A Dynamic Time Warping Method for Improved Arterial Wall-Tracking using A-mode Ultrasound Frames: A Proof-of-Concept

Abstract

Existing ultrasound systems for the measurement of arterial wall dynamics make use of techniques such as doppler processing, phase locking, threshold detection, or cross-correlation based echo tracking. Applications that require only the maximum distension measure may not impose stringent demand on accuracy. However, the wall-tracking accuracy is a primary methodological consideration for the applications that depend on the true morphology of the entire distension waveform. In this work, we propose a novel image-free ultrasound approach to auto-track the arterial walls in a reliable manner, even in the presence of other dynamic echoes very adjacent to the wall echoes. The method uses the concept of dynamic time warping for estimating the varying shifts across various echoes in the scanned A-mode frames. We have demonstrated the method’s functionality in this article via. systematic simulation experiments. Contrary to the widely used cross-correlation technique, the proposed method was capable of distinguishing the motion of the walls from that of other dynamic echoes. We have also assessed the performance of the proposed method by varying the signal-to-noise ratio of the simulated ultrasound frames. As inference, the method demonstrated acceptable accuracies for frames with SNR above 10 dB.