Minimal invasive ear, nose and throat surgery--advances through modern technologies

Three fundamentals have to be fulfilled to optimize minimally invasive surgery: three-dimensional imaging, free maneuverability of the instruments, sensorial feedback. Projection of two pictures from a stereoendoscope and subsequent separation with a LCD shutter allows three-dimensional videoendoscopy to be performed. A high frequency shutter technique (100/120 Hz) presents pictures from the two video cameras to the right and left eye, respectively, so that the surgeon has spatial vision of the operative field. Steerable instruments have four components: a control unit, rigid shaft, steerable multijoint, distal effector. The steerable multijoints give two additional degrees of freedom compared to conventional rigid instruments in endoscopic surgery. For intuitive movements, however, an electronic control system is necessary that is comparable to the "master slave" priniciple in remote technology. A remote manipulator system with six degrees of freedom is now available. Additionally, a multifunctional distal tip permits different surgical steps to be performed without changing the instrument. For better control of the instrument and the operative procedure tactile feedback can be achieved with appropriate microsensor system. Recent projects suggest that an artificial sensor system can be established within the foreseeable future.