A method for assisting in the production of an implantable unfurlable made-to-measure device that can be implanted in a cavity of a body of a living being, based on a series of radiographic images of the cavity, the method comprising steps of: a. Three-dimensional reconstruction of a complex surface delimiting a part of the cavity in which the unfurlable made-to-measure device is intended to be installed; b. Production of a first finite element mesh of a geometry of the complex surface thus reconstructed; c. Choosing of one or more generic components of the unfurlable made-to-measure device that is to be personalized; d. Production of a second finite element mesh of the generic component or components chosen and assembled to form the unfurlable made-to-measure device; e. Determination of the parameters of a morphing of the obtained first mesh to a mesh of a geometry formed from a set of simple volumes linked to each other representative of the part of the cavity, and then deformation of the first mesh by this morphing; f. Simulation, by the finite elements method, of the deformation of the second mesh thus obtained, by inverse morphing, dependent on the previously determined morphing parameters, to the geometry of the complex surface of the cavity, so as to simulate the unfurling of the unfurlable made-to-measure device once installed in the cavity; characterized in that the method comprises: g. Determination of a dimensioning of points of interest of the part in question of the cavity by projecting them onto the second mesh thus deformed; and h. Generation of a dimensioned drawing of the generic component or components onto which the previously determined dimensioning has been transposed, the dimensioned drawing allowing the unfurlable made-to-measure device to be produced. a. Three-dimensional reconstruction of a complex surface delimiting a part of the cavity in which the unfurlable made-to-measure device is intended to be installed; b. Production of a first finite element mesh of a geometry of the complex surface thus reconstructed; c. Choosing of one or more generic components of the unfurlable made-to-measure device that is to be personalized; d. Production of a second finite element mesh of the generic component or components chosen and assembled to form the unfurlable made-to-measure device; e. Determination of the parameters of a morphing of the obtained first mesh to a mesh of a geometry formed from a set of simple volumes linked to each other representative of the part of the cavity, and then deformation of the first mesh by this morphing; f. Simulation, by the finite elements method, of the deformation of the second mesh thus obtained, by inverse morphing, dependent on the previously determined morphing parameters, to the geometry of the complex surface of the cavity, so as to simulate the unfurling of the unfurlable made-to-measure device once installed in the cavity; g. Determination of a dimensioning of points of interest of the part in question of the cavity by projecting them onto the second mesh thus deformed; and h. Generation of a dimensioned drawing of the generic component or components onto which the previously determined dimensioning has been transposed, the dimensioned drawing allowing the unfurlable made-to-measure device to be produced.