Abstract
Direct injection of retinal cells into the eyes of patients is a new and better therapeutic method for cataract, but the challenge is that the survival rate of cells during injection is very low. In order to solve this problem, in this study, the force distribution of retinal cells in the injectors with two needle shapes was analysed using coupled discrete element method with computational fluid dynamics (DEM-CFD), in which an immersed boundary method was implemented. Two injectors were considered: one with a straight needle and the other with a curved needle. It was found that the velocities of retinal cells in the injector with a straight needle were slightly higher than that with a curved needle. In addition, the injection speed greatly affected the force distribution of retinal cells, and the retinal cells near the piston were subjected to the highest forces during injection. It was also found that the forces on retinal cells increased as the concentration of the cells increase, and the forces of retinal cells increased evidently with the increasing of piston displacement.