(19)

(11)

EP 0 493 523 A1

(12)

(43) Date of publication: 08.07.1992 Bulletin 1992/28 (21) Application number: 90915509.0 (22) Date of filing: 20.09.1990

(51) International Patent Classification (IPC):  A61F 2/ 00( . ) A61F 2/ 40( . ) A61F 2/ 08( . ) A61F 2/ 30( . ) A61B 19/ 02( . ) (86) International application number: PCT/GB1990/001457 (87) International publication number: WO 1991/003993 (04.04.1991 Gazette 1991/08)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB IT LI LU NL SE (30) Priority: 21.09.1989 GB 19890021324 (71) Applicant: The University of Nottingham Nottingham NG7 2RD (GB)	(72) Inventor: WALLACE, William, Angus University Park Nottingham NG7 2RD (GB) (74) Representative: Bassett, Richard Simon  ERIC POTTER & CLARKSON St. Mary's Court St. Mary's Gate Nottingham NG1 1LE Nottingham NG1 1LE (GB)