Numerical simulation of stent deployment is very important to the surgical planning and risk assess of the interventional treatment for the cardio-cerebrovascular diseases. Our group developed a framework to deploy the braided stent and the stent graft virtually by finite element simulation. By using the framework, the whole process of the deployment of the flow diverter to treat a cerebral aneurysm was simulated, and the deformation of the parent artery and the distributions of the stress in the parent artery wall were investigated. The results provided some information to improve the intervention of cerebral aneurysm and optimize the design of the flow diverter. Furthermore, the whole process of the deployment of the stent graft to treat an aortic dissection was simulated, and the distributions of the stress in the aortic wall were investigated when the different oversize ratio of the stent graft was selected. The simulation results proved that the maximum stress located at the position where the bare metal ring touched the artery wall. The results also can be applied to improve the intervention of the aortic dissection and the design of the stent graft.
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.
Simulations can mimic the environment that refers to the surgery operation to improve the technical skills of the trainees. In this paper, we designed a new cardiac surgery simulative training system. The isolated pig heart was selected as the heart model. A mechanical device was designed to achieve the beating of heart model. At the same time, adjusting frequencies of mechanical movement could change the rating of heartbeat. In order to validate the rationality of the system, 12 non-medical specialty students and 12 medical specialty students were divided into two groups, which consecutively accepted seven-days of training for off-pump coronary artery bypass grafting using the cardiac surgery simulative training system. The time for completing bypass grafting before and after training were recorded. And the bridging outcomes of each trainee were assessed by 3 surgery cardiac surgeons using the object structured assessments of technical skill (OSATS) criteria. After training, each trainee could finish the bypass suturing in a shorter time than before training, and the scores of each trainee assessed by OSATS criteria were also improved. The results showed that the cardiac surgery simulative training system had better training effect in improving the surgical techniques, operation skills and proficiency of surgical instruments of trainees.
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.
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.
Medical simulation teaching is a bridge course from theoretical knowledge to clinical practice. At present, the medical simulation teaching is facing many problems. The iSIM is a systematic method to optimize medical simulation teaching. It aims to maximize the effect of medical simulation teaching by various teaching methods and assistant technologies. The combination of iSIM and medical simulation teaching can develop the correct clinical thinking, improve the clinical skills and strengthen the communication skills, so as to improve the medical quality in the real clinical environment. Based on experience Center of Experimental Teaching on Clinical Skills of West China Hospital , this paper introduces how to use iSIM to optimize medical simulation teaching.
The prevalence of cardiovascular disease in our country is increasing, and it has been a big problem affecting the social and economic development. It has been demonstrated that early intervention of cardiovascular risk factors can effectively reduce cardiovascular disease-caused mortality. Therefore, extensive implementation of cardiovascular testing and risk factor screening in the general population is the key to the prevention and treatment of cardiovascular disease. However, the categories of devices available for quick cardiovascular testing are limited, and in particular, many existing devices suffer from various technical problems, such as complex operation, unclear working principle, or large inter-individual variability in measurement accuracy, which lead to an overall low popularity and reliability of cardiovascular testing. In this study, we introduce the non-invasive measurement mechanisms and relevant technical progresses for several typical cardiovascular indices (e.g., peripheral/central arterial blood pressure, and arterial stiffness), with emphasis on describing the applications of biomechanical modeling and simulation in mechanism verification, analysis of influential factors, and technical improvement/innovation.
ObjectiveTo propose a path planning method for precise robot-assisted bronchial intervention. MethodsIn the MuJoCo dynamic simulation environment, a simulation model and a simulated bronchus model which could accurately represent the motion process of the robot were built. Based on the Informed RRT* algorithm, the known spatial information was used to improve the path planning method and the motion characteristics of the robot were simulated to verify the ability of the robot algorithm to reach the target position. ResultsIn the dynamic simulation environment, the robot could move as required, and could explore the target point of the planning task in a short time, and the position accuracy was improved by more than 50% compared with the existing electromagnetic navigation and other methods. ConclusionThe established simulation model can restore the motion of the robot, and the robot has the ability to move in the bronchial environment. The proposed method can precisely control the simulated robot to enter the more peripheral airway position. It has the advantages of accuracy and faster speed than traditional manual interventional surgery, and can be used for the human-machine coordinated control task of robot-assisted bronchoscopy.
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.
Heat sensitive protein medicines are increasingly exhibiting their critical importance on treatment of various diseases at present. But their popularization and application meet a great challenge because of their heat instability. In the present study, insulin was taken as a heat sensitive protein medicine and amino acid as bio-protective agent in order to investigate if these amino acids can protect the insulin from losing its bioactivity due to desiccation. The experiment was performed by using replica exchange molecular simulation (REMD) method and Gromacs software with Gromos96 (53a6) force field. The REMD results indicated that these amino acids could protect the bioactive structure of insulin during desiccation. The configurations of the protected insulin were preserved very well. Those results proved that amino acid is a kind of good bioactive protective agent for the heat sensitive protein medicines.