(19)

(11)

EP 0 987 980 A1

(12)

(43) Date of publication: 29.03.2000 Bulletin 2000/13 (21) Application number: 98915020.6 (22) Date of filing: 09.04.1998

(51) International Patent Classification (IPC)7: A61B 5/00, A61B 17/22 (86) International application number: PCT/GB9801/045 (87) International publication number: WO 9846/123 (22.10.1998 Gazette 1998/42)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (30) Priority: 11.04.1997 GB 9707414 (71) Applicant: IMPERIAL COLLEGE OF SCIENCE,TECHNOLOGY & MEDICINE London SW7 2AZ (GB)	(72) Inventors: KITNEY, Richard, Ian,Cnt. for Bio & Med. Sys. London SW7 2BX (GB) DOWDY, Cliff Piedmont, OK 73078 (US) (74) Representative: Maggs, Michael Norman  Kilburn & Strode20 Red Lion Street London WC1R 4PJ London WC1R 4PJ (GB)