title: Dynamic multi-channel TMS with reconfigurable coil.
abstract: Investigations of the causal involvement of particular brain areas and interconnections in behavior require an external stimulation system with reasonable spatio-temporal resolution. Current transcranial magnetic stimulation (TMS) technology is limited to stimulating a single brain area once in a given trial. Here, we present a feasibility study for a novel TMS system based on multi-channel reconfigurable coils. With this hardware, researchers will be able to stimulate multiple brain sites in any temporal order in a trial. The system employs a wire-mesh coil, constructed using x- and y-directional wires. By varying the current direction and/or strength on each wire, we can configure the proposed mesh-wire coil into a standard loop coil and figure-eight coil of varying size. This provides maximum flexibility to the experimenter in that the location and extent of stimulation on the brain surface can be modified depending on experimental requirement. Moreover, one can dynamically and automatically modify the site(s) of stimulation several times within the span of seconds. By pre-storing various sequences of excitation patterns inside a control unit, one can explore the effect of dynamic TMS on behavior, in associative learning, and as rehabilitative therapy. Here, we present a computer simulation and bench experiments that show the feasibility of the dynamically-reconfigurable coil.
authors.affiliation: Department of Electrical and Computer Engineering, University of Houston, Houston, TX 77204, USA.
authors.forename: Ruoli
authors.initials: R
authors.lastname: Jiang
authors.forename: Ben H
authors.initials: BH
authors.lastname: Jansen
authors.forename: Bhavin R
authors.initials: BR
authors.lastname: Sheth
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D008280:Magnetics / Q000295:instrumentation*; D008962:Models, Theoretical; D011874:Radiometry; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation*; D014159:Transducers