What's New @ IEEE in Signal Processing, November 2005

-- PROTOTYPE COMBINES THERAPEUTIC AND 3-D IMAGING CAPABILITY
High frequency ultrasound waves may allow physicians to both visualize the heart's interior in three dimensions and selectively destroy heart tissue with heat to correct arrhythmias, according to engineers at Duke University who are developing the technology. Building on previous work, the Duke team has created dual-function ultrasound probes that use tiny cables, as many as two hundred of them in a three-millimeter catheter. To destroy aberrant tissue in the heart, physicians currently use electrodes that must touch the target tissue, and are guided by x-rays, which do not provide sharp images of soft tissue. The Duke engineers say their prototype can destroy target tissue without touching it, and is guided by much cleared three-dimensional imaging. The work is described in two research papers published in last month in the journals "IEEE Transactions on Ultrasonics, Ferroelectronics and Frequency Control" and "Ultrasonic Imaging." Read more

-- USING ULTRASOUND TECHNOLOGY TO LOOK INSIDE CONCRETE
Researchers at Cambridge Ultrasonics, in conjunction with UK firm Sonatest, have developed an ultrasound sensor that can "see" inside concrete. The sensor works by firing sound waves from up to six different transducers and then registering the returning echoes. A visual map of the inside of the concrete is then displayed as a three-dimensional image. The system, still in the testing stage, was designed to monitor concrete structures for interior corrosion, such as cracks and fissures, particularly in a building's tendons, which act as the skeletons of structures. But the sensor is also of particular interest to police organizations, which could use the device to locate corpses buried in concrete. Bodies buried in concrete break down and leave voids which the sensor would record. Cambridge Ultrasonics is also working on a monitoring system which could be attached to structures to provide regular feedback on corrosion. Read more