FIG. 5.

LG-380 waveforms at selected locations relative to the target point. SWs were collected during mapping along the acoustic axis (Z-axis, see inset) early in the lifetime (SWs 900–1500, PL-9) of the electrode, and waveforms (mean of 30 SWs) are aligned so that the transition from positive to negative pressure is at the zero point on the time scale. This illustrates the evolution of the focused shockwave along the Z-axis, showing that SWs are relatively low amplitude (∼20 MPa) at the point where the stone is targeted (target point, Z=0 in inset), but achieve much higher amplitude (∼30 MPa) at ∼35 mm beyond the target point.