A control system alters one or more characteristics of an ablating element to ablate tissue. In one aspect, the control system delivers energy nearer to the surface of the tissue by changing the frequency or power. In another aspect, the ablating element delivers focused ultrasound which is focused in...http://www.google.com/patents/US6805129?utm_source=gb-gplus-sharePatent US6805129 - Apparatus and method for ablating tissue
