| 摘要 |
Doppler principle has been widely applied to calculate the velocity of the object in motion. In medical ultrasonic imaging, it can be used to detect blood flow or myocardial motion. However, due to the inherent limitation of the Doppler effect, the measured velocity is only the projection of the actual velocity onto the ultrasound beam direction instead of the actual velocity. In previously proposed methods for measuring or correcting the Doppler angles, some need manual correction, others use complicated algorithms. They are either inconvenient to use or difficult to implement in current systems. In the method of Doppler motion detection with automatic angle correction according to the instant invention, it focuses on the relation between the Doppler angle and signal bandwidth to compute the Doppler angle by efficient correlation processing. Specifically, it uses variance of the Doppler signal to approximate square of the Doppler bandwidth. In addition, the actual velocity can be computed using the two-dimensional color mapping function existing in current color Doppler imaging systems. This method is not only suitable for efficient implementation, but also can be easily realized in current imaging systems to provide more accurate velocity information.
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