(19)

(11)

EP 0 835 458 A2

(12)

(43) Date of publication: 15.04.1998 Bulletin 1998/16 (21) Application number: 96922638.0 (22) Date of filing: 28.06.1996

(51) International Patent Classification (IPC):  A61B 8/ 00( . ) G01S 7/ 52( . ) G01S 15/ 89( . ) A61B 8/ 12( . ) G01S 7/ 00( . ) G01S 7/ 523( . ) A61B 7/ 04( . ) (86) International application number: PCT/US1996/011166 (87) International publication number: WO 1997/001768 (16.01.1997 Gazette 1997/04)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 29.06.1995 US 19950496804 29.06.1995 US 19950496805 12.02.1996 US 19960599816 (71) Applicant: Teratech Corporation Burlington, MA 01803 (US)	(72) Inventors: CHIANG, Alice, M. Weston, MA 02193 (US) BROADSTONE, Steven, R. Woburn, MA 01801 (US) (74) Representative: Greenwood, John David, et al  Graham Watt & Co. Riverhead Sevenoaks Kent TN13 2BN Sevenoaks Kent TN13 2BN (GB)