Paraplegic patients and certain other paralyzed patients who suffer from an upper motor unit spinal cord injury and undergo FNS (Functional Neuromuscular Stimulation) experience muscle fatigue within a time span that is usually shorter than is normal, but have no sensation of this fatigue due to paralysis. When FNS is used functionally, as is its implied purpose, to stand and walk, the patients need the support of a walker or canes or elbow crutches, and are unable to manually adjust FNS levels or pulse widths to compensate for that fatigue, since the time for this adjustment is exactly when the patients cannot divert attention and hands to anything else. Under FNS, the stimulated muscles produce an EMG (electromyographic) signal at the stimulated site, in response to that stimulation. This response-EMG undergoes pattern changes with the progression of fatigue. The present invention employs pattern recognition of the response-EMG where pattern parameters are identified whose variation with time is a function of the progression of muscle fatigue. This time variation is employed to adjust FNS pulse width and/or pulse level to compensate for that fatigue in an automatic manner that does not require the patient's attention. The present invention also provides for diagnostic uses of this pattern recognition, and for muscle contractions other than for standing or walking.
IMPROVED CONTROL OF FNS VIA PATTERN VARIATIONS OF RESPONSE EMG