An artificial valve for implantation in a mammal body, in or adjacent to a mammal blood vessel, the artificial valve comprising a casing and a closing mechanism. The closing mechanism comprises a curved part with a groove in it, said groove comprising parts which are alternatingly slanted with respect to each other, and the closing mechanism also comprises at least one pin arranged on one of the moving parts, said pin being arranged to run in said groove, with the moving part being caused to move as a result of the pin's movement in the groove.
