Fluid pressure sensor, this sensor including: - a flexible pipe extending around and along a central axis, this pipe being adapted to contain the fluid the pressure of which must be measured and to be deformed by the effect of the pressure exerted by the fluid, between: • a first deformed position for a first pressure exerted by the fluid, the pipe having in this first position different first and second locations on its periphery the orthogonal projections of which in a plane perpendicular to the central axis are separated by a distance d 1, and • a second deformed position for a second pressure exerted by the fluid higher than the first pressure in the second position the orthogonal projections of the first and second locations in the plane perpendicular to the central axis are separated by a distance d 2, the difference between the distances d 2 and d 1 being at least greater than 0.1d 2, - a coil (20; 120; 138; 150; 200; 262; 270; 280) the self inductance of which varies as a function of the pressure of the fluid inside the flexible pipe, this coil including at least one turn (22; 160, 168; 214, 220; 274; 284) wound around a winding axis of the coil coinciding with the central axis of the pipe, said at least one turn including: • a first portion of its periphery mechanically connected to the first location on the periphery of the pipe by a first mechanical connection which rigidly connects this first portion to this first location, and • a second portion of its periphery, separate from the first portion, mechanically connected to the second location on the periphery of the pipe by a second mechanical connection separate from the first mechanical connection which rigidly connects this second portion to this second location so that the tranverse area of this turn varies as a function of the deformation of the pipe, - a unit for calculating the pressure of the fluid as a function of the self inductance of the coil, characterized in that the turn includes a third and a fourth free portions situated between the first and second portions and each on a respective side of the central axis of the pipe, these third and fourth free portions being each separated from the flexible pipe by a clearance (52, 54). - a flexible pipe extending around and along a central axis, this pipe being adapted to contain the fluid the pressure of which must be measured and to be deformed by the effect of the pressure exerted by the fluid, between: • a first deformed position for a first pressure exerted by the fluid, the pipe having in this first position different first and second locations on its periphery the orthogonal projections of which in a plane perpendicular to the central axis are separated by a distance d 1, and • a second deformed position for a second pressure exerted by the fluid higher than the first pressure in the second position the orthogonal projections of the first and second locations in the plane perpendicular to the central axis are separated by a distance d 2, the difference between the distances d 2 and d 1 being at least greater than 0.1d 2, • a first deformed position for a first pressure exerted by the fluid, the pipe having in this first position different first and second locations on its periphery the orthogonal projections of which in a plane perpendicular to the central axis are separated by a distance d 1, and • a second deformed position for a second pressure exerted by the fluid higher than the first pressure in the second position the orthogonal projections of the first and second locations in the plane perpendicular to the central axis are separated by a distance d 2, the difference between the distances d 2 and d 1 being at least greater than 0.1d 2, - a coil (20; 120; 138; 150; 200; 262; 270; 280) the self inductance of which varies as a function of the pressure of the fluid inside the flexible pipe, this coil including at least one turn (22; 160, 168; 214, 220; 274; 284) wound around a winding axis of the coil coinciding with the central axis of the pipe, said at least one turn including: • a first portion of its periphery mechanically connected to the first location on the periphery of the pipe by a first mechanical connection which rigidly connects this first portion to this first location, and • a second portion of its periphery, separate from the first portion, mechanically connected to the second location on the periphery of the pipe by a second mechanical connection separate from the first mechanical connection which rigidly connects this second portion to this second location so that the tranverse area of this turn varies as a function of the deformation of the pipe, • a first portion of its periphery mechanically connected to the first location on the periphery of the pipe by a first mechanical connection which rigidly connects this first portion to this first location, and • a second portion of its periphery, separate from the first portion, mechanically connected to the second location on the periphery of the pipe by a second mechanical connection separate from the first mechanical connection which rigidly connects this second portion to this second location so that the tranverse area of this turn varies as a function of the deformation of the pipe, - a unit for calculating the pressure of the fluid as a function of the self inductance of the coil,