An optimized high resolution radial ultrasound endoscope for digestive tract imaging

An EUS probe integrating radial electrical scanning transducer and wide-angle camera module has been fabricated and evaluated. The 8 MHz 128 elements radial ultrasound transducer, which can provide 360° high-resolution ultrasound imaging, has a less than 9.58 mm external diameter. A 128.3° wide-angle lens driving with a 5-million-pixel CMOS camera module can improve optical imaging resolution. After the optical and ultrasound parts integrated and packaged, a 9.58 mm external diameter EUS produced. The anthropomorphic digestive tract phantom can be distinctly imaged with camera module. The measured center frequency and -6 dB fractional bandwidth of the radial array were 8.2 MHz and 83%, respectively. A two-way insertion loss of -39.6 dB was obtained at the average center frequency. According to the measured results, the radial EUS ensure a desirable imaging resolution in digestive tract imaging.