Pulsed Wave Doppler

Introduction
Pulsed Waved Doppler Imaging, or PW Mode, is a method to use ultrasound for determining blood velocity and direction.



Pulsing Sequencing

 * The echo signals from the gate are acquired at a predefined Pulse Repetition Frequency (PRF).
 * These echo signals are then used to measure the component of the motion along the direction of beam propagation.

Signal Processing

 * The acquired RF echo signals go through a demodulation to generate in-phase and quadrature components (I/Q).
 * I/Q signals then go through a high pass filter, also known as a wall filter, to remove strong slower motions.
 * The wall filtered signals are then used to generate the spectrum using short time Fourier analysis.