| 摘要 |
<p>An improvement to the method for harmonic imaging including the steps of transmitting ultrasonic energy at a fundamental frequency, and receiving reflected ultrasonic energy at a harmonic of the fundamental frequency is provided. For the improvement the transmitting step includes the step of transmitting a unipolar waveform (82), or a waveform (82, 92) characterized by an amplitude change rate of 8 or fewer times per carrier cycle. Said waveform comprises an envelope shape rising gradually to a respective maximum value, and falling gradually from the respective maximum value.</p> |
