Objective To systematically analyze and compare the research literature of thoracic surgery simulation-based medical education (SBME) at home and abroad, and provide ideas for the future development of thoracic surgery SBME in China. Methods Using word frequency analysis and cluster analysis as analysis methods, CiteSpace visualization software and Excel statistical software as tools, the domestic and foreign SBME literature retrieved from PubMed and CNKI databases were visualized and statistically analyzed respectively. Results A total of 2 491 domestic and foreign literature on SBME in thoracic surgery were included. The annual number of foreign publications showed an increasing trend. The top three countries in terms of number of publications were the USA (n=581), Canada (n=105) and Germany (n=57); "cardiac surgery", "medical knowledge medical knowledge" and "medical education" are the hotspots of research in the direction of thoracic surgery simulation, while "lung cancer", "surgical training" and "3D printing" were still in the process of explosion. The core research themes were endoscope simulation trainer, scenario-based simulation teaching methods, standardized patients and virtual reality models. Conclusion Domestic SBME in thoracic surgery should learn from foreign development experience, keep up with the frontier and integrate cutting-edge technology, innovate the curriculum and offer non-technical skills teaching, and improve the system and focus on software construction.
Objective To precisely treat compl icated calcaneal fracture by 3D simulation through computer aid designed operation. Methods From November 2007 to March 2008, 38 patients of calcaneal fracture were treated. There were 29 males and 9 females aged 14-69 years old (average 29.8 years old). According to Sanders classification, there were 4 patients oftype I, 14 of type II, 12 of type III, and 8 of type IV. The time between injury and surgery was 3 hours to 5 days. The CT images of calcaneal fracture of 38 patients were put into computer for 3D reconstruction, then the Bouml;hler angles were measured and bone grafting angles were designed. According to the angle surveyed by the computer, the individual-oriented operation program was made, and then the operation was done under C-arm X-ray machine. Results The preoperative Bouml;hler angel was (34.58 ± 4.38)° in the normal side and (8.33 ± 12.62)° in the injured side, indicating there was significant difference (P lt; 0.05). During the process of the poking reduction by 3D simulation, when the bone rotating angle was (28.84 ± 6.51)°, the Bouml;hler angel was restored to (32.86 ± 1.72)°, indicating there was no significant difference when compared with the normal side before operation (P gt; 0.05), and significant difference compared with the injured side before operation (P lt; 0.05). Twenty-eight patients were followed up for 12-22 months (average 18 months). The Bouml;hler angel was restored to (32.41 ± 1.42)° 1 year after operation. According to the foot function scoring system made by American Ankle Surgery Association, 16 cases were graded as excellent, 10 as good, 1 as fair, 1 as poor, and the excellent and good rate was 92.9%. Conclusion Computer aid designed operation of compl icated calcaneal fracture by 3D simulation technique can restore the Bouml;hler angel and subtalar joint precisely. It is aneffective supplementary treatment method for calcaneal fracture.
One of the main technical challenges when integrating magnetic resonance imaging (MRI) systems with medical linear accelerator is the strong interference of fringe magnetic fields from the MRI system with the electron beams of linear accelerator, making the linear accelerator not to work properly. In order to minimize the interference of magnetic fields, a magnetic shielding cylinder with an open structure made of high permeability materials is designed. ANSYS Maxwell was used to simulate Helmholtz coil which generate uniform magnetic field instead of the fringe magnetic fields which affect accelerator gun. The parameters of shielding tube, such as permeability, radius, length, side thickness, bottom thickness and fringe magnetic fields strength are simulated, and the data is processed by MATLAB to compare the shielding performance. This article gives out a list of magnetic shielding effectiveness with different side thickness and bottom thickness under the optimal radius and length, which showes that this design can meet the shielding requirement for the MRI-linear accelerator system.
The purpose of this paper is to report the research and design of control system of magnetic coupling centrifugal blood pump in our laboratory, and to briefly describe the structure of the magnetic coupling centrifugal blood pump and principles of the body circulation model. The performance of blood pump is not only related to materials and structure, but also depends on the control algorithm. We studied the algorithm about motor current double-loop control for brushless DC motor. In order to make the algorithm adjust parameter change in different situations, we used the self-tuning fuzzy PI control algorithm and gave the details about how to design fuzzy rules. We mainly used Matlab Simulink to simulate the motor control system to test the performance of algorithm, and briefly introduced how to implement these algorithms in hardware system. Finally, by building the platform and conducting experiments, we proved that self-tuning fuzzy PI control algorithm could greatly improve both dynamic and static performance of blood pump and make the motor speed and the blood pump flow stable and adjustable.
ObjectiveTo analyze the effect of 3D simulation technique in thoracoscopic lobectomy.MethodsFrom June 2015 to January 2018, 124 patients with left lower lobe resection underwent thoracoscopy with single-port thoracoscopic surgery, including 64 males and 60 females, aged 42–83 years. They were randomly divided into two groups including an experimental group (preoperatively given 3D simulation surgery in 59 patients) and a control group (preoperatively not given 3D simulation surgery in 65 patients). The clinical effect between the two groups was compared.ResultsAll patients recovered without any death during hospitalization. In the experimental group, the operation time, intraoperative blood loss and postoperative hospital stay were significantly less than those in the control group (P<0.05). There was no significant difference in postoperative drainage volume, and duration of drainage tube retention and analgesic drug usage between the two groups (P>0.05).Conclusion3D simulation technique for thoracoscopic lobectomy has advantage in short operation time, minor trauma and quick recovery. It has a guiding role in the preoperative planning of lung cancer surgery and is worthy of popularization and application.
In this study, a closed-loop controller for chest compression which adjusts chest compression depth according to the coronary perfusion pressure (CPP) was proposed. An effective and personalized chest compression method for automatic mechanical compression devices was provided, and the traditional and uniform chest compression standard neglecting individual difference was improved. This study rebuilds Charles F. Babbs human circulation model with CPP simulation module and proposes a closed-loop controller based on a fuzzy control algorithm. The performance of the fuzzy controller was evaluated and compared to that of a traditional PID controller in computer simulation studies. The simulation results demonstrated that the fuzzy closed-loop controller produced shorter regulation time, fewer oscillations and smaller overshoot than those of the traditional PID controller and outperforms the traditional PID controller in CPP regulation and maintenance.
The mechanical behavior modeling of human soft biological tissues is a key issue for a large number of medical applications, such as surgery simulation, surgery planning, diagnosis, etc. To develop a biomechanical model of human soft tissues under large deformation for surgery simulation, the adaptive quasi-linear viscoelastic (AQLV) model was proposed and applied in human forearm soft tissues by indentation tests. An incremental ramp-and-hold test was carried out to calibrate the model parameters. To verify the predictive ability of the AQLV model, the incremental ramp-and-hold test, a single large amplitude ramp-and-hold test and a sinusoidal cyclic test at large strain amplitude were adopted in this study. Results showed that the AQLV model could predict the test results under the three kinds of load conditions. It is concluded that the AQLV model is feasible to describe the nonlinear viscoelastic properties of in vivo soft tissues under large deformation. It is promising that this model can be selected as one of the soft tissues models in the software design for surgery simulation or diagnosis.
Objective To explore the effectiveness and predictive value of computer simulated thoracic endovascular aortic repair (TEVAR). Methods The clinical data of the patients with Stanford type B aortic dissection who underwent TEVAR from February 2019 to February 2022 in our hospital was collected. According to whether there was residual false cavity around the stent about 1 week after TEVAR, the patients were divided into a false cavity closure group and a false cavity residual group. Based on computer simulation, personalized design and three-dimensional construction of the stent framework and covering were carried out. After the stent framework and membrane were assembled, they were pressed and placed into the reconstructed aortic dissection model. TEVAR computer simulation was performed, and the simulation results were analyzed for hemodynamics to obtain the maximum blood flow velocity and maximum wall shear stress at the false lumen outlet level at the peak systolic velocity of the ventricle, which were compared with the real hemodynamic data of the patient after TEVAR surgery. The impact of hemodynamics on the residual false lumen around the stent in the near future based on computer simulation of hemodynamic data after TEVAR surgery was further explored. Results Finally a total of 28 patients were collected, including 24 males and 4 females aged 53.390±11.020 years. There were 18 patients in the false cavity closure group, and 10 patients in the false cavity residual group. The error rate of shear stress of the distal decompression port of the false cavity after computer simulation TEVAR was 6%-25%, and the error rate of blood flow velocity was 3%-31%. There was no statistical difference in age, proportion of male, history of hypertension, history of diabetes, smoking history, prothrombin time or activated partial thromboplatin time at admission between the two groups (all P>0.05). The blood flow velocity and shear stress after TEVAR were statistically significant (all P<0.05). The maximum shear stress (OR=1.823, P=0.010) of the false cavity at the level of the distal decompression port after simulated TEVAR was an independent risk factor for the residual false cavity around the stent. Receiver operating characteristic curve analysis showed that the area under the curve corresponding to the maximum shear stress of false cavity at the level of distal decompression port after simulated TEVAR was 0.872, the best cross-sectional value was 8.469 Pa, and the sensitivity and specificity were 90.0% and 83.3%, respectively. Conclusion Computers can effectively simulate TEVAR and perform hemodynamic analysis before and after TEVAR surgery through simulation. Maximum shear stress at the decompression port of the distal end of the false cavity is an independent risk factor for the residual false cavity around the stent. When it is greater than 8.469 Pa, the probability of residual false cavity around the stent increases greatly.
Aiming at the problem of scaffold degradation in bone tissue engineering, we studied the feasibility that controlls bone defect repair effect with the inhomogeneous structure of scaffold. The prediction model of bone defect repair which contains governing equations for bone formation and scaffold degradation was constructed on the basis of analyzing the process and main influence factors of bone repair in bone tissue engineering. The process of bone defect repair and bone structure after repairing can be predicted by combining the model with finite element method (FEM). Bone defect repair effects with homogenous and inhomogeneous scaffold were simulated respectively by using the above method. The simulation results illustrated that repair effect could be impacted by scaffold structure obviously and it can also be controlled via the inhomogeneous structure of scaffold with some feasibility.
Brain-controlled wheelchair (BCW) is one of the important applications of brain-computer interface (BCI) technology. The present research shows that simulation control training is of great significance for the application of BCW. In order to improve the BCW control ability of users and promote the application of BCW under the condition of safety, this paper builds an indoor simulation training system based on the steady-state visual evoked potentials for BCW. The system includes visual stimulus paradigm design and implementation, electroencephalogram acquisition and processing, indoor simulation environment modeling, path planning, and simulation wheelchair control, etc. To test the performance of the system, a training experiment involving three kinds of indoor path-control tasks is designed and 10 subjects were recruited for the 5-day training experiment. By comparing the results before and after the training experiment, it was found that the average number of commands in Task 1, Task 2, and Task 3 decreased by 29.5%, 21.4%, and 25.4%, respectively (P < 0.001). And the average number of commands used by the subjects to complete all tasks decreased by 25.4% (P < 0.001). The experimental results show that the training of subjects through the indoor simulation training system built in this paper can improve their proficiency and efficiency of BCW control to a certain extent, which verifies the practicability of the system and provides an effective assistant method to promote the indoor application of BCW.