Recoil momentum induced by laser ablation : Risk for laser middle ear surgery?

Laser ablated material escapes from the surface with high velocities up to the speed of sound. Due to the conservation of momentum, the same amount of momentum which is in the ablated material is also transferred to the remaining tissue. The effect of this recoil momentum is like a force which accelerates the tissue. In the case of the tiny middle ear bones, the acceleration may be so large that it harms structures of the inner ear. Laser Doppler vibrometry was used to measure the recoil momentum induced by infrared lasers like Holmium, Erbium and CO 2 laser. This paper focuses on the effect of repetitive laser pulses of a short pulse CO 2 laser.