Abstract: A sensing guidewire device used to measure physiological parameters within a living body. In one embodiment, the device is used to measure the fractional flow reserve (FFR) across a stenotic lesion in a patient's vasculature. The device includes a sensor that is adapted to be affixed near the distal end of a guidewire. The guidewire contains a corewire, processed to enclose electrical conductors in a sealed, off-centered interstice or channel, with an outer diameter approximate to the outer diameter of the device, running substantially the full length of the device, and has a homogenous outer surface. The enclosed eccentric channel provides space for electrical conductors to move freely. The corewire can have a tapered segment to create desirable flexibility. A solid connector comprised of alternating conductive and insulating elements for connecting the conductors to an external device is disclosed.