Figure 3.

Automatic trajectory design of MRasp. The optimal spinal puncture trajectory for MRasp was calculated automatically by using the Reacool medical mixed reality system and Huadong MRsp pathway algorithm. A: The skin zone corresponds to the spinous process of L3-L4 (entry zone). P: The subarachnoid space corresponding to the intervertebral space of L3-L4 (target point). B: All bony obstacles, such as the vertebral lamina, pedicle, articular process, spinous process, and irregular osteoproliferation, on the trajectory from A to P. L: The shortest distance between zone A and point P.