The invention relates to an occlusion system implantable in a human or animal body, comprising:a fluidic circuit comprising: an inflatable occlusive sleeve (3),a reservoir (5) with variable volume filled with a fluid, said reservoir comprising a fixed portion and a movable portion,an actuator mechanically coupled with the movable portion of the reservoir so as to linearly displace said movable portion relatively to the fixed portion for adjusting the volume of the reservoir,the actuator and the reservoir with variable volume being laid out in a sealed casing (1) containing a gas,a sensor (21, 22) mechanically bound to the actuator and/or to the movable portion of the reservoir, measuring a traction and/or compressive force in the direction of displacement of the movable portion of the reservoir,a device for measuring the fluid pressure (P1) in the fluidic circuit taking into account at least the force measured by said sensor (21, 22), the effective pressure surface area (Seff) of the movable portion of the reservoir, and the force exerted on the movable portion of the reservoir with variable volume related to the pressure of the gas in the casing.
