Currently the robotic system is fully setup. Since the last report, the Polaris optical system has been added. The optical system is being used to assess the LWR precision, as well as its calibration. Optical frames have been attached to the robot end-effector and the bone. Calibration is performed through pivoting motions of the optical frames for both the bone and robot end-effector. The main focus is to quantify maximum error in relative positioning and orientation between the drill and the bone. This maximum error is using the native cartesian impedance controller of the LWR.

The 2D ultrasound system is now being prepared for integration with the robot arm. An artificial bone embedded in silicone gel is being prepared, which will serve for the first tests. Three optical frames are initially used, one on the bone, one on the ultrasound probe, and one on the dril (robot end-efffector). Cross comparisons will allow us to fully assess precision under impedance control. The first system integration is planned for the last week of April.