You can see there's a little wave line under the patient's axilla there, but basically there's your parts of the machine: the generator, the coupling and the localization on this machine was by x-ray, you would get the stone in two planes. This is the ellipsoid deflector. If you remember back to your high school geometry, if you think of a perfect ellipse, and you take at any F1 point and go to any point on the ellipse and draw the angle that comes off that, they all have to meet at an F2 point, and that's the theory behind an elliptical deflector. If you put the spark at an F1 point, no matter where it goes, it has to come back out to that F2 point.