Matching layer having gradient in impedance for ultrasound tranducers
AssigneeGeneral Electric Company
InventorsVenkat Subramaniam Venkataramani, Lionel Monty Levinson, Lowell Scott Smith
Life of this patent
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Abstract
A matching layer for ultrasound transducers has a gradient in impedance value from one surface to the other surface of the matching layer. The matching layer is composed of a plurality of sublayers made of composite materials and securely attached together and is disposed on the surface of the transducer element. The first sublayer adjacent to the transducer element has an impedance value less than or equal to that of the transducer element. The last sublayer adjacent to the target has an impedance value greater than or equal to that of the target. The impedance values of the sublayers decrease monotonically from the first to the last sublayer.
Claims24
A matching layer for an ultrasound probe comprising a plurality of sublayers attached together, the sublayers having different impedance values, a first sublayer of the plurality of sublayers being disposed adjacent to an element of a transducer of the ultrasound probe, a last sublayer of the plurality of sublayers being disposed adjacent to a target, the impedance value of the first sublayer being less than or equal to the impedance value of the element of the transducer, the impedance value of the last sublayer being greater than or equal to the impedance value of the target, the impedance values of the sublayers decreasing from the first to the last sublayer.
A method of making a matching layer for an ultrasound probe comprising the steps of:
- forming a plurality of sublayers having different impedance values;
- and attaching the sublayers together such that a first sublayer, being disposed adjacent to an element of a transducer of the ultrasound probe, has an impedance value equal to or less than an impedance value of the transducer element;
- the last sublayer, being disposed adjacent to a target, has an impedance value greater than or equal to the impedance value of the target;
- and the impedance values of the sublayers decrease from the first to the last sublayer;
- wherein the forming of each of the sublayers comprising the steps of:
- forming a sheet of a first material;
- forming openings in the sheet;
- and
- filling the openings with at least one other material having a different impedance than the impedance of the first material.
A method of making a matching layer for an ultrasound probe comprising the steps of:
- forming a first sublayer on a temporary substrate;
- forming at least one other sublayer on the first sublayer to provide a plurality of sublayers comprising a first and a last sublayer, the plurality of sublayers being attached together;
- and
- removing the plurality of sublayers from the substrate;
- wherein impedance values of the sublayers change monotonically from the first to the last sublayer.
A method of making a matching layer for an ultrasound probe comprising the steps of:
- providing a first material in a particulate form, the first material having a first impedance value;
- forming a plurality of sheets of the particulate first material;
- said plurality of sheets having different porosities;
- sintering the particulate first material to produce porous sheets of the first material;
- infiltrating the porous sheets of the first material with a liquid of a second material having a second impedance value different from the first impedance value;
- solidifying the second material to form a plurality of sublayers having varying sublayer impedance value;
- attaching the sublayers together to form the matching layer for an ultrasound probe in an order such that the sublayer impedance value varies monotonically through the matching layer.
Dependencies are inferred from the claim text.