Pairing a Mechanical Device with Stroke Patients

The repetitive facilitation exercise (RFE) is one of the most common rehabilitation tactics for stroke patients attempting to regain wrist movement. To aid rehabilitating stroke patients, a team of Georgia Tech researchers has created a functional MRI-compatible hemiparesis rehab device that creates a long latency stretch reflex at the exact time as a brain signal. Thus far, the research team has worked only with healthy individuals in their study. Study participants lie on a bed with the arm extended beneath a pneumatic actuator tendon hammer. In order to simulate the weak signal created by hemiparesis individuals to move their wrist, a transcranial magnetic stimulator (TMS) is placed on the heads of these healthy individuals at a 45-degree angle. Milliseconds after the hammer taps the wrist’s tendon, the TMS creates a weak signal in the motor cortex. The responses overlap, produce and send a strong signal back to the arm, and the wrist moves. The team has successfully varied the timing of the TMS signal and speed of the hammer to strike faster or slower, depending on how much of a boost is needed to complement the brain signal. Now that the researchers have proven the viability of the TMS-actuator system, they will next work with stroke individuals. Because the machine is MRI-compatible, it will allow the team to study what is happening in the brain during rehab, opening the door for robotics. To learn more about the study, click here.