UC Irvine

For in vivo medical applications, endoscopy shows great potential for its minimally invasive manner, flexibility and close-up imaging characteristic. A miniaturized imaging probe combining ultrasound and photoacoustic endoscopy has been developed. The output of a 532-nm pulse laser was coupled into and delivered to the probe by a 200-micron-core multimode fiber. A 40 MHz ring shape ultrasound transducer was fabricated to receive pulse echo ultrasound and photoacoustic signals as well. The light-guiding optical fiber, the ring ultrasound transducer, and a mirror-based reflective material for the coaxial laser beam and ultrasound signal were integrated into the probe with a final packaged diameter of 2.5 mm. The performance of the probe was tested by imaging a graphite rod. The imaging ability of this dual-modality system was demonstrated by imaging the cross section of a rabbit aorta. © 2011 SPIE.