Modern ultrasound scanners use large either linear or phased array of piezoelectric transducers. Design principle of electronic beamforming networks thus draws heavily from that of adaptive antenna array. However, the interaction of ultrasound with human tissue appears to be much more complicated than that of the electromagnetic wave. While with Xrays we get a shadow image of the system, with u...

A high frequency ultrasound imaging technique was applied for quality control of several kinds of projection welds originating from automotive production. The projection welds were formed between V-shaped surfaces of solid components and zinc-coated steel sheets. Acoustic images were obtained both in high resolution and in express regime. Detailed three-dimensional data cubes were acquired usin...

Conventional diagnostic ultrasound images portray differences in the acoustic properties of soft tissues, whereas ultrasound-based elasticity images portray differences in the elastic properties of soft tissues (i.e. stiffness, viscosity). The benefit of elasticity imaging lies in the fact that many soft tissues can share similar ultrasonic echogenicities, but may have different mechanical prop...

Multi-element ultrasonic transducer arrays open the possibility for rapid and flexible tomographic imaging systems. By electronic switching of the individual array elements, different schemes of reflection tomography and transmission tomography can be realized. This contribution firstly introduces general tomographic measurement principles to some detail. It then describes two multi-channel low...

A methodology is presented for health monitoring and subsequent inspection of critical structures. Algorithms have been developed to detect and approximately locate damaged regions by analyzing signals recorded from a permanently mounted, sparse array of transducers. Followup inspections of suspected flaw locations are performed using a dual transducer ultrasonic approach where a permanently mo...

A novel methodology to obtain three-dimensional (3D) acoustic tissue models (3DATMs) is introduced. 3DATMs can be used as computational tools for ultrasonic imaging algorithm development and analysis. In particular, 3D models of biological structures can provide great benefit to better understand fundamentally how ultrasonic waves interact with biological materials. As an example, such models w...

Imaging of defects in engineering components is gaining importance and wider acceptability. Imaging enables automation of measurement process by the use of sensor, enhanced detection and characterisation of defects. Further, it helps in assessing incremental damage in a critical region by performing periodic imaging and comparing. Raster-scan based single sensor imaging and line-scan based arra...

Tubes/Pipes employed in critical applications such as Power Plants, Petrochemical industry and others, demand very stringent quality control. Various Non-Destructive Testing (NDT) techniques are used for inspection of such objects both during fabrication as well as in-service stages. Ultrasonic testing (UT) is a very popular NDT technique adopted in such applications. Flaw detection and thickne...

This paper investigates the potential use of airborne ultrasonic phased arrays for imaging in outdoor environments as a means of overcoming the limitations experienced by kinect sensors, which may fail to work in the outdoor environments due to the oversaturation of the infrared photo diodes. Ultrasonic phased arrays have been well studied for static media, yet there appears to be no comparable...