Evaluation of an Improved Ultrasonic Imaging Helmet for Observing Articulatory Data

Abstract

Ultrasonic imaging is one of the most popular methods for tracking tongue motion. Imaging plane shift and contact variation are crucial factors affecting the consistency of the obtained ultrasonic images. To solve this issue, researchers proposed many different helmets. In this study, we propose an evaluation framework to quantitatively assess the helmet’s imaging plane shift and contact variation. The framework is applied to one helmet we designed. Compared to the baseline, the imaging plane shift using our helmet is less than 0.1°, and the contact variation is reduced by 68.5%, decreasing the mean difference of the extracted contours by 50.3% and increasing the contrast and sharpness of the obtained images by 9.0% and 28.4%. The proposed framework provides an approach for quantitatively proofing helmet structure with data accuracy and consistency.