Authors: Gromit Yeuk-Yin Chan, Luis Gustavo Nonato, Alice Chu, Preeti Raghavan, Viswanath Aluru, Claudio Silva
Abstract: The brachial plexus is a complex network of peripheral nerves that enables sensing from and control of the movements of the arms and hand. Injuries to the brachial plexus invariably involve changes to the muscles, and impede movement, particularly in the absence of timely nerve repair. Nowadays, there is still a lack of understanding on the coordination between the muscles to generate simple movements, leading to confusion as to how to best treat patients with this type of peripheral nerve injury. Sophisticated motion analysis assessments can produce a rich dataset of electromyographic signals from multiple muscles recorded with joint movements during real-world tasks. These assessments provide detailed information on muscle coordination during natural movements to develop customized strategies to restore arm and hand functions. However, tools for the analysis and visualization of the data in a succinct and interpretable manner are currently not available. Thus, the usefulness of the available data in answering clinical questions and generating hypotheses for research is limited. To address this challenge, we have developed Motion Browser, an interactive visual analytics system that helps users analyze bundles of time series integrated from muscle signals with movement and visual task information. Motion Browser provides an efficient framework to extract and compare muscle activity patterns across both arms of a single individual or across individuals, and to help users explore and interpret the multimodal data in the context of different tasks. The system was developed as a result of a collaborative endeavor between computer scientists and orthopedic surgery and rehabilitation physicians. We present case studies which show that physicians are able to utilize the information displayed to understand how individuals with brachial plexus injuries use their muscles to initiate appropriate treatment and generate new hypotheses for future research.