Ultrasonic scanning head with reduced geometrical distortion

• US 4,325,381 A
• Filed: 11/21/1979
• Issued: 04/20/1982
• Est. Priority Date: 11/21/1979
• Status: Expired due to Term

• Current Assignee: New York Institute of Technology Incorporated
• Original Assignee: New York Institute of Technology Incorporated
• Inventors: Glenn, William E.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Jaworski, Francis J.
• Application Number:
  US06/096,322
• Time in Patent Office: 881 Days
• Field of Search: 367/150-151, 310/335, 73/620, 73/627, 73/629, 73/642, 73/644, 128/660-663
• US Class Current: 600/446
• CPC Class Codes: A61B 8/00 Diagnosis using ultrasonic, sonic or infrasonic waves imaging of objects using sonar G01S15/00
• CPC Class Codes: G10K 11/30 using refraction, e.g. acoustic lenses

Abstract

An improved ultrasonic scanning head is disclosed for use in an apparatus for imaging sections of a body by transmitting ultrasonic energy into the body and determining the characteristics of the ultrasonic energy reflected therefrom. The scanning head includes a scanning window which comprises an acoustic lens for converging the scan of the ultrasound beam. This serves to reduce geometrical distortion.

Claims

1. In an apparatus for ultrasonically imaging sections of a body by transmitting ultrasonic energy into the body and determining the characteristics of the ultrasonic energy reflected therefrom, said apparatus including timing means for generating timing signals;

energizing/receiving means operative in response to timing signals; and

display/record means synchronized with said timing signals for displaying and/or recording image-representative signals from the energizing/receiving means;

an improved portable scanning module, comprising;

a fluid-tight enclosure having an ultrasonically-transmissive window which can be placed in contact with the body;

a fluid contained in said enclosure;

transducer means coupled to said energizing/receiving means for converting electrical energy to a beam of ultrasonic energy and for converting reflected ultrasonic energy to electrical signals.

means for focusing the ultrasound beam emanating from said transducer means;

reflective scanning means pivotably mounted in said fluid in the path of said ultrasound beam for effecting scanning of said beam across said body via said window;

said window comprising an acoustic lens for converging the scan of the ultrasound beam incident thereon from within said enclosure, whereby said acoustic lens reduces geometrical distortion of the scan of said ultrasound beam.

2. Apparatus as defined by claim 1 wherein said acoustic lens has a focal length of between one and two times the distance between said reflective scanning means and said acoustic lens.

3. Apparatus as defined by claim 1 wherein said acoustic lens has a focal length of about one-and-a-half times the distance between said reflective scanning means and said acoustic lens.

4. Apparatus as defined by claim 1 wherein said means for focusing the ultrasound beam emanating from said transducer means comprises another acoustic lens, said another acoustic lens contacting said transducer.

5. Apparatus as defined by claim 4 wherein said means for focusing the ultrasound beam emanating from said transducer means comprises aother acoustic lens, said another acoustic lens contacting said transducer.

6. The scanning module as defined by claim 1 wherein said acoustic lens is of a substantially plano-concave shape with the concave surface facing the inside of said enclosure.

7. Apparatus as defined by claim 6 wherein said acoustic lens has a focal length of between one and two times the distance between said reflective scanning means and said acoustic lens.

8. Apparatus as defined by claim 6 wherein said acoustic lens has a focal length of about one-and-a-half times the distance between said reflective scanning means and said acoustic lens.

9. The scanning module as defined by claim 6 wherein said acoustic lens is formed of a rigid plastic material.

10. Apparatus as defined by claim 9 wherein said acoustic lens has a focal length of between one and two times the distance between said reflective scanning means and said acoustic lens.

11. Apparatus as defined by claim 10 wherein said means for focusing the ultrasound beam emanating from said transducer means comprises another acoustic lens, said another acoustic lens contacting said transducer.

12. Apparatus as defined by claim 9 wherein said means for focusing the ultrasound beam emanating from said transducer means comprises another acoustic lens, said another acoustic lens contacting said transducer.

13. Apparatus as defined by claim 9 wherein said acoustic lens has a focal length of about one-and-a-half times the distance between said reflective scanning means and said acoustic lens.