Claim Construction: "A sodium phosphate" limited to one type of sodium phosphate.

Norian v. Stryker (Fed. Cir. 2005).

In the second claims construction appeal, the CAFC found that the term “a sodium phosphate” was limited to a single type of sodium phosphate.  In its decision, the Court found that if the patentee had intended to cover multiple types of sodium phosphate then it should have used “at least one” language.  This decision was supported by two factors: (1) the claim was amended to use the transition “consisting of” rather than the open ended “comprising” and (2) none of the listed examples in the specification used multiple types of sodium phosphate. 

Judgment of noninfringement affirmed.

Links:

• Read the Decision.
• Norian v. Stryker — First Decision (Fed. Cir. 2004).