The Infection Control Measures Taken in MRI Examination During the COVID-19 Pandemic Prevention and Control Period

Objective:To optimize the magnetic resonance imaging(MRI)detection process in view of the COVID-19 pandemic,standardize and strengthen the infection control and management MRI rooms.Methods:According to the Technical Guide for COVID-19 Prevention and Control in Medical Institutions(3rd Edition),with reference to the current COVID-19 infection control plan,there are three aspects involved in the planning of MRI examination:MRI room management,medical staff management and protection,and patient management,especially the use of full plastic nose strip medical masks.Infection prevention measures are formulated,scientific prevention and control are made,and accurate policies are implemented.Results:MRI examination was carried out according to the infection control and management of MRI room plan during the epidemic,so as to ensure the safety of examination,the safety of patients and the safety of medical staff and no cross infection in hospital.Conclusion:The implementation of proper infection prevention measures during MRI examination in light of COVID-19 ensures that patients wear medical surgical masks with full plastic nose strips throughout the process to avoid cross-infection,ensure the safety of doctors and patients,and maintain the health of the population.

A Model Coupling Method for Shape Prediction

The shape of strip is calculated by iterative method which combines strip plastic deformation model with rolls elastic deformation model through their calculation results, which can be called results coupling method. Be- cause the shape and rolling force distribution are very sensitive to strip thickness transverse distribution% variation, the iterative course is rather unstable and sometimes convergence cannot be achieved. In addition, the calculating speed of results coupling method is low, which restricts its usable range. To solve the problem, a new model cou- pling method is developed, which takes the force distribution between rolls, rolling force distribution and strip＇s exit transverse displacement distribution as basic unknowns, and integrates strip plastic deformation model and rolls elas- tic deformation model as a unified linear equations through their internal relation, so the iterative calculation between the strip plastic deformation model and rolls elastic deformation model can be avoided. To prove the effectiveness of the model coupling method, two examples are calculated by results coupling method and model coupling method re- spectively. The results of front tension stress, back tension stress, strip^s exit gauge, the force between rolls and rolling force distribution calculated by model coupling method coincide very well with results coupling method. How- ever the calculation course of model coupling method is more steady than results coupling method, and its calculating speed is about ten times as much as the maximal speed of results coupling method, which validates its practicability and reliability.