Observation in laparoscopic surgery: Overview of impeding effects and supporting aids

Within a Dutch research program on minimally invasive surgery, a large lite rature survey has been carried out. This article describes the state of the art in research on observation in laparoscopy. It gives an overview of fac tors impeding the surgeon and technical developments designed to overcome t hese problems. A large number of journals, proceedings, patents, and books starting from the year 1991 have been consulted. The survey was completed w ith a thorough MEDLINE search. The survey showed that many authors have an incomplete background in the fundamentals of visual perception. This leads to a lack of understanding and to the design of supporting aids that often are not very useful. The new aspect of this study is that it gives a comple te and structured overview of laparoscopic observation problems and current solutions. The observation problems are structured according to visual per ception theory. The solutions are critically considered, and their benefits and drawbacks are identified. The study shows that the benefits of stereo- endoscopes and motorized endoscope positioners are questionable. The additi on of shadows and movement parallax is still a very important research topi c.