The Effect of Low-Pass Filtering on Target Detection in Simulated Ultrasound Images

This study investigates the potential benefits of a novel image processing filter, based on introducing persistence to an image to increase visual sensitivity for ultrasound-guided nerve block procedures. The effectiveness of the filter was examined for multiple levels of target velocity and filter persistence, using simulated ultrasound-like images. Subjects were asked to detect a covert target in twelve experimental conditions. The experimental results show that the persistence filter augments the target's saliency and consequently contributes to an effective increase in visual sensitivity. In addition, the results show that the filter is most effective for mid-range target velocities combined with high levels of visual persistence. The study concludes that the filter has the potential to improve present ultrasound-guided nerve block procedures and provides recommendations for implementing the filter in real-world settings.