Masimo Fires Back at Apple in Delaware Smart Watch Patent Suits

Masimo Corp. filed counterclaims Monday against Apple Inc. in two patent cases, part of the companies’ dispute over health-focused smart watch technology.

In one of two filings on Monday, Masimo accused Apple of obtaining its patents fraudulently, violating antitrust laws, and engaging in false advertising, deceptive trade practices, and unfair competition. It also alleges that Apple infringed 10 of Masimo’s US patents—Nos. 10,912,501, 10,912,502, 10,945,648, 10,687,743, 10,687,745, 10,722,159, 7,761,127, 8,190,223, 10,736,507, and 10,984,911.

The counterclaims allege Apple used patented pulse oximetry technology invented by Masimo—a maker of signal-processing technology for ...