EMG Signals Can Improve Robotic Leg Prostheses Control
Case study shows robust and intuitive control with electromyographic signals, mechanical sensor data
WEDNESDAY, Sept. 25 (HealthDay News) -- Electromyographic signals can be used in conjunction with mechanical sensor data to improve control of robotic leg prostheses, according to a case report published in the Sept. 26 issue of the New England Journal of Medicine.
Noting that the lack of control of prosthetic knees and ankles has limited clinical application of robotic technology, Levi J. Hargrove, Ph.D., from the Rehabilitation Institute of Chicago, and colleagues assessed whether use of EMG signals from natively innervated and surgically reinnervated residual thigh muscles in a patient who had undergone knee amputation could improve control of a robotic leg prosthesis.
The researchers found that the reinnervated muscles generated strong EMG signals, and each attempted motion generated distinct signal patterns. A pattern-recognition algorithm was used to decode EMG signals, and mechanical data sensors on the prosthesis were used to interpret the intended movements of the patient. Robust and intuitive control of ambulation resulted and transitions between walking on level ground, stairs, and ramps were seamless. In addition, the patient was able to reposition the leg when seated.
"Although this study establishes the feasibility of using EMG signals to improve the control of robotic leg prostheses, several challenges remain in making the control system clinically viable," the authors write.