An endoscopic system can include an endoscope shaft having a proximal end and a distal end. The endoscopic system can have a sensor system that includes an electrically active sensor mounted proximate the distal end and positioned to sense at least one characteristic of an environment in which the distal end is located, a data signal transmission line connected to the sensor to transmit data signals between the sensor and a signal processor, and an electrical power transmission line connected to the sensor to transmit power to the sensor. The endoscopic system also can include a floating ground element arranged to provide an electrical reference for the sensor system. Voltage induced by an electromagnetic interference external to the endoscopic system on at least one of the data signal transmission line or electrical power line is substantially similar to the voltage induced by the electromagnetic interference on the floating ground element.