Abstract:
MRI interference with a co-existing ultrasound system may be reduced or avoided by carrying out RF-sensitive operations of the treatment system only when gradient field activity of the MRI system is suppressed.
Abstract:
A system (10) for treating tissue within a body is configured to deliver a first level of ultrasound energy to a target tissue region (42) for a first duration resulting in the generation of micro-bubbles (56) in the target tissue region, determine one or more characteristics of the target tissue region in the presence of the micro-bubbles, and deliver a second level of ultrasound energy to the target tissue region for a second duration, wherein one or both of the second energy level and the second duration are based, at least in part, on the determined one or more characteristics of the target tissue region.
Abstract:
In ultrasound therapy, the frequency of sonications can be optimized, within a certain frequency range, to maximize the absorption or the acoustic intensity at the target in a manner specific to the patient.
Abstract:
A focused ultrasound system includes a transducer array, a controller for providing drive signals to the transducer array, and a switch. The transducer array includes a plurality of “n” transducer elements, and the controller includes a plurality of “m” output channels providing sets of drive signals having respective phase shift values, “m” being less than “n.” The switch is coupled to the output channels of the controller and to the transducer elements, and is configured for connecting the output channels to respective transducer elements. The controller may assign the transducer elements to respective output channels based upon a size and/or shape of a desired focal zone within the target region, to steer or otherwise move a location of the focal zone, and/or to compensate for tissue aberrations caused by tissue between the transducer array and the focal zone, geometric tolerances and/or impedance variations of the transducer elements.
Abstract:
A system (10) for treating tissue within a body is configured to deliver a first level of ultrasound energy to a target tissue region (42) for a first duration resulting in the generation of micro-bubbles (56) in the target tissue region, determine one or more characteristics of the target tissue region in the presence of the micro-bubbles, and deliver a second level of ultrasound energy to the target tissue region for a second duration, wherein one or both of the second energy level and the second duration are based, at least in part, on the determined one or more characteristics of the target tissue region.
Abstract:
A focused ultrasound system includes a transducer array, a controller for providing drive signals to the transducer array, and a switch. The transducer array includes a plurality of “n” transducer elements, and the controller includes a plurality of “m” output channels providing sets of drive signals having respective phase shift values, “m” being less than “n.” The switch is coupled to the output channels of the controller and to the transducer elements, and is configured for connecting the output channels to respective transducer elements. The controller may assign the transducer elements to respective output channels based upon a size and/or shape of a desired focal zone within the target region, to steer or otherwise move a location of the focal zone, and/or to compensate for tissue aberrations caused by tissue between the transducer array and the focal zone, geometric tolerances and/or impedance variations of the transducer elements.
Abstract:
An apparatus for delivering acoustic energy to a target site adjacent a body passage includes first and second elongate members, each carrying one or more transducer elements on their distal ends. The first and/or second elongate members include connectors for securing the first and second elongate members together such that the transducer elements together define a transducer array. The first and second elongate members are introduced sequentially into a body passage until the transducer elements are disposed adjacent a target site. Acoustic energy is delivered from the transducer elements to the target site to treat tissue therein. In another embodiment, the apparatus includes a tubular member and an expandable structure carrying a plurality of transducer elements. The structure is expanded between a contracted configuration during delivery and an enlarged configuration when deployed for delivering acoustic energy to a target site adjacent the body passage.
Abstract:
Method for adjusting the output of a phased array ultrasonic transducer using surface mapping. The transducer surface is mapped using a sensor, such as a hydrophone, to determine the actual location of each transducer element relative to the expected location of each transducer element. Mapping can be performed by measuring a distance between a hydrophone and each transducer element. At least one of the hydrophone and the transducer are moveable relative to each other to map the transducer surface. A determination is made whether the actual location of a transducer element differs from the expected location. Drive signals of certain transducer elements having actual locations that differ from expected locations are adjusted to control the output of the transducer.
Abstract:
A system for treating tissue within a body is configured to deliver a first level of ultrasound energy to a target tissue region for a first duration resulting in the generation of microbubbles in the target tissue region, determine one or more characteristics of the target tissue region in the presence of the microbubbles, and deliver a second level of ultrasound energy to the target tissue region for a second duration, wherein one or both of the second energy level and the second duration are based, at least in part, on the determined one or more characteristics of the target tissue region.
Abstract:
Techniques for temperature measurement and correction in long-term MR thermometry utilize a known temperature distribution in an MR imaging area as a baseline for absolute temperature measurement. Phase shifts that arise from magnetic field drifts are detected in one or more portions of the MR imaging area, facilitating correction of temperature measurements in an area of interest.