Quoted from http://www.bizjournals.com/seattle/stories/2007/08/20/daily6.html:
In July, the Bothell maker of hand-carried ultrasound machines filed a counterlawsuit after General Electric sued SonoSite in May, alleging that SonoSite ultrasound products infringed on GE products.
In an Aug. 17 amendment to its July countersuit, SonoSite alleged that GE, (NYSE: GE) of Fairfield, Conn., infringed on additional SonoSite patents.
"We continue to believe that GE's claims of patent infringement are without merit and we have now expanded our claims against them. We will continue to vigorously assert our rights," said Kevin Goodwin, SonoSite (NASDAQ: SONO) president and CEO, in a statement.