Supreme Court Mandates More Patent Claim Clarity

Background of the Case

Biosig sued Nautilus for infringement of U.S. Patent No. 5,337,753 (the '753 patent) which is directed to a heart rate monitoring device for use during exercise. The patent purports to address the problem of inaccurate heart rate measurement during exercise because signals generated by skeletal muscle activity (electromyogram or EMG signals) mask signals generated by the heart (electrocardiograph or ECG signals), impeding their accurate measurement. EMG signals generated by the left and right hands are in opposite phases, while ECG signals are in the same phase. The solution in the patent is to measure EMG and ECG at each hand and, relying on the opposite phase EMG signals, cancel out interference from EMG.

Claim 1 of the '753 patent, which includes the feature at issue, defines a heart-rate monitor contained within a hollow cylindrical bar that a user holds with both hands so that each hand contacts two electrodes, one “live” and one “common.” The contemplated placement of the bar, was, e.g., near the handle bar for an exercise bike or comparable location on a stair-climbing machine.

Claim 1 includes, among other elements: an “elongate member” (cylindrical bar); “electronic circuitry including a difference amplifier” (to cancel the opposing phase signals); and, on each half of the cylindrical bar, a live electrode and a common electrode “mounted ' in spaced relationship with each other.” At issue in the case was whether the term “in spaced relationship with each other” was indefinite.

The district court construed the term. It held “spaced relationship” meant that “there is a defined relationship between the live electrode and the common electrode on one side of the cylindrical bar and the same or a different defined relationship between the live electrode and the common electrode on the other side of the cylindrical bar.” At the time, however, the district court warned Biosig's counsel that it viewed that construction may leave the claim indefinite. Subsequently, the district court granted summary judgment of invalidity for indefinitenesss because the patent “did not tell [the court] or anyone what precisely the space should be” or even supply “any parameters” for determining the appropriate spacing.

The Federal Circuit reversed. Applying its test, because the term was amenable to construction, it viewed the issue of definiteness turned on whether the construction was “insoluably ambiguous.” Finding that “the claims provide inherent parameters sufficient for a skilled artisan to understand the bounds of 'spaced relationship,'” and that “a skilled artisan could apply a test and determine the 'spaced relationship' as pertaining to the function of substantially removing the EMG signals,” the Federal Circuit held that the term was not indefinite. In particular, the Federal Circuit reasoned that the distance between the live and common electrodes could not be further apart than the width of the user's hands, while the distance could also not be so small as to effectively combine the live and common electrodes into one. Nautilus appealed.

Supreme Court Establishes New Definiteness Test

Before the Supreme Court, the dispute centered around the competing positions of “how much imprecision '112, '2 tolerates” offered by the parties and amici . Nautilus argued that “a patent is invalid when a claim is 'ambiguous, such that readers could reasonably interpret the claim's scope differently.'” Biosig, joined by the Solicitor General, argued that '112, '2 “require[s] only that the patent provide reasonable notice of the scope of the claimed invention.”

Balancing Competing Goals

Analytically, the Court reasoned that the standard for '112, '2 definiteness must balance competing goals. “On the one hand, the definiteness requirement must take into account the inherent limitations of language ' [and] [s]ome modicum of uncertainty ' is the 'price of ensuring the appropriate incentives for innovation.'” “At the same time, a patent must be precise enough to afford clear notice of what is claimed, thereby 'appris[ing] the public of what is still open to them '. Otherwise there would be '[a] zone of uncertainty which enterprise and experimentation may enter only at the risk of infringement claims.”

Rejection of the Federal Circuit Test In Favor Of 'Reasonable Certainty'

“Cognizant of the competing concerns,” the Court held the Federal Circuit's test did not balance them correctly and stated its own standard. Specifically, the Court held that '112, '2, “requir[es] that a patent's claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.” In doing so, it rejected the Federal Circuit's “amenable to construction” and “insolubly ambiguous” standards as “breed[ing] lower court confusion” and “lack[ing] the precision '112, '2 demands.” Id. at 11-12.

Ultimately, the Court vacated the Federal Circuit's opinion and remanded for the courts below to apply the new test it articulated.

Issues, Analysis and Implications

In addition to ultimate resolution of the case at bar, the Nautilus opinion raises a number of issues likely to develop in the lower courts. Perhaps at the top of the list is what the Supreme Court's new standard will mean in practice. In its decision, the Court rejected Nautilus' position that a claim is indefinite if it is “ambiguous, such that readers could reasonably interpret the claim's scope differently.” However, the Court also indicated that a defect in the Federal Circuit's jurisprudence was that it treated some ambiguous claims differently than others. These points give litigants on either side of the issue grounds to argue whether an admittedly ambiguous claim should be invalid as indefinite: One might argue that the rejection of Nautilus' position indicates that some ambiguity is tolerable, and one might also argue criticism of the Federal Circuit's acceptance of some ambiguous claims suggests they are not. In any event, litigants likely will look to prior Supreme Court decisions in crafting arguments to apply the Nautilus standard. The Court's opinion cites its prior opinions in Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45 (1923) (upholding as definite a patent for an improvement to a paper-making machine, which provided that a wire be placed at a “high” or “substantial elevation,” where “readers ' skilled in the art of paper making and versed in the use of the ' machine” would have “no difficulty ' in determining ' the substantial [elevation] needed” for the machine to operate as specified) and Carnegie Steel Co. v. Cambria Iron Co., 185 U.S. 403 (1902) (also stating that “any description which is sufficient to apprise [steel manufacturers] in the language of the art of the definite feature of the invention, and to serve as a warning to others of what the patent claims as a monopoly, is sufficiently definite to sustain the patent”). Those facing indefiniteness issues likely will want to review these and other decisions of the Court.

Another issue the case raises is what proof will be required to support a finding of indefiniteness, and when will district courts take up the issue. Under the Federal Circuit's prior standard, the issue was linked closely to claim construction (a matter of law): Could the term be construed and, if not, was the construction still insoluably ambiguous. The Supreme Court's Nautilus standard, which looks to whether the claim informs the “scope of the invention with reasonable certainty,” arguably shifts focus. In practice, it may be that when the claims are sought to be applied to the accused product and/or prior art, ambiguities about the scope of the invention come to the fore. What role, if any, evidence outside of the patent and prosecution history will be considered during application of the Nautilus standard remains to be seen. Furthermore, if the inquiry extends significantly beyond claim construction, whether the issue of indefiniteness will be taken up in connection with claim construction, as it often has been, may also change.

One of the Supreme Court's stated concerns in rejecting the Federal Circuit's standard is that it might lead to a “zone of uncertainty” about ambiguous patent claims. It remains to be seen the extent to which the Nautilus standard reduces or changes uncertainty about such claims. For good or ill, if a patent claim term could be construed, application of the Federal Circuit's prior test was relatively predictable. Some might view Nautilus' “reasonable certainty” as shifting uncertainty from what an ambiguous (but not indefinite) claim meant under the Federal Circuit standard to uncertainty about whether the scope of a claim is reasonably certain. The lower courts will surely be cognizant of that risk when implementing the Supreme Courts' mandate for increased patent claim clarity and the manner in which they go about achieving it will be a matter stakeholders will want to track as the law develops.

Finally, patent practitioners will want to monitor the portfolios they prosecute, Patent Office practice, as well as developments in the courts. For claims being prosecuted now and in the near future, practitioners may wish to consider critically evaluating the claims under the Nautilus standard and whether any amendments are prudent. One issue for patent practitioners to watch is how the Patent Office, in practice, applies the standard and what, if any, examination guidelines are provided for determining whether claims inform of their scope with reasonable certainty.

Ultimately, patent practitioners, the district courts, and the Patent Office, will respond to the Supreme Court's mandate for increased patent claim clarity.

While the law evolves, the important issue of claim definiteness will warrant close attention by those with a stake in the scope and validity of patents.

Darren Donnelly is a Partner in the Mountain View, CA, office of Fenwick & West LLP. His practice emphasizes data management, technical computing, telecommunications and Internet technologies. He can be reached at [email protected].

In Nautilus, Inc. v. Biosig Instruments, Inc., No. 13-369, 572 U.S. __ (2014), a unanimous Supreme Court held that the test for patent claim definiteness in 35 U.S.C. '112, '2 (2006) “require[s] that a patent's claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.” Vacating a Federal Circuit opinion applying that court's test, the Supreme Court concluded that such test “lack[ed] the precision '112, '2 demands,” and could “breed lower court confusion.”

'Definiteness' Requirement For Patent Claims

The relevant text of 35 U.S.C. 112, '2 requires patent claims “particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.” This provision had come to be known as the “definiteness” requirement for patent claims and those failing to meet the requirement are invalid as “indefinite.” 35 U.S.C. '282. The Federal Circuit had evolved a strict standard under which a claim was invalid as indefinite only if the claim was “not amenable to construction” or, if construed, remained “insolubly ambiguous.” Perhaps because the Federal Circuit's standard focused on construction of the claim term at issue, as a practical matter, district courts often substantively applied the definiteness standard in connection with claim construction proceedings, granting summary judgment of indefiniteness, if the claim failed to meet the standard during claim construction.

Background of the Case

Biosig sued Nautilus for infringement of U.S. Patent No. 5,337,753 (the '753 patent) which is directed to a heart rate monitoring device for use during exercise. The patent purports to address the problem of inaccurate heart rate measurement during exercise because signals generated by skeletal muscle activity (electromyogram or EMG signals) mask signals generated by the heart (electrocardiograph or ECG signals), impeding their accurate measurement. EMG signals generated by the left and right hands are in opposite phases, while ECG signals are in the same phase. The solution in the patent is to measure EMG and ECG at each hand and, relying on the opposite phase EMG signals, cancel out interference from EMG.

Claim 1 of the '753 patent, which includes the feature at issue, defines a heart-rate monitor contained within a hollow cylindrical bar that a user holds with both hands so that each hand contacts two electrodes, one “live” and one “common.” The contemplated placement of the bar, was, e.g., near the handle bar for an exercise bike or comparable location on a stair-climbing machine.

Claim 1 includes, among other elements: an “elongate member” (cylindrical bar); “electronic circuitry including a difference amplifier” (to cancel the opposing phase signals); and, on each half of the cylindrical bar, a live electrode and a common electrode “mounted ' in spaced relationship with each other.” At issue in the case was whether the term “in spaced relationship with each other” was indefinite.

The district court construed the term. It held “spaced relationship” meant that “there is a defined relationship between the live electrode and the common electrode on one side of the cylindrical bar and the same or a different defined relationship between the live electrode and the common electrode on the other side of the cylindrical bar.” At the time, however, the district court warned Biosig's counsel that it viewed that construction may leave the claim indefinite. Subsequently, the district court granted summary judgment of invalidity for indefinitenesss because the patent “did not tell [the court] or anyone what precisely the space should be” or even supply “any parameters” for determining the appropriate spacing.

The Federal Circuit reversed. Applying its test, because the term was amenable to construction, it viewed the issue of definiteness turned on whether the construction was “insoluably ambiguous.” Finding that “the claims provide inherent parameters sufficient for a skilled artisan to understand the bounds of 'spaced relationship,'” and that “a skilled artisan could apply a test and determine the 'spaced relationship' as pertaining to the function of substantially removing the EMG signals,” the Federal Circuit held that the term was not indefinite. In particular, the Federal Circuit reasoned that the distance between the live and common electrodes could not be further apart than the width of the user's hands, while the distance could also not be so small as to effectively combine the live and common electrodes into one. Nautilus appealed.

Supreme Court Establishes New Definiteness Test

Before the Supreme Court, the dispute centered around the competing positions of “how much imprecision '112, '2 tolerates” offered by the parties and amici . Nautilus argued that “a patent is invalid when a claim is 'ambiguous, such that readers could reasonably interpret the claim's scope differently.'” Biosig, joined by the Solicitor General, argued that '112, '2 “require[s] only that the patent provide reasonable notice of the scope of the claimed invention.”

Balancing Competing Goals

Analytically, the Court reasoned that the standard for '112, '2 definiteness must balance competing goals. “On the one hand, the definiteness requirement must take into account the inherent limitations of language ' [and] [s]ome modicum of uncertainty ' is the 'price of ensuring the appropriate incentives for innovation.'” “At the same time, a patent must be precise enough to afford clear notice of what is claimed, thereby 'appris[ing] the public of what is still open to them '. Otherwise there would be '[a] zone of uncertainty which enterprise and experimentation may enter only at the risk of infringement claims.”

Rejection of the Federal Circuit Test In Favor Of 'Reasonable Certainty'

“Cognizant of the competing concerns,” the Court held the Federal Circuit's test did not balance them correctly and stated its own standard. Specifically, the Court held that '112, '2, “requir[es] that a patent's claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.” In doing so, it rejected the Federal Circuit's “amenable to construction” and “insolubly ambiguous” standards as “breed[ing] lower court confusion” and “lack[ing] the precision '112, '2 demands.” Id. at 11-12.

Ultimately, the Court vacated the Federal Circuit's opinion and remanded for the courts below to apply the new test it articulated.

Issues, Analysis and Implications

In addition to ultimate resolution of the case at bar, the Nautilus opinion raises a number of issues likely to develop in the lower courts. Perhaps at the top of the list is what the Supreme Court's new standard will mean in practice. In its decision, the Court rejected Nautilus' position that a claim is indefinite if it is “ambiguous, such that readers could reasonably interpret the claim's scope differently.” However, the Court also indicated that a defect in the Federal Circuit's jurisprudence was that it treated some ambiguous claims differently than others. These points give litigants on either side of the issue grounds to argue whether an admittedly ambiguous claim should be invalid as indefinite: One might argue that the rejection of Nautilus' position indicates that some ambiguity is tolerable, and one might also argue criticism of the Federal Circuit's acceptance of some ambiguous claims suggests they are not. In any event, litigants likely will look to prior Supreme Court decisions in crafting arguments to apply the Nautilus standard. The Court's opinion cites its prior opinions in Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45 (1923) (upholding as definite a patent for an improvement to a paper-making machine, which provided that a wire be placed at a “high” or “substantial elevation,” where “readers ' skilled in the art of paper making and versed in the use of the ' machine” would have “no difficulty ' in determining ' the substantial [elevation] needed” for the machine to operate as specified) and Carnegie Steel Co. v. Cambria Iron Co., 185 U.S. 403 (1902) (also stating that “any description which is sufficient to apprise [steel manufacturers] in the language of the art of the definite feature of the invention, and to serve as a warning to others of what the patent claims as a monopoly, is sufficiently definite to sustain the patent”). Those facing indefiniteness issues likely will want to review these and other decisions of the Court.

Another issue the case raises is what proof will be required to support a finding of indefiniteness, and when will district courts take up the issue. Under the Federal Circuit's prior standard, the issue was linked closely to claim construction (a matter of law): Could the term be construed and, if not, was the construction still insoluably ambiguous. The Supreme Court's Nautilus standard, which looks to whether the claim informs the “scope of the invention with reasonable certainty,” arguably shifts focus. In practice, it may be that when the claims are sought to be applied to the accused product and/or prior art, ambiguities about the scope of the invention come to the fore. What role, if any, evidence outside of the patent and prosecution history will be considered during application of the Nautilus standard remains to be seen. Furthermore, if the inquiry extends significantly beyond claim construction, whether the issue of indefiniteness will be taken up in connection with claim construction, as it often has been, may also change.

One of the Supreme Court's stated concerns in rejecting the Federal Circuit's standard is that it might lead to a “zone of uncertainty” about ambiguous patent claims. It remains to be seen the extent to which the Nautilus standard reduces or changes uncertainty about such claims. For good or ill, if a patent claim term could be construed, application of the Federal Circuit's prior test was relatively predictable. Some might view Nautilus' “reasonable certainty” as shifting uncertainty from what an ambiguous (but not indefinite) claim meant under the Federal Circuit standard to uncertainty about whether the scope of a claim is reasonably certain. The lower courts will surely be cognizant of that risk when implementing the Supreme Courts' mandate for increased patent claim clarity and the manner in which they go about achieving it will be a matter stakeholders will want to track as the law develops.

Finally, patent practitioners will want to monitor the portfolios they prosecute, Patent Office practice, as well as developments in the courts. For claims being prosecuted now and in the near future, practitioners may wish to consider critically evaluating the claims under the Nautilus standard and whether any amendments are prudent. One issue for patent practitioners to watch is how the Patent Office, in practice, applies the standard and what, if any, examination guidelines are provided for determining whether claims inform of their scope with reasonable certainty.

Ultimately, patent practitioners, the district courts, and the Patent Office, will respond to the Supreme Court's mandate for increased patent claim clarity.

While the law evolves, the important issue of claim definiteness will warrant close attention by those with a stake in the scope and validity of patents.

Darren Donnelly is a Partner in the Mountain View, CA, office of Fenwick & West LLP. His practice emphasizes data management, technical computing, telecommunications and Internet technologies. He can be reached at [email protected].