Researchers at the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg, Germany have developed a sensor that can capture 3-D images from an endoscope using special microlenses. Together with their partners at the EU project “Microsurg”, they now made it possible to use CMOS image sensors with their special microlenses instead of CCD’s that provided lower resolution results.
The CMOS sensor has a cylindrical microlens placed in front of every two lines of pixels. Another lens captures the light falling on the microlenses, which focus it on the pixels. The lens has two apertures: two beams of light are captured by the lenses. The CMOS sensor eventually receives two sets of image data, like our brain receives “image data” from each of our eyes. Software further processes the data for displaying 3-D images on the screen.
To develop the special microlens, the researchers at Fraunhofer had to calculate a shape to ensure that no more than five percent of the energy from one light ray was captured by the line of sensors serving the other channel.
The end result is an endoscope with a diameter of 10 millimeters. The camera integrated in the endoscope tube will enable a surgeon more detail in a 3D image with higher resolution. The stereoscopic vision promises to simplify the work of surgeons, enabling them to navigate safer and faster through the body.
Article link: Microlenses for 3-D endoscopes