Ultrasonic diagnosing apparatus

• US 7,029,445 B2
• Filed: 01/12/2001
• Issued: 04/18/2006
• Est. Priority Date: 01/12/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Baba, Hirotaka, Shinomura, Ryuichi, Miwa, Yuichi
• Primary Examiner(s): IMAM, ALI M
• Application Number:
  US10/169,979
• Publication Number:
  US 20050075570A1
• Time in Patent Office: 1,922 Days
• Field of Search: 600437-472, 367/7, 367/11, 367/130, 367/138, 128/916, 736/25, 736/26
• US Class Current: 600/443
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: A61B 8/4494 characterised by the arrangement of the transducer elements devices for short-range imaging using particular transducer elements arrangements under G01S15/8909; arrangements of transducers in generation of mechanical vibrations of infrasonic, sonic or ultrasonic frequency B06B1/0607
• CPC Class Codes: B06B 1/0625 Annular array
• CPC Class Codes: G01S 15/8922 the array being concentric or annular
• CPC Class Codes: G01S 15/8925 the array being a two-dimensional transducer configuration, i.e. matrix or orthogonal linear arrays
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G01S 7/52049 using correction of medium-induced phase aberration
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

An ultrasonic diagnostic apparatus transmits an ultrasonic beam into an object to be examined using a multi-ring arrangement formed with transducer elements arrayed two-dimensionally in concentric rings and receives an echo so as to create a tomogram or a three-dimensional image of the object. To correct for focusing error due to the difference in length of ultrasound propagating paths, the ultrasonic diagnostic apparatus groups the transducer elements so as to form a multi-ring arrangement, transmits/receives ultrasonic beams with a delay to each ring of the multi-ring arrangement and scans the ultrasonic beam so as to create an ultrasonic image, measures delay error due to presence of a sound speed non-uniformity portion of the object and changes either the coupling of the multi-ring or the delay time based on the measurement error.

Claims

1. An ultrasonic diagnostic apparatus comprising a probe having two-dimensional array of transducer elements for transmitting and receiving ultrasonic waves to an object to be examined, in which a circular pattern of transducer elements is formed for transmitting and receiving an ultrasound signal by bundling the transducer elements of said two-dimensional array electronically to compose a multi-ring arrangement of transducer elements in concentric rings, and an ultrasound beam is transmitted and received with application of a delay time between each ring of said multi-ring arrangement, wherein said ultrasonic diagnostic apparatus further comprises means for transmitting and receiving an ultrasonic beam that has been corrected using said multi-ring arrangement by measuring a focusing error due to the presence of a sound speed non-uniformity interior of said object and modifying at least one of the manner of bundling of said multi-ring arrangement or the delay time based on the measuring error, and means for imaging the object with an echo signal formed of the corrected ultrasonic beam, wherein the multi-ring arrangement of transducer elements formed by bundling transducer elements of the two-dimensional array in said probe in concentric rings is divided into a plural number of sections in a radial shape from the center to the outside of the circular pattern, and a focusing error due to the presence of a sound speed non-uniformity part in the object is measured between each section of the divided circular pattern or each section of the concentric rings, and the ultrasonic beam is corrected by feeding back a measured value to delay circuits in said transmitting and receiving means.

2. An ultrasonic diagnostic apparatus according to claim 1, wherein the measuring of focusing error includes correcting a phase error by calculating a delay amount that brings about a maximum intensity by changing the delay amount consecutively to each ring.

3. An ultrasonic diagnostic apparatus comprising a probe having two-dimensional array of transducer elements for transmitting and receiving ultrasonic waves to an object to be examined, in which a circular pattern of transducer elements is formed for transmitting and receiving an ultrasound signal by bundling the transducer elements of said two-dimensional array electronically to compose a multi-ring arrangement of transducer elements in concentric rings, and an ultrasound beam is transmitted and received with application of a delay time between each ring of said multi-ring arrangement, wherein said ultrasonic diagnostic apparatus further comprises means for transmitting and receiving an ultrasonic beam that has been corrected using said multi-ring arrangement by measuring a focusing error due to the presence of a sound speed non-uniformity interior of said object and modifying at least one of the manner of bundling of said multi-ring arrangement or the delay time based on the measuring error, and means for imaging the object with an echo signal formed of the corrected ultrasonic beam,

wherein a bundled arrangement of transducer elements is provided that is different from that of said multi-ring arrangement composed by bundling said transducer elements of said two-dimensional array of said probe in concentric rings, and a focusing error due to the presence of a sound speed non-uniformity part in the object is measured between each circular pattern, and the ultrasonic beam is corrected by feeding back a measured value to delay circuits in said transmission and receiving means and returning the multi-ring arrangement to an initial setting.

4. An ultrasonic diagnostic apparatus according to claim 3, wherein the measuring of focusing error includes correcting a phase error by calculating a delay amount that brings about a maximum intensity by changing the delay amount consecutively to each ring.

5. An ultrasonic diagnostic apparatus comprising:

a probe having a two-dimensional array of transducer elements;

transducer selection means for electronically bundling transducer elements into a multi-ring arrangement of a circular pattern composed of a plural number of rings,

said multi-ring arrangement of transducer elements formed by bundling transducer elements of the two-dimensional array in said probe in concentric rings being divided into a plural number of sections in a radial shape from a center to an outside of the circular pattern;

means for calculating a focusing error between sections in said multi-ring arrangement;

means for feed-back correcting said calculated focusing error relative to a set delay time to produce a corrected focusing error signal;

means for beam-forming comprised of delay circuits for applying a delay time to each ring of said multi-ring arrangement of transducer elements in response to a corrected focusing error signal and an adder circuit for adding the outputs of said each delay circuits; and

means for imaging an output signal of said means for beam-forming.

6. An ultrasonic diagnostic apparatus according to claim 5, wherein means for calculating the focusing error between sections in said multi-ring arrangement includes means for calculating the focusing error between rings in one section.

7. An ultrasonic diagnostic apparatus according to claim 5, wherein the means for calculating the focus error includes means for correcting a phase error by calculating a delay amount that brings about a maximum intensity by changing the delay amount consecutively to each ring.

8. An ultrasonic diagnostic apparatus comprising:

transducer selection means for initially forming a multi-ring arrangement of transducer elements composed of a plural number of rings from a two-dimensional array of transducer elements;

means for specifying transducer elements having a focusing error in each ring of said multi-ring arrangement;

ring correction means for changing a specified transducer element to a different ring from initial ring location to correct the focusing error;

a beam-forming part comprised of delay circuits for applying a delay time to the transducer elements of each ring of said multi-ring arrangement and an adder circuit for adding the outputs of each of said delay circuits; and

means for imaging an output signal of said beam-forming part.

9. Ultrasonic diagnosing apparatus according to claim 8, wherein means for specifying transducer elements having a focusing error includes means for bundling a group of adjacent transducer elements different from a ring and assigning a transmitter and beam-forming circuit to this bundled transducer group.

10. An ultrasonic diagnostic apparatus according to claim 8, further comprising means for correcting a phase error by calculating a delay amount that brings about a maximum intensity by changing the delay amount consecutively to each ring.

11. An ultrasonic diagnostic apparatus comprising:

a probe having a two-dimensional array of transducer elements arranged in a circular pattern so as to produce a multi-ring arrangement of transducer elements formed by bundling transducer elements of the two-dimensional array in said probe in concentric rings which are divided into a plural number of sections in a radial shape from a center to an outside of the circular pattern;

means for calculating a focusing error between sections of the concentric rings;

means for feed-back correcting said calculated focusing error relative to a set delay time to produce a corrected focusing error signal;

means for beam-forming comprised of delay circuits for applying a delay time each ring of said multi-ring arrangement of transducer elements in response to a corrected focusing error signal and an adder circuit for adding the outputs of said each delay circuits; and

means for imaging an output signal of said means for beam-forming.

12. An ultrasonic diagnostic apparatus according to claim 11, wherein the means for calculating the focus error includes means for correcting a phase error by calculating a delay amount that brings about a maximum intensity by changing the delay amount consecutively to each ring.