Patents Reinstated Due to the Acceptance of a
                      Late Maintenance Fee From 04/17/98
   
Patent           Serial            Filing          Issue          Granted
Number           Number            Date            Date           Date

4,430,739        06/304,232        09/21/81        02/07/84       04/22/98
4,502,665        06/644,662        08/27/84        03/05/85       04/23/98
4,813,520        07/082,359        08/06/87        03/21/89       04/22/98
4,826,051        06/544,736        10/24/83        05/02/89       04/23/98
4,833,048        07/175,782        03/31/88        05/23/89       04/23/98
4,841,110        07/091,368        08/27/87        06/20/89       04/23/98
5,150,972        07/766,016        09/26/91        09/29/92       04/23/98
5,156,029        07/568,794        08/17/90        10/20/92       04/17/98
5,163,549        07/782,655        10/25/91        11/17/92       04/22/98
5,186,830        07/708,809        05/31/91        02/16/93       04/23/98
5,245,075        07/803,721        12/09/91        09/14/93       04/23/98
5,247,601        07/879,638        05/07/92        09/21/93       04/17/98
5,283,422        07/927,798        08/10/92        02/01/94       04/17/98