Realistic model of spine geometry in the human skeleton in the Vicon system

International audienceThe human spine is definitively one of the most important parts of a living body. From biomechanical point of view, this organ is the most complicated structure, and a dynamic analysis of its motion still requires more detailed models be created. The aim of this study is to build an accurate computer model of the geometry of the spine and insert it into available skeleton models, used in Vicon. Up to now such models were simplified and that is why they were not sufficient for research of detailed motion of the spine. The paper describes the process of creating models of the vertebrae. During research, authors simultaneously used two techniques: 3D scanning of the vertebrae and computed modeling in 3D graphics software. A universal data format: .obj used to keep the information about surface shape of an object, its colour, texture etc. is presented in detail. In a discussion on Vicon data formats and relations between them, several file types are taken under consideration: marker files: .mkr, global model parameters files: .mp, files of the model structure: .mod. But first of all, step-by-step instructions of how to connect the files with geometrical objects for the visualization purposes, are presented

An improved kinematic model of the spine for three-dimensional motion analysis in the Vicon system

International audienceThe mechanism of creation and pathomechanics of lateral spinal deformation is still not fully explained. Modern medical imaging techniques give scientists possibility to understand some aspects, but vast majority of those techniques is based on static trials. A motion capture system belongs to techniques which enable visualization of a spine during dynamic trials; however, due to lack of appropriate computational model, it is unsuitable for scoliosis imaging. A few years ago our group has proposed a kinematic model of the spine to be used with Vicon Motion Capture System, which was based on Bézier curves. That model allowed for much more precise investigation of spinal kinematics during dynamic trials as compared with other computational models. However, it did not allowed to restrict only selected movements for particular segments of the spine (e.g. axial rotation for lumbar spine). The aim of the current work is to improve the proposed model in order to be able to restrict selected movements according to the knowledge concerning spinal anatomy and spinal range of motion. The new kinematic model of the spine was written in BodyBuilder for Biomechanics Language. For the purpose of visualization also an accurate graphical representation of each vertebra (polygon mesh) was computed and adapted to be compatible with the kinematic model. Using a new version of the model it is possible to perform precise analysis of movement of all vertebrae during such dynamic activities as e.g. gait and forward or lateral bending, as well as to present the results not only on the charts, but also as a 3D animation of movements of a realistically looking spine. The paper describes the new kinematic model and the process of creating graphical representation of the vertebrae. Also sample results obtained using that model are presented

An improved kinematic model of the spine for three-dimensional motion analysis in the Vicon system

International audienceThe mechanism of creation and pathomechanics of lateral spinal deformation is still not fully explained. Modern medical imaging techniques give scientists possibility to understand some aspects, but vast majority of those techniques is based on static trials. A motion capture system belongs to techniques which enable visualization of a spine during dynamic trials; however, due to lack of appropriate computational model, it is unsuitable for scoliosis imaging. A few years ago our group has proposed a kinematic model of the spine to be used with Vicon Motion Capture System, which was based on Bézier curves. That model allowed for much more precise investigation of spinal kinematics during dynamic trials as compared with other computational models. However, it did not allowed to restrict only selected movements for particular segments of the spine (e.g. axial rotation for lumbar spine). The aim of the current work is to improve the proposed model in order to be able to restrict selected movements according to the knowledge concerning spinal anatomy and spinal range of motion. The new kinematic model of the spine was written in BodyBuilder for Biomechanics Language. For the purpose of visualization also an accurate graphical representation of each vertebra (polygon mesh) was computed and adapted to be compatible with the kinematic model. Using a new version of the model it is possible to perform precise analysis of movement of all vertebrae during such dynamic activities as e.g. gait and forward or lateral bending, as well as to present the results not only on the charts, but also as a 3D animation of movements of a realistically looking spine. The paper describes the new kinematic model and the process of creating graphical representation of the vertebrae. Also sample results obtained using that model are presented