RANCHO SANTA MARGARITA, Calif., Sept. 12 /PRNewswire/ -- Applied Medical Resources Corporation announced today that, in response to a patent suit filed by Tyco Healthcare (NYSE: TYC - News), Applied Medical has filed a patent infringement countersuit in the Eastern District of Texas against Tyco Healthcare and its subsidiary U.S. Surgical. Applied Medical asserts Tyco infringes three Applied Medical trocar-related patents by making and selling certain U.S. Surgical STEP and VERSAPORT trocar products. Applied Medical is seeking an injunction to stop further distribution of the infringing products.