| 摘要 |
<p>An ultrasonic imaging system comprising means for forming an ultrasonic beam (B) and means for steering the beam (B), wherein the steering means operates independently of the forming means. The steering means comprises an array of transducers (12) on a catheter (10) such that the transducers (14 to 30) are spaced linearly along an axis (130) of the catheter. The beam is steered by an active aperture which comprises adjacent subsets of the transducers. By selectively activating the transducers according to a predetermined linear delay profile the active aperture is translated along the array and the desired direction of the beam is achieved. A quadratic portion of a beam forming equation is implemented in the beam forming means to focus the beam.</p> |
