A research on epilepsy source localization from scalp electroencephalograph based on patient-specific head model and multi-dipole model / 生物医学工程学杂志

Accurate source localization of the epileptogenic zone (EZ) is the primary condition of surgical removal of EZ. The traditional localization results based on three-dimensional ball model or standard head model may cause errors. This study intended to localize the EZ by using the patient-specific head model and multi-dipole algorithms using spikes during sleep. Then the current density distribution on the cortex was computed and used to construct the phase transfer entropy functional connectivity network between different brain areas to obtain the localization of EZ. The experiment result showed that our improved methods could reach the accuracy of 89.27% and the number of implanted electrodes could be reduced by (19.34 ± 7.15)%. This work can not only improve the accuracy of EZ localization, but also reduce the additional injury and potential risk caused by preoperative examination and surgical operation, and provide a more intuitive and effective reference for neurosurgeons to make surgical plans.

Research progress and application of head finite element model / 医用生物力学

The finite element method (FEM) is a technology for numerical analysis which based on the development of the electronic computer, and also a more advanced biomechanical research method. Early FEM was applied in the fields of engineering science and technology. In recent years, FEM has been widely used for brain research in biomedical engineering. With the rapid development of traffic and transportation, the high incident of craniocerebral injury has become a serious threat to human health year by year. The biomechanical mechanism of craniocerebral injury can be well researched by establishing the finite element model of human head. In this review, establishment, development and application of human head finite element model are summarized, and the future research direction is discussed as well.

Research progress and application of head finite element model / 医用生物力学

The finite element method (FEM) is a technology for numerical analysis which based on the development of the electronic computer,and also a more advanced biomechanical research method.Early FEM was applied in the fields of engineering science and technology.In recent years,FEM has been widely used for brain research in biomedical engineering.With the rapid development of traffic and transportation,the high incident of craniocerebral injury has become a serious threat to human health year by year.The biomechanical mechanism of craniocerebral injury can be well researched by establishing the finite element model of human head.In this review,establishment,development and application of human head finite element model are summarized,and the future research direction is discussed as well.

Monte Carlo dose calculation based on the virtual source model with linear accelerator and its preliminary application in independent dose calculation for IMRT plans / 中华放射肿瘤学杂志

Objective To investigate the feasibility of the virtual source model in Monte Carlo dose calculation for clinical radiotherapy.Methods The Monte Carlo simulation was used to obtain the phase space files which recorded the physical properties of the particles emitted by a medical linear accelerator, and the information on the type, energy spectrum, and distribution of particles were extracted from these files and analyzed to establish the semi-empirical model of virtual two-photon source.The GMC dose calculation engine was used to obtain the 3 cm×3 cm, 5 cm×5 cm, 10 cm×10 cm, 20 cm×20 cm, and 30 cm×30 cm fields of radiotherapy and the results of Monte Carlo simulation of dose distribution in three-dimensional water phantom in 2 intensity-modulated radiotherapy ( IMRT) plans.These results were compared with the results of water phantom measurement or the results of Elekta Monaco planning system to verify the accuracy of Monte Carlo dose calculation based on a virtual source.Results As for the percentage depth-dose distribution curves of the central axis of the water phantom and the off-axis dose curves at different depths in the five fields for radiotherapy, the difference between the results of Monte Carlo simulation and the results of measurement was within 1%.As for the two IMRT plans, the three-dimensional passing rates of Monaco calculation results and Monte Carlo simulation results were 98.9%and 99.4%, respectively, for 3%/3 mm, and 95.1%and 95.4%, respectively, for 2%/2 mm.Conclusions Monte Carlo simulation based on the virtual source model can obtain accurate results of radiotherapy dose calculation.