摘要 |
<p>Systems and methods for controlling the phase and amplitude of individual drive sinus waves of a phased-array focused ultrasound transducer employ digitally controlled components to scale the amplitude of three or more bases sinuses into component sinus vectors. The component sinus vectors are linearly combined to generate the respective sinus of a selected phase and amplitude. The use of digitally controlled controlled components allows for digitally controlled switching between various distances, shapes and orientations ('characteristics') of the focal zone of the transducer. The respective input parameters for any number of possible focal zone characteristics may be stored in a comprehensive table or memory for readily switching between focal zone characteristics in ν seconds. Changes in the output frequency are accomplished without impacting on the specific focal zone characteristics of the transducer output. Sequential changes in the transducer focal zone characteristics are implemented in the form of sequential sets of digital control signals transmitted from the central controller to respective control channels for generating the individual sinus waves. The digital control signals may be changed in accordance with a time-domain function as part of a single thermal dose.</p> |