A medical device comprising a corewire, sensor core, and coupler is presented. A portion of the corewire is disposed within a first end of the coupler, and a portion of the sensor core is disposed within a second end. Alternatively, the device comprises a corewire and a sensor assembly comprising a sensor core having first and second ends and a bore in the first end. A portion of the corewire is disposed within the bore. A method of manufacture comprises providing a corewire, sensor core, and coupler. The method further comprises inserting a portion of the corewire into a first end of the coupler, and a portion of the sensor core into a second end. Alternatively, the method comprises providing a sensor core having first and second ends, and a corewire. The method further comprises forming a bore in the first end, and inserting the corewire into the bore.