GB1449622A - Catheter assembly - Google Patents

Abstract

1449622 Catheters MEDICAL PRODUCTS CORP 24 Oct 1973 [26 Oct 1972] 49668/73 Heading A5R A balloon catheter having a central passage and an inflation lumen has a substantially cylindrical inflatable expansible cuff member 16 which conforms generally to the outer surface of the catheter in its deflated condition and is made of silicone rubber having a Shore hardness of not more than 30 so that at complete seal it conforms to irregularities of the contacted tissue surfaces without producing lesions. The catheter is used for the supply of oxygen or anaesthetic from a connector 6, the cuff 12 being inflatable from a connector 10 via a tube 8 and the lumen 9 formed in the wall of the catheter tube 2, which has a moulded tip 4, the tube 2 being formed of PVC and the outer cuff member 16 being attached by adhesive 17 to two seals 14, 15 which have a hardness greater than the cuff member and which in their relaxed condition have a diameter less than the outer diameter of tube 2 to provide a tight seal. The tip 4 of a plastics or elastomeric material has a hardness equal to or greater than that of the tube 2 and is secured to the tube by adhesive, thermal bonding, or friction or mechanical interlock. The distal end of the tip 4 is tapered and provided with a chamfer 25, the opposite tip end having a flange 20, which may be tapered, and into which the end of tube 2 fits against an abutment 21. The seals may protrude beyond the ends of cuff member 17, e.g. seal 15, or may be overlapped by member 16, e.g. seal 14. In a modification (Figure 7) the lumen 9 is provided by the passage extending through tube 8 which opens directly into the cuff, the seals 14, 15 being replaced by a cylindrical seal 43. Seal 43 may extend beyond member 16 or may be overlapped thereby and a space between the cuff and tip may either be left free or filled with adhesive. The ends of the cuff may alternatively extend into circumferential grooves in the tube 2. In Figure 10 (not shown) the cuff member 16 and the to seals are integrally formed, the seals either lying flat against tube 2 or having ridges located in circumferential grooves in the tube. The catheter may be set into a hyperbolic shape, and the tip material may be colour coded to identify the inner diameter of tube 2 and may be made radioopaque to render its position locatable in use. The durometer reading of the tube 2 may be in the range 60-85 with that of the tip from 60-95 and the seal or seals have a compression factor of from 5-50%. The cuff member 16 may have a tensile strength below 700 psi, an elongation greater than 1000 per cent, and a stress value upon sealing inflation of less than 30% of the breaking stress.