title: Charge and energy minimization in electrical/magnetic stimulation of nervous tissue.
abstract: In this work we address the problem of stimulating nervous tissue with the minimal necessary energy at reduced/minimal charge. Charge minimization is related to a valid safety concern (avoidance and reduction of stimulation-induced tissue and electrode damage). Energy minimization plays a role in battery-driven electrical or magnetic stimulation systems (increased lifetime, repetition rates, reduction of power requirements, thermal management). Extensive new theoretical results are derived by employing an optimal control theory framework. These results include derivation of the optimal electrical stimulation waveform for a mixed energy/charge minimization problem, derivation of the charge-balanced energy-minimal electrical stimulation waveform, solutions of a pure charge minimization problem with and without a constraint on the stimulation amplitude, and derivation of the energy-minimal magnetic stimulation waveform. Depending on the set stimulus pulse duration, energy and charge reductions of up to 80% are deemed possible. Results are verified in simulations with an active, mammalian-like nerve fiber model.
authors.affiliation: Altran, Seestrasse 513, CH-8038 Zürich, Switzerland. saso.jezernik@altran.ch
authors.forename: Saso
authors.initials: S
authors.lastname: Jezernik
authors.forename: Thomas
authors.initials: T
authors.lastname: Sinkjaer
authors.forename: Manfred
authors.initials: M
authors.lastname: Morari
mesh_terms: D000200:Action Potentials / Q000502:physiology* / Q000528:radiation effects*; D000818:Animals; D003198:Computer Simulation; D004056:Differential Threshold / Q000502:physiology* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D004735:Energy Transfer / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology* / Q000528:radiation effects*; D011829:Radiation Dosage; D055672:Static Electricity