Stroke patients often lose control over limbs. Recovery is possible in many cases, but rehabilitation can be difficult and lengthy. One procedure use by therapists is “repetitive facilitation exercise” (RFE). The therapist asks the patient to think about moving the target area, such as a wrist. At the same moment, the therapist flexes the wrist. The problem is that the patient’s brain may be sending a signal to move the wrist, but the signal is too weak to cause movement. By flexing the wrist at the same instant, the brain receives a strong signal that wrist has moved. This in turn sends a stronger signal back to the wrist, reinforcing the brain’s ability to initiate the motion. RFE can be effective, but it is difficult to coordinate the timing between the patient’s thought and the therapist’s moving the wrist.
Researchers at Georgia Tech have created a mechanical device to eliminate the human factor in the process. A transcranial magnetic stimulator creates a weak signal in the part of the brain responsible for motor control, and at a precise interval, a hammer taps the tendons in the wrist, causing it to flex. This is enough to send the stronger signal back to the brain and reinforce the control so that the wrist moves.
The team hopes that this research can lead to robots that will help stroke victims perform these exercises to speed the recovery of different muscles. It is conceivable to me, however, that miniaturization could possibly make this system wearable with components that could communicate wirelessly. It’s conceivable that it could ultimately lead to devices that could be worn at home for a set period of exercise, making this type of rehabilitation available widely, without requiring that patients travel to a center for the therapy.