A method and apparatus for scrolling a display includes detecting contact relative to a touch pad having a plurality of regions which individually correspond to a plurality of different scrolling directions, and determining which region of the plurality of regions the contact is detected. A converter converts the fluence distributions to treatment device settings. The tissue sample is placed on a holder submerged in a cooling bath comprising a liquid such as saline or water to minimize thermal effects and to provide a sink for dissociated ions.