Ultrasonic imaging system

• US 4,237,737 A
• Filed: 09/12/1978
• Issued: 12/09/1980
• Est. Priority Date: 09/14/1977
• Status: Expired due to Term

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Nitadori, Kazuhiko
• Primary Examiner(s): Kreitman, Stephen A.
• Application Number:
  US05/941,472
• Time in Patent Office: 819 Days
• Field of Search: 367/7, 367/12, 367/103, 367/105, 367/108, 73/625, 73/626, 73/628, 340/5 MP, 340/1 P, 340/3 R, 128/2 V, 128/660
• US Class Current: 73/625
• CPC Class Codes: G01N 2291/02854 Length, thickness
• CPC Class Codes: G01N 29/0609 Display arrangements, e.g. colour displays indicating or recording in connection with measuring in general G01D
• CPC Class Codes: G01S 15/8913 using separate transducers for transmission and reception
• CPC Class Codes: G01S 15/8925 the array being a two-dimensional transducer configuration, i.e. matrix or orthogonal linear arrays
• CPC Class Codes: G10K 11/346 using phase variation

Abstract

An ultrasonic imaging system is provided for forming an orthographic and a tomographic image of an object. The system comprises a receiving transducer array having a plurality of elements positioned at the lattice points of a parallelogram and a transmitting transducer array having a plurality of elements arranged in a straight line parallel to one side of the parallelogram at a period equivalent to the length of the side. A receiving beam former compensates for the delay time of the received signal for each element in the receiving transducer array and adds the compensated signals for all the elements. The receiving beam former comprises a quadrature demodulator which decomposes the output of a receiving transducer element into the inphase component and the quadrature component of a transmitting carrier signal. The beam former also includes means for delaying the components, means for performing the complex multiplication of the delayed components, means for adding the real parts of the output of the complex multiplication means for all channels, means for adding the imaginary parts of the output of the complex multiplication means for all channels, a pair of square circuits for providing the square of the real sum and the imaginary sum respectively, and an adder for adding the outputs of the square circuits. Further, means are provided for extracting the received beams in accordance with the timing of the transmitted beam and are provided for displaying the extracted received beams thereby forming an image.

Claims

1. An ultrasonic imaging system for forming an orthographic image and a tomographic image of an object comprising:

(a) a receiving transducer array having a plurality of elements positioned at the lattice points of a parallelogram,

(b) a transmitting transducer array having a plurality of elements arranged on a straight line parallel to one side of said parallelogram at a period equivalent of the length of said side,

(c) means for applying an electrical signal, having a delay time defined for each element, to said transmitting transducer array to project an acoustic pulse to an object,

(d) said receiving transducer array receiving the reflected sound waves from said object,

(e) a receiving beam former for compensating for the delay time of the received signals of each element in the receiving transducer array and adding the compensated signals of all the elements, said receiving beam former comprising of a quadrature demodulator which decomposes the output of a receiving transducer element into the inphase component and the quadrature component of a transmitting carrier signal, means for delaying said components, means for performing the complex multiplication for the delayed components, means for adding the real parts of the output of the complex multiplication means of all the channels, means for adding the imaginary parts of the output of the complex multiplication means of all the channels, a pair of square circuits for providing the square of the real sum and the imaginary sum respectively, and an adder for adding the output of said square circuits,

(f) means for extracting the received beams in accordance with the timing of the transmitted beam, and

(g) means for displaying the extracted received beams thereby forming an image.