Ultrasonic Real-time Imaging Using Acoustic Fourier Transform

使用声学傅里叶变换的超声实时成像

• 批准号: 07650508
• 负责人: NAKAJIMA Masato
• 金额: $ 1.34万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650508/
• 关键词: Ultrasound; Ultimate environment; Invisible information; Real time; Imaging; Fourier Transform; Holography

The purpose of this research is1. Development of the new method that performs Fourier Transform of the object by the ultrasound (Acoustic Fourier Transform) and reconstructs the object by Inverse Fast Fourier Transform in the computer.2. Experiment of reconstructionabout the glass, the stainless steel, which are transparent by the optical method, and the object in the flame, the mud, the mist, which is called the ultimated environment, for the verification of this method.We made the reflection type Acoustic Fourier Transform system. An object and a reference source are arranged in the front of the transmitter-receiver array which arranged many receivers in the circumference of one transmitter. Here, these elements are arranged sot that they may be on the same perimeter. Then, Fourier Transform of the object can be obtained at the receiver array by interference of the reference wave and the reflection wave from the object (the object wave). Moreover, in this method, it was decided with the system that the reference signal made in the computer was electrically added on the circuit for the substitute of arranging a reference source in the neighborhood of the object. And, automatical focusing, which measured a distance to the object by the pulse echo method, was included to adjust the delay quantity of the reference signal made in the computer.Using this system, we reconstructed the object (geometrical easy figures, alphabet characters) made of the acrylic fiber as an example of the optical transparent object, and the object in the smoke as an example of the object under the ultimated environment. As a result, each object was reconstructed sufficiently, and the validity of this method was confirmed. We could perform all of the processing in about 20 seconds using the personal computer which had the CPU of Pentium 133MHz.

本研究的目的是1。研究开发了一种利用超声(声波傅里叶变换)对物体进行傅里叶变换，并在计算机上通过快速傅立叶逆变换重建物体的新方法。为了验证该方法的有效性，对光学方法透明的玻璃、不锈钢以及火焰、泥土、雾气中的物体进行了重建实验，制作了反射式声学傅里叶变换系统。在发射机-接收机阵列的前面设置有物体和参考源，该发射机-接收机阵列在一个发射机的圆周上设置多个接收器。在这里，这些元素被安排成它们可能在同一周长上。然后，通过参考波和来自物体(物体波)的反射波的干涉，可以在接收器阵列处获得物体的傅里叶变换。此外，在该方法中，系统决定将计算机中产生的参考信号电加到电路上，以代替在物体附近布置参考源。并利用脉冲回波法测量物体与物体距离的自动调焦，调节计算机产生的参考信号的延迟量。利用该系统，我们以光学透明物体为例，重建了由聚丙烯腈纤维制成的物体(几何简易图形、字母字符)，并以烟雾中的物体为例，对最终环境下的物体进行了重建。结果对每个物体进行了充分的重建，验证了该方法的有效性。我们可以用奔腾133 MHz的CPU的个人计算机在大约20秒内完成所有的处理。