Possibilities and limitations of current stereo-endoscopy.

BACKGROUND: Stereo-endoscopy has become a commonly used technology. In many comparative studies striking advantages of stereo-endoscopy over two-dimensional presentation could not be proven. To show the potential and fields for further improvement of this technology is the aim of this article. METHOD: The physiological basis of three-dimensional vision limitations of current stereo-endoscopes is discussed and fields for further research are indicated. New developments in spatial picture acquisition and spatial picture presentation are discussed. RESULTS: Current limitations of stereo-endoscopy that prevent a better ranking in comparative studies with two-dimensional presentation are mainly based on insufficient picture acquisition. CONCLUSION: Devices for three-dimensional picture presentation are at a more advanced developmental stage than devices for three-dimensional picture acquisition. Further research should emphasize the development of new devices for three-dimensional picture acquisition.

Comparison between three-dimensional presentation of endoscopic procedures with polarization glasses and an autostereoscopic display.

BACKGROUND: Most endoscopic procedures are done with a two-dimensional (2D) view or a spatial presentation with polarization glasses. A new method of presenting three-dimensional (3D) spatial views is the autostereocopic display. We compared the performances of untrained test persons using these methods. METHODS: We designed three tests that had to be performed with one of the presentations. We used a Karl Storz 3D set with a 0 degrees stereooptic and a grasper. The autostereoscopic display was the Dresden 3D display. The 59 test persons were students who had never before worked with endoscopic devices. RESULTS: There were few differences between the tests, and none were statistically significant. The results with 2D were slightly better than those with polarization glasses, and the results with polarization glasses were slightly better than those with the autostereoscopic display. CONCLUSIONS: There are few differences between the procedures. A true spatial view is limited by the similarity of the two half-pictures.