What This Means to You
- To avoid indefiniteness, be careful when reciting parameters in claims—consider specifying a method of determining that parameter in the specification.
- Special attention should be given when claiming a parameter that can be calculated/determined using more than one method.
- This case provides an example of claims that have survived an indefiniteness attack post-Nautilus, and may be used to rebut indefiniteness arguments.
The Supreme Court set a new indefiniteness standard in Nautilus, stating that a “patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”
In several Federal Circuit cases after Nautilus, claims were invalidated as being indefinite because they recited parameters that had more than one calculation method (e.g. “molecular weight,” which has more than one commonly used calculation method).
The patents at issue in this case are directed to ultrasonic surgical shears that are used to cut and seal tissue and blood vessels. Covidien, the accused infringer, asserted that Ethicon’s patents were invalid as indefinite.
The claims at issue recite a required numerical range for “clamping pressure” of the shears. The accused infringer argued that, because there were four ways to calculate “clamping pressure,” the claims should be found indefinite.
Even though there were four calculation methods to determine the recited “clamping pressure” range, the Federal Circuit found that the claims were not indefinite. It reasoned that the court should focus on what a skilled artisan would have understood based on the specification, not on what the patentee actually did in-house during testing. Further, the Federal Circuit reasoned that, on average, the four methods ended up giving results that are “quite similar,” so the existence of the four different methods was not a concern.
This case provides an example of claims that have survived an indefiniteness attack. However, to be safe, caution should be used when reciting parameters in claims, especially when the parameter can be determined using more than one method. To avoid indefiniteness, consider specifying a method of determining that parameter in the specification.