Patent ID: 8419647

Claim:
A method, comprising: providing a pressure-sensing guidewire that includes: an elongate tubular member having an outer diameter of 0.018″ or less, the elongate tubular member having a proximal portion and an opposing distal portion; a core wire extending within the elongate member from the proximal portion to the distal portion; a flexible element coupled to the distal portion of the elongate tubular member, the flexible element having an outer diameter of 0.018″ or less and an increased flexibility compared to the elongate tubular member; a sensor housing coupled to the flexible element, the sensor housing having an outer diameter of 0.018″ or less and a length between 1 mm and 5 mm, the sensor housing having an external wall, a lumen, and an opening extending through a portion of the external wall to the lumen; a pressure sensor assembly disposed within the sensor housing and in fluid communication with the opening of the sensor housing; a first electrical conductor electrically coupled to the pressure sensor assembly, the first electrical conductor extending from the pressure sensor assembly to the proximal portion of the elongate member; a second electrical conductor electrically coupled to the pressure sensor assembly, the second electrical conductor extending from the pressure sensor assembly to the proximal portion of the elongate member; a third electrical conductor electrically coupled to the pressure sensor assembly, the third electrical conductor extending from the pressure sensor assembly to the proximal portion of the elongate member; and a flexible structure coupled to and extending distally from the sensor housing, the flexible structure including a radiopaque material and having an outer diameter of 0.018″ or less; inserting at least a distal portion of the pressure-sensing guidewire into a vessel having a stenosis; obtaining a first pressure measurement within the vessel with the pressure sensor assembly positioned proximal of the stenosis; and obtaining a second pressure measurement within the vessel with the pressure sensor assembly positioned distal of the stenosis.