Ultrasonic Doppler imaging apparatus

An ultrasonic Doppler imaging apparatus comprising:

• ultrasonic means for emitting ultrasonic pulse waves to an object body under test in a selective-scanning manner and receiving dispersed ultrasonic waves dispersed for said object body;
• means for A/D converting, in synchronism with said ultrasonic means, a first part of said dispersed ultrasonic wave signals into digital data and outputting a digital data string;
• addition/subtraction means, receiving said data string from said A/D converting means, for performing a quadrature addition/subtraction operation on a selected set of data elements including D.sub.i, D.sub.i+1, D.sub.i+2, and D.sub.i+3 selected from said data string to obtain complex Doppler data having a real part R and an imaginary part X expressed by, where i is an odd number:
• R=C.sub.i .multidot.D.sub.i +C.sub.i+2 .multidot.D.sub.i+2
• X=C.sub.i .multidot.D.sub.i+1 +C.sub.i+2 .multidot.D.sub.i+3, and
• expressed by, where i is an even number:
• R=C.sub.i .multidot.D.sub.i+1 +C.sub.i+2 .multidot.D.sub.i+3
• X=C.sub.i .multidot.D.sub.i -C.sub.i+2 .multidot.D.sub.i+2
• where, C.sub.i =(-1).sup.i/2, and i/2 is an integer operation,
• wherein said addition/subtraction operation for the real part R and the imaginary part X have a quadrature relation;
• means for implementing frequency analysis for said complex Doppler data provided by said addition/subtraction means to obtain a Doppler shift frequency;
• means for detecting a second part of said dispersed ultrasonic wave signals to obtain a tomographic image signal of said object body;
• and
• display means for displaying the output of said frequency analysis means and the output of said detection means as one picture frame.

A quadrature addition/subtraction device comprising:

• latch clock means for generating a latch clock;
• input means for receiving digital data;
• a plurality of latch means, connected in series, for sequentially latching elements of said digital data so as to shift a phase thereof, in accordance with said latch clock;
• first addition/subtraction means for implementing addition/ subtraction between two first data elements, which are 1/2 period apart from each other, said two first data elements being selected from digital elements appearing at said input means and at outputs of said plurality of latch means;
• second addition/subtraction means for implementing addition/subtraction between two second data elements, selected from said digital data elements appearing at said input means and at said outputs of said plurality of latch means, said two second data elements being 1/4 period apart from said two first data elements, respectively;
• wherein said two first data elements respectively have a quadrature relation with corresponding ones of said two second digital elements;
• and
• control means for controlling the adding/subtracting operation of said first and second addition/subtraction means.

A quadrature addition/subtraction device comprising

• latch clock means for generating a latch clock;
• input means for receiving digital data;
• a plurality of latch means, connected in series, for sequentially latching elements of said digital data supplied thereto so as to shift a phase thereof in accordance with said latch clock;
• first addition/subtraction means for implementing addition/ subtraction between two first data elements, which are 1/2 period apart, selected from elements of digital data appearing at said input means and at outputs of said plurality of latch means;
• second addition/subtraction means for implementing addition/subtraction between two second data elements, selected from said digital data elements appearing at said input means and at said outputs of said plurality of latch means, said two second data elements being 1/4 period apart from said two first data elements, respectively;
• wherein said two first data elements have a respective quadrature relation with corresponding ones of said two second data pieces;
• first cumulative summing means for cumulatively summing outputs of said first addition/subtraction means;
• second cumulative summing means for cumulatively summing outputs of said second addition/subtraction means;
• and
• control means for controlling the adding/subtracting operation of said first and second cumulative summing means.

A quadrature addition/subtraction device comprising:

• latch clock means for generating a latch clock;
• input means for receiving digital data;
• latch means, responsive to the latch clock, for latching said digital data supplied thereto by said input means;
• delay means for delaying an output of said latch means;
• subtraction means for implementing subtraction between an output of said latch means and an output of said delay means;
• first and second cumulative addition/subtraction means for alternately implementing cumulative addition/subtraction for outputs of said subtraction means;
• and
• control means for controlling the adding/subtracting operation of said first and second cumulative addition/ subtraction.