Infringement Reversed over Improper Certificate of Correction

Central Admixure Pharmacy Services v. Advanced Cardiac Solutions (06-1307), April 3, 2007

Central Admixture Pharmacy Services (CAPS) sued Advanced Cardiac Solutions (ACS) for infringing a patent on a chemical solution used during heart surgery. When the litigation started, the patent was issued a certificate of correction from the USPTO, where all instances of the word "osmolarity" were replaced with the word "osmolality."

The two terms describe the concentration of a chemical solution contributing to that solution’s osmotic pressure. "Osmolarity" refers to the amount of solute (dissolved chemical) per liter of total solution. At the concentrations involved in the case, osmolarity is measured in milliosmoles per liter (mOsmol/L). In contrast, "osmolality" refers to the amount of solute per kilogram of solvent. It is measured in milliosmoles per kilogram (mOsmol/kg).

The district court interpreted the patent using the corrected "osmolality" term, finding that the certificate of correction was proper as a matter of law. The CAFC disagreed.

A patentee who has made "a mistake of a clerical or typographical nature, or of minor character" may apply to the PTO for a "certificate of correction, if the correction does not involve such changes in the patent as would constitute new matter or would require re-examination" . . . [i]f a certificate of correction broadens a claim, it is only valid if it corrects a "clerical or typographical" error that would have been clearly evident to one of skill in the art reading the intrinsic evidence . . . Since the result is to invalidate a certificate of correction which is part of a duly issued patent, the party seeking invalidation must meet "the clear and convincing standard of persuasion."

Invalidating a certificate of correction for impermissible broadening therefore requires proof of two elements: (1) the corrected claims are broader than the original claims; and (2) the presence of the clerical or typographical error, or how to correct that error, is not clearly evident to one of skill in the art . . . We find that these claims were broadened by the certificate of correction, since the claims as corrected cover less-concentrated solutions which would not be covered under the original claims.

* * *

Since the error corrected here was not clearly evident to one of skill in the art and the result of its correction was to broaden the claims, ACS should be granted summary judgment that the certificate of correction is not valid. The patent therefore continues to read as it did prior to the issuance of the certificate . . . Because the district court’s summary judgments of infringement and willfulness were both explicitly contingent on the validity of the certificate of correction, both of those judgments are vacated. On remand, the infringement inquiry should proceed under the original "osmolarity" versions of the claims.

AFFIRMED-IN-PART, REVERSED-IN-PART, VACATED and REMANDED

NOTE: Oddly enough, the certificate of correction was granted in 2001, but a reexamination certificate was issued in 2005 (see here) - none of the changes from the certificate of correction were implemented in the reexamination.