Abstract

Background: In conventional pedicle screw placement, the surgeon adjusts the position of the instrument by hand. The hand feel is very important for the accuracy of the surgery, and the hand feel mainly depends on the surgical experience of the doctor. The essence of hand feel is the force information between the intraoperative instrument and the biological tissue.

Objective: To digitize the intraoperative force information, a screw placement instrument with multi- dimensional force information perception capabilities was designed and calibrated.

Methods: Firstly, based on the analysis of force perception schemes for the screw placement instrument, a micro-strain gauge sensor array was integrated into the main body unit of the instrument. Subsequently, a multi-dimensional force perception instrument calibration experiment platform was established, and the impact of various factors such as load size and loading depth on force coupling was analyzed experimentally. Finally, through relevant loading force experiments, a comprehensive force perception model for precise sensing of force information in pedicle screw placement surgery. Established and verified by experiments.

Results: The results show that the deviation force in X direction and Y direction calculated by theory is close to the actual deviation force measured by 3D force sensor at different depths, different angles and different corners, and the error is small.

Conclusions: The correctness of the perceived force model was verified through precision validation experiments. This research will provide technical support.

Keywords: Surgical robot, Force perception, calibration, perception model.