It also expired at the end of 2000 https://fees.uspto.gov/MaintenanceFees/fees/details?applicationNumber=08339523&patentNumber=5588199 https://fees.uspto.gov/M

It also expired at the end of 2000 https://fees.uspto.gov/MaintenanceFees/fees/details?applicationNumber=08339523&patentNumber=5588199 https://fees.uspto.gov/MaintenanceFees/fees/details?applicat...