Haptic model of milling a virtual petrosal bone

Introduction:

For the milling simulation at the petrosal bone, realistic haptic VR interaction between CT bone-data and burr is required. Known linear models can calculate the abrasion but do not represent the reality. We present a new exponential model for abrasion calculation in combination with a physic simulation.

Methods:

Blades and diamond burrs with diameters from 1.4 to 4.0 mm are modeled. Forces for the interaction between mill bit and bone in respect of stiffness, velocity, angle and friction are calculated. We compute the abrasion via an exponential function, depending on rotation speed, force and 2 parameters. The bullet engine estimates forces and torques by collision detection between shaft and bone data. These values depend on the position of the collision, stiffness and roughness of the bone.

The new model is compared quantitatively to a linear abrasion model from the literature. Qualitative evaluation in the simulator has been made by 5 ENT surgeons.

Results:

The exponential model delivers quantitatively similar values as the values from literature. The first ENT surgeon compared both model, and found that the exponential model performed better in all aspects. Further 4 surgeons reviewed the model positively.

Conclusions:

The developed haptic model simulates the interaction between burr and bone quite well. There are smaller adaptions to do and as next steps we will model new burr types and further tissues.

Publication History

Publication Date:
23 April 2019 (online)