Patent ID: 7662114

Claim:
A method of treating tissue with HIFU including a transducer, the method comprising the steps of: providing HIFU Therapy to a first portion of the tissue, the first portion being located at a first distance from the transducer; providing HIFU Therapy to a second portion of the tissue, the second portion being located at a second distance from the transducer, the second distance being further from the transducer than the first distance; and maintaining a generally constant f-number with the transducer when providing HIFU Therapy to both the first portion of the tissue and the second portion of the tissue, wherein the transducer includes an active surface having a plurality of transducer elements and wherein the step of maintaining the generally constant f-number comprises the steps of: selecting a first aperture of the active surface including a first number of the plurality of transducer elements for the provision of HIFU Therapy to the first portion of the tissue, the first number of transducer elements being configured to emit acoustic energy which will focus at the first distance from the transducer; and selecting a second aperture of the first active surface including a second number of the plurality of transducer elements for the provision of HIFU Therapy to the second portion of the tissue, the second number of transducer elements being configured to emit acoustic energy which will focus at the second distance from the transducer, wherein a ratio of the second distance to an active extent of the second aperture is generally equal to a ratio of the first distance to an active extent of the first aperture.