Since the application for the patent was filed before 1995, the lifespan of the patent is 17 past the grant date of the patent. And the patents was granted in 1998. So it should expire until 2015.
The other patent on the case was filed in 2002 and granted in 2009, so it'll expire in 2022. (starting in 1995 patents expired 20 years past the application date).