An active catheter design incorporating a distal loop coil that is electrically connected to an ultrasonic transducer having a comparable profile. The ultrasonic transducer induces ultrasonic waves at the Larmor frequency at the distal end of a dielectric optical fiber that runs along the active catheter shaft. The optical fiber serves as the transmission line instead of a convention conductor, eliminating the RF induced heating. The dynamic strain generated by the ultrasonic transducer can be measured using optical interferometry by coupling a laser at the proximal end of the optical fiber using the acousto-optical effect. A fiber embedded Bragg reflector grating, for example, can be used for this purpose. The device can also be used for simultaneous temperature measurements among other parameters.
