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US 4,307,613 AGranted
Electronically focused ultrasonic transmitter
AssigneeUniversity of Connecticut
InventorMartin D. Fox
Life of this patent
Estimating the term…
Abstract
An array of transducer segments is arranged in columns, each of which has a multiplicity of segments. The segments are wired to permit excitation by one or the other of two opposite phases of high-frequency signal, and groups of segments can be excited with the same phase to approximate the shape of an annular-ring phase-reversal zone plate. By changing the groupings of the elements that are similarly excited, the position of the focal region produced by the zone plate is translated in lateral position. A ferrite-core transformer is conveniently employed for both phase splitting and addition of the echo signals received by the device.
Claims13
An electronically focused ultrasound transmitter comprising:
- a. a transducer-element array arranged in mutually perpendicular rows and columns, said columns being provided at substantially equal intervals, said rows being provided at intervals having substantially a zone-plate progression and including first, second, third, and fourth generally circular groups of transducer elements, said first and second groups being concentric and forming a first zone-plate pattern, said third and fourth groups being concentric about a center spaced from the center of said first and second groups by a given directed distance and forming a second zone-plate pattern spaced from said first zone-plate pattern by said given directed distance, said first and third groups having no transducer elements in common with said second and fourth groups, respectively;
- b. signal generator means, including first and second output ports, for generating first and second excitation signals of equal frequency and opposite phase and impressing said first and second output ports, respectively;
- c. a multiplicity of switch means, each of said switch means being electrically connected between one output port and at least one transducer element associated with said switch means and being operable by application of control signals thereto to connect and disconnect each transducer element associated with it to said output port to which it is connected;
- and
- d. control circuit means, electrically connected to said switch means for application of control signals thereto, for generating control signals and applying them to said switch means to simultaneously connect said first output port to said transducer elements of said first group and said second output port to said transducer elements of said second group, thereby focusing acoustic power from said transducer elements on a first focal region, and subsequently to simultaneously connect said first output port to said transducer elements of one of said third and fourth groups and said second output port to said transducer elements of the other of said third and fourth groups, thereby focusing acoustic energy on a second focal region spaced by said given directed distance from said first focal region.
2 more elements
An electronically focused ultrasound transmitter comprising:
- a. a transducer-element array arranged in mutually perpendicular rows and columns, said columns being provided at substantially equal intervals, said rows being provided at intervals having substantially a zone-plate progression and including first, second, third, and fourth generally circular groups of transducer elements, said first and second groups being concentric and forming a first zone-plate pattern, said third and fourth groups being concentric about a center spaced from the center of said first and second groups by a given directed distance and forming a second zone-plate pattern spaced from said first zone-plate pattern by said given directed distance, said first and third groups having no transducer elements in common with said second and fourth groups, respectively;
- b. signal generator means, including at least one output port, for generating and impressing upon each output port an excitation signal associated with said output port, each excitation signal having the same frequency;
- c. a multiplicity of switch means, each of said switch means being electrically connected between one output port and at least one transducer element associated with said switch means and being operable by application of control signals thereto to connect and disconnect each transducer element associated with it to said output port to which it is connected;
- and
- d. control circuit means, electrically connected to said switch means for application of control signals thereto, for generating control signals and applying them to said switch means to simultaneously connect an output port to said transducer elements of said first group and an output port to said transducer elements of said second group, thereby focusing acoustic power from said transducer elements on a first focal region, and subsequently to simultaneously connect an output port to said transducer elements of said third group and an output port to said transducer elements of said fourth group, thereby focusing acoustic power on a second focal region spaced by said given directed distance from said first focal region.
2 more elements
A method of electronically focusing acoustic power comprising the steps of:
- a. providing a transducer-element array arranged in mutually perpendicular rows and columns, said columns being provided at substantially equal intervals, said rows being provided at intervals having substantially a zone-plate progression and including first, second, third, and fourth generally circular groups of transducer elements, said first and second groups being concentric and forming a first zone-plate pattern, said third and fourth groups being concentric about a center spaced from the center of said first and second groups by a given directed distance and forming a second zone-plate pattern spaced from said first zone-plate pattern by said given directed distance, said third and fourth groups having no transducer elements in common with said first and second groups, respectively;
- b. simultaneously driving said first group with a first excitation signal and said second group with a second excitation signal equal in frequency to said first excitation signal but opposite in phase, thereby concentrating acoustic power on a first focal region;
- and
- c. subsequently driving said third group with one of said first and second excitation signals and said fourth group with the other of said excitation signals, thereby concentrating acoustic power on a second focal region spaced by said given directed distance from said first focal region.
1 more element
Dependencies are inferred from the claim text.