US Patent 10244951 Physiological sensor delivery device and method

Methods of measuring Fractional Flow Reserve (FFR) including advancing a sensor delivery device within a guiding catheter to a location of interest, the sensor delivery device comprising a distal sleeve including a distal sensor and a proximal sensor, advancing only a distal portion of the distal sleeve outside of the guiding catheter such that the distal sensor is outside of the guiding catheter and downstream of the location of interest and the proximal sensor is inside of the guiding catheter, measuring a distal fluid pressure with the distal sensor distal to the location of interest, measuring a reference fluid pressure with the proximal sensor inside of the guiding catheter, and calculating FFR. One or both of the proximal and distal sensor may be comprised of a material having a low thermal coefficient.