Robotic–electronic platform for autonomous and accurate transcranial magnetic stimulation targeting

摘要

Dear Editor, to improve the safety and efficacy of non-invasive brain stimulation techniques, we need to embrace automation and precise targeting of cortical structures. Multi-locus transcranial magnetic stimulation (TMS) enables the stimulation of nearby cortical regions electronically, without physically moving the coil set [1Koponen L.M. Nieminen J.O. Ilmoniemi R.J. Multi-locus transcranial magnetic stimulation—theory and implementation.Brain Stimul. 2018; 11: 849-855https://doi.org/10.1016/j.brs.2018.03.014Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar, 2Nieminen J.O. Sinisalo H. Souza V.H. Malmi M. Yuryev M. Tervo A.E. et al.Multi-locus transcranial magnetic stimulation system for electronically targeted brain stimulation.Brain Stimul. 2022; 15: 116-124https://doi.org/10.1016/j.brs.2021.11.014Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar, 3Souza V.H. Nieminen J.O. Tugin S. Koponen L.M. Baffa O. Ilmoniemi R.J. TMS with fast and accurate electronic control: measuring the orientation sensitivity of corticomotor pathways.Brain Stimul. 2022; 15: 306-315https://doi.org/10.1016/j.brs.2022.01.009Abstract Full Text Full Text PDF PubMed Scopus (16) Google Scholar]. This technology opens the possibility to engage with local cortical networks at millisecond and millimeter scales and to create automated closed-loop mapping protocols [[4]Tervo A.E. Metsomaa J. Nieminen J.O. Sarvas J. Ilmoniemi R.J. Automated search of stimulation targets with closed-loop transcranial magnetic stimulation.Neuroimage. 2020; 117082https://doi.org/10.1016/j.neuroimage.2020.117082Crossref Scopus (26) Google Scholar,[5]Rösch J. Emanuel Vetter D. Baldassarre A. Souza V.H. Lioumis P. Roine T. et al.Individualized treatment of motor stroke: a perspective on open-loop, closed-loop and adaptive closed-loop brain state-dependent TMS.Clin Neurophysiol. 2023; https://doi.org/10.1016/j.clinph.2023.10.004Crossref Scopus (2) Google Scholar]. However, existing mTMS coil sets have two major issues: a limited range for electronic targeting (30-mm diameter region) and heavy construction (approximately 5 kg for a 5-coil set), mainly due to cabling. Therefore, the manual placement of the coil set on the scalp is slow and physically demanding, requiring highly trained personnel to manipulate the coil sets. Collaborative robots improve the reproducibility and accuracy of TMS coil placements [[6]Goetz S.M. Kozyrkov I.C. Luber B. Lisanby S.H. Murphy D.L.K. Grill W.M. et al.Accuracy of robotic coil positioning during transcranial magnetic stimulation.J Neural Eng. 2019; 16054003https://doi.org/10.1088/1741-2552/ab2953Crossref Scopus (18) Google Scholar,[7]Harquel S. Bacle T. Beynel L. Marendaz C. Chauvin A. David O. Mapping dynamical properties of cortical microcircuits using robotized TMS and EEG: towards functional cytoarchitectonics.Neuroimage. 2016; 135: 115-124https://doi.org/10.1016/j.neuroimage.2016.05.009Crossref PubMed Scopus (32) Google Scholar]; they can compensate automatically for patients’ head movements and can be flexibly programmed to be guided by suitable algorithms. Yet, traditional robotized TMS systems can shift the stimulation focus only physically and are limited by robot velocities that are safe for human applications to avoid harmful collisions (around 0.2 m/s) [[8]Kantelhardt S.R. Fadini T. Finke M. Kallenberg K. Siemerkus J. Bockermann V. et al.Robot-assisted image-guided transcranial magnetic stimulation for somatotopic mapping of the motor cortex: a clinical pilot study.Acta Neurochir. 2010; 152: 333-343https://doi.org/10.1007/s00701-009-0565-1Crossref PubMed Scopus (46) Google Scholar]. Furthermore, commercial robotic TMS solutions rely on closed-source platforms associated with a specific robotic arm, which can be costly and difficult to implement without the necessary flexibility for researchers to incorporate novel algorithms on demand. We developed an open-source platform combining rapid mTMS electronic ta