uCALF: Ultrasound Catheter-Based Automated Leg Fascicle Tracking

Abstract

Mobility-enhancement systems, such as soft robotic exosuits, aim to reduce user burden and improve life quality by providing assistance during locomotion. How- ever these systems currently lack methods for providing individualized assistance to wearers. This hinders the optimization of actuator activation, leading to suboptimal performance. The magnitude and timing of the extension and contraction of the leg muscles are key pieces of information that can lead to an exosuit that is in sync with the user. This project specifically sought to develop a portable system that utilizes a non-invasive sensing method to automatically quantify fascicle lengths in the gastrocnemius muscle during locomotion. The constructed system successfully leverages portable ultrasound catheter technology by employing a robust, wearable, 3D-printed polymer stabilization attachment to fix the ultrasound transducer to the leg, and an image-processing algorithm that extracts fascicle length and timing of the length change from the acquired video. This will enable further research and insight into human biomechanics and advanced locomotion assistance devices.