Objective To evaluated the application effect of reverse digital modeling combined with three-dimensional (3D)-printed disease models in the standardized training of orthopedic residents focusing on pelvic tumors. Methods From August 2022 to August 2023, 60 orthopedic residents from West China Hospital, Sichuan University were randomly assigned to a trial group (n=30) and a control group (n=30). The trial group received instruction using reverse digital modeling and 3D-printed pelvic tumor models, while the control group underwent traditional teaching methods. Teaching outcomes were evaluated and compared between groups through knowledge tests, practical skill assessments, and satisfaction surveys. Results Before training, there was no statistically significant difference in knowledge tests or practical skill assessments between the two groups (P>0.05). After training, the trial group showed significantly better performance than the control group in knowledge tests (90.5±5.2 vs. 78.4±6.8, P<0.05), skill assessments (92.7±4.9 vs. 81.3±6.2, P<0.05), and satisfaction surveys (9.40±1.10 vs. 7.60±1.20, P<0.05). One month after training, the trial group still showed significantly better performance than the control group in knowledge tests (88.1±6.4 vs. 72.3±7.1, P<0.05) and skill assessments (90.3±5.8 vs. 75.6±6.9, P<0.05). Conclusions Reverse digital modeling combined with 3D printing offers an intuitive and effective teaching approach that improves comprehension of pelvic tumor anatomy and strengthens clinical and technical competencies. This method significantly enhances learning outcomes in standardized residency training and holds promise for broader integration into medical education.
Valvular heart disease is a structural or functional disease of the heart due to rheumatic fever, congenital malformation, infection, or trauma, resulting in abnormal cardiac hemodynamics and ultimately heart failure. Implantation of artificial heart valves has become the main way to treat heart valvular disease. Because the structure of the artificial heart valve plays a key role in the stress distribution and hemodynamic performance of the valve and stent, the geometric configuration of the artificial heart valve is constantly updated and improved during its development from mechanical valve to biological valve, which closely mimics the geometric characteristics of the normal natural heart valve. This article sums up the design process of geometric configuration of artificial heart valves and the influence of geometric configuration on the central disc stress and durability of artificial heart valves, analyzes the important parameters of geometric modeling for artificial heart valves, and discusses the development of the corresponding modeling method, to provide reference and new ideas for the biomimetic optimization design of artificial valves.
ObjectiveSystemic lupus erythematosus (SLE) patients from a SLE family with homogeneity can provide experimental basis for individualized diagnosis and treatment by studying the characteristics of laboratory tests and symptoms.
MethodsLaboratory tests were analyzed for three SLE patients in the family, and set up the screen model by three laboratory tests (anitnuclear antibody positive, rheumatoid factor positive and IgE positive, ANA+RF+IgE+). All SLE cases were screened from latest four years as SLE subtype patients (named "similar family SLE patients"), then the family laboratory tests and clinical characteristics were analyzed.
ResultsA total of 55 patients (6.27%) were screened as similar family SLE patients from individual SLE patients according to model from 877 cases. The laboratory tests of similar family SLE patients including creatinine, WBC, CRP were significant lower than other SLE patients (P < 0.05), but significant higher for the IgG, positive rate of anti-SSA and anti-SSB (P < 0.05), and the alopecia and skin rashes were more common in similar family SLE patients than other SLE patients.
ConclusionsThe ANA+RF+IgE+ SLE patients are of lower inflammatory state and kidney involvement; Clinical symptom is priority to alopecia and skin rashes.
The Monte Carlo N-Particle (MCNP) is often used to calculate the radiation dose during computed tomography (CT) scans. However, the physical calculation process of the model is complicated, the input file structure of the program is complex, and the three-dimensional (3D) display of the geometric model is not supported, so that the researchers cannot establish an accurate CT radiation system model, which affects the accuracy of the dose calculation results. Aiming at these two problems, this study designed a software that visualized CT modeling and automatically generated input files. In terms of model calculation, the theoretical basis was based on the integration of CT modeling improvement schemes of major researchers. For 3D model visualization, LabVIEW was used as the new development platform, constructive solid geometry (CSG) was used as the algorithm principle, and the introduction of editing of MCNP input files was used to visualize CT geometry modeling. Compared with a CT model established by a recent study, the root mean square error between the results simulated by this visual CT modeling software and the actual measurement was smaller. In conclusion, the proposed CT visualization modeling software can not only help researchers to obtain an accurate CT radiation system model, but also provide a new research idea for the geometric modeling visualization method of MCNP.
During transfer tasks, the dual-arm nursing-care robot require a human-robot mechanics model to determine the balance region to support the patient safely and stably. Previous studies utilized human-robot two-dimensional static equilibrium models, ignoring the human body volume and muscle torques, which decreased model accuracy and confined the robot ability to adjust the patient’s posture in three-dimensional spatial. Therefore, this study proposes a three-dimensional spatial mechanics modeling method based on individualized human musculoskeletal multibody dynamics. Firstly, based on the mechanical features of dual-arm support, this study constructed a foundational three-dimensional human-robot mechanics model including body posture, contact position and body force. With the computed tomography data from subjects, a three-dimensional femur-pelvis-sacrum model was reconstructed, and the individualized musculoskeletal dynamics was analyzed using the ergonomics software, which derived the human joint forces and completed the mechanic model. Then, this study established a dual-arm robot transfer platform to conduct subject transfer experiments, showing that the constructed mechanics model possessed higher accuracy than previous methods. In summary, this study provides a three-dimensional human-robot mechanics model adapting to individual transfers, which has potential application in various scenarios such as nursing-care and rehabilitating robots.
【Abstract】 Objective To investigate the qual itative rotation al ignment of components in total knee arthroplastyand the accuracy and the effectiveness of Bone Morphing computer assisted system when qual itatively practicing. MethodsFrom November 2002 to June 2003, 21 patients with three compartments osteoarthritis(21 knees) were treated by primarytotal knee arthroplasty after the conservative medical treatment failed, with the assistance of a “Bone Morphing” CeravisionSystem, implanted posterior stabil ized total knee prosthesis. Twenty-one patients included 5 males (5 knees) and 16 females (16knees) with an average age of 72.4 years (64-79 years) . The locations were left knee in 10 cases and right knee in 11 cases. Thepatients suffered from knee pain and l imitation of movement from 2 to 10 years. There were 14 genu varum and 7 genu valgumpreoperatively. The relative preoperative, intraoperative and postoperative data from cl inical check-up, the X-ray films and theintraoperative components rotational al ignment real-time records in CD Rom were analyzed. Results All operative incisionshealed up by first intension. Twenty-one patients were followed up 12-16 months(mean 13.3 months). For the achievement ofproper lower l imb al ignment and normal frontal laxity of knee, rotational al ignment of femoral components was from internalrotation (IR)1° to external rotation (ER) 5°, tibial components from IR 0° to ER 5°. In patients with genu varum, the rotationalal ignment of the femoral components was ER 1°- ER 5°, of tibial components ER 2°- ER 5°. In patients with genu valgum, the rotationalal ignment of femoral components was IR 1°- ER 4°, of tibial components IR 0°-ER 4°. After 3 months of operation, themean flexion angle measured as range of motion (ROM) was 115°(105-130°), the frontal laxsity measured as 0.2-0.5 cm (mean0.27 cm) of internal laxity and 1.0-2.5 cm (mean 1.7 cm) for external laxity, there were no knee pain, paterllar instabil ity or dislocationand abnormal knee frontal laxity. Conclusion Using Bone Morphing computer-assisted system can optimise theindividual components rotation al ignment accurately.
The human skeletal muscle drives skeletal movement through contraction. Embedding its functional information into the human morphological framework and constructing a digital twin of skeletal muscle for simulating physical and physiological functions of skeletal muscle are of great significance for the study of "virtual physiological humans". Based on relevant literature both domestically and internationally, this paper firstly summarizes the technical framework for constructing skeletal muscle digital twins, and then provides a review from five aspects including skeletal muscle digital twins modeling technology, skeletal muscle data collection technology, simulation analysis technology, simulation platform and human medical image database. On this basis, it is pointed out that further research is needed in areas such as skeletal muscle model generalization, accuracy improvement, and model coupling. The methods and means of constructing skeletal muscle digital twins summarized in the paper are expected to provide reference for researchers in this field, and the development direction pointed out can serve as the next focus of research.
It is very difficult for stroke patients to complete the action of squatting-standing because their equilibrium function ability has been seriously declined. It was necessary, therefore, to do a deep research on the action of human squatting-standing and to set up an accurate model and simulation. In our modeling research, the movements of upper limbs and head was neglected, and a seven-segment model was developed to establish the coordinate system of human squatting-standing action. It calculated the knee joint moment and hip joint moment during squatting and standing by utilizing Lagrange method, and then simulated this mathematical model by utilizing Matlab. Geometric model of human squatting-standing was developed and simulated in ADAMS which proved that the established Lagrange model was reasonable. It would also provide significant theoretical references for further study and development of squatting-standing rehabilitation training equipment.
In the present study, a finite element model of L4-5 lumbar motion segment was established based on the CT images and a combination with image processing software, and the analysis of lumbar biomechanical characteristics was conducted on the proposed model according to different cases of flexion, extension, lateral bending and axial rotation. Firstly, the CT images of lumbar segment L4 to L5 from a healthy volunteer were selected for a three dimensional model establishment which was consisted of cortical bone, cancellous bone, posterior structure, annulus, nucleus pulposus, cartilage endplate, ligament and facet joint. The biomechanical analysis was then conducted according to different cases of flexion, extension, lateral bending and axial rotation. The results showed that the established finite element model of L4-5 lumbar segment was realistic and effective. The axial displacement of the proposed model was 0.23, 0.47, 0.76 and 1.02 mm, respectively under the pressure of 500, 1 000, 1 500 and 2 000 N, which was similar to the previous studies in vitro experiments and finite element analysis of other people under the same condition. The stress distribution of the lumbar spine and intervertebral disc accorded with the biomechanical properties of the lumbar spine under various conditions. The established finite element model has been proved to be effective in simulating the biomechanical properties of lumbar spine, and therefore laid a good foundation for the research of the implants of biomechanical properties of lumbar spine.
