摘要 |
<p>The invention discloses a method and apparatus for effectively localizing a stone and targeting a shock wave in connection with extracorporeal shock wave lithotripsy ('ESWL'). The technique disclosed by this invention can be adapted for use in connection with any conventional lithotripter. In this invention, an array of at least 3 and preferably 4 or more pressure transducers are used to sense the reflection from the target in response to an initial shock wave or ultrasonic wave. The sensor readings are then temporally shifted relative to one another in such a way as to maximize correlation between the signals from each sensor. The required time shifts for maximum correlation are used to calculate the differences in arrival times of reflected waves at the sensors. By knowing the original location of the sensors and establishing the time differences at which the reflected wave reaches the different sensors, a technique is disclosed to determine the vector coordinates extending between the target location and the focal point of the lithotripter.</p> |