Ultrasound Capsule Endoscopy Components for in vivo and ex vivo Microultrasound Near-Field Imaging

Ultrasound capsule endoscopy (USCE) has attracted increased interest recently. In order to image the walls of the gastrointestinal (GI) tract with USCE efficiently, both high-frequency ultrasound (i.e. microultrasound) imaging and good acoustic coupling are needed. Tissue to be scanned is expected close to the transducer surface, but the near-field tissue echoes may be easily lost in the acoustic ring-down. Here, we present experimental ex vivo and in vivo porcine small bowel imaging results from an USCE prototype. The preliminary results show that the near-field image can be recovered after post-processing. Although some limitations in imaging the GI tract are inherent in the use of focused single element transducers, solving the problem of near-field imaging is relevant to all USCE implementations.