Optimized nerve fiber stimulation

Abstract

Optimization of nerve fiber stimulation to substantially increase the activity of the then selected nerve fibers is disclosed, with optimization being achieved through utilization of electrical pulses that are caused to occur in a predetermined pattern with respect to polarity, spacing, frequency and duration so as to interact with the electro-neurophysiological characteristics of the particular nerve fibers then to be electrically stimulated. Bi-phased pulse pairs are repeatedly generated and applied to the nerve fibers to be stimulated with the first pulse of each pulse pair being a positive polarity pulse causing the nerve to be set into the refractory period, while the second pulse of each pulse pair is a negative polarity pulse that is made to occur substantially at the end of the refractory period for the particular nerve fibers then being stimulated to thereby excite those nerve fibers, and the pulse pairs are repeated at a rate based upon the timewise occurrence of the enhanced excitability condition of the nerve fibers then being stimulated. Electrode polarity is absolute, meaning that nerve activity is stimulated almost entirely adjacent to the electrode which has the polarity relationship as above stated. Frequency of occurrence of the pulse pairs and duration of the pulses are preselected to provide a cumulative optimizing effect. Additional normal pulses occurring during the period following occurrence of the first pulse of the pair and before the occurrence of the second pulse of the pair do not normally adversely affect performance, and interleaved pulses can therefore be utilized to simultaneously stimulate a plurality of different types of nerve fibers without adversely affecting optimum stimulation of at least one selected type of the plurality of types of nerve fibers then being stimulated.