Broadest Reasonable Interpretation of a Claim in the US Should be in Light of the Specification
This was a case tried at the US Federal Circuit between St Jude Medical LLC and Snyders Heart Valve LLC and related to US patent no. US 6,540,782.
Snyders' Heart Valve Patent
Snyders' patent was to an artificial heart valve that crucially can be inserted into place without removing the native damaged valve. This is explicitly stated in the description with further details of how the artificial valve includes a bendable frame that fits in natural valve position and hooks into place. However, unfortunately for Snyders, this detail was not explicitly mentioned in claim 1. Claim 1 read:
An artificial valve for repairing a damaged heart valve having a plurality of cusps separating an upstream region from a downstream region, said artificial valve comprising:
a flexibly resilient frame sized and shaped for insertion in a position between the upstream region and the downstream region, the frame having a plurality of peripheral anchors for anchoring the frame in the position between the upstream and the downstream region and a central portion located between the plurality of peripheral anchors.
a band attached to the frame...
The Prior Art
The key prior art document here was Bessler and related to an artificial valve for fitting after removal of the native damaged valve.
First Instance Decision
At the first instance the board focused on the phrase " … a flexibly resilient frame sized and shaped for insertion in a position between the upstream region and the downstream region…" and construed "sized and shaped" to cover cases where the native valve is removed and therefore determined that Bessler anticipated claim 1 of the patent. The reasoning provided was "[t]he claim language does not require the frame be sized and shaped for insertion into a damaged heart valve," but "only that the frame is sized and shaped for insertion in a position between the upstream region and the downstream region."
Federal Circuit Decision
The Federal Circuit stated that the phrase "sized and shaped" suggests a focus on fitting to the surrounding material. The Federal Circuit further noted that claim 1 mentioned "repairing damaged heart valve" but did not mention removal of the native valve. It was also noted that claim 1 referred to "a plurality of cusps" and this reference would be superfluous if claim 1 involved removing the native damaged heart valve.
The specification stressed that damaged heart valves were not removed and even referenced Bessler to make the observation that contrastingly to Snyders' patent, Bessler required removal of the native valve.
Importantly, the Federal Circuit was considering the "broadest reasonable interpretation" of the claim "in light of the specification". Whilst the claims did not explicitly state that the native heart valve remained, this was clear from the full specification and therefore the broadest reasonable interpretation of the claim was limited to situations where the native valve remained.
It was therefore determined that Bessler did not anticipate claim 1 of the patent.
For more detail, please see the links below to the patent and the full decision.
US Patent No. US 6,540,782: https://patents.google.com/patent/US6540782B1/en
The Federal Circuit Decision: http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/19-2108.OPINION.10-15-2020_1669672.pdf