EP-4736052-A1 - DEVICE AND METHOD FOR THE FINITE-ELEMENT MODELLING OF AT LEAST ONE PART OF THE HUMAN OR ANIMAL BODY

EP4736052A1EP 4736052 A1EP4736052 A1EP 4736052A1EP-4736052-A1

Abstract

The present invention relates to a computer-implemented method for the finite-element modelling of at least one part of the human or animal body, the method comprising the following steps: - defining a plurality of anatomical element control entities and a plurality of functional element control entities for an image representative of the at least one part of the human or animal body; - obtaining a mesh of the at least one part of the human body on the basis of the anatomical element control entities and the functional element control entities, wherein the anatomical element control entities and the functional element control entities are controlled during a geometric transformation of the mesh, the anatomical element control entities being positioned so as to define at least the geometric shape of the part and the functional element control entities being positioned so as to define mechanical connections associated with the part.

Inventors

SKALLI, WAFA
SHINDO, Kyo

Assignees

Skairos

Dates

Publication Date: 20260506
Application Date: 20240626

Claims (20)

[Claim 1] A method of finite element modeling, implemented by a computer, of at least one part of the human or animal body comprising the following steps: - definition of a plurality of anatomical element control entities and a plurality of functional element control entities for an image representative of said at least one part of the human or animal body, - obtaining a mesh of said at least one part of the human body from said anatomical element control entities and said functional element control entities, wherein said anatomical element control entities and said functional element control entities are controlled during a geometric transformation of said mesh, said anatomical element control entities being positioned on said image to define at least the geometric shape of said part and said functional element control entities being positioned on said image to define mechanical connections associated with said part.
[Claim 2] A method according to claim 1 such that said representative image of said at least one part of the human or animal body represents - an image obtained by medical imaging of said part, or - a synthesized image of said part or - a parametric model generated from values of descriptors representative of the average of images representative of a plurality of patients.
[Claim 3] Method according to one of claims 1 or 2 in which said plurality of anatomical element control entities and/or said plurality of functional element control entities are organized hierarchically, and respectively comprise: - a first level of anatomical element control entities and/or a first level of functional element control entities: - at least one second level of anatomical element control entities and/or at least one second level of functional element control entities, a higher level comprising respectively the functional element control entities of said lower level and additional functional element control entities, - said mesh being obtained from a selection of said control entities of anatomical and functional elements.
[Claim 4] Method according to claim 3 in which said selection selects at least one of said levels according to a mesh fineness to be obtained and/or an extent of the desired modeling in said part.
[Claim 5] A method according to claim 4 wherein said at least one part of the human body comprises at least one region of interest and said selection comprises a selection of a greater number of levels for said at least one region of interest than for said at least one part outside said region of interest, in order to obtain a mesh whose fineness is finer for said at least one region of interest.
[Claim 6] Method according to one of the preceding claims comprising - labeling, from said representative image of at least part of said plurality of anatomical and functional element control entities to obtain at least one location descriptor of said anatomical and functional element control entities, - said mesh of said at least one part of the human body being obtained from said at least one location descriptor of said control entities of anatomical and functional elements.
[Claim 7] Method according to one of the preceding claims in which said mesh is obtained from a transformation of a reference mesh.
[Claim 8] A method according to claim 7 wherein said transformation is a deformation.
[Claim 9] The method of claim 6 wherein said at least one location descriptor of at least a portion of said anatomical element control entities or said functional element control entities is obtained by a statistical estimation of a positioning of said functional element control entities. control of anatomical elements or said functional element control entities.
[Claim 10] Method according to one of the preceding claims comprising a back projection of said mesh into said representative image.
[Claim 11] A method according to claims 9 and 10 comprising - an adjustment of at least part of said estimated location descriptors when their position in said mesh projected onto said representative image and their real position exhibit a difference greater than a determined value.
[Claim 12] Method according to one of the preceding claims such that said part comprises at least one osteoarticular or musculoskeletal segment consisting of one or more bone structures and associated connecting elements which can be instrumented by orthopedic implants.
[Claim 13] Method according to one of the preceding claims as it comprises - the estimation, for at least one region of said part, of the bone mineral density from said representative image and - the modification, in said obtained mesh, of mechanical properties associated with at least certain control entities of anatomical elements or said control entities of functional elements of said at least one region as a function of the estimation of bone mineral density.
[Claim 14] Method according to one of the preceding claims such that it further comprises obtaining a stiffness matrix.
[Claim 15] Method according to one of the preceding claims such that it further comprises obtaining clinical indices from said obtained mesh.
[Claim 16] Computer program comprising instructions for executing the steps of the method according to one of claims 1 to 15 when said program is executed by a computer.
[Claim 17] A computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to one of claims 1 to 15.
[Claim 18] Device for finite element modeling of at least one part of the human or animal body comprising one or more processors configured together or separately for: - defining a plurality of anatomical element control entities and a plurality of functional element control entities for an image representative of said at least one part of the human or animal body, - obtaining a mesh of said at least one part of the human body from said anatomical element control entities and said functional element control entities, wherein said anatomical element control entities and said functional element control entities are controlled during a geometric transformation of said mesh, said anatomical element control entities being positioned on said image to define at least the geometric shape of said part and said functional element control entities being positioned on said image to define mechanical connections associated with said part.
[Claim 19] Use of a model obtained by a finite element modeling method according to one of claims 1 to 15 for evaluating mechanical constraints brought about by modifications of the musculoskeletal structure of said human body.
[Claim 20] Use of a model obtained by a finite element modeling method according to one of claims 1 to 15 to obtain clinical indices relating to said human body.

Description

Description Title of the invention: device and method for finite element modeling of at least one part of the human or animal body Technical Domain [1] The present invention relates to the field of geometric and biomechanical models and more particularly to a method and a device for generating a geometric and biomechanical model in finite elements of at least one part of the human or animal body. Previous technique [2] The invention relates to the field of geometric and biomechanical models in finite elements of a structure consisting of all or part of the human or animal body. These models are virtual mock-ups which in particular make it possible to virtually exert localized forces or movements on the structure considered, and to deduce the mechanical response in terms of quantities of interest such as the amplitudes of mobility and mechanical constraints in specific areas. These structures can be damaged, and restored using orthopedic or surgical treatments, which treatments can give rise to mechanical complications, linked to overstresses in the implants or in the surrounding biological tissues. [3] These models are often based on a single individual or an average individual considered representative. However, the great diversity of individuals requires that the model can be adapted to represent the form and function of the specific structures of different individuals. The construction of personalized models is important to understand which specificities have generated the mechanical over-constraints at the origin of the failure, and thus specify possible contraindications, or strategies adapted to certain specificities of the patient. However, creating the model for each of these situations can be particularly tedious, which is why these personalized models are very little developed today. [4] We are particularly familiar with methods such as that disclosed by the document by Pei et al, published on January 19, 2023 and entitled “Biomechanical comparative analysis of conventional pedicle screws an cortical bone trajectory fixation in the lumbar spine: An in vitro and finite element study”. [5] This method of building a biomechanical model is complex and tedious because it requires a lot of adjustments, and the example cited illustrates this complexity and its cost by the number of software that must be used for each step. This method is shown in Figure 1. [6] This process includes - a first step U1 of obtaining a series of scanner sections, - a U2 segmentation step to obtain a 3D reconstruction, - a U3 step of manipulation of the 3D reconstruction, - a U4 step of meshing the implants and connecting elements, - a U5 step of generating the finite element mesh, - a U6 step of applying boundary conditions and integrating them into calculation software. [7] The type of three-dimensional reconstruction obtained during step U2 may prove to be inconsistent on certain physical aspects, for example the interarticular facets may not be respected, which poses a problem in finite element models. These functional inconsistencies must therefore be corrected a posteriori, which in the example requires reworking the 3D reconstruction made before the finite element meshing process. In addition, mesh convergence processes are often required to validate finite element models, which requires generating, for the same structure, meshes with different mesh finesse, and this part (not carried out in the example) is often extremely tedious. [8] The complexity of generating a finite element mesh from the external surface of the structures that compose it is one of the important obstacles that limit their development. Many methods have been proposed, which start from the envelope surface obtained. [9] It is therefore necessary to propose new finite element modeling methods, making it possible to overcome all or part of these drawbacks. Disclosure of the invention [10] For this purpose, the present invention relates to a method of finite element modeling, implemented by a computer, of at least one part of the body. human or animal including the following steps: - definition of a plurality of anatomical element control entities and a plurality of functional element control entities for an image representative of said at least one part of the human or animal body, - obtaining a mesh of said at least one part of the human body from said anatomical element control entities and said functional element control entities, wherein said anatomical element control entities and said functional element control entities are controlled during a geometric deformation of said mesh, said anatomical element control entities being positioned on said representative image to define at least the geometric shape of said part and said functional element control entities being positioned on said representative image to define mechanical connections associated with said part. [11] Thus, advantageously, the present invention can allow a saving of time and p