1. A computer-implemented method for neuromodulation in a live mammalian subject, comprising: triggering, by a processor, a leadwire to apply energy to a site in a nervous system of the subject in a series of pulses, wherein: inter-pulse intervals between the pulses vary; the triggering includes selecting, by the processor, the varying inter-pulse intervals according to output of an equation that defines a deterministic, non-linear, dynamical system of its output as varying over time by iterative execution of the equation using output of each iteration of its execution as input for its immediately succeeding iteration of its execution; a coefficient of variation in the inter-pulse intervals is less than 1.0; and the equation is one of: defined to produce output over time by its iterative execution such that the output over time exhibits chaotic behavior, the dynamical system having a positive Lyapunov exponent; 
 x (n+1) =Rx n (1−x n ); a combination of 
 x n+1 =1−αx 2 n +y n and 
 y n+1 =βx n ; and  a combination of 
 P n+1 =P n +K sin(θ n+1 ) and 
 θ n+1 =θ n +P n+1.