Computer technologies for formation of acoustic images of defects of the scanned environment with high accuracy

Abstract

The development of a computer technology for the formation of acoustic images of defects in the scanned medium, which includes the development of architecture, hardware and software for ultrasonic echoscopy systems, using both the amplitude and phase of the reflected echo signal as an information parameter, is urgent. Also, an urgent scientific task is the development of an effective computational algorithm for the reconstruction of acoustic images of an object (environment) according to the corresponding hologram descriptions. The algorithm should be fast enough to operate in real time, poorly sensitive to noise and fluctuations in the ultrasound velocity. In the theory of ultrasonic echoscopy systems, high potentialities of holographic information processing methods are known, associated with the registration and computer processing of sound holograms - phase and amplitude-phase spatial spectra of a sound wave reflected from an object. In the descriptions of the latest medical diagnostic systems, for example, the Sequoia S512 from Acuson, there have already been reports of using the phase of the reflected echo signal to form images of pathologies in the tissues of the human body. In addition, the use of computer digital models of physical holograms has inherent advantages only – the possibility of using algorithmic processing at all stages of the formation of a sound hologram and reconstruction of hologram images. This allows to carry out various preliminary computer processing of images in order to improve them before being displayed on the operator's screen. The development of tools and new technologies to improve the images of environmental defects in real time is another urgent problem in this area. The resolution of the holographic system depends on the depth (range) of the area under study. With an increase in the operating frequency and the size of the aperture, the resolution of the system improves. Spatial resolution does not depend on the number of sensors on the measurement aperture. This is a fundamental difference from acoustic control systems with transverse filtering algorithms when forming a probing beam in the mode of receiving echo signals.