Improved Accuracy in Pelvic Tumor Resections Using a Real-Time Vision-Guided Surgical System

Pelvic bone tumor resections remain significantly challenging due to complex three-dimensional anatomy and limited surgical visualization. Current navigation systems and patient-specific instruments, while accurate, present limitations including high costs, radiation exposure, workflow disruption, long production time, and lack of reusability. This study evaluates a real-time vision-guided surgical system combined with modular jigs to improve accuracy in pelvic bone tumor resections. A vision-guided surgical system combined with modular cutting jigs and real-time optical tracking was developed and validated. Five female pelvis sawbones were used, with each hemipelvis randomly assigned to either the vision-guided and modular jig system or traditional freehand method. A total of twenty resection planes were analyzed for each method. Accuracy was assessed by measuring distance and angular deviations from the planned resection planes. The vision-guided and modular jig system significantly improved resection accuracy compared to the freehand method, reducing the mean distance deviation from 2.07 $\pm$ 1.71 mm to 1.01 $\pm$ 0.78 mm (p=0.0193). In particular, all specimens resected using the vision-guided system exhibited errors of less than 3 mm. Angular deviations also showed significant improvements with roll angle deviation reduced from 15.36 $\pm$ 17.57$^\circ$ to 4.21 $\pm$ 3.46$^\circ$ (p=0.0275), and pitch angle deviation decreased from 6.17 $\pm$ 4.58$^\circ$ to 1.84 $\pm$ 1.48$^\circ$ (p<0.001). The proposed vision-guided and modular jig system significantly improves the accuracy of pelvic bone tumor resections while maintaining workflow efficiency. This cost-effective solution provides real-time guidance without the need for referencing external monitors, potentially improving surgical outcomes in complex pelvic bone tumor cases.

Motion Planning for Object Manipulation by Edge-Rolling

A common way to manipulate heavy objects is to maintain at least one point of the object in contact with the environment during the manipulation. When the object has a cylindrical shape or, in general, a curved edge, not only sliding and pivoting motions but also rolling the object along the edge can effectively satisfy this condition. Edge-rolling offers several advantages in terms of efficiency and maneuverability. This paper aims to develop a novel approach for approximating the prehensile edge-rolling motion on any path by a sequence of constant screw displacements, leveraging the principles of screw theory. Based on this approach, we proposed an algorithmic method for task-space-based path generation of object manipulation between two given configurations using a sequence of rolling and pivoting motions. The method is based on an optimization algorithm that takes into account the joint limitations of the robot. To validate our approach, we conducted experiments to manipulate a cylinder along linear and curved paths using the Franka Emika Panda manipulator.