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</style></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div>Dear Fieldtrip community,<br></div><div><br></div><div>while trying to integrate online head-position monitoring into our standard pipeline during MEG recordings with our CTF WC 275 channel system, </div><div>I noticed that the ‘ft_realtime_headlocalizer’ function (as in the attached example script aw_trackHeadPosition) applied on Matlab (e.g. applied on our stimulation computer) terminates with the following message:</div><div><br></div><div>Error Message:</div><div><br></div><div>Unrecognized field name "grad".</div><div><br></div><div>Error in ft_realtime_headlocalizer (line 115)</div><div>isneuromag = ft_senstype(hdr.grad, 'neuromag');</div><div> ^^^^^^^^</div><div>Error in aw_trackHeadPosition (line 7)</div><div>ft_realtime_headlocalizer(cfg);</div><div>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</div><div><br></div><div>The problems seems to happen only when I transfer (live) data using the Linux command-line program ‘ctf2ft_v3’ or when I transfer an existing dataset using the 'ft_realtime_fileproxy' function </div><div>(see the scripts in the appendix for an example) both from the acquisition computer.</div><div><br></div><div>When I play back the head movements from the same dataset using the `ft_realtime_headlocalizer` function (see attached script aw_replayHeadPosition.m) on the same computer as above (e.g. stimulation computer), everything works.</div><div>So the `grad` structure is essentially present in the data set (header).</div><div><br></div><div>Has anyone else had a similar experience, or perhaps even found a solution?</div><div><br></div><div>Please let me know if you need any additional information.</div><div> </div><div>Thanks a lot for the help.</div><div><br></div><div>Best, Andreas<br></div><div><br></div><div><br></div><div><span><pre></pre></span></div><div><br></div><div><span><pre></pre></span></div><div><br></div><div><span><pre>-- <br></pre><div class=""><i>Andreas Wollbrink, Dipl.-Ing., Biomedical Engineer</i></div><div class=""><hr align="center"></div><div class=""><i style="font-size: 13.333333px;">Lab Manager</i></div><div class=""><i style="font-size: 13.333333px;">IT-Administrator</i></div><div class=""><div><br></div></div><div class=""><span style="font-size: 13.333333px;">University Hospital, University of Muenster</span></div><div class=""><div><div><span style="font-size: 13.333333px;">Institute for Biomagnetism and Biosignalanalysis<br><br></span></div></div><div>Malmedyweg 15, 48149 Muenster, Germany</div></div><div class=""><br></div><div class="">office: +49-251-83-52546</div><div class="">email: <a href="mailto:a.wollbrink@wwu.de">a.wollbrink@uni-muenster.de</a></div><div class="">web: <a href="https://www.medizin.uni-muenster.de/biomag/das-institut/mitarbeiter/andreas-wollbrink.html">https://www.medizin.uni-muenster.de/biomag/das-institut/mitarbeiter/andreas-wollbrink.html</a></div><div class=""><br></div><div class=""><div><i style="font-family: "Times New Roman", serif; font-size: 16px;"><span style="font-size: 8pt; font-family: Arial, sans-serif;">Wir erfüllen unsere Informationspflichten zum Datenschutz gem. Art. 13-14 DS-GVO durch Veröffentlichung auf unserer Internetseite unter <a href="http://www.datenschutz.ukmuenster.de/" title="Click to open http://www.datenschutz.ukmuenster.de/" style="color: purple;"><span style="transform: scaleX(1.03413);">www.datenschutz.ukmuenster.de</span></a></span></i></div></div><div class=""><br></div><div class=""><br></div></span></div></body></html>