Neurological and Biomechanical Fusion
Dr. John Jeka internationally recognized for his work on human locomotion and balance, with a specific interest in how information from multiple senses is fused for upright stance control.
His lab at the University of Delaware Science, Technology and Advanced Research (STAR) campus – CoBal Lab -is a brilliant display of motion capture integrating technologies fused with a passionate team that uses a Virtual Reality Dome to simulate a variety of scenes that manipulate a subject’s senses as human motion is investigated.
Both biomechanical and neural components contribute to the functionality of a human’s ability to stand upright. The CoBal Lab is constantly pursuing neurological and biomechanical fusion projects in hopes of promoting a lower cost of injuries related to falls in older adults while influencing new treatments for individuals with balance disorders.
Understanding human upright balance
The bipedal human is inherently unstable and needs a sophisticated control system to remain upright. Researchers at the CoBal Lab strive to understand the biomechanical and neurological components of balance to better facilitate rehabilitation practices in patients with neurological disease and injury that lead to balance problems.Researchers at the CoBaL lab use various techniques to manipulate the three sensory systems:
- Vestibular system (inner ear) is controlled by a Galvanic Vestibular Stimulation (GVS) in which an electric current is sent to the vestibular complex biasing the signal.
- Vision is engineered with the Virtual Reality (VR) Dome System
- Proprioception is conducted with a pair of vibrators on the Aquiles tendon
The CoBal Lab team performed a study on Multi Sensory Fusion and sensory re-weighting in college athletes. The long-term goal of this project is to investigate potential mechanisms underlying brain injury due to mild mechanical impact, touching upon common areas of interest for neuroscience.
Participants stand in front the virtual reality Dome as researchers perturb the three sensory systems. Some subjects walk on the treadmill as the VR environment is rotated, creating a perceived visual fall to the side. The same thing is done with the GVS by inducing artificial fall sensations.These tactics replicate the stress level experienced in sports/recreational activities to isolate underlying concussion symptoms.
Another project focuses on characterizing neural control strategies while walking for children with Cerebral Palsy (CP), in which researchers hope to recognize relationships between sensory processing and functional mobility in children with CP.
The research team has also used Stochastic Resonance (SR) stimulation to study potential deficits in the dynamic integration of the sensory system’s modalities contributing to balance.
The Qualisys Motion Capture system is mounted around the VR dome to track biomechanical movement patterns and responses to the controlled stimulation. In studies involving Parkinson’s disease, subjects are immersed into a virtual scene while electrical currents stimulate the Vestibular system, posing an extreme challenge for the subject’s sense of balance.
By collecting movement data, EMG activity, and ground reaction force data, the group is able to get a larger context of function and rehabilitation.