A Panoramic Ultrasonic Internal Imager and Related Minimally Invasive CMUT Arrays for Medical Imaging and Treatment

Professor Jingkuang Chen,
Department of Electrical and Computer Engineering,
The University of New Mexico, Albuquerque, NM 87131

This talk will highlight the development of capacitive micromachined ultrasonic transducer (CMUT) arrays for minimally invasive use that delivers diagnostic information, including images with a better resolution, as well as treatment functions not available from conventional non-invasive ultrasonic tools. Examples of these devices include a needle-shaped CMUT array that is smaller than a human hair for imaging, blood-flow-rate measurement, and hearing aids, and a panoramic ultrasound internal imager as small as 1mm-across for cardiovascular and gastrointestinal diagnosis. In addition to imaging and sensing, with a thicker membrane and/or a higher gap, CMUT devices capable of delivering an ultrasound pressure higher than 1.3MPa have been monolithically integrated with imager CMUT arrays on these miniature platforms, aiming for use on image-guided therapy (IGT). The imaging capability of these endoscopes has also been extended from conventional pulse-echo ultrasound to photoacoustic imaging. Different from conventional ultrasound imaging or X-ray, photoacoustic imaging can capture images of blood, and is exceptionally useful for identifying diseases/abnormalities related to blood, such as internal bleeding from stroke or early-stage cancer. The development of the first system-in-a-package photoacoustic brain imaging system composed of a planar array of ultrasound elements based on CMUT technology and an integrated light delivery system will be briefed. Design parameters, such as bandwidth of the ultrasound receivers, were tailored for the application and provide spatial resolution ranging from ~30 µm with the device placed on the surface of the target tissue to approximately one millimeter when imaging through the human skull.
Jingkuang Chen received the B.S. and M.S. degree in electrical engineering from the National Taiwan University, Taipei, Taiwan, R.O.C., and the Ph.D. degree in electrical engineering from the University of Michigan, Ann Arbor, in 1996. His Ph.D. dissertation focused on the development of microfluidic systems on silicon for selective drug delivery to the central nervous system and for inkjet printing. From 1996 to 2004, he was a member of research staff with Xerox Wilson Research Center, Webster, NY, working on the development of SOI MEMS optical systems and plastic microfluidic devices for printing application. He joined the faculty of the University of New Mexico, Albuquerque, NM, in 2004, where he is currently an associate professor with the Department of Electrical and Computer Engineering. His research interests are invasive capacitive micromachined ultrasonic transducer arrays that incorporate ultrasound with light sources, and/or a drug-delivery network on a miniature platform for imaging, hearing aids, diagnosis, and treatment.