(19)

(11)

EP 0 611 294 A1

(12)

(43) Date of publication: 24.08.1994 Bulletin 1994/34 (21) Application number: 92922620.0 (22) Date of filing: 03.11.1992

(51) International Patent Classification (IPC):  A61B 18/ 02( . ) (86) International application number: PCT/GB1992/002028 (87) International publication number: WO 1993/008751 (13.05.1993 Gazette 1993/12)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL SE (30) Priority: 05.11.1991 GB 19910023415 (71) Applicant: CRYOGENIC TECHNOLOGY LIMITED Belper, Derbyshire DE5 1UU (GB)	(72) Inventor: CLARKE, Brian, Kevin, Roderick Oakwood Derby DE2 2JL (GB) (74) Representative: Swindell & Pearson  48 Friar Gate Derby DE1 1GY Derby DE1 1GY (GB)