the proximal end 70 of a guide wire 80 is shown in cross section it comprises an outer tube member 72 an inner core 74 with an insulating layer 75 disposed between said core and said tube in order to make a connector having two contact elements or surfaces a circumferential recess 71 is made in the outer tube 72 down to the insulating layer 75 this embodiment is shown in fig7 a or through the insulating layer 75 down to a depth at which the inner core 74 is exposed fig7 b it is of course essential that there be no electrical connection between the distal and the proximal end of the outer tube the recess is filled with an insulating material 76 e g some polymer teflon u00ae poly imide or parylene or the like or an inorganic material such as ceramic type materials e g alumina or silicon nitride in its various possible forms finally the very end surface of the coaxial wire 80 is u201c capped u201d with a layer 78 of conductive material so as to short circuit the core 74 with the proximal end portion of the tube now electrically insulated from the remainder of the tube on the distal side of the recess 71 filled with insulating material 76 fig8 illustrates an alternative way of providing the sensor mount at the distal end of the wire it encompasses providing a tube segment 82 having an inner diameter corresponding to the outer diameter of the coaxial wire 84 and positioning said tube segment 82 over the distal end of the wire 84 thereby a portion.