An iris-type valve assembly for controlling a flow of fluid. The assembly comprises a base member, a rotatable member, and an elongated elastomeric valve sheath. The distal end of the valve sheath is secured to the base member and the proximal end of the valve sheath is secured to the rotatable member....http://www.google.com.au/patents/US20050171479?utm_source=gb-gplus-sharePatent US20050171479 - Hemostatic valve assembly
