The pressure's off: KCI v Smith & Nephew in the Court of Appeal

Following a remarkably swift turn-around, the Court of Appeal last Thursday handed down its judgment in KCI Licensing Inc and others v Smith and Nephew plc and others [2010] EWCA Civ 1260.

Two patents were in issue: European Patent No. 0 777 504 (‘504) concerning “wound drainage equipment” and No. 0 853 950 (‘950), a divisional of ‘504, concerning “wound drainage canisters” designed to fit in said equipment. Both relate to apparatus for the treatment of wounds by negative pressure wound therapy. The apparatus claimed in the patents essentially consists of a pump in connection with a disposable canister and tubing system that operates to collect exudate and prevent contamination of the pump unit (KCI's InfoVAC system - above right). Both patents claimed the use of reticulated foam as a dressing, and ‘904 additionally claimed the use of a gelling agent in the canister so as to prevent spills. KCI had brought an action against Smith & Nephew (S&N) alleging infringement of both patents; S&N counterclaimed for revocation.

The judgment of the Court of Appeal comes less than 5 months after Mr Justice Arnold ([2010] EWHC 1487 (Pat) – noted by the IPKat here) found: that the patents were entitled to their priority date (22nd August 1994); that S&N’s attacks on the validity of the relevant claims failed; that S&N’s GO and EZ pumps and canisters fell within the scope of the relevant parts of the patents’ claims; and that there was infringement pursuant to s60(2) PA 1977.

S&N's RENAYSIS GO system (left)

Before the Court of Appeal, the issues had been reduced to questions of whether the GO system infringed claim 5 of the ‘504 patent; whether sales of the GO canisters had been intended to put the inventions of claims 7 and 8 of ‘950 into effect within the meaning of s60(2); and whether the patent was invalid for obviousness.

Infringement of the ‘504 patent
Turning first to construction: the Court focused on the elements of claim 1 of the ‘504 patent (upon which claim 5 was dependent). A key element of this required interpretation of “means for detecting when the canister is substantially filled with liquid and generating a signal which causes the pump to be deactivated”. According to the Court, this required ‘means’ for three things: (1) detecting… (2) generating a signal, and (3) which causes the pump to be deactivated.

S&N’s GO device did not contain a separate detector and deactivation element, however, in the words of the judge below (see [186] and [187] of the first instance judgment): “When the canister is full, the system detects that the vacuum level in the headspace is increasing and slows the pump motor down to below a predetermined (but unspecified) threshold level. After this, the pump just ticks over and no more liquid is pumped into the canister.” The Judge had concluded that this fell within the meaning of the term “deactivated” in the claim as it was considered unnecessary for the pump to be switched off so long as it was “rendered sufficiently less active that no more fluid is pumped into the canister.”

The Court of Appeal disagreed. It noted (at [33]) that the specific embodiment of the patent showed “an actual detector. It detects when the fluid has reached a certain level and sends a signal which switches the pump motor off. Nothing like that happens with the GO device. The way GO works is quite different.” Accordingly, the GO device was found not to possess a “relevant “full” detector at all, that is to say no detector which responds to a full condition so as to deactivate the pump”. The Court’s construction of the term deactivated was said to be further reinforced when considering the manner in which the term was used in the wider specification. It noted (at [36]) that:

“The judge considered that the purpose of the element was to “stop the canister being over-filled with fluid” at [186]. And so it is. So the element should, using purposive construction, be construed as limited to a means which does just that. There is nothing in the GO device which stops over-filling. The canister fills to the brim. It fills no more because there is no room, not because the pump is deactivated.”

The GO device was therefore considered not to be within this element of the claim.

The claim also required “said canister and said housing having a guide for aligning the container in a recess in the housing such that the suction port is connected to the pump.” The judge had held that the claim did not require the canister to be situated wholly or partially within a recess in the housing, but could be satisfied if the housing had something which could be called “a recess” and the canister fitted over that. What really mattered was a guide for aligning the canister so that the suction port is connected to the pump, that being the real purpose of the integer.

Again the Court of Appeal disagreed. It noted (at [41]) that:

“The claim requires a “recess in the housing” and that the “container” be aligned “in” (our underlining) that recess. The language of the claim simply does not extend to a case where the container is fitted over the housing…. Although [in the case of the GO apparatus] the purpose of the claim (connection) is achieved, it is achieved in a different way from that called for by the claim.”

Accordingly, S&N’s GO system was held not to infringe claim 5 of the ‘504 patent.

Infringement of the ‘950 patent pursuant to s60(2)
Moving on to the s60(2) points, the Court reiterated its recent clarification of the requirements made under that section in Grimme v Scott [2010] EWCA Civ 1110 (noted by the IPKat here). Following this guidance, it was clear that the judge had misdirected himself when concluding that the ultimate users must have decided to use the means to put the invention into effect at the time they first take possession of the means. The Court explained that “The relevant intention may be formed at a later time. But the supplier must know (or it must be obvious to him in all the circumstances) that some ultimate users will indeed form that intention.”

Accordingly, S&N were found to have infringed because it was “probable that from time to time some medical personnel using the GO system have clamped the end of the inlet tube when changing the canister. Further, it would have been obvious to a reasonable person supplying GO canisters that that this would be likely to occur.”

Obviousness
Completing its tour of the issues, the Court finally turned its attention to the question of obviousness. Here it considered that the judge had proper material upon which to base his finding of non-obviousness in relation to the use of reticulated foam. The “very open-celled structure” of the foam would have made concerns over keeping the wound moist and avoiding tissue ingress particularly acute, such that the skilled team (including a clinician and a design engineer) would have rejected its use. In contrast, the judge’s (“somewhat reluctant…”) conclusion that the addition of a gel-forming substance to the drainage canister before use was not an obvious step to take was overturned. The judge had fallen into error on this issue.

Other uses for negative pressure here