TECHNOLOGY SPOTLIGHT

—by Richard Mandel

During the thousands of surgical procedures performed each year, many surgeons — regardless of their years of experience — may well wish there were some means of seeing exactly where to make the incision. A Siemens prototype for augmented reality image guidance, or in-situ visualization, may essentially render a patient transparent to the surgeon. The device employs a head-mounted display (HMD) that carries three miniature cameras — two of the video cameras capture a stereoscopic view of the surgical site; the third is used for viewpoint tracking, in combination with optical markers framing the surgical site. A computer superimposes 3-D computer images taken from the patient’s own CT or MR data onto the video view for display on the surgeon’s HMD. Looking at the patient, the surgeon perceives computer models of anatomical structures at the location of the actual structures. “The ability to look inside the patient and see the tumor in three-dimensional space from different angles helps the surgeon determine the best route to the tumor,” notes Frank Sauer, Ph.D., project manager in the Imaging and Visualization Department. “The dynamic viewpoint provides a very direct and intuitive understanding of even complex anatomy.” Siemens or connect at www.rsleads.com/206df-152

Time was when we just sat and listened to the music. Then, pop groups like The Beatles and Black Sabbath were accused of sneaking satanic messages into songs, only heard when the music was played backward. Now it seems one of the world’s most popular electronic musicians has discovered the modern digital equivalent. The spooky image of a creature with a diabolical grin has been accidentally discovered on electronic artist Aphex Twin’s 1999 hit EP “Windowlicker.” It isn’t a separate file on the CD — the sinister face is encoded in the actual sound waves of the music, and is revealed when the song is played on a computer through special software that visualizes sound waves, the aural equivalent of steganography: the practice of hiding secret messages and watermarks in images. A 19-year-old named Jarmo Niinisalo, who tweaked the settings in his spectrographic software to reveal the image of Aphex Twin himself — born Richard James — discovered the image. James apparently created the hidden pictures in his songs using a clever piece of synthesizer software called MetaSynth, a Mac-only application that can take any image and generate sounds from it. Musicians who use the application input abstract pictures because they can generate meaningful sounds. U&I Softwares LLC, or connect at www.rsleads.com/206df-153