Fisher & Paykel Healthcare, the medical devices maker, has filed a patent infringement lawsuit in the US against ResMed, claiming its rival used its technology in its breathing masks and air flow products.

Auckland-based F&P Healthcare said it is "seeking all available remedies, including damages and injunctive relief" in its proceedings in the US District Court for the Central District of California.

The lawsuit says ResMed's "AirSense 10 and AirCurve 10 range of flow generator products, ClimateLineAir heated air tubing for use with such flow generator products and Swift LT and Swift FX masks, infringe patents held by Fisher & Paykel Healthcare".

"Fisher & Paykel Healthcare has invested substantial resources in the research and development of its technologies over the past 45 years," said managing director Lewis Gradon, in a statement.


"The company has protected that investment through the development of a significant portfolio of more than 1,400 issued and pending patents and takes infringement of its intellectual property rights very seriously."

F&P Healthcare shares fell 0.5 percent to $10.70 in early trading this morning on the NZX and have gained 20 percent this year.

The stock is rated a 'buy' based on the consensus of seven analysts surveyed by Reuters with a median price target of $10.75. ResMed shares last traded at US$70.60 and have gained 32 percent this year.