Force quantification and simulation of pedicle screw tract palpation using direct visuo-haptic volume rendering

Area of Science:

• Medical Simulation
• Virtual Reality in Surgery
• Haptic Feedback Technology

Background:

• Surgical training relies on realistic simulation for skill development.
• Virtual reality (VR) offers immersive training environments.
• Haptic feedback enhances the realism of VR surgical simulations by replicating touch sensations.

Purpose of the Study:

• To assess the feasibility of a visuo-haptic simulation for pedicle screw tract palpation in VR.
• To develop a simulation approach that bypasses manual processing or segmentation of medical data.
• To create a realistic simulation of the tactile feel during pedicle screw placement.

Main Methods:

• Quantified forces and torques during real boar vertebra palpation using a 6-axis sensor and motion capture.
• Replayed recorded palpation movements in a simulator to fine-tune haptic rendering.
• Evaluated simulator realism by having neurosurgeons palpate a virtual vertebra and logging haptic device forces and torques.

Main Results:

• Real vertebra palpation yielded maximum forces of 7.78 N and torques of 0.13 Nm.
• The simulation generated forces and torques comparable in magnitude and progression to real-world measurements.
• Surgeons' feedback indicated similar force/torque distributions in the simulation, with higher values occurring more frequently.

Conclusions:

• Direct visual and haptic volume rendering is suitable for simulating surgical procedures like pedicle screw placement.
• Fine-tuning simulations using measured forces and torques from real-world palpation yields promising results.
• This VR approach offers a viable tool for enhancing surgical training in spinal procedures.