Patents Reinstated Due to the Acceptance of a
                      Late Maintenance Fee From 02/20/98
   
Patent           Serial            Filing          Issue          Granted
Number           Number            Date            Date           Date

4,516,913        06/289,892        08/04/81        05/14/85       02/25/98
4,539,341        06/582,348        02/22/84        09/03/85       02/20/98
4,553,280        06/602,574        04/20/84        11/19/85       02/20/98
4,797,830        07/006,853        01/27/87        01/10/89       02/25/98
4,837,829        07/106,936        10/08/87        06/06/89       02/20/98
4,853,529        07/152,436        02/05/88        08/01/89       02/20/98
4,875,361        07/186,190        07/05/88        10/24/89       02/25/98
4,886,808        07/171,141        03/16/88        12/12/89       02/23/98
4,907,950        07/238,093        08/29/88        03/13/90       02/26/98
4,908,212        07/296,998        01/13/89        03/13/90       02/24/98
4,923,446        07/181,387        04/14/88        05/08/90       02/26/98
5,004,404        07/305,810        02/03/89        04/02/91       02/26/98
5,015,981        07/570,894        08/21/90        05/14/91       02/26/98
5,057,020        06/852,193        04/15/86        10/15/91       02/25/98
5,060,417        07/426,976        10/25/89        10/29/91       02/26/98
5,061,463        07/397,990        08/24/89        10/29/91       02/25/98
5,077,619        07/427,178        10/25/89        12/31/91       02/20/98
5,077,844        07/440,591        11/22/89        01/07/92       02/25/98
5,101,589        07/682,340        04/09/91        04/07/92       02/20/98
5,109,874        07/732,172        07/18/91        05/05/92       02/24/98
5,135,298        07/581,544        09/12/90        08/04/92       02/20/98
5,181,542        07/659,989        02/22/91        01/26/93       02/25/98
5,209,258        07/837,661        02/14/92        05/11/93       02/25/98
5,217,800        07/690,990        06/05/91        06/08/93       02/24/98
5,244,117        07/856,690        03/24/92        09/14/93       02/25/98
5,245,181        07/901,666        06/22/92        09/14/93       02/20/98