Implantable medical device

A medical device comprising:

• a sealed casing, containing a gas, suitable for being implanted in a body of a human or animal patient,
• an inflatable element, suitable for being implanted in the body of the patient, outside of the casing,
• a fluid circuit comprising a fluid reservoir having a variable fluid volume and arranged inside the casing with a tube ensuring a fluid connection between said reservoir and said inflatable element,
• an actuator arranged inside the casing and mechanically coupled to the fluid reservoir in a manner as to selectively vary the volume of fluid in said reservoir,
• a control unit configured to control the actuator in a manner as to transfer the fluid between the reservoir and the inflatable element,
• at least one sensor suitable for measuring at least one physical quantity linked to an altitude of the patient in which the medical device is implanted, the at least one physical quantity being among:
• an absolute pressure of the fluid in the fluid circuit, a force exerted on the reservoir, a gas pressure inside the casing, and an atmospheric pressure,
• the control unit being further configured to:
• on the basis of a measurement of the at least one physical quantity from said sensor while the actuator is inactive, determine a value relating to the altitude of the patient,
• detect a differential between the value relating to the altitude of the patient and a reference value, and
• as a function of said differential, determine a command to be issued to the actuator in a manner as to control the pressure of fluid in the fluid circuit.