Patent ID: 8118784

Claim:
A haemostatic valve assembly including a chamber able to be pressurized, an elongate resiliently deformable valve element located within the chamber, a passage through which an elongate element can pass, the valve element being located so as to envelop at least a part of the passage, and a fluid supply for supplying a volume of pressurized fluid to within the chamber, wherein pressurization of the chamber causes the valve element to be biased towards a closed position; wherein the fluid supply includes a source of pressurized fluid external to the chamber, including a variable volume drop bag coupled to the chamber in a closed path, wherein gravity acts on the pressurized fluid from the drop bag, causing the fluid to apply pressure to the valve element and deform the valve element to bias it into a sealing condition against an elongate element therein or to a closed position; the volume of fluid within the valve chamber being self-adjusting so as to provide a substantially constant sealing force at all operating conditions of the valve element, said sealing force being sufficient to seal against leakage around an elongate element passing through the valve without any other means assisting to apply mechanical pressure to seal against leakage around an elongate element passing through the valve.