Patent ID: 8388535

Claim:
A method for determining exposure parameters for a high intensity focused ultrasound system used to noninvasively target a blood vessel in a patient with a high intensity focused ultrasound beam, the method comprising: providing the high intensity focused ultrasound system including at least one ultrasound transducer having a plurality of transducer elements imaging the blood vessel to be treated with the high intensity focused ultrasound beam; identifying tissue along an ultrasound energy path through which there will be a subsequent application of ultrasound energy between the blood vessel and the at least one ultrasound transducer; estimating high intensity ultrasound energy intensities at the blood vessel and non-zero ultrasound energy intensities at the tissue for a subsequent application of high intensity focused ultrasound through the tissue to the blood vessel along the ultrasound energy path between the blood vessel and the at least one ultrasound transducer based at least in part on the relative position between the transducer(s) and the blood vessel and the relative position between the transducer(s) and the tissue along the ultrasound energy path between the blood vessel and the at least one ultrasound transducer; and determining exposure parameters for the high intensity focused ultrasound beam that cause the estimated energy intensity delivered to the blood vessel to remain above a first level while the estimated energy intensity at the tissue along the ultrasound energy path between the blood vessel and the at least one ultrasound transducer remains below a second level, wherein the second level is less than the first level but greater than zero, wherein the exposure parameters include at least one of ultrasound intensity level, exposure interval, and scan geometry, and wherein the exposure parameters are determined to ensure that the second level will not result in irreversible damage to the tissue along the ultrasound energy path between the blood vessel and the at least one ultrasound transducer.