Acoustic wave imaging apparatus and method

Abstract

An acoustic imaging apparatus and method that achieves desired delays with coded signals. Linear, curved linear and sector scanning is provided in 1-D arrays and planar, curved planar and sector scanning is provided in 2-D arrays. Composite and non-linear implementations are presented. Dynamic and discrete dynamic focusing is disclosed for the relevant arrays. The 2-D array makes possible 3-D imaging.

Description

FIELD OF THE INVENTION[0001]The present invention relates to acoustic wave imaging systems.BACKGROUND OF THE INVENTION[0002]Conventional acoustic wave imaging systems use a one dimensional (1-D) array of electro-acoustic transducers, for example, a 1×100 array, and have been configured to achieve linear, curved linear and sector scanning. Coherence in the transmission and receipt of acoustic signals is achieved by the utilization of delay devices in the signal processing channels. Present one dimensional systems are disadvantageous due to (1) the manner in which they are constructed and (2) inherent limitations in their scanning capabilities. With respect to the manner in which they are constructed, one disadvantage is that the use of delay elements, and related electronics adds considerably to the cost of one dimensional systems. With respect to inherent limitations, one dimensional scanning systems are disadvantageous in that they only provide two dimensional images.[0003]To incr...

AI Technical Summary

Benefits of technology

[0014]Amongst other aspects, the present invention discloses a manner of using coded signals to achieve desired delays in 1-D, 2-D and annular array imaging systems. For 1-D imaging array systems, a manner of making and practicing linear, curved linear and sector scanning arrays that are low cost and potentially portable is presented. This teaching also applies to annular arrays. For 2-D array imaging systems, a manner of making and practicing these systems for rapid 3-D volume images and / or real time, arbitrary scan plane, 2-D sector, planar, or curved planar images is presented. In addition, the 2-D array taught herein allows for the implementation of multi-dimensional aberration correction which may allow ultrasonic images to approach the image acuity of MRI and X-ray CAT imaging systems, and to do so at a fraction of the cost of these imaging modalities.

Problems solved by technology

Present one dimensional systems are disadvantageous due to (1) the manner in which they are constructed and (2) inherent limitations in their scanning capabilities.

With respect to the manner in which they are constructed, one disadvantage is that the use of delay elements, and related electronics adds considerably to the cost of one dimensional systems.

With respect to inherent limitations, one dimensional scanning systems are disadvantageous in that they only provide two dimensional images.

A problem with applying current 1-D technology to 2-D array imaging is that a vast number of electrical connections and processing electronics are required to serve an array of practical size.

As a result of the disadvantageous aspects of providing large numbers of processing channels, current research efforts are directed towards achieving high performance with fewer array elements.

Due to reduced aperture, 1.5-D arrays may not offer the increase in elevation resolution that will justify their added expense and complexity.

Furthermore, research has shown that the use of aberration correction with 1.5-D arrays may not improve the image quality over that obtained using correction with a 1-D array.

This approach, however, has lead to significantly higher sidelobes in the beam profile of the system, compared to sidelobes in a beam profile for a full 2-D array.

Thus, these systems are not suitable for such common uses as medical diagnostic imaging and the like which requires low and extremely low level sidelobes.

They produce only a single ray, and while they perform dynamic focusing, they do not provide sector scanning.

Images