Abstract: An embryo-transfer catheter has an extruded shaft with a gas-filled lumen that extends helically along the catheter to provide an ultrasound marker. The catheter has a side opening close to a closed rounded patient end. The catheter could be completely transparent to x-rays or the plastics from which it is formed could incorporate an x-ray opaque filler, such as barium sulphate.

Abstract: A laryngeal mask airway has a tubular shaft with a mask portion secured at its patient end. The mask portion comprises a PVC mount and an inflatable cuff secured around an edge of the mount. The posterior surface of the mount and cuff has a coating of a hydrophilic polymer or copolymer which becomes slippery when hydrated to ease insertion of the airway into the patient.

Abstract: An embryo-transfer catheter has an extruded shaft with a gas-filled lumen that extends helically along the catheter to provide an ultrasound marker. The catheter has a side opening close to a closed rounded patient end.

Abstract: New materials having improved biocompatibility have novel zwitterionic groups at the surface. The zwitterion is characterized by having at least one monovalent substituent at the atom carrying the cationic charge which is an aryl group. Preferably the atom carries at least two, and preferably three such aryl, usually phenyl, groups. The cationic group is preferably a triphenylphosphonium. Treatment of surfaces to provide pendant zwitterionic groups of the specified type have reduced platelet activation, whilst they do not appear to reduce platelet adhesion. The invention has utility in the field of blood contacting device, especially devices for implantation, such as vascular grafts.

Abstract: The present invention relates to materials which comprise a surface having pendant groups of formula (I), in which the groups --B-- are the same or different, preferably the same, and each is --CH.sub.2 -- or --C(.dbd.O)--, preferably --CH.sub.2 --, R.sup.1 is hydrogen alkyl of 1 to 12, preferably 1 to 4 carbon atoms, or a group capable of bonding to, or bonded to, a ligand or R.sup.1 is a polymerisable, preferably ethylenically unsaturated, group and Z is a zwitterionic group. Usually both groups B are the same and are joined to identical groups so that the compound of formula (I) is achiral. New compounds are achiral glyceryl phosphatidyl choline analogues. Surfaces having the groups (I) at their surface have improved biocompatibility, and show reduced fibrinogen absorption, reduced platelet activation, reduced microorganism adhesion and are useful in the production of implants or prostheses, for extra-corporeal circuitry for body fluids, for treating membranes of various type, for contact lenses.

Abstract: The present invention provides materials which comprise a surface having pendant zwitterionic groups Z comprising, as anion, a phosphate, sulphonate, carboxylate or phosphate-ester group or a phosphate ester group in which one or more of the ester oxygen atoms is replaced by --S--, --NH-- or by a valence bond and, as cation, an ammonium, phosphonium or sulphonium moiety, provided that where the anion is a phosphate-ester group or derivative thereof or sulphonate and the cation is a trialkyl quaternary ammonium group (the alkyl groups each containing from 1 to 4 carbon atoms) and the group linking the anion and cation moieties is an alkylene group, the alkylene group, contains at least 5, preferably at least 6, and more preferably at least 7, carbon atoms. The materials have improved biocompatibility for instance as evidenced by reduced protein deposition and reduced platelet activation.