GE Healthcare Ltd v Perkinelmer Life Sciences (UK) Ltd & Anor

Patent claims are assessed by their full breadth. The inventive concept cannot be narrowed by selecting only embodiments showing particular technical advantages. Obviousness is determined by identifying the inventive concept, the skilled team’s common general knowledge, the differences from the prior art and whether those differences required invention. A technically obvious route remains obvious even if it is not commercially attractive or is one of several possible routes. The obvious-to-try approach requires caution and is ordinarily insufficient unless success is more or less self-evident. Applying those principles, using a CCD camera for scintillation proximity tests with a red-shifted phosphor was obvious. The patent was therefore invalid and revoked.

GE Healthcare, formerly Amersham, sued PerkinElmer for infringement of European Patent (UK) No 1,007,971, concerning scintillation proximity tests using phosphors emitting at 480–900 nm and a charge coupled device. PerkinElmer counterclaimed for revocation on novelty and inventive-step grounds, and alternatively sought entitlement to the patent and alleged breach of confidence.

The court considered the skilled addressee, common general knowledge, two novelty documents and six citations relied upon for obviousness. It also considered, notwithstanding the validity conclusion, whether PerkinElmer had established entitlement and breach of confidence. The central issues were whether the claims were anticipated or obvious, and whether the patent had been derived from confidential disclosures.

1. Novelty. The applicable requirements were prior disclosure and enablement. The prior art had to disclose subject matter which, if performed, would necessarily infringe the patent. Hooper disclosed an intensified CCD camera for SPT imaging but used phosphors outside the claimed wavelength range. Rushbrooke concerned principally autoradiography and did not give a clear and unmistakable direction to perform an SPT using a phosphor within the claimed range. Neither document anticipated the claims.
2. Inventive concept and approach. The inventive concept was the use in an SPT of a phosphor with an emission maximum within the claimed range together with a CCD detector. The broad claims covered all SPT formats, CCD cameras and phosphors within the range, without performance limitations. The inventive step therefore had to apply across the claims and could not be defined by reference to narrower successful embodiments.
3. The court applied the structured approach in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59. The primary evidence was that of the experts, and the court guarded against hindsight. The technical possibility of using a CCD with an SPT was not itself common general knowledge, but it was obvious to develop the detector and scintillant together. Cooled CCDs and intensified CCDs were both obvious alternatives. Matching the phosphor’s emission to the detector’s spectral response was technically obvious, and red-shifting the phosphor was an obvious way to reduce quenching by yellow or brown samples.
4. The invention did not wholly solve either low sensitivity or colour quenching. Red-shifting ameliorated colour quenching for some samples but did not eliminate the need for correction. That limitation did not prevent the route from being technically obvious. The claims were obvious over common general knowledge and, for the reasons separately given, over Hooper, Rushbrooke, Bosworth, Beverloo, Tafti and Cook.
5. Entitlement. The entitlement issue did not arise because the patent was invalid. Nevertheless, the court held that the relevant enquiry identifies the inventive concept, identifies its deviser or devisers, and then asks whether the claimant has a legal basis for title to the patent, such as contract or breach of confidence. A contribution to claim wording is insufficient unless it contributes to the inventive concept. The evidence showed that Dr Jessop independently arrived at the inventive concept in July 1995, although Packard and CIL later disclosed the concept to Amersham in June 1996. PerkinElmer therefore failed on entitlement.
6. Subject to validity, PerkinElmer had infringed each claim by supplying Image FlashPlates and the ViewLux CCD camera for use together. The patent was invalid and was revoked.