1. The case concerns whether the description of electrodes being ‘in spaced relationship with each other’ meets the definiteness requirement. The Federal Circuit had reversed the District Court’s findings of indefiniteness on this point.
2. The Federal Circuit felt that the test for indefiniteness should be based on whether a claim is ‘amenable to construction’ and as construed is not ‘insolubly ambiguous’. In this case the Federal Circuit said there were certain inherent parameters limiting the distance between the electrodes. The electrodes had to independently detect electrical signals at two points in the hand and could of course not be overlapping. This allowed the skilled person to understand the ‘metes and bounds’ of the spaced relationship.
3. The Supreme Court disagreed with the Federal Circuit’s test seeing it as tolerating some ambiguous claims and not others. The Supreme Court said the correct test was that a patent would be invalid for indefiniteness if the claims read in the light of the specification and prosecution history fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.
4. The Supreme Court noted that the parties agreed that definiteness should be evaluated from the perspective of the skilled person, in light of the specification and prosecution history and at the time the patent was filed.
5. The Supreme Court noted the need for a ‘delicate balance’, taking into account the inherent limitations of language and providing a ‘modicum of certainty’. It noted the need to avoid a zone of uncertainty and also the need for a meaningful definiteness check to stop applicants purposely drafting ambiguous claims.
6. The Supreme Court noted that the certainty which the law requires is not greater than is reasonable having regard to the subject matter, and this may turn on the evaluations of expert testimony.
7. The Federal Circuit’s test of ‘amenable to construction’ and ‘insolubly ambiguous’ was seen as the Court taking the approach of ascribing ‘some meaning’ to a patent claim leaving a ‘zone of uncertainty’. This was seen as more ‘amorphous’ than the statute allows.
8. The Supreme Court also said it does not ‘micromanage’ the Federal Circuit’s word choice in applying patent-law-doctrine, but it must ensure that the test is at least ‘probative of the essential inquiry’.
The decision can be found here.