The United States District Court for the Southern District of Texas held AllVoice Computing PLC's patent invalid on summary judgment due to indefiniteness and because the patent specification did not disclose the best mode of practicing a certain claim. The district court did not decide whether Nuance Communications, Inc.'s software infringed the patent-in-suit. On appeal, the Federal Circuit held that the district court erred in applying both indefiniteness and best mode. The case was reversed and remanded. 
| AllVoice Computing PLC’s U.S. Patent No. 5,799,273 ("the '273 patent") covers an interface between a speech recognition engine and various end-user application programs on a personal computer. When a user speaks into a computer's audio input device, the computer's speech recognition engine receives the message. Then, the claimed invention creates an interface that facilitates translation of the apprehended message directly into application programs, typically word processors. At suit was whether claims 60, 61 and 67 sufficiently claimed the subject matter which the applicant regards as his invention under 35 U.S.C. 112. Dependent claim 61 of the '273 patent claims the maintenance its own data structures to keep track of the relative positions of words in the application programs. Claim 60 allows users to edit documents produced through speech recognition without losing the ability to play back the recorded speech in a coherent manner. Independent claim 67 includes the editing function and independence from any computer-related application. In applying the test for definiteness of whether one skilled in the art would understand the bounds of the claims when read in light of the specification, the Federal Circuit held that means-plus-function software claims (claims 60, 61 and 67) were not indefinite where there was "sufficient algorithmic structure to give meaning to the claim terms from the vantage point of an ordinarily skilled artisan." Further, the court opinioned that in software cases, algorithms in the specification need only disclose adequate defining structure to render the bounds of the claim understandable to one of ordinary skill in the art. In reversing the lower court, the Federal Circuit asserted that AllVoice expert’s statement to the court set forth several ways that the algorithm represented in Figure 8A could be implemented by one skilled in the art using well-known features of the Windows operating system. Accordingly, the appellate court found the record to contain sufficient algorithmic structure to give meaning to the claim terms for one skilled in the art. Further, the district court’s finding of invalidity based upon claim 73 (which includes instructions for performing a variety of processor functions) for failing to satisfy the best mode requirement was in error. The Federal Circuit opined that the alleged undisclosed best mode was not actually a best mode of practicing the claimed invention, but rather the best mode subject matter fell outside the scope of claim 73. Accordingly, the alleged best mode was not a way of practicing the claimed invention at all. Accordingly, the Federal Circuit reversed both the district court’s determination that claims 60, 61 and 67 were indefinite and its grant of summary judgment of invalidity for failure to satisfy the best mode requirement with respect to claim 73. |