CPLRG™ 0020 - Therasense, Inc. v. Becton, Dickinson & Co. - Jan. 25, 2010

Therasense, Inc. v. Becton, Dickinson & Co.  593 F.3d 1325, 2010 U.S. App. LEXIS 1623 (Fed. Cir. 2010) (LINN, Friedman & Dyk)


MAJOR ISSUES: Jury verdict of invalidity; “anticipation or obviousness”; erroneous “could-have-combined” instruction on anticipation; harmless error harmless; claims obvious based on prior art reference showing all claim examples in multiple examples; long-felt need for solution to a problem as evidence of unobviousness; claimed invention broadly covering devices that do–and do not–solve the problem

CROSS REFERENCES. On the standard for anticipation, see Chisum on Patents 3.02, 3.03; Chisum Patent Law Digest 1211. On jury verdicts on obviousness, see Chisum Patent Law Digest 1565. On long felt need as evidence of non-obviousness, see Chisum on Patents 5.05[1].

COMMENT: JURIES AND PATENT INVALIDITY. In times past, patent owners frequently tried to steer infringement suits to juries on the belief that juries were sympathetic to patent claimants and were less likely than trial judges to find patent claims invalid. This case shows that juries can and do find patent claims invalid when given persuasive evidence.

DESCRIPTION:  JURY: INVALID FOR “ANTICIPATION OR OBVIOUSNESS”; ERRONEOUS “COULD HAVE” INSTRUCTION ON ANTICIPATION: HARMLESS. Here, a jury found the asserted claims invalid for “anticipation or obviousness.” On appeal, the Federal Circuit held that the trial court erred in its instruction to the jury on anticipation by stating that the jury could find anticipation if an ordinarily skilled person “could have” arranged the elements in a prior art reference as in a claimed combination. However, it also held that the error was harmless because the jury could not have found that the claims were other than obvious in view of a prior art reference showing all the claims’ elements in multiple examples.   Also, the patent owner’s evidence of “long felt” need did not save the claims because they were too broader, covering devices that solved the problem but also ones that did not.

1. The patent concerned a sensor or measuring glucose in a patient’s blood. U.S. Pat. No. 5,628,890.   USPatNo5628890

      a. A disposable test strip has a sample (blood) transfer path, a “working electrode” with enzymes and a “counter electrode.” The enzymes cause glucose molecules in the sample (blood) to lose electrons, thereby creating a current which the working electrode detects and correlates with glucose concentration in the blood. The electrons flow back into the blood through the counter electrode.

     b. “SHORT-FILL” PROBLEM. A problem, known in the art as “short-fill,” arose when blood did not fully cover the working electrode. A short-fill resulted in fewer electrons flowing and an erroneously low glucose reading.

     c. PATENT: PLACE COUNTER ELECTRODE DOWNSTREAM OF WORKING ELECTRODE. The patent’s solution to the “short-fill” problems was to place the counter electrode on the downstream side of the working electrode. In that configuration, blood must necessarily contact the working electrode before contracting the counter electrode.

2. An accused infringer alleged that a patent’s asserted claims (11 and 12) were invalid based on two references (Nankai and Ikeda).

     a. A jury rendered a verdict that the asserted claims (11 and 12) were invalid “by reason of anticipation or obviousness.”

     b. The district court gave an erroneous instruction on anticipation, but the error was not prejudicial because the jury could not have failed to find the claims invalid for obviousness in view one reference (Nankai).

3. The patent owner conceded that a figure in the reference disclosed all the claims’ limitations except for two.

     a. A first limitation required a counter electrode downstream from a working electrode. The prior art figure showed three working electrodes some of which were not downstream. However, the claim only required that one working electrode be downstream.

     b. PRIOR ART REFERENCE; FEATURE MISSING FROM ONE FIGURE SHOWN IN ANOTHER FIGURE; EXPRESS TEACHING TO LOOK TO ALL FIGURES. A second limitation required an aperture on a cover. The prior art reference’s figure showed the aperture on a sensor side, but the reference showed a cover-placed aperture in another figure. It stated that the same figure numbers were used for all examples. That statement was an express teaching to look at other drawings in the reference.

4. REFERENCE’S FAILURE TO SOLVE LONG-FELT NEED; “SHORT FILL” PROBLEM. The patent owner argued that the prior art Nankai did not solve the long-felt need for a solution to the “short fill” problem because, in Nankai, a short fill could occur when only two of the three channels fill. However, the patent owner’s asserted claims are not limited to solving the short fill problem. 

     a BROAD CLAIMS COVERING DEVICES THAT DO (AND DO NOT) SOLVE PROBLEM. The claims cover devices that do–and do not–solve the “short fill” problem.

     b. OBJECTIVE EVIDENCE: NOT COMMENSURATE IN SCOPE WITH CLAIMS; GRASSELI (1983); KUBIN (2009). The patent owner’s “objective evidence of non-obviousness,” to wit, meeting a long-felt need, was not commensurate in scope with the claims. See In re Grasselli, 713 F.2d 731, 743 (Fed. Cir. 1983); In re Kubin, 561 F.3d 1351, 1356 (Fed. Cir. 2009).

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