Advanced Bionics AG & Anor. v Med-El Elektromedizinische Gerate GMBH

A patent claim must be construed purposively in the context of the specification. A claim to an attachment magnet may encompass a plurality of magnets having a net magnetic dipole. In this patent, the required rotatability and parallel magnetic dipole were confined to rotation and magnetisation substantially in the plane of the implant coil housing.

For indirect infringement under section 60(2) of the Patents Act 1977, a supplied component may relate to an essential element even if it does not embody the inventive concept. The supplier nevertheless incurs no liability if the recipient's use is, as a matter of fact and degree, repair rather than making the patented product.

A claimed MRI-compatible cochlear implant was obvious where the prior art taught rotatable magnets and the skilled team would plainly use the known thin disk-shaped implant magnet, change its magnetisation across the rotational axis, and make the corresponding external-magnet choice.

The claimants sought revocation of European Patent (UK) 3,138,605 and a declaration of non-infringement concerning their HiRes Ultra 3D cochlear implant. The defendant, proprietor of the patent for an MRI-safe disk magnet for implants, counterclaimed for direct and indirect infringement.

The defendant applied unconditionally to amend the patent. The claims as amended concerned an implant coil housing with a rotatable internal attachment magnet whose magnetic dipole was parallel to the housing plane. The claimants alleged obviousness over Zimmerling and insufficiency. They denied direct infringement and contended that replacement headpieces and magnets did not give rise to indirect infringement under section 60(2) of the Patents Act 1977.

1. The amendment application was allowed, but the asserted claims were invalid for obviousness. The amendments added no matter, did not extend protection, and were supported and sufficiently clear. They did not cure invalidity.

2. On purposive construction, a “first attachment magnet” could comprise several magnets acting with a net dipole. The claim required the internal magnet's rotation to be confined to the plane of the implant coil housing and its magnetic dipole to be substantially parallel to that plane. Those features expressed the patent's compromise between MRI torque reduction and a thin implant profile.

3. If valid, the Ultra 3D directly infringed under section 60(1) of the Patents Act 1977. Its four internal magnets had a net magnetic dipole and their housing rotated in the relevant plane. It infringed at rest, in use with the external headpiece, and through a range of external magnetic-field strengths. The fact that it fell outside the claim in some stronger fields did not remove infringement.

4. The Ultra 3D did not infringe by equivalents. Although it achieved the same advantages in substantially the same way, strict compliance with the planar rotation and parallel-dipole requirement was essential to the patented invention.

5. The external headpiece and external magnets were means relating to an essential element, because they functionally interacted with the implant and contributed to implementing the technical teaching. Their supply did not, however, put the invention into effect. Replacing those relatively perishable external accessories was, on the facts and degree of the case, repair rather than making the patented system. There was therefore no indirect infringement under section 60(2).

6. Zimmerling taught the use of implant magnets rotatable to reduce MRI torque. The skilled team, concerned to retain the existing thin form factor and avoid bone drilling and regulatory difficulty, would regard the known disk-shaped implant magnet as an obvious option. It was then obvious from common general knowledge and Zimmerling to orient the dipole across the rotational axis, and to use a matching external diametric magnet. The remaining implementation was routine and expected to succeed. Claims 1, 10 and 14 as amended were therefore obvious.

not stated in the judgment.