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Fisher & Paykel v Flexicare

The Patents Court has handed down judgment upholding Fisher & Paykel (“F&P”)’s patent EP (UK) No. 2 025 359 entitled “Components for breathing circuits” (the “Patent”) as valid and infringed.

The judgment also provides useful guidance on the stepwise approach to instructing experts in patent actions.

The Patent covers the use of breathable materials to reduce or eliminate condensation in the expiratory limbs of breathing circuits, a type of ventilator system used to assist patients with breathing. The condensation is known as ‘rainout’ and can cause a number of problems in breathing circuits, not least the collection of water in the lowest points of the expiratory limbs, which can in some cases completely block the breathing tube.

The Patent sought to reduce the occurrence of rainout by allowing diffusion of the water vapour from the expiratory limb and thereby drying the humidified air as it flows through the breathing circuit.

F&P sued for infringement of the Patent. The Defendants (together, “Flexicare”) admitted that their product would infringe, and counterclaimed for revocation based on anticipation, obviousness, and lack of technical contribution/sufficiency which were run as squeezes against obviousness.

The Skilled addressee
The parties had agreed that the skilled addresses would be a team consisting of a design engineer and a materials scientist, though as the case progressed the materials scientist faded away.

On addressing the proper legal approach to the skilled addressee, the Judge confirmed that whilst the skilled addressee is deemed to read the prior art with care and interest, he or she would not have any expectation in advance that it will be useful, either generally or something specific.

The Judge also addressed the ability of the skilled address to implement the Patent and to treat it consistently with the expectation of success based on the prior art. Flexicare was worried that F&P might try to argue that the skilled addressee would have no reasonable expectation of successfully implementing the prior art. On that basis, Flexicare ran a squeeze that if the expectation of success from the prior art would be absent or too low, then the Patent was insufficient because it provided no more teaching than the prior art.

The Judge recognised that it is often possible to deduce attributes of the skilled addressed from the assumptions the patent in suit makes about their abilities, and found that Flexicare’s squeeze did its job insofar as F&P did not end up relying on evidence purely directed to the perceived problems with implementing the prior art.

As no technical primer had been ordered, the Judge requested that the parties produce a joint summary of CGK after the trial, which formed and the CGK section of the judgment was taken almost entirely from that document). The Judge noted that the lack of a primer, textbook or agreed CGK was not too much of a problem in this case, given its relative simplicity, but urged the parties to produce at least one of those in future cases.

Flexicare relied on one piece of prior art for novelty, a patent application by Siemens published in 1993 (Psaros). There was no dispute over the applicable legal principles to anticipation, that there has to be clear and unambiguous disclosure of all the features of the claim. Although Meade J found that Psaros was directly and unambiguously directed to the same problem as the Patent, it did not anticipate it. The dehumidifying device disclosed in Psaros was just part of the expiratory limb, whereas the claim requires a tube that is the expiratory limb.

Flexicare argued that the patent was obvious over three pieces of prior art: Psaros, Kertzman and Inoue.

Addressing the approach to obviousness, Meade J commented that this was not the type of case where it is useful to try to define the inventive concept separately from the claim. That approach, he said, can be helpful in some circumstances to focus on what really matters and to strip away “unnecessary verbiage”, though it can also lead to unproductive arguments about paraphrasing the claim.

Meade J also accepted F&P’s submission that hindsight must be avoided and is especially a danger with simple inventions, relying on Jacob LJ’s comments in Technip race SA’s Patent [2004] EWCA Civ 384.

Addressing each of the prior art citations in turn:

– Kertzman was dated from the 1980s, and concerned a breathable sampling tube reinforced with braided netting. The Judge held that Kertzman’s sampling tube differed from claim 1 because it was not a breathing tube, it was not an expiratory limb of a breathing circuit, and it was not adapted to be located between a patient and a ventilator. Despite the problem of rainout in breathing circuits having been CGK for some time, the fact that no one had actually thought to make the expiratory limb of a breathing circuit out of breathable material was a “powerful real-world point against obviousness”.

– Inoue was a Japanese patent application published in Jan 2000, disclosing a coaxial two-tube arrangement for use in anaesthesia. Flexicare argued that it would have been obvious to modify Inoue to arrive at the disclosure of the Patent. However, the Judge agreed with F&P that the goal of Inoue was the passive humidification of inhaled gases, and although that was necessarily accompanied by drying of the exhalation, Inoue did not mention it because it was not part of that goal. Any modification to improve drying would remove the humidification and so the goal of Inoue would be lost. The proximity to the priority date of the Patent was noted by the Judge, but did not affect his decision that the Patent was inventive over Inoue.

– The obviousness case over Psaros was also rejected by the Judge, on the basis that it would not occur to the skilled person, without knowledge of the Patent, to move to a device that was less compact and did not provide the protection required by the authors of Psaros.
Lack of technical contribution and insufficiency

Flexicare argued that the technical contribution of the Patent – the use of a ‘breathable’ material to dry the humidified gases that flow through the expiratory limb of a breathing circuit – was not inventive at all. However, the Judge found this argument circular and one that would not arise if the invention was in fact obvious. Compared to the prior art documents Kertzman, Psaros and Innoue, the products falling within the claims of the Patent solve a useful problem.

Flexicare’s case on insufficiency was run primarily as a squeeze against obviousness. That was successful insofar as it caused F&P to drop its case on expectation of success based on the prior art.

Expert witnesses
The Judge also made some helpful comments about the correct approach to instructing experts and preparing their reports. The Judge effectively approved Arnold J’s comments in MedImmune concerning the sequential approach to showing documents to experts in order to avoid hindsight, but noted that in the real world it is often not possible to achieve (especially if the expert already knows what the invention is).

In those circumstances, there can still be value in sequencing the documents correctly, not least to help to focus the expert’s mind on avoiding hindsight, and so there is no reason why an expert cannot give cogent evidence on obviousness. In order to do so, they must identify how they were already aware of the invention and think about how such knowledge might influence them – something Flexicare’s expert was unable to show. The Judge further notes that what matters are the expert’s reasons for his/her conclusions, rather than the conclusions themselves.

A copy of the judgment can be read here.

Headnote: Nick Fischer, Marks & Clerk