| 摘要 |
A system employing ultrasound for the reconstruction of the absorptivity and refractivity properties of ultrasonic radiation internal to a solid, liquid or partly solid and liquid object, air vacuoles being excluded, in the vase that this radiation is highly scattered (reflected or refracted). The reconstruction consists of a three-dimensional simulation of these acoustic properties in a powder mixture which allows access to absorptivity and refractivity information without disturbance either to itself or to the object which it simulates. The reconstruction method is a multi-stage process in which the absorptivity and refractivity of the object are sampled layer-by-layer and recorded in mirror-image layers in the reconstruction. At each stage of the process, the previously constructed image layers are used as "corrective optics" to decode the highly distorted information from the object into the exact wave front geometry and wave form at the given layer that this wave had in the corresponding, mirror-image layer in the object, except for being inverted with respect to one spatial dimension as a mirror image. The necessary sonic data processing is done with a powder mixture, each particle of which is a microscopic mechanism capable of amplifying, recording, erasing and recalling the acoustic impedance information by means of mechanical flexions and other movements. |
