Hand-eye calibration for surgical cameras: a Procrustean Perspective-n-Point solution

PurposeSurgical cameras are prevalent in modern operating theatres often used as surrogates for direct vision. A surgical navigational system is a useful adjunct, but requires an accurate “hand-eye” calibration to determine the geometrical relationship between the surgical camera and tracking markers.MethodsUsing a tracked ball-tip stylus, we formulated hand-eye calibration as a Perspective-n-Point problem, which can be solved efficiently and accurately using as few as 15 measurements.ResultsThe proposed hand-eye calibration algorithm was applied to three types of camera and validated against five other widely used methods. Using projection error as the accuracy metric, our proposed algorithm compared favourably with existing methods.ConclusionWe present a fully automated hand-eye calibration technique, based on Procrustean point-to-line registration, which provides superior results for calibrating surgical cameras when compared to existing methods.