| 摘要 |
The invention concerns a method of operating a minimally invasive medical system comprising a manipulator (10) having an effector unit (12) with a 6-DOF force/torque sensor (30), which has a sensor reference frame (X,Y,Z), and a minimally invasive instrument (14). The method comprises determining a position of the instrument relative to the external fulcrum (23) including determining an initial reference distance vector (D Fulcrum 0 ) from the origin of the sensor reference frame (X,Y,Z) to the external fulcrum (23); wherein determining an initial reference distance vector ( D Fulcrum 0) comprises:
moving the minimally invasive instrument (14) along both axes (X,Y) of the sensor reference frame (X,Y,Z), which are perpendicular to the instrument axis (Z) respectively, until reaction forces along both axes (X,Y) are below a given threshold;
and determining the position of the external fulcrum (23) along the instrument axis (Z) using the lever principle, in particular by
pivoting the instrument (14) until a sufficient contact force is reached;
measuring the module of a moment vector and the module of a force vector corresponding to said contact force; and
calculating the position of the external fulcrum (23) along said instrument axis (Z) by dividing said moment vector module by said force vector module. |
