Reliable and Efficient TMS-EEG Using Ultra-Thin Active Electrodes

Reliable and Efficient TMS-EEG Using Ultra-Thin Active Electrodes | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Reliable and Efficient TMS-EEG Using Ultra-Thin Active Electrodes Johannes Gruenwald, Leonhard Schreiner, Sebastian Sieghartsleitner, and 10 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6725617/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Nov, 2025 Read the published version in Communications Engineering → Version 1 posted You are reading this latest preprint version Abstract Transcranial magnetic stimulation combined with electroencephalography (TMS-EEG) enables direct assessment of cortical excitability and connectivity via TMS-evoked potentials (TEPs). While passive electrodes remain the gold standard, they require extensive preparation and are sensitive to impedance. Active electrodes offer practical advantages but are limited by increased height and susceptibility to decay artifacts requiring manual correction. We present a novel TMS-EEG setup with ultra-thin active electrodes (3 mm height), combined with hardware and software-based artifact suppression. In 10 healthy subjects, we performed simultaneous active and passive EEG recordings during TMS over the left primary motor cortex. We evaluated early (15–80 ms) and late (80–350 ms) TEPs using concordance correlation coefficients (CCC), linear mixed-effects modeling of amplitude variability, and convergence analysis across trial counts. Active and passive electrodes showed high signal consistency (median CCC: 0.97 for early, 0.96 for late TEPs). Within-type CCCs ranged from 0.91 to 0.97. TEP amplitudes did not differ significantly between electrode types, while distance from stimulation site affected amplitude. Reliable waveforms emerged quickly: mean CCC > 0.8 after 20 trials and > 0.9 after 30. Our results demonstrate the potential of active TMS-EEG as a reliable and efficient alternative to passive setups, overcoming key technical limitations that have previously restricted its broader adoption. Physical sciences/Engineering/Biomedical engineering Biological sciences/Neuroscience Full Text Additional Declarations Yes there is potential Competing Interest. JG, LS, SS, and ST were employed by g.tec medical engineering GmbH. CG served as the CEO of g.tec medical engineering GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Supplementary Files ReliableandEfficientTMSEEGUsingUltraThinActiveElectrodesSupplementary.pdf Reliable and Efficient TMS-EEG Using Ultra-Thin Active Electrodes - Supplementary Material Cite Share Download PDF Status: Published Journal Publication published 28 Nov, 2025 Read the published version in Communications Engineering → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6725617","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":464518761,"identity":"bad16e0d-8619-4878-89fa-22f33a75a8f5","order_by":0,"name":"Johannes 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While passive electrodes remain the gold standard, they require extensive preparation and are sensitive to impedance. Active electrodes offer practical advantages but are limited by increased height and susceptibility to decay artifacts requiring manual correction. We present a novel TMS-EEG setup with ultra-thin active electrodes (3 mm height), combined with hardware and software-based artifact suppression. In 10 healthy subjects, we performed simultaneous active and passive EEG recordings during TMS over the left primary motor cortex. We evaluated early (15–80 ms) and late (80–350 ms) TEPs using concordance correlation coefficients (CCC), linear mixed-effects modeling of amplitude variability, and convergence analysis across trial counts. Active and passive electrodes showed high signal consistency (median CCC: 0.97 for early, 0.96 for late TEPs). Within-type CCCs ranged from 0.91 to 0.97. TEP amplitudes did not differ significantly between electrode types, while distance from stimulation site affected amplitude. Reliable waveforms emerged quickly: mean CCC \u003e 0.8 after 20 trials and \u003e 0.9 after 30. Our results demonstrate the potential of active TMS-EEG as a reliable and efficient alternative to passive setups, overcoming key technical limitations that have previously restricted its broader adoption.","manuscriptTitle":"Reliable and Efficient TMS-EEG Using Ultra-Thin Active Electrodes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-01 07:21:32","doi":"10.21203/rs.3.rs-6725617/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"communications-engineering","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"commseng","sideBox":"Learn more about [Communications Engineering](http://link.springer.com/journal/44172)","snPcode":"44172","submissionUrl":"https://mts-commseng.nature.com/cgi-bin/main.plex","title":"Communications Engineering","twitterHandle":"@commseng","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ed33339a-2e3f-41fa-90d4-691ba9490700","owner":[],"postedDate":"August 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":49324408,"name":"Physical sciences/Engineering/Biomedical engineering"},{"id":49324409,"name":"Biological sciences/Neuroscience"}],"tags":[],"updatedAt":"2025-11-29T08:10:53+00:00","versionOfRecord":{"articleIdentity":"rs-6725617","link":"https://doi.org/10.1038/s44172-025-00538-8","journal":{"identity":"communications-engineering","isVorOnly":false,"title":"Communications Engineering"},"publishedOn":"2025-11-28 05:00:00","publishedOnDateReadable":"November 28th, 2025"},"versionCreatedAt":"2025-08-01 07:21:32","video":"","vorDoi":"10.1038/s44172-025-00538-8","vorDoiUrl":"https://doi.org/10.1038/s44172-025-00538-8","workflowStages":[]},"version":"v1","identity":"rs-6725617","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6725617","identity":"rs-6725617","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}