Nonlinear Mechanic Model Of Zebrafish Embryo Cell Based On Microgripper Fixation

Cell microinjection technology has the characteristics of high transmission efficiency and low toxicity,which is widely used in medical and biological research and is the basis of biomedicine.Most of the existing microinjection studies focus on the use of micropipettes to immobilize cells,while the use of mechanical clamping devices to immobilize cells is relatively less.Compared with the micropipette,the mechanical clamping device can not only stabilize the cells,but also reduce the deformation of the cells in the process of microinjection.However,under mechanical clamping,the force of the cell is complex,and through the injection experiment,it is found that the cell deformation is obviously different at different injection speed,so the effect of injection speed on cell deformation is studied under the condition of microclamp.Thus a reasonable injection speed is obtained,which is of great significance to reduce cell deformation and improve cell survival rate.It mainly includes the following contents:(1)Aiming at the problem that the original microoperation system could not measure the injection force of cells in the process of injection,a microforce measurement system is added to build and improve the microinjection system.In order to ensure the normal supply of embryonic cells,a set of equipment is built and a complete set of experimental procedures are designed,which laid a foundation for subsequent microinjection experiments.(2)Aiming at the problem that the linear viscoelastic model could not describe the mechanical behavior of cells fixed with microclamps well,a nonlinear viscoelastic model is proposed to describe the mechanical behavior of zebrafish embryo cells during injection based on the linear viscoelastic model,and the cell injection experiments at different speeds are carried out.The results provide theoretical and experimental support for reducing cell deformation.(3)To solve the problem that the traditional optimization algorithm is not accurate enough to solve the model parameters,an intelligent optimization algorithm is introduced into the viscoelastic model solution,and a new objective function(Loss)is designed as the fitness function of ant lion optimization algorithm,which solves the problem of the proportion of key data and ordinary data in the model solution.After several models are solved by ant lion optimization algorithm,the superiority of the twolayer nonlinear model is verified by comparing the evaluation indexes of several models.(4)Based on the above experimental data and two-layer nonlinear model,BP neural network is used to fit the relationship between injection speed and injection force,and then the optimal injection speed with the minimum cell deformation is obtained.Experiments using this speed proved that the optimal injection speed can effectively reduce the deformation of cells,which is of great significance to improve the survival rate of cells.