关键词: 虚拟手术, 力反馈, 力觉交互, Tri-dexel, 切削力

Abstract:

Real-time visual and precise haptic interaction algorithms are critical for achieving accurate "tactile sensation" in virtual surgical training. Taking the key bone milling operation in orthopedic surgery as an example,the Tri-dexel model is first employed to represent the bone and the surgical milling tool. Real-time geometric deformation during the virtual bone milling is achieved through boolean operations and rapid surface reconstruction algorithms. Next, by integrating the geometric parameters of the surgical milling tool, a haptic interaction model based on the micro-element cutting force is proposed. This model utilizes the boolean operation results between the bone and surgical millimg tool to quickly achieve accurate calculation of the instantaneous undeformed chip thickness. The cutting force coefficients are identified and the haptic interaction model is validated through milling experiments to achieve haptic rendering. Finally, based on the aforementioned algorithms, an orthopedic virtual surgical training system is developed, and evaluation experiments are conducted. The results show that the predicted forces align with experimental measurements, with an average force error of less than 7%. The visual and haptic interactive algorithm satisfies a visual refresh rate of 30 Hz and a haptic refresh rate of 1 kHz. The developed orthopedic virtual surgical training system provides users with a highly immersive virtual bone milling training experience that can effectively improve users' hand-eye coordination.

Key words: virtual surgery, force feedback, haptic interaction; Tri-dexel, cutting force