Friday, September 7, 2007

New 3D Display Technology - In the O.R.

philips-3d.bmpthis sure beats the old system!

3d_glasses.jpgBetter for Creature Features than the OR

Phillips just demo’d an intriguing display at the Berlin consumer-electronics show. It is an amalgam of 9 x 42-inch displays on a grid creating a 132 inch display that reportedly can display 3D images without the need for glasses.

Why this is so important: 3D display technology is badly needed for endoscopic surgery. In order to see in 3D you need stereo vision which requires 2 separate images taken from slighly different angles and them superimposed. You body does this with your 2 eyes slighly separate on your face. In traditional laparoscopic surgery there is a single telescope and a single camera so all the images are in 2D. Unfortunately, depth perception is lost. How does the surgen operate then? What heppens with training and practice is that your brain picks up and other clues primarily shadowing and touch perception from your hands and the surgeon becomes able to interpolate a 3D space even though all of the visual skills are mising. This is one of the hardest if not the hardest step to learn when I teach surgeons to first perform laparoscopic surgery and some people just have a much harder time than others. Interestingly, with HD displays there is a pseudo-enhancement of depth perception that engineers and visual scientists tell me is due to the enhanced color fidelity and resolution and shadowing which allows the brain to pick up more 3D clues of the space from the 2D image! Still, the lack of true 3D data increases the difficulty of the procedures especially complex ones requiring suturing.

What is available today: Currently there are some attempts to address this limitation. They have required the use of head mounted displays with separate displays for each eye and separate imaging chips or lenses on the scopes but these have been heavy and cumbersome to use. Others such as some of the robotic solutions have immersed the surgeon’s head in a remote 2-panel display station but this also is a very complex solution. For years I have seen many many attempts at no-glasses 3D displays from various companies but all suffered from narrow viewing angles or poor resolution or other design issues.

2dpd.jpg 2d

How this solution works. This is a display technology that they call 2D + depth. In order to generate a 3D image, the display requires a regular 2D representation of the image and a depth-map. This depth-map indicates the distance between each pixel and the viewer. The 2D image and the depth-map are used to create images on the screen, and these images are then merged by the viewer’s brain into a 3D sensation.

Lenticular Screen: The system works with lenses on the screen that provide a slgly different view for each eye (without the red-green glasses of the 50’s). A sheet of transparent lenses, is fixed on an LCD screen. This sheet sends different images to each eye, and so a person sees two images. These two images are combined by our brain, to create a 3D effect.


I’ll have to get ahold of one of these displays to see if it holds promise for the OR…

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