This new volumetric medical display from the Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut (HHI) in Berlin offers not only 3D visualization for radiologists and surgeons, but also has a built in function that allows the manipulation and rotation of the image without touch, hence allowing clinicians not to break the scrub during sterile procedures:
The physician leans back in a chair and studies the three-dimensional image floating before his eyes. After a little reflection, he raises a finger and points at a virtual button, likewise floating in the air. At the physician’s command, the CAT scan image rotates from right to left or up and down – precisely following the movement of his finger. In this way, he can easily detect any irregularities in the tissue structure. With another gesture, he can click on to the next image. Later, in the operating room, the surgeon can continue to refer to the scanner images. Using gesture control to rotate the images, he can look at the scan of the patient’s organs from the same perspective as he sees them on the operating table. There is no risk of contaminating his sterile gloves, because there is no mouse or keyboard involved.
But how does the system know which way the finger is pointing? “There are two cameras installed above the display that projects the three-dimensional image,” explains Wolfgang Schlaak, who heads the department at the Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut HHI in Berlin that developed the display. “Since each camera sees the pointing finger from a different angle, image processing software can then identify its exact position in space.” The cameras record one hundred frames per minute. A third camera, integrated in the frame of the display, scans the user’s face and eyes at the same frequency. The associated software immediately identifies the inclination of the person’s head and the direction in which the eyes are focused, and generates the appropriate pair of stereoscopic images, one for the left eye and one for the right. If the person moves their head a couple of inches to the side, the system instantly adapts the images. “In this way, the user always sees a high-quality three-dimensional image on the display, even while moving about. This is essential in an operating theater, and allows the physician to act naturally when carrying out routine tasks,” says Schlaak. “The unique feature of this system is that it combines a 3-D display screen with a non-contact user interface.” The three-dimensional display costs significantly less than conventional 3-D screens of comparable quality. Schlaak is convinced that “this makes our gesture-controlled 3-D display an affordable option even for smaller medical practices.”