Ergonomic deficiencies in the operating room: examples from minimally invasive surgery.

The importance of minimally invasive surgery (MIS) has constantly increased in the last 20 years. Laparoscopic removal of the gallbladder has become the gold standard with advantages for patients. However, in laparoscopy, the surgeon loses direct contact with the surgical site. Rather than seeing the entire surgical field including adjacent organs, the surgeon's vision is restricted by an optic and camera system. Pictures of the surgical site in the abdomen are presented on a monitor. Hand eye coordination is decreasing because the operating team is not able to position the monitor at an ergonomically preferable position given that operation tables, constructed for open surgery where surgeons use short instruments, are too high for laparoscopic procedures where surgeons use long-shafted instruments. Additionally the degrees of freedom for camera movements and the instruments are limited, tactile feedback given in open surgery is lost. The typical design of instrument handles leads to pressure areas and nerve lesions. All these aspects force the surgeon into unnatural and uncomfortable body postures that can affect the outcome of the operation. An ideal posture for laparoscopic surgeons is described and ergonomic requirements for an optimal height of operation tables, monitor positions and man-machine interfaces are discussed.