Abstract: An artificial contractile structure generally devised to be used in the medical field to assist the functioning of an organ, includes a support (2) and one or more fibers (5) fixed thereto. The fibers are made of a contractile material which can be activated by an activator so as to provide the structure in a rest or activated position, the activated position being defined with fibers of reduced length compared to their length in the rest position. The structure is adapted to be placed around a hollow part of an organ to be contracted. The fibers are distributed along the support in order to be able to reduce the volume of the hollow part, when the fibers are contracted. The fibers and the activator are designed so that the temperature of fluids or tissues surrounding the organ does not increase above 40° C., preferably 39° C., and more preferably 38° C.

Abstract: Artificial contractile tissue including a structure (b,f) and several fibers (a,g) of variable length which are fixed at their ends to the structure (b,f). The fibers (a,g) are made of a contractile material which can be activated by an activator in such a way as to provide a tissue in a rest or in an activated position, the rest position being defined with non-rectilinear fibers (a,g) and the activated position being defined with fibers (a,g) of reduced length; the transition from the rest towards the activated position or vice-versa being defined by a fiber movement along a lateral direction which is perpendicular with respect to the fiber length.