Examination of a spectral-based ultrasonic analysis method for materials characterization and evaluation

Ultrasonic analysis has long been used as a diagnostic tool for materials and medicine, and measurements that are able to detail internal structure are often desirable. Peak density has previously been used as an assessment for tissue pathology. This quantity has potential for use in the study of tissue and soft materials. However, the use of this parameter is still in its early stages, and the signal processing techniques used are limited. In this work, other signal processing methods commonly used in ultrasonic measurement are applied to the resulting ultrasound pulses transmitted through a soft phantom material to study their effects on peak density calculations. This study examines the outcomes due to the selection of pulse width, the use of standard window functions, and spectral normalization using a reference spectrum. The consequences are assessed through the inspection of individual frequency spectra as well as two dimensional images based upon the peak density parameter. It was found that peak density was highly dependent on the window function employed and was also subject to the pulse width. Spectral normalization was found to have little effect on peak density calculations.