Effect of tool center point angles on drilling performance in robotic cortical bone procedures

Area of Science:

• Robotics in Surgery
• Biomechanical Engineering
• Orthopedic Surgery

Background:

• Cortical bone drilling is critical for orthopedic procedures, impacting screw fixation and surgical outcomes.
• Robotic-assisted drilling (RAD) offers potential for enhanced precision but requires optimization of parameters like tool orientation.
• Understanding the dynamic behavior of robotic systems during bone drilling is essential for improving accuracy and reducing complications.

Purpose of the Study:

• To investigate the impact of varying tool center point (TCP) angles on drilling precision and accuracy in cortical bone.
• To analyze the dynamic characteristics and vibrations associated with different robotic configurations during bone drilling.
• To evaluate the effect of TCP angle optimization on drilling performance metrics and hole quality.

Main Methods:

• Utilized a six-axis robot to implement various tool center point (TCP) angles and robot postures for cortical bone drilling.
• Performed experimental modal analysis to determine natural frequencies and damping ratios for different configurations.
• Measured spindle displacement to quantify drilling vibrations and conducted drilling experiments on cortical bone specimens.

Main Results:

• Identified specific TCP angle configurations that significantly reduced drilling vibrations.
• Achieved an average reduction of 20.77% in drilling torque and 7.42% in the delamination factor (DF).
• Demonstrated a correlation between TCP angle selection, reduced vibrations, and improved hole quality.

Conclusions:

• The selection of tool center point (TCP) angles is a critical factor influencing drilling performance and hole quality in robotic-assisted cortical bone surgery.
• Optimized TCP angle control in robotic-assisted drilling (RAD) can lead to reduced torque, minimized delamination, and potentially stronger screw-bone fixation.
• Findings highlight the importance of considering angular parameters for enhancing the efficacy and safety of robotic systems in orthopedic procedures.