A collaboration between Rice University, the University of Houston and TIRR Memorial Hermann Hospital has led to MAHI-EXO II, a sophisticated exoskeleton that could help stroke victims regain movement in the arms by reading the patients' intended actions and nudging them along when needed. The robot wraps the arm from the fingertips to the elbow and uses a non-invasive EEG interface to anticipate gestures and help patients build up strength and accuracy over time.
When the subject thinks about performing an action, an electrode-studded cap reads the electrical impulses from the motor cortex of the brain and then outputs them to the artificial limb, initiating motion with a simple thought.
But patients can't just think their way into rehabilitation—they need to have the drive and motivation to exercise their muscles as much as possible. And so, the robot includes a feedback mechanism requiring patients to make a continuous effort, sometimes assisting and sometimes resisting their movements, to build strength and accuracy.
The exoskeleton could have applications beyond rehabilitation: monitoring brain waves over a long period of time could provide a real-time assessment of the plasticity of brain networks, giving researchers information that could potentially help reverse-engineer the human brain.
Initially, the technology will be refined by testing it on healthy subjects. Then, the researchers plan to start a two-year validation trial with 40 volunteer stroke survivors at TIRR Memorial Hermann Hospital before proper clinical trials begin.
The video below illustrates the exoskeleton at work.
Source: Rice University