The patent system is intended to incentivize invention and the spread of knowledge. As part of dispatching this task, patent laws require that patents be described clearly—the statutory term is "definiteness"—to ensure that later inventors can read those patents and build upon them. How strongly the law will adhere to the demand for definiteness and how strongly the patent system will protect those later inventors, are the central issues in the case Nautilus v. Biosig Instruments, heard before the Supreme Court on April 28, 2014.
A patent, seen simply, is a legal instrument that encircles a portion of the space of human activities, placing a fence defining what infringes the patent. Throughout history, one point has been made central: that fence, called a "patent claim," must be clearly drawn to serve a public notice function informing future inventors of what is within the boundaries and what is not.
Historical developments in patent law dating back a hundred years lend strong support to the rigorous demand for public notice in patent claims. In its original inception, patent law used a "central claiming" [PDF] mechanism, where the inventor simply described the invention and the courts decided how widely the fence of infringement was to be drawn. However, toward the late nineteenth century, the US moved toward what is known as a "peripheral claiming" [PDF] system, in which the patent applicant, at the time of applying for the patent, specified the boundaries of that fence, in the form of a patent claim.
Permitting patent applicants to name the size of their own patent monopoly was a significant power, and with great power came great responsibility to clearly delineate that size. As the Supreme Court said in the 1876 case Merrill v. Yeomans:
The public should not be deprived of rights supposed to belong to it without being clearly told what it is that limits these rights. The genius of the inventor, constantly making improvements in existing patents—a process which gives to the patent system its greatest value—should not be restrained by vague and indefinite descriptions of claims in existing patents from the salutary and necessary right of improving on that which has already been invented.
Thus, Merrill recognized three important points: first, the "greatest value" in the patent system is that it permits inventors to build off of the work of other inventors; second, this value belongs to the public; and third, to account for this public interest, patents must at a minimum use clear, definite language to define what infringes and what does not.
This public interest in patent clarity has been reiterated by numerous cases. White v. Dunbar held that a patent claim should not be "a nose of wax, which may be turned and twisted in any direction." United Carbon v. Binney reiterated that claim definiteness "seeks to guard against unreasonable advantages to the patentee and disadvantages to others arising from uncertainty as to their rights." The list of precedents goes on and on.
It is in this backdrop of law that the Supreme Court considered Nautilus.
In Nautilus, the patent at issue involved the metal electrodes for measuring heart rates, as commonly found on handlebars of exercise machines. Generally each handlebar has two electrodes that, when grasped by a person's hand, complete an electrical circuit used to measure the person's heart rate.
The patent claims specified that an exercise machine would infringe the patent if the two electrodes to be held by one hand were in a "spaced relationship" with each other. Based on rules of construing patent claims, there were at least two ways to understand that term "spaced relationship": either the electrodes had to be spaced in such a way that they performed particularly well at measuring heart rates or they could be spaced at any distance within the grasp of a human hand. The text of the patent offered very little guidance as to which of these two constructions was correct and so the accused infringer, Nautilus, argued that the claim was impermissibly indefinite.
The US Court of Appeals for the Federal Circuit disagreed. According to that appellate court, a claim is only indefinite if it is "insolubly ambiguous" or "not amenable to construction." The court then applied twenty-one paragraphs of analysis spanning ten pages of its opinion, citing to a great deal of expert testimony from the district court, to determine that construction number one was correct. Accordingly, and in spite of a concurrence finding construction number two to be more appropriate, a majority of the court concluded that the claim was not "insolubly ambiguous" and accordingly was sufficiently definite.
It may seem strange to call something "definite" when it takes expert testimony and twenty-one paragraphs of analysis to decide its meaning, but the Federal Circuit laid out several justifications for its stringent "insolubly ambiguous" test for definiteness. According to the court, a patent claim may be acceptably definite even when the task of discerning the claim's meaning "may be formidable and the conclusion may be one over which reasonable persons will disagree." Such a rule is necessary, according to the court, to "accord respect to the statutory presumption of validity" and to "protect the inventive contribution of patentees, even when the drafting is less than ideal."
But does the Federal Circuit's rationale of protecting patentees comport with the Supreme Court's understanding of the purpose of definiteness of patent claims? Protecting patentees "even when the drafting is less than ideal" would seem to be in direct conflict with the Supreme Court's mandate that the patentee is responsible for ensuring that the public is "clearly told what it is that limits these rights." And it would seem that a "formidable" claim would cause later inventors to be "restrained ... from the salutary and necessary right of improving on that which has already been invented."
This conflict between the "insolubly ambiguous" test and the interest of protecting later inventors was a concern at the oral argument in Nautilus. Justice Sotomayor observed this discrepancy immediately. "There is a big difference between 'can I read this and give it a construction,' and whether or not a construction is definite enough so someone skilled in the art could understand it," she said [PDF], implicitly recognizing that the Patent Act demands the latter and not the former. She later reiterated, in questioning counsel for the patent owner Biosig, that "it seems logical, that you're going to stifle inventiveness if people can't, once the patent is issued, know how to get around it." Indeed, no Justice and no attorney in the Court, was willing to support the "insolubly ambiguous" test—Justice Scalia called it "extravagant language."
It may be tempting to think of Nautilus, as with many other patent cases, as a private case between two companies over an obscure area of law. But, as I argued in my amicus brief in the case, the problems of this dispute extend well beyond the individual parties, to an important concern about a very public interest in ensuring that all inventors continue to be free to exercise the "salutary and necessary right" of learning about and improving upon existing knowledge. "The future of patents will shape the future of innovation," I have written before, and Nautilus will play an important role in shaping both.
Charles Duan is the Director of the Patent Reform Project at Public Knowledge, a nonprofit public interest organization that focuses on promoting the consumer interest in technology policy. Mr. Duan received his A.B. in Computer Science from Harvard College and his J.D. from Harvard Law School. He is a member of the D.C. Bar and is a registered patent attorney.
Suggested citation: Charles Duan, A Definite Problem of Patent Law: Nautilus v. Biosig Instruments, JURIST-Hotline, May 7, 2014, http://jurist.org/hotline/2014/May/charles-duan-patent-nautilus.php.
This article was prepared for publication by Jason Kellam, a section editor with JURIST's commentary service. Please direct any questions or comments to him at firstname.lastname@example.org