What is the duty factor of Continuous Wave Doppler?

The duty factor of Continuous Wave Doppler is 100%. This is due to the fact that in Continuous Wave Doppler ultrasound, the transducer continuously emits ultrasound waves without interruption, meaning the system is always transmitting. Therefore, the duty factor, which represents the ratio of the time the ultrasound is actively transmitted to the total time of the cycle, is equal to 1 or 100%.

In contrast, pulsed wave Doppler systems have a duty factor less than 100% because they emit ultrasound pulses and then switch to receive mode, leaving a segment of time where no transmission occurs. This difference is significant because a continuous wave system allows for the measurement of higher velocities and more accurate Doppler shifts, whereas pulse wave systems are limited to the Nyquist limit. Understanding this fundamental concept is essential for grasping Doppler ultrasound mechanics and applications in clinical settings.