1) bed elevator shows consideration for medical needs and is humanized designed 2) its super-smooth moving provides quiet and comfort for patients 3) its fine structure shows care for patients and warm color improves the confident for patients 4) it adopts advanced technology and introduces the newest vvvf (variable voltage and variable frequency) speed regulation system 5) it absolutely satisfies the needs of modern society and the needs of the physical conditions of patients 6) the smooth speed command curve generated by the computer makes the elevator starting, accelerating, decelerating and stopping strictly follow this ideal curve, which is safer, more comfortable and smoother than other elevators