An assembly of devices intended for tracking spatial markers attached to a surgical instrument(s) and/or the patient, based on movement through a variable electromagnetic (EM) field. It is designed to generate visual diagrams of the relative position/orientation of the instrument/marker during surgery and may additionally allow surgical navigation through overlay of radiological images [e.g., ultrasound (US)]. It consists of a console with display and an EM field generator/receiver; spatial markers, instruments, a foot switch, or trolley may in addition be packaged with the system. It is intended for use during multiple types of surgical procedure (e.g., breast, gastrointestinal, lung).