ObjectiveTo investigate the effect of virtual scene simulation training combined with midium frequency impulse electrotherapy on upper limb function and daily living ability of hemiplegia patients.MethodsFrom March to October 2019, 50 hemiplegic patients were recruited and randomly assigned to the trial group and the control group, with 25 patients in each group. The control group was given routine rehabilitation training, while the trial group was given virtual scene simulation training and medium frequency impulse electrotherapy on the basis of routine rehabilitation training. The Fugl-Meyer Assessment-Upper Extremities (FMA-UE), Simple Test for Evaluating Hand Function (STEF), and Modified Barthel Index (MBI) were used to assess patients’ upper limb function and daily living ability before treatment and after 8 weeks of treatment.ResultsBefore treatment, the FMA-UE, STEF, and MBI scores of the trial group vs. the control group were 22.88±5.18 vs. 23.44±6.26, 40.12±4.82 vs. 41.44±4.54, and 51.40±7.29 vs. 48.60±7.00, respectively, and none of the between-group differences was statistically significant (P>0.05); after 8 weeks of treatment, the FMA-UE, STEF, and MBI scores of the two groups were 39.48±6.35 vs. 33.52±6.53, 59.08±7.54 vs. 52.52±5.83, and 71.00±8.78 vs. 62.40±9.37, respectively, and all of the between-group differences were statistically significant (P<0.05). After 8 weeks of treatment, the FMA-UE, STEF and MBI scores of the two groups of patients were significantly improved compared with those before treatment (P<0.05), and the improvement of each score of the trial group was significantlybetter than that of the control group (P<0.05). No stroke recurrence, electric burn, or other adverse reactions occurred in the two groups after treatment. ConclusionVirtual scene simulation training combined with midium frequency impulse electrotherapy can effectively improve the upper limb function of patients with hemiplegia and improve their quality of life.
In order to investigate the application of lattice Boltzmann method (LBM) in the numerical simulation of computed tomography angiography-derived fractional flow reserve (FFRCT), an idealized narrowed tube model and two coronary stenosis arterymodels are studied. Based on the open source code library (Palabos), the relative algorithm program in the development environment (Codeblocks) was improved. Through comparing and analyzing the results of FFRCT which is simulated by LBM and finite element analysis software ANSYS, and the feasibility of the numerical simulation of FFRCT by LBM was verified . The results show that the relative error between the results of LBM and finite element analysis software ANSYS is about 1%, which vertifies the feasibility of simulating the coronary FFRCT by LBM. The simulation of this study provides technical support for developing future FFRCT application software, and lays the foundation for the calculation of clinical FFRCT.
Artificial bone replacement has made an important contribution to safeguard human health and improve the quality of life. The application requirements of rapid prototyping technology based on reverse engineering in individualized artificial bone with individual differences are particularly urgent. This paper reviewed the current research and applications of rapid prototyping and reverse engineering in artificial bone. The research developments and the outlook of bone kinematics and dynamics simulation are also introduced.
The pulse amplitude of fingertip volume could be improved by selecting the vascular dense area and applying appropriate pressure above it. In view of this phenomenon, this paper used Comsol Multiphysics 5.6 (Comsol, Sweden), the finite element analysis software of multi-physical field coupling simulation, to establish the vascular tissue model of a single small artery in fingertips for simulation. Three dimensional Navier-Stokes equations were solved by finite element method, the velocity field and pressure distribution of blood were calculated, and the deformation of blood vessels and surrounding tissues was analyzed. Based on Lambert Beer's Law, the influence of the longitudinal compression displacement of the lateral light surface region and the tissue model on the light intensity signal is investigated. The results show that the light intensity signal amplitude could be increased and its peak value could be reduced by selecting the area with dense blood vessels. Applying deep pressure to the tissue increased the amplitude and peak of the signal. It is expected that the simulation results combined with the previous experimental experience could provide a feasible scheme for improving the quality of finger volume pulse signal.
Red blood cells are destroyed when the shear stress in the blood pump exceeds a threshold, which in turn triggers hemolysis in the patient. The impeller design of centrifugal blood pumps significantly influences the hydraulic characteristics and hemolytic properties of these devices. Based on this premise, the present study employs a multiphase flow approach to numerically simulate centrifugal blood pumps, investigating the performance of pumps with varying numbers of blades and blade deflection angles. This analysis encompassed the examination of flow field characteristics, hydraulic performance, and hemolytic potential. Numerical results indicated that the concentration of red blood cells and elevated shear stresses primarily occurred at the impeller and volute tongue, which drastically increased the risk of hemolysis in these areas. It was found that increasing the number of blades within a certain range enhanced the hydraulic performance of the pump but also raised the potential for hemolysis. Moreover, augmenting the blade deflection angle could improve the hemolytic performance, particularly in pumps with a higher number of blades. The findings from this study can provide valuable insights for the structural improvement and performance enhancement of centrifugal blood pumps.
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.
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.
The objective of the mock circulatory system (MCS) is to construct the characteristics of cardiovascular hemodynamics. Westerhof ’s resistor that often regarded as the laminar flow resistance in the MCS, is commonly used to simulate the peripheral resistance of the cardiovascular system. However, the theoretical calculation value of fluid resistance of the Westerhof ’s resistor shows distinguished difference with the actual needed value. If the theoretical resistance is regarded as the actual needed one and be used directly in the experiment, the experimental accuracy would not be acceptable. In order to improve the accuracy, an effective correction method for calculating the resistance of Westerhof ’s resistor was proposed in this paper. Simulation software was also developed to compute accurately the capillary number, total length and resistance. The results demonstrate the proposed method is able to reduce the difficulty and complexity of the design of the resistor, which would obviously increase the manufactured precision of the Westerhof ’s resistor. Simulation software would provide great support to the construction of various MCSs.
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.
Virtual clinical trials are clinical trials conducted through computer simulation technology, which breaks through the limitations of traditional clinical trials and has the advantages of saving time, reducing costs, and reducing the risk of human trials. With the application of new computer technologies such as population pharmacokinetics, physiologically-based pharmacokinetics, quantitative systems pharmacology, and artificial intelligence, the field of virtual clinical trials in healthcare has become an important development direction. This article will give a preliminary review of the connotation, methods and future development trends of virtual clinical trials, aiming to provide reference for the application of new technologies and methods in clinical trials.