Device and method for high intensity focused ultrasound ablation with acoustic lens
First Claim
1. A method of ablating tissue, comprising:
- exciting at least one ultrasonic emitter to generate high intensity ultrasonic energy along a beam path, the high intensity ultrasonic energy having an instantaneous power density of at least about 1000 W/cm2 at one or more locations within the beam path;
directing the high intensity ultrasonic energy in at least one direction with at least one polymeric ultrasonic lens positioned in the beam path and acoustically coupled to the at least one ultrasonic emitter, the at least one polymeric ultrasonic lens having an attenuation less than about 2 dB/cm-MHz when measured at about room temperature; and
delivering the directed high intensity ultrasonic energy to tissue to be ablated while using at least one stress mitigation feature to mitigate thermal expansion mismatch stresses arising between the at least one ultrasonic emitter and the at least one polymeric ultrasonic lens.
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Accused Products
Abstract
A high intensity focused ultrasound transducer includes an ultrasonic emitter having a surface that emits ultrasonic energy along a beam path, at least one low attenuation polymeric ultrasonic lens acoustically coupled to the surface in the beam path of the ultrasonic energy, such that the lens can direct the ultrasonic energy in at least one direction, and at least one stress mitigation feature, such as a kerf, a heat sink, or an acoustic matching layer, to mitigate thermal expansion mismatch stresses within the transducer. For manufacturing simplicity, the first surface is typically either flat or monotonically curvilinear. The lens may take a variety of shapes, including Fresnel features, and may focus, collimate, or defocus the ultrasonic energy. Any orientation and positioning of the at least one ultrasonic lens relative to the first ultrasonic emitter is contemplated. Manufacture is further simplified by molding, casting, or thermoforming the lens.
74 Citations
17 Claims
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1. A method of ablating tissue, comprising:
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exciting at least one ultrasonic emitter to generate high intensity ultrasonic energy along a beam path, the high intensity ultrasonic energy having an instantaneous power density of at least about 1000 W/cm2 at one or more locations within the beam path; directing the high intensity ultrasonic energy in at least one direction with at least one polymeric ultrasonic lens positioned in the beam path and acoustically coupled to the at least one ultrasonic emitter, the at least one polymeric ultrasonic lens having an attenuation less than about 2 dB/cm-MHz when measured at about room temperature; and delivering the directed high intensity ultrasonic energy to tissue to be ablated while using at least one stress mitigation feature to mitigate thermal expansion mismatch stresses arising between the at least one ultrasonic emitter and the at least one polymeric ultrasonic lens. - View Dependent Claims (2, 3, 4)
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5. A high intensity focused ultrasound tissue ablation device, comprising a plurality of transducers, at least some of said plurality of transducers comprising:
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at least one ultrasonic emitter having a substantially flat first surface, wherein said at least one ultrasonic emitter generates ultrasonic energy that propagates along a beam path from said first surface, the ultrasonic energy having a power density of at least about 1000 W/cm2 at one or more locations within the beam path; and at least one ultrasonic lens acoustically coupled to said first surface in the beam path of the ultrasonic energy propagating therefrom, such that said at least one ultrasonic lens can direct the ultrasonic energy propagating from the first ultrasonic emitter in at least one direction in order to deliver it to tissue to be ablated, wherein an attenuation of the at least one ultrasonic lens is low enough to prevent thermal damage to the at least one ultrasonic lens during operation of the tissue ablation device. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A high intensity focused ultrasound tissue ablation device, comprising a plurality of transducers, at least some of said plurality of transducers comprising:
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at least one ultrasonic emitter having a monotonically curvilinear first surface, wherein said at least one ultrasonic emitter generates ultrasonic energy that propagates along a beam path from said first surface, the ultrasonic energy having a power density of at least about 1000 W/cm2 at one or more locations within the beam path; and at least one ultrasonic lens acoustically coupled to said first surface in the beam path of the ultrasonic energy propagating therefrom, such that said at least one ultrasonic lens can direct the ultrasonic energy propagating from the first ultrasonic emitter in at least one direction in order to deliver it to tissue to be ablated, wherein an attenuation of the at least one ultrasonic lens is low enough to prevent thermal damage to the at least one ultrasonic lens during operation of the tissue ablation device.
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Specification