Comparing the accuracy of the da Vinci Xi and da Vinci Si for image guidance and automation

Background Current laparoscopic surgical robots are teleoperated, which requires high fidelity differential motions but does not require absolute accuracy. Emerging applications, including image guidance and automation, require absolute accuracy. The absolute accuracy of the da Vinci Xi robot has not yet been characterized or compared to the Si system, which is now being phased out. This study compares the accuracy of the two. Methods We measure robot tip positions and encoder values assessing accuracy with and without robot calibration. Results The Si is accurate if the setup joints are not moved but loses accuracy otherwise. The Xi is always accurate. Conclusion The Xi can achieve submillimetric average error. Calibration improves accuracy, but excellent baseline accuracy of the Xi means that calibration may not be needed for some applications. Importantly, the external tracking systems needed to account for setup joint error in the Si are no longer required with the Xi.