<title>Excimer laser drilling of bone: shock wave and profile measurements</title>

Abstract

The shock wave generation in stapes models during laser ear surgery is experimentally investigated The intensity absolute measurements of shock waves generated by excimer laser in the treated bone is performed. It is shown that the roughness of the crater bottom profile depends on the laser beam fluence. it is revealed that in pulse repetition regime of bone drilling there exists an optimal laser beam fluence, which provides as high rate of drilling as smooth bottom of crater. For ArF and KrF excimer lasers the optimal fluence is equal to about 0.4-0.5 i/cm2 at the repetition rote 5 Hz. The amplitude of shock wave induced at these parameters of laser beam in the back side of the bone sample of 1.1 mm thickness was measured to be about 25 bar. For 0.5 mm thick bone sample the amplitude of such a shock wave was measured to be about 60 bar and the corresponding pressure gradient 0.35 bar/pm.