Complex sentence: Many studies on the mechanical properties of brain edema were conducted in the 2000s, most of them based on Finite Element Analysis (FEA), a widely used numerical method in solid mechanics.
Split into simpler sentences: Many studies on the mechanical properties of brain edema have been conducted in the 2000s. Most are based on the technique of Finite Element Analysis (FEA), which is a widely used numerical method in solid mechanics.