Abstract: A transcutaneous electrical nerve stimulation (TENS) apparatus includes first, second, and third oscillators. The first oscillator produces a first train of pulses at a main frequency. The second oscillator produces a second train of pulses at a modulation frequency. Output levels of the second train of pulses vary as a function of the modulation frequency. A frequency control simultaneously controls both the main and modulation frequencies. The third oscillator is responsive to the first and second oscillators and produces a third train of pulses at the main frequency. Intensity and frequency of the pulses of the third pulse train are modulated as a function of the output levels of the second train of pulses. An output driver responsive to the third oscillator converts the third train of pulses into a train of stimulation pulses having electrical characteristics adapted to be applied to a human body to suppress pain.

Abstract: A transcutaneous electrical nerve stimulation (TENS) apparatus includes first, second, and third oscillators. The first oscillator produces a first train of pulses at a main frequency. The second oscillator produces a second train of pulses at a modulation frequency. Output levels of the second train of pulses vary as a function of the modulation frequency. A frequency control simultaneously controls both the main and modulation frequencies. The third oscillator is responsive to the first and second oscillators and produces a third train of pulses at the main frequency. Intensity and frequency of the pulses of the third pulse train are modulated as a function of the output levels of the second train of pulses. An output driver responsive to the third oscillator converts the third train of pulses into a train of stimulation pulses having electrical characteristics adapted to be applied to a human body to suppress pain.

Abstract: A muscle stimulator provides an electrical output pulse train which provides functional electrical stimulation (FES) of muscles or muscle groups. The muscle stimulator includes a manually operated amplitude control which provides an amplitude control signal for controlling the amplitude of the output pulse train. During a PROGRAM mode, a clinician manipulates the amplitude control to establish a desired FES regimen. An analog-to-digital converter periodically samples the amplitude control signal during the PROGRAM mode, and data from the analog-to-digital converter is stored. When an EXECUTE mode is selected, the pulse width of the output pulse train is automatically controlled as a function of the stored data to reproduce the desired FES regimen which had been established during the PROGRAM mode.