Apparatus and methods for identifying and counting objects having identifiers entering and exiting a surgical field are provided. In one embodiment, the apparatus has an entry scanner, a hand held scanner and an exit scanner for generating a detection field and for receiving data which identifies said objects. In another embodiment, the apparatus has a plurality of lower antennas and an upper antenna for generating a detection field and for receiving data which identifies said objects. Various surgical devices with identifiers and methods for preventing electromagnetic coupling between and protecting objects and identifier are also provided. The invention further provides apparatus and methods comprising a handheld scanner and a mat adapted to underlie a patient during a surgical procedure.