Monitor-Position in Laparoscopic Surgery

Abstract

One of the key problems in laparoscopy is the correct positioning of the monitor. In this study we tested task performance and muscle-strain of subjects in relation to monitor-position during laparoscopic surgery. 18 subjects simulated laparoscopic suturing. This was repeated in three monitor positions (15 minutes each) frontal at eye level (A), frontal in height of the operating field (B) and 45° to the right side at eye level (C). No head movements were allowed during a single session. In a fourth measurement the subjects were allowed to move the head and to look at any monitor. After the test they were asked for their preferred monitor position. During all tests the electromyographic (EMG) activity of six main neck muscles was recorded and the number of pearls was counted. The EMG activity was significantly (p<0.05) lower for position A compared to position B or C. No significant difference was found between the positions B and C. The number of threaded pearls as an indicator for task performance was highest for position B. The difference was statistically significant compared to position C but not between positions A and C or A and B. Asked for the preferred monitor position 9 subjects chose two monitors in the frontal positions A and B. No subject preferred the monitor at the side (C). Regarding EMG data the monitor positioned frontal at eye level is preferable. Reflecting personal preferences of subjects and task performance it should be of advantage to place two monitors for the surgeon: one in position A for lowest neck strain, and the other one in position B for difficult tasks with optimal task performance. The monitor position at the side is not advisable.