See also Chadwick Final Presentation.

Team members

Ed Chadwick, Restorative Medicine Group, Institute for Science and Technology in Medicine, Keele University, Staffordshire, UK.
Dimitra Blana, Visiting Researcher, Restorative Medicine, ISTM, Keele, and Case Western Reserve University, Cleveland, Ohio*.

(*Much of this work done in collaboration with the Kirsch lab at Case Western Reserve University and Ton van den Bogert of Cleveland State University.)

Big picture

Our overall aim is to develop tools for real-time musculoskeletal simulation to enable model-based design and testing of neuroprosthesis systems to restore function in the upper limb in spinal cord injury and other neuromuscular disorders. To facilitate adoption of these models, we want to integrate our real-time model with the OpenSim visualiser to provide real-time visual feedback on the state of the musculoskeletal system to clinicians and biomedical engineers.

The figure below shows how our model integrates with OpenSim and how users interact with the system. The user controls the 'virtual arm' (real-time, dynamic model) using a BCI, residual EMGs, head-tracking device or other command source, and the clinician can visualise the state of the muscles and joint reaction forces in real time on the OpenSim visualiser interface.

Workshop goals

Our specific aims for the workshop are:

To link the OpenSim visualisation with our real-time model
To extend the OpenSim visualisation to represent joint contact forces

Results

The movie on the left shows the activation coloring of the muscles in the Simbody visualiser (red is more active). The movie on the right shows arm abduction with the real-time model linked to Simbody Visualizer. It shows the visualization of glenohumeral stability as it is affected by deltoid and rotator cuff activation. When the deltoid is activated alone it causes glenohumeral instability (shown as a red vector), rotator cuff activation increases the stability (green vector).

For more information, see our project page on Simtk: https://simtk.org/home/das.

Related papers

Bogert, A. J. Van Den, Blana, D., & Heinrich, D. (2011). Implicit methods for efficient musculoskeletal simulation and optimal control. Procedia IUTAM, 2, 297–316.
Chadwick, E. K., Blana, D., Simeral, J. D., Lambrecht, J., Kim, S. P., Cornwell, A. S., Taylor, D. M., et al. (2011). Continuous neuronal ensemble control of simulated arm reaching by a human with tetraplegia. Journal of Neural Engineering, 8(3), 034003.
Blana, D., Kirsch, R. F., & Chadwick, E. K. (2009). Combined feedforward and feedback control of a redundant, nonlinear, dynamic musculoskeletal system. Medical & Biological Engineering & Computing, 47(5), 533–42.

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