A Deep Dive Into Current Marker-Less Motion Capture Systems and Integrating Theia3D Outputs Into OpenSim

This project aimed to explore the various marker-less motion capture systems available for biomechanical analysis and identify the most suitable option for our laboratory. Marker-less systems are becoming more prominent in biomechanical analysis due to their non-invasive approach and reduced data collection time. Upon choosing an appropriate marker-less system, the biggest challenge was integrating the output into OpenSim, a flexible platform that provides musculoskeletal modelling. The initial leg of this research compared the different marker-less systems available and how accurately they compared to marker-based systems. The variables considered included accuracy, precision, hardware, coordinate system, and more. The systems included Deep Lab Cut, Theia3D, Open Pose, HRnet, DARI motion. Upon comparison, it was decided objectively that Theia3D provided the most accurate calculations, but the output produced was difficult to integrate into other 3D models. The default 3D model produced by Theia3D used Visual3D, which cannot be altered through MATLAB. As a result, the next step of the research was to produce a script that could manipulate the Theia3D data so that it could be read and imported into OpenSim. The subsequent phase of this research required developing the outputs of Theia3D data into a file compatible with OpenSim. A sample script with a similar goal was provided and used as a framework for the task. The existing script provided an outline of how to process Theia3D data and extract segment angles but required a method to save the variables in an OpenSim compatible format. The final and ongoing step of the research requires this code to be integrated into MATLAB and produce a GUI that would allow specific angles to be extracted from a dataset.