RESUMO
Objective To explore the parameters and effects of local Euler angle in the kinematic simulation of lower limb joints. Methods The hip, femur, patella, tibia, fibula and foot bones were segmented and reconstructed based on one set of computed tomographic (CT) data. The virtual models were imported into 3DSMax for smoothing, optimization, axis regulation and other processing. Models were imported into Unity3D after being processed, and the hip, knee, ankle and metatarsophalangeal joints were simulated with local Euler angle. The scripts were tested to adjust the relevant parameters. The documents were released as executable documents. Results The movement of hip, knee, ankle and metatarsophalangeal joints could be simulated as real movement without exceeding the range of articular fossa (- 170°- 170° in flexion and extension, -30°-80° in abduction and adduction, -40°-60° in rotation of hip joint; 0-140 degrees in flexion of knee joint; -60°-55°in flexion and extension and -30°-20° in varus and evagination of ankle joint; -40°-30° in flexion and extension of metatarsophanlangeal joint). Conclusion The local Euler angle used in Unity3D based on "parent-children" relationship is adapt to simulate the real range of single and whole motion of lower limb joints.
RESUMO
Objective To explore the accuracy of double modality fusion between CT and MRI for human head, based on pair anatomical points registration. Methods CT and MRI were approached in 4 patients, digital imaging and communications in medicine (DICOM) files were loaded on 3D Slicer (version 4. 8. 1), the surface and brain were reconstructed automatically with volume rendering as reconstructed models, 10 surface characters were tested with localization error and would be used as fiducial points, 8 of the points would be chosen as pair-points for registration according the localizing error after 5 localizations, 5 registration groups based on 4, 5, 6, 7, 8 fiducial points were divided. Singular value decomposition (SVD) was employed for registration as a basic algorithm, and fiducial registration error (FRE) was used to evaluate the registration error. Results FRE values of double modality fusion were 2. 68-6. 54 mm. FRE values of 4, 5, 6, 7, 8 fiducial points were (5. 14± 0.97) mm, (4. 71 ±0. 64) mm, (4. 45±0. 59) mm, (4. 13± 0. 55)mm, (3. 54±0. 72) mm respectively. There was no statistical difference between neighbor groups, while in 4 and 8 points groups, the FRE values were different statistically. Conclusion Surface anatomic characters can be used for double modality fusion between CT and MRI; FRE values after CT-MRI double modality fusion are reduced with the increase of points.