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Virtual Animation of the Kinematics of the Human for Industrial, Educational and Research Purposes

Preliminary results

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Tutorials have been written from VAKHUM results. They have been integrated in both multimedia presentations (*.AVI) and 3D environment (*.wrl).

Three fully interactive VRML simulations are available from here. Do not forget to read the introduction file before using the simulations.

Data collection for the full limb has to be performed in two steps because of the limited scanning size of the CT installation.Therefore, two datasets (A and B) were obtained. From A: full data for the pelvic bone, femoral bone, patella (in green) were obtained. From B: full data for the tibial bone, fibula and foot (in yellow) were obtained. Obviously, the beginning of the animation shows that the dataset B is not correctly aligned under dataset A. Therefore, we developed a fully automated registration procedure to align B to A (average RMS error: < 0.5 mm). A simulation of the registration result is shown here. At the end, the dataset B is aligned according to A. Therefore, full dataset for the lower limb is obtained.

This simulation of motion have been obtained after registration of 1- medical imaging (CT-scan) data and 2- 6 dofs electrogoniometry. All data were collected in vitro on the same specimen. The simulation uses all 6 degrees-of-freedom available from the goniometry. This animation shows the recorded motion for 1- the hip, 2- the knee, 3- the ankle, 4- a combination of 1, 2 and 3.

These animations shows the results of a registration between a skeleton obtained from a specimen (female, 1m55, in vitro from medical imaging) and in vivo gait analysis obtained on a volunteer (male, 1m75). Six degrees-of-freedom can be interpolated from the original gait files. Note three degrees-of-freedom, i.e. the rotations, have been used here, and allow therefore a smooth and natural simulation. The other three degrees-of-freedom, i.e. the translations, have been discarded because of the typical inaccuracy of the translations by gait analysis protocols. Several daily activities (walk, stair ascend/descend, chair sitting/rising, squad, biking, jump) have been collected on each volunteer. Small artefacts are still present (joint dislocation/collision): the VAKHUM consortium keeps working to improve the results. Note, no data on the forefoot kinematics nor the patella was used for these simulations.

This animation shows the location of the helical axis for a motion of flexio-extension, and the mean helical axis for the pro-supination of the forearm. Note, these results have been obtained from experimental protocols developed within VAKHUM to validate our protocol.

A menu has been integrated within the interface of the VRML animations (see beside). "Flexion" allows you to start the motion simulation. Other buttons allow displaying of either the main helical axis of motion, or the anatomical axes, or both. Do not forget you are in a fully interactive environment, and therefore you are able to rotate/scale/translate the model. We made several pre-selected point-of-views available from the control list included in the interface.

This is already history ... we are keeping it to visualize our progresses. These simulations of motion have been obtained after registration of 1- medical imaging (CT-scan) data and 2- full gait analysis data. All data were collected on the same volunteer. The simulation use all 6 degrees-of-freedom from the gait analysis to animate the 3D models of the subject knee. Registration occurs using a rigid protocol for the location of the anatomical landmarks.



We hope you will enjoy it !!
We do like criticims, so please feel free to send us any comment (to sintjans@ulb.ac.be).
Last update: 16 December 2002