Barry Liversidge v Owen Mumford Limited and Anor, HHJ Birss QC sitting in the Patents County Court, London, UK, 26 July 2012, Case No.  EWPCC 33
The action was for infringement of European Patent (UK) 2 067 496, a divisional patent entitled “Medical Injector" owned by the Claimant, Mr Liversidge (the "Patent"). The Patent cut out almost all of the application as filed apart from one part of the disclosure relating to one of the embodiments which had “protuberances”. New text was also introduced by way of characterisation of the prior art describing the “sequencing problem” of ensuring two steps in delivery by injector devices: that the needle should be inserted to the correct depth within the patient’s body, followed by the medicament being expelled from the device into the patient’s body. The claimant alleged that the Patent is infringed by the Humira Pen, which is an automatic medical injection device manufactured and supplied by the defendants. The defendants denied infringement and counterclaimed for invalidity, including by added matter in respect of the changes made in the divisional application.
It was held that a key aspect of the patented invention was the use of protuberances on the plunger. These were to engage with the rear of the syringe so that the plunger pushes the syringe (and needle) forward. Once the needle has reached the correct depth, extra force is needed to squeeze the protuberances inside the barrel of the syringe so that now the plunger pushes the piston forwards inside the syringe and expels the drug into the body. The skilled reader would understand that this is how the device in the Patent is supposed to work. If a small amount of static friction is involved then that would not be regarded as important but the patented device is not supposed to work by static friction.
The way the Defendants' pen works, on the other hand, is by relying on static friction between the piston and the syringe. To move the syringe the plunger has to push the piston. Claim construction might be difficult in a case in which the action of the protuberances on the rear part of the syringe made a non-negligible contribution to the motion of the syringe but in the Defendants' pen, at most, the contribution of the protuberances engaging with the syringe is trivial.
The court also held that the Patent was invalid for added matter. The focus of the application as filed was on a safety arrangement for a syringe. The Patent, however, amounts to a clear, focussed teaching about protuberances as a general solution to sequencing steps in an injection. It is nothing to do with a needle stick safety arrangement. A skilled person reading the patent and putting it into practice would build a device with protuberances. Whether they went on to seek to include the safety arrangement which is also described would be a matter of choice. A qualification in the Patent that the plunger may have an X-shaped cross-section, and the disclosure that the protuberances can be partway along the plunger were also added matter.
Claims 1 and 3 were also anticipated and the invention was obvious, but not insufficient.
Read the entire decision (in English) here.
Head note: Paul England