Objective To evaluate clinical efficacy of four-claw Ti-planes for internal fixation of multiple rib fractures and flail chest. Methods Clinical data of 93 patients with multiple rib fractures and flail chest who were admittedto Shanghai Pudong Hospital from December 2011 to November 2012 were retrospectively analyzed. There were 78 male and 15 female patients with their age of 20-80 years. All the patients received internal fixation of rib fractures using four-clawTi-planes. Finite element modeling and analysis were performed to investigate biomechanical behaviors of rib fractures after internal fixation with four-claw Ti-planes. Results The average number of rib fractures of the 93 patients was 5.9±2.1，and each patient received 3.8±1.3 four-claw Ti-planes for internal fixation. The operations were performed 6.3±3.2 days after admission. After the rib fractures were fixed with four-claw Ti-planes，rib dislocations and chest-wall collapse of flail chest were restored，and patients’ pain was relieved. Postoperative CT image reconstruction of the chest showed no dislocationor displacement at the fixation areas of the four-claw Ti-planes. Rib fractures were stabilized well，and normal contours of the chest were restored. Finite element analysis showed that the maximum bearable stress of the rib fractures after internal fixation with four-claw Ti-planes was twice as large as normal ribs. Conclusion Clinical outcomes of four-claw Ti-planesfor internal fixation of rib fractures are satisfactory with small incisions and less muscle injury of the chest wall，so this technique deserves wide clinical use.
【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.
Objective To investigate effectiveness of applying the Bone Morphingbased image-free computer-assisted system for the ligament balancing managementin the total knee arthroplasty (TKA). Methods Between November 2002 and June 2003, twenty-one posterior stabilized total knee prostheses (Ceraver, France) were implanted in 21 patients using the Bone Morphing based image-free Ceravision system.This cohort included 5 men and 16 women with an average age of 72.4 years, two undergoing high tibial osteotomy and 1 undergoing distal femoral osteotomy before. The preoperative deviation was measured by the full-length AP X-rays. The knees were in varus deviation in 14 patients and in valgus deviation in 7 patients, with an average of 2.36°(varus 13°-valgus 13°). The frontal X-rays ofthe knee were assessed, the mean value of the varus force-stress test was 8.47°(varus 2°-varus 20°), and the mean value of the valgus forcestress test was 3.63°(varus 7°-valgus 12°). Results With the Ceravisionrecorded data, the intraoperative alignment was assessed, the mean lower limb axis was 3.33°(varus 12°-valgus 10°),and compared with the preoperative data, the difference was significant (Plt;0.05); the mean value of the varus force-stress test was 6.47°(varus 0°-varus 24°), the mean value of the valgus force-stress test was 4.32°(varus 8°- valgus 15°), and compared with the preoperative data, the difference was significant (Plt;0.05). The post-prosthetic alignment on Ceravision with a deviation of 0.175°(varus 2°- valgus 3°) was compared with the postoperative alignment by the full-length AP X-rays, with a deviation of 0.3°(varus 3.5°-valgus 1.5°), the difference wasn’t significant(Pgt;0.05).The clinical check-up performed 3 months after operation showed that the average range of movement (ROM) was 115°(105-130°), the mean frontal laxity was 0.27 mm(0.2-0.5 mm). The femoral and tibial components were implanted in the satisfactory 3 dimensional position without ligament imbalance in all the patients, andthere were no instability or patella complications.Conclusion Utilization of the Bone Morphing based image-free computer-assisted system can achieve an accurate component 3 dimensional alignment, optimal bone resection, optimal control of surgical decision in releasing the soft tissues, rotating the femoral component to gain an extension/flexion rectangular gap, and managing theligament balancing so as to achieve a satisfactory initial clinical outcome. This system can be routinely used in the TKA.
A good cushion can not only provide the sitter with a high comfort, but also control the distribution of the hip pressure to reduce the incidence of diseases. The purpose of this study is to introduce a computer-aided design (CAD) modeling method of the buttocks-cushion using numerical finite element (FE) simulation to predict the pressure distribution on the buttocks-cushion interface. The buttock and the cushion model geometrics were acquired from a laser scanner, and the CAD software was used to create the solid model. The FE model of a true seated individual was developed using ANSYS software (ANSYS Inc, Canonsburg, PA). The model is divided into two parts, i.e. the cushion model made of foam and the buttock model represented by the pelvis covered with a soft tissue layer. Loading simulations consisted of imposing a vertical force of 520N on the pelvis, corresponding to the weight of the user upper extremity, and then solving iteratively the system.
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.
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.
Integration of heterogeneous systems is the key to hospital information construction due to complexity of the healthcare environment. Currently, during the process of healthcare information system integration, people participating in integration project usually communicate by free-format document, which impairs the efficiency and adaptability of integration. A method utilizing business process model and notation (BPMN) to model integration requirement and automatically transforming it to executable integration configuration was proposed in this paper. Based on the method, a tool was developed to model integration requirement and transform it to integration configuration. In addition, an integration case in radiology scenario was used to verify the method.
The present paper proposed a central-driven structure of upper limb rehabilitation robot in order to reduce the volume of the robotic arm in the structure, and also to reduce the influence of motor noise, radiation and other adverse factors on upper limb dysfunction patient. The forward and inverse kinematics equations have been obtained with using the Denavit-Hartenberg (D-H) parameter method. The motion simulation has been done to obtain the angle-time curve of each joint and the position-time curve of handle under setting rehabilitation path by using SolidWorks software. Experimental results showed that the rationality with the central-driven structure design had been verified by the fact that the handle could move under setting rehabilitation path. The effectiveness of kinematics equations had been proved, and the error was less than 3°by comparing the angle-time curves obtained from calculation with those from motion simulation.
The hydrodynamic behavior of the perfusion process (cleaning) of the liver endovascular before the operation was studied to provide a theoretical guidance to the relative operations. A straight and a curved first-class vascular entity model with foreign matter and the control equations of turbulence liquid in vessel was established. With the physical parameters of a medical infusion liquid measured, an estimation method of perfusion parameters as an example, the perfusion velocity was proposed. The simulation was performed by changing technical parameters of the perfusion. Based on the control equations of turbulent liquid in vessel and the preliminarily calculated results using the vessel model, the results fitted the values of the real operation. The simulation results showed clearly the fluid dynamics behavior around the foreign matter, for example the swirling flow. The results also showed the distribution of velocity of the fluid and the wall pressure of the vessels. With the increasing velocity of the entrance perfusion, the pressure and the velocity field were increased in the two types of the vessel model. The negative wall pressure and recirculation region appeared and located in the foreign matter. Because of influence of the shape, the fluid dynamics behavior in the curved vessel model was more complicated than that in the straight vessel model. The swirling flow and the phenomenon of stagnation of the perfusion fluid were more likely to appear in the curved vessel than in the straight vessel. The most important conclusion of this paper is that the appropriate perfusion velocity can be esti-mated using the methods proposed in this paper.