Doppler signal processing apparatus and ultrasonic diagnostic apparatus

A Doppler signal processing apparatus for cutting signals of a predetermined length from a time-domain Doppler signal;

• performing window processing on said cut signals;
• transforming said window-processed signals into frequency-domain signals by Fourier transformation;
• inversely transforming said transformed frequency-domain signals into a time-domain signal by inverse Fourier transformation after performing predefined processing on said signals, comprising:
• an output device for outputting said inversely transformed time-domain signal as an acoustic signal;
• and
• an amplitude modulating device for performing amplitude modulation with a property opposite to that of amplitude modulation by said window processing before outputting said inversely-transformed time-domain signal as the acoustic signal.

An ultrasonic diagnostic apparatus for transmitting ultrasound and acquiring a Doppler signal of an echo of the ultrasound;

• cutting signals of a predetermined length from said Doppler signal in a time domain;
• performing window processing on said cut signals;
• transforming said window-processed signals into frequency-domain signals by Fourier transformation;
• inversely transforming said transformed frequency-domain signals into a time-domain signal by inverse Fourier transformation after performing predefined processing on said signals;
• and outputting said inversely transformed time-domain signal as an acoustic signal, comprising:
• a window processing device for performing said window processing using a window having a profile with a flat top;
• and
• a signal cutting device for performing said cutting from the Doppler signal such that a former cut signal and a latter cut signal overlap in a portion corresponding to the flat portion of said window.

A method for removing an effect of window processing in imaging systems comprising:

• cutting signals of a predetermined length from a time-domain Doppler signal that is obtained after processing echo signals received from an object;
• performing window processing on said cut signals that are obtained after processing the echo signals received from the object;
• transforming said window-processed signals into frequency-domain signals by Fourier transformation;
• inversely transforming said transformed frequency-domain signals into time-domain signals by inverse Fourier transformation;
• modulating said inversely transformed time-domain signals with a property opposite to that of modulation by said window processing to generate modulated signals;
• and
• outputting said modulated signals as a Doppler image.