WASHINGTON, April 28 (Reuters) - The U.S. Supreme Court on Monday took up the thorny issue of how to assess if a patent is so vague that it should be thrown out, a case that could impact other fights dealing with patent infringement.
The high court heard arguments in the long-running case between Nautilus Inc and Biosig Instruments Inc, which centers on monitors built into fitness machines like treadmills that register electrical waves to estimate a user's heart rate.
Far beyond the gym, the case has implications for the ongoing dispute against "patent trolls," the derisive name given to companies that sue for infringement, or attempt to extract licensing fees, by using weak or overly broad patents.
If the Supreme Court uses Nautilus vs. Biosig to raise the bar on how much detail needs to be in a patent to avoid charges of being "indefinite," it will become easier to get other vague patents declared invalid as well.
Congress and the Federal Trade Commission, with backing from the White House, have various efforts under way to review or reform the patent system in response to a steep rise in infringement cases in recent years.
Neither Biosig nor Nautilus is accused of being a troll. Biosig first sued Nautilus in 2004, saying that Nautilus infringed a 1994 patent. A district court said its patent was invalid because of "indefiniteness" - essentially, it was too vague - and as a result, could not be infringed.
The U.S. Court of Appeals for the Federal Circuit, however, disagreed and said the patent was valid because it was not "insolubly ambiguous."
Some justices seized on that phrase. Justice Antonin Scalia said that the court had taken the case because of "really extravagant language."
Justice Sonia Sotomayor said the appeals court failed to take into consideration whether Biosig's patent could be understood by a person familiar with the technology in question.
When patents are written they tend to be worded in a way that includes very narrow descriptions of what the invention does, but also some very broad notions as a way of best being able to defend against potential infringement.
But a claim that is overly broad can get the patent thrown out as "indefinite," and many patents straddle that line.
The Supreme Court last took up the issue of how detailed patents need to be more than 70 years ago, according to Hal Wegner, a patent expert at Foley & Lardner LLP.
Beyond the broader patent debate, the justices seemed divided on whether the Biosig patent in this particular case should be thrown out.
A decision is expected in late June.
On Wednesday, the top U.S. court will hear a second closely followed patent case involving technology for managing Web images and video that features Limelight Networks Ltd and Akamai Technologies. (Reporting by Diane Bartz, editing by Ros Krasny and G Crosse)