla Occluder did not infringe the patent.

AGA appealed the case, and the Appeal Court ruled on a number of issues. The perhaps most interesting question was whether the Figulla Occluder fulfilled a claim element providing that “clamps are adapted to clamp the strands [forming a metal mesh] at the opposed ends of the device”.

This is the Figulla Occluder
The strands of the Figulla Occluder were brought together and sealed only at one end of the device, and the Appeal Court found that the claim element was not literally fulfilled.

The Appeal Court then went on to consider the doctrine of equivalents. AGA had added this particular claim element during prosecution as a characterizing feature to distinguish the claimed invention from certain prior art disclosing a similar device with two open ends. In particular, AGA had stated that the amendment was made “to clarify this distinction over the prior art”.  The Appeal Court felt that this made it clear that AGA must have considered it to be essential for the patentability that the device was closed by a fixation of the strands at both ends. The element was in other words essential in connection with the grant of the patent. This spoke strongly against expanding the scope of protection to encompass a product that differed from this element of the claim. This was despite the fact that when making the amendment AGA alleged that the unamended claim was in any case distinguished over the prior art

Hence there was no room for applying the doctrine of equivalents here. AGA could not distinguish the claimed device over the prior art by specifying that the strands were fixated at both ends and then come back and contend that a product where the strands were only fixated at one end infringed.

(Interestingly, however, the Appeal Court interpreted another term in the very same – essential – claim element beyond its literal meaning. According to the Court, the claim term “clamps” included welds to keep the strands together. The Court does not seem to have regarded this as an application of the doctrine of equivalents, but rather as a “functional”, “contextual” or “purposive” interpretation.)

The Appeal Court’s ruling accordingly confirms the established practice in Sweden. The courts here have applied a form of prosecution history estoppel for a long time. As an example of this, the Swedish Supreme Court stated in a case from 2002 that “material from the prosecution history should be used to interpret unclarities in patent claims and description when it is a question about a limitation of the scope of protection” (my English translation).

Last, it might be interesting to note that the courts in Germany, the Netherlands and the UK have also decided on this case, with different ways of reasoning. The courts in the Netherlands and the UK found that there was no infringement. In Germany, the Appeal Court in Düsseldorf held that there was an infringement, but the Federal Court of Justice reversed the decision.



9 comments:

Anonymous said...

"No infringement" seems to be a very reasonable decision.

However, I have some doubts about “material from the prosecution history should be used to interpret unclarities in patent claims and description when it is a question about a limitation of the scope of protection”.

It undermines, in a way, legal certainty, because assumes that "the prosecution history" is available to everybody and should be consulted.

Well, in any case, it is good to know that, in Sweden, one more argument is available, if needed ...

Japser said...

"The courts in the Netherlands and the UK found that there was no infringement. In Germany, the Appeal Court in Düsseldorf held that there was an infringement, but the Federal Court of Justice reversed the decision."

Apparently, we already HAVE a unified patent court in Europe :-)

As to the anonymous poster @ 15h02:
The prosecution is available to everybody. In the on line EPO register. Except for those who do not have an internet connection...

Anonymous said...

RE: "The prosecution is available to everybody. In the on line EPO register. Except for those who do not have an internet connection..."

Really? What if the prosecution of a patent application was in French or German? Do you seriously think that this prosecution history on the EPO website is available in Sweden?

Anonymous said...

It undermines, in a way, legal certainty, because assumes that "the prosecution history" is available to everybody and should be consulted.

As Japser has already pointed out, the prosecution history for a European patent IS available to everybody (even without an Internet connection, BTW: putting the already public EPO register online is just an extra facility).

Mind you, not all national patent offices are so generous...

Anonymous said...

Well... It is not about physical availability of this or another information. Readers of this Blog are aware of the EPO online register....

It is about availability from a legal point of view. The question is whether it is reasonable to expect that in Sweden the German, for example, text of the prosecution history is consulted in order to interpret an (alleged) unclarity.

There are some language issues here. It is not for nothing under EPC there are requirements for translations of the claims and/or description.

Anonymous said...

What if the prosecution of a patent application was in French or German?

It would still be available...in French or German. Even in Sweden. A good patent litigator won't hesitate to chase Korean-language prior art, I don't see why a French- or German-language estoppel should be an obstacle.

MaxDrei said...

For me the main reason why courts should generally decline to decide on the basis of the Patent Office file wrapper is that everything possible must be done to keep the patent litigation process efficient. File Wrapper Estoppal, lets in to the process at least the following inefficiencies:

1. The Patent Office no longer cares whether the text intended for grant is clear on its face. It doesn't matter any more. Examiners will think: let the judges read my wrapper, if they need more clarity.

2. Anybody troubled by the granted patent has much more reading and opining to do.

3. If it goes to litigation, you can add a big lump of money to the cost, a big lump of time until the decision issues, a bunch of additional issues on which to appeal and a big slab of additional legal uncertainty about the eventual (delayed) outcome.

That Art 84 EPC is NOT a ground of invalidity has the effect that the EPO is under unrelenting heavy pressure not to issue till the text intended for grant is clear on its face (to readers of English as a foreign language). Let's continue, shall we, to pressure Patent Offices into issuing only patents that are self-sufficiently clear?

Anonymous said...

Max, I really can't follow your argument. If my client is being accused of infringement, and there's any doubt about the interpretation of some term in the claims, I'm most certainly going to search anything that the patentee may have said, in prosecution or otherwise, in Europe or elsewhere, that may be useful to restrict the scope of the claims and let my client off the hook. With or without estoppel, I'm going to study the prosecution history, and possibly not just in Europe.
As for Art. 84, I don't think that estoppel is going to weaken its application by the EPO. If anything, more awareness of what happens to patents after grant would make examiners apply it more appropriately. Currently, many tend to apply an overly formalistic approach and/or to confuse the requirements of clarity and disclosure. If they were more aware that the whole purpose of Art. 84 is to clearly define the scope of protection, it could only help.

MaxDrei said...

Anon, yes of course one reads the wrapper, at the EPO and elsewhere, for material with which to dispute validity, regardless which is the jurisdiction in which the assault on validity is being prosecuted. But that's not strict "estoppal" as I understand it. I would regret it, if patent litigation in Europe became as formalistic as it is in the USA.

EPO Examiners get a reasonable amount of experience, even now, of clarity issues post-grant, in their Opposition Division work, especially judging whether an amendment offends Art 123(3) EPC.

But I do agree with you, that EPO Examiners need to be trained better, to appreciate that Art 84 and Art 69 EPC are two sides of the same coin. As you say, why else did they put Art 84 in the EPC, and what exactly does it add to Art 83?

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