CMUT Based Microscale Integrated Ultrasound Systems for Minimally Invasive Intracardiac and Intravascular Imaging

High frequency ultrasonic imaging devices are widely used in minimally invasive catheter-based interventions especially in intravascular imaging, but there is still a need for more flexible devices with true 3-D volumetric imaging capability in front of the catheter tip. Single chip capacitive micromachined ultrasonic transducer (CMUT) arrays with on-chip CMOS electronics implementation provides great flexibility in designing array geometry and integrated front-end electronics. We have successfully implemented dual ring CMUT arrays for forward-looking intravascular ultrasound (IVUS) and intracardiac echography (ICE) imaging which provide 3-D volumetric imaging functionality. In this paper, we report on the details of the single-chip microscale imaging system and experimental results. We also discuss system improvements with initial experimental results.