Method for biomehcanically simulating of a set of osseous joints

• US 20070093998A1
• Filed: 12/30/2003
• Published: 04/26/2007
• Est. Priority Date: 12/30/2002
• Status: Abandoned Application

• Current Assignee: AXS Ingénierie
• Original Assignee: AXS Ingénierie
• Inventors: El-Baroudi, Fouad
• Application Number:
  US10/541,250
• Publication Number:
  US 20070093998A1
• Time in Patent Office: Days
• US Class Current: 703/11
• CPC Class Codes: G16H 30/20 for handling medical images, e.g. DICOM, HL7 or PACS
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders

Abstract

Method for biomechanical simulation of a set of osseous joints of a patient, in particular rachis, includes recording a digital three dimensional model embodied at least partially in the form of rigid bodies interconnected by joints in a reference position, personalizing the model geometry by specific data of the patient in the reference position, personalizing the digital model by particulating interaction parameters of each joint connecting the rigid bodies according to detected client'"'"'s characteristics. The particularization of the interaction parameters consists in obtaining the space position of at least the part of the rigid bodies and interpolating for determining the calculated position of other rigid bodies in order to produce a numerical index containing the relative position of each rigid body, performing at least one defined constraint on the patient and collecting information on the general balance position of the patient, and in determining analytical functions which make it possible to approximate the interaction parameters, thereby reproducing the measured relative positions for each couple of rigid bodies.

Claims

1. Method for biomechanical simulation of a set of bone joints in a patient, and particularly the spine, comprising:

a step in which a three-dimensional digital model, at least partly represented by rigid bodies connected by joints, is recorded in a reference position;

a step to personalize the geometry of the said model, using data specific to a patient in the said reference position;

a step to personalize the said digital model by particularization of interaction parameters of each joint connecting the said rigid bodies as a function of characteristics observed on the patient;

characterized in that

the step to particularize the interaction parameters consists of;

acquiring the positions in space of at least a part of the rigid bodies, and making an interpolation to determine the calculated position of other rigid bodies to build up a digital table containing the relative positions of each rigid body;

applying at least one determined constraint on the patient and acquiring information about the resultant general equilibrium position of the patient;

determining analytic functions to approximate interaction parameters in order to reproduce the measured relative positions, for each pair of rigid bodies.

2. Method for biomechanical simulation of a set of bone joints according to claim 1, characterized in that the digital model is defined by geometric position parameters of the rigid bodies and by stiffness parameters of the joints connecting the rigid bodies.

3. Method for biomechanical simulation of a set of bone joints according to claim 1, characterized in that the step representing the result of a constraint consists of recalculating the personalized model resulting from a set of constraints comprising at least one static constraint applied on at least two rigid bodies, and imposing a relative position with a mobility or stiffness different from that corresponding to the behavioral law.

4. Method for biomechanical simulation of a set of bone joints according to claim 1, characterized in that the step recording the digital model of the set of standard joints consists of defining an alternation of rigid bodies and joints, and for each pair of bodies defining a set of digital parameters characterizing the mobility or the global stiffness resulting from the action of all insertion elements and connecting elements that have an effect on the interaction parameters between the two bodies.

5. Method for biomechanical simulation of a set of bone joints according to claim 1, characterized in that the personalisation step consists of acquiring at least one image of the set of joints of a given patient, extracting information necessary for construction of a real model from the said image by recognition of the position of joints visible in the said image, and modifying the standard model as a function of the said real model.

6. Method for biomechanical simulation of a set of bone joints according to claim 1, characterized in that the step recording a digital model consists of defining a standard set of digital data comprising the following for each joint represented in the form of a rigid body:

a first geometric reference position descriptor corresponding to the geometry of the set of joints for a “

standard”

patient in a “

reference”

position, the said descriptor being determined for each rigid body relative to an adjacent body;

a second mechanical descriptor interacting with each adjacent body, the said mechanical descriptor being representative of the behavioral law when at least one external constraint is applied to the set of joints;

the personalisation step consisting of modifying the said standard set of data by personalized data.

7. Method for biomechanical simulation of a set of bone joints according to claim 1, characterized in that it also comprises a correction step consisting of making radiograph image data and external acquisition data correspond, this step being broken down into two sub-steps:

correct the radiograph reconstruction relative to the 3D curve derived from external acquisition data in the same position;

determine the distribution of points in the 3D curve associated with the vertebras, positioned in the Stokes coordinate system and their associated tangent.

8. Method for biomechanical simulation of a set of bone joints according to claim 2, characterized in that the step representing the result of a constraint consists of recalculating the personalized model resulting from a set of constraints comprising at least one static constraint applied on at least two rigid bodies, and imposing a relative position with a mobility or stiffness different from that corresponding to the behavioral law.

9. Method for biomechanical simulation of a set of bone joints according to claim 2, characterized in that the step recording the digital model of the set of standard joints consists of defining an alternation of rigid bodies and joints, and for each pair of bodies defining a set of digital parameters characterizing the mobility or the global stiffness resulting from the action of all insertion elements and connecting elements that have an effect on the interaction parameters between the two bodies.