Local application microprocessor based nerve and muscle stimulator

Abstract

A transcutaneous electroneural stimulation (TENS) device employing microprocessor control of carrier pulse frequency, modulation pulse frequency, intensity, and frequency/amplitude modulation factors has been developed. The microprocessor monitors battery status and keypad-entered commands that select the various TENS modalities, and generates the driver signals to produce the output waveform provided to a utilization device via a transformer arrangement. The microprocessor is programmed to calculate all stimulation parameters which are stored in nonvolatile memory to provide concise and predictable programmed functions which can be updated as required. By selecting a program, the system may be programmed to relieve pain or reduce edema in the application area. Thus, a variety of therapeutic applications may be realized. The output pulse train employs a unique pulse modulation scheme which matches the carrier frequency to the electrode-tissue load for location specific applications. By pulse modulating the high frequency carrier and matching the carrier frequency to the electrode-tissue load, a more efficient energy transfer is realized. This matching significantly reduces the required amplitude of the electrode voltage pulse and reduces the overall power requirements for the system. In addition to enhanced power efficiency, the unpleasant burning sensation associated with most TENS stimulation units is virtually eliminated. The unit can be integrated into a hermetically sealed miniaturized composite package which allows the unit to be worn in a non-interfering manner at the treatment location.