Transcranial Magnetic Stimulation: An Automated Procedure to Obtain Coil-specific Models for Field Calculations

TY - JOUR

T1 - Transcranial Magnetic Stimulation

T2 - An Automated Procedure to Obtain Coil-specific Models for Field Calculations

AU - Madsen, Kristoffer H

AU - Ewald, Lars

AU - Siebner, Hartwig R

AU - Thielscher, Axel

N1 - Copyright © 2015 Elsevier Inc. All rights reserved.

PY - 2015/11

Y1 - 2015/11

N2 - BACKGROUND: Field calculations for transcranial magnetic stimulation (TMS) are increasingly implemented online in neuronavigation systems and in more realistic offline approaches based on finite-element methods. They are often based on simplified and/or non-validated models of the magnetic vector potential of the TMS coils.OBJECTIVE: To develop an approach to reconstruct the magnetic vector potential based on automated measurements.METHODS: We implemented a setup that simultaneously measures the three components of the magnetic field with high spatial resolution. This is complemented by a novel approach to determine the magnetic vector potential via volume integration of the measured field.RESULTS: The integration approach reproduces the vector potential with very good accuracy. The vector potential distribution of a standard figure-of-eight shaped coil determined with our setup corresponds well with that calculated using a model reconstructed from x-ray images.CONCLUSION: The setup can supply validated models for existing and newly appearing TMS coils.

AB - BACKGROUND: Field calculations for transcranial magnetic stimulation (TMS) are increasingly implemented online in neuronavigation systems and in more realistic offline approaches based on finite-element methods. They are often based on simplified and/or non-validated models of the magnetic vector potential of the TMS coils.OBJECTIVE: To develop an approach to reconstruct the magnetic vector potential based on automated measurements.METHODS: We implemented a setup that simultaneously measures the three components of the magnetic field with high spatial resolution. This is complemented by a novel approach to determine the magnetic vector potential via volume integration of the measured field.RESULTS: The integration approach reproduces the vector potential with very good accuracy. The vector potential distribution of a standard figure-of-eight shaped coil determined with our setup corresponds well with that calculated using a model reconstructed from x-ray images.CONCLUSION: The setup can supply validated models for existing and newly appearing TMS coils.

U2 - 10.1016/j.brs.2015.07.035

DO - 10.1016/j.brs.2015.07.035

M3 - Journal article

C2 - 26297386

SN - 1935-861X

VL - 8

SP - 1205

EP - 1208

JO - Brain Stimulation

JF - Brain Stimulation

IS - 6

ER -