Movement Analysis for Surgical Skill Assessment and Measurement of Ergonomic Conditions

A measurement for ergonomic conditions is derived from motion analysis of surgical instruments. Several features for surgical skill assessment are examined and an overall grading system for surgical skill assessment and evaluation of ergonomic conditions based on the movement of the instruments´ tool tips is presented. The grading system is applied to different ergonomic conditions provided by different types of displays, including three 3D displays. The features examined for skill evaluation include a movement alphabet derived from recorded trajectories by the k-Means algorithm. The system is trained with expert knowledge about the expertise of surgeons. The findings show that surgeons working under better ergonomic conditions perform less movements during an intervention. The time in which they move the instruments to complete the intervention is less. There is less depth oscillation with the tool-tips. The variety of different types of movements is less. The path length of the tool tips is shorter. There are less unnecessary movements. Results of a qualitative study show that measurements for skill evaluation can be applied for measuring ergonomic conditions.