Radiofrequency safety of switchable segmented transmission lines

A transmission line for use in a radio-frequency and/or magnetic field, comprising:

• at least two electrically conductive transmission line segments separated by a non-conductive gap;
• an electrically conductive bridge having two states, a closed state which electrically connects two of the transmission line segments across the non-conductive gap and a open state which electrically disconnects the at least two transmission line segments across the non-conductive gap;
• an impedance bridge connected electrically in parallel to the electrically conductive bridge which electrically connects the line segments across the non-conductive gaps, the impedance bridge having an impedance which suppresses radiofrequency (RF) current between the line segments;
• a bridge controller which controls the state of the electrically conductive bridge;
• and
• a measurement unit which measures the impedance across the line segments and the impedance bridge while the conductive bridge controlled to be in the open state.