A catheter system for use in minimally invasive cardiac surgical procedures. Menus for displaying the operation screens are also registered in the distribution server, the menus being arranged in a tree-shape configuration. The cartridge spreader includes an activation controller for activating and deactivating the cartridge. Unlike polyester, polypropylene accomplishes its antiadhesive function very well on the marble agglomerate and therefore, polypropylene is used in the production of marble agglomerate. The coating may be selectively formed on the conductive material.