{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T22:56:24Z","timestamp":1788044184215,"version":"build-2784847793"},"reference-count":38,"publisher":"Cambridge University Press (CUP)","license":[{"start":{"date-parts":[[2024,11,22]],"date-time":"2024-11-22T00:00:00Z","timestamp":1732233600000},"content-version":"unspecified","delay-in-days":326,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Wearable Technol."],"published-print":{"date-parts":[[2024]]},"abstract":"<jats:title>Abstract<\/jats:title>\n\t  <jats:p>Advancements in wearable robots aim to improve user motion, motor control, and overall experience by minimizing energetic cost (EC). However, EC is challenging to measure and it is typically indirectly estimated through respiratory gas analysis. This study introduces a novel EMG-based objective function that captures individuals\u2019 natural energetic expenditure during walking. The objective function combines information from electromyography (EMG) variables such as intensity and muscle synergies. First, we demonstrate the similarity of the proposed objective function, calculated offline, to the EC during walking. Second, we minimize and validate the EMG-based objective function using an online Bayesian optimization algorithm. The walking step frequency is chosen as the parameter to optimize in both offline and online approaches in order to simplify experiments and facilitate comparisons with related research. Compared to existing studies that use EC as the objective function, results demonstrated that the optimization of the presented objective function reduced the number of iterations and, when compared with gradient descent optimization strategies, also reduced convergence time. Moreover, the algorithm effectively converges toward an optimal step frequency near the user\u2019s preferred frequency, positively influencing EC reduction. The good correlation between the estimated objective function and measured EC highlights its consistency and reliability. Thus, the proposed objective function could potentially optimize lower limb exoskeleton assistance and improve user performance and human\u2013robot interaction without the need for challenging respiratory gas measurements.<\/jats:p>","DOI":"10.1017\/wtc.2024.9","type":"journal-article","created":{"date-parts":[[2024,11,22]],"date-time":"2024-11-22T08:13:19Z","timestamp":1732263199000},"update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":5,"title":["Human-in-the-loop optimization of wearable device parameters using an EMG-based objective function"],"prefix":"10.1017","volume":"5","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6811-2055","authenticated-orcid":false,"given":"Mar\u00eda Alejandra","family":"D\u00edaz","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8351-9702","authenticated-orcid":false,"given":"Sander","family":"De Bock","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5703-6029","authenticated-orcid":false,"given":"Philipp","family":"Beckerle","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1870-8264","authenticated-orcid":false,"given":"Jan","family":"Babi\u010d","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7398-5398","authenticated-orcid":false,"given":"Tom","family":"Verstraten","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin","family":"De Pauw","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2024,11,22]]},"reference":[{"key":"S2631717624000094_r28","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0171535"},{"key":"S2631717624000094_r5","doi-asserted-by":"publisher","DOI":"10.3389\/fncom.2013.00048"},{"key":"S2631717624000094_r1","doi-asserted-by":"publisher","DOI":"10.1186\/2193-1801-2-229"},{"key":"S2631717624000094_r6","doi-asserted-by":"publisher","DOI":"10.1038\/nature14288"},{"key":"S2631717624000094_r3","first-page":"1","article-title":"Optimized hip-knee-ankle exoskeleton assistance reduces the metabolic cost of walking with worn loads","volume":"18","author":"Bryan","year":"2021","journal-title":"J. Neuroeng. Rehab."},{"key":"S2631717624000094_r16","doi-asserted-by":"publisher","DOI":"10.1152\/jn.00109.2014"},{"key":"S2631717624000094_r24","doi-asserted-by":"publisher","DOI":"10.1109\/TNSRE.2019.2936383"},{"key":"S2631717624000094_r29","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00445.2014"},{"key":"S2631717624000094_r27","first-page":"54","volume-title":"Actuators","volume":"13","author":"Ma","year":"2024"},{"key":"S2631717624000094_r31","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbiomech.2017.05.010"},{"key":"S2631717624000094_r37","doi-asserted-by":"publisher","DOI":"10.1126\/science.aal5054"},{"key":"S2631717624000094_r9","first-page":"1","article-title":"An emg-based objective function for human-in-the-loop optimization","volume":"2023","author":"D\u00edaz","year":"2023","journal-title":"IEEE Int. Conf. Rehabil. Robot."},{"key":"S2631717624000094_r35","doi-asserted-by":"publisher","DOI":"10.3389\/fbioe.2023.1006326"},{"key":"S2631717624000094_r10","doi-asserted-by":"publisher","DOI":"10.1126\/scirobotics.aar5438"},{"key":"S2631717624000094_r25","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-023-28229-4"},{"key":"S2631717624000094_r12","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0135342"},{"key":"S2631717624000094_r34","doi-asserted-by":"publisher","DOI":"10.18494\/SAM.2021.3227"},{"key":"S2631717624000094_r19","doi-asserted-by":"publisher","DOI":"10.1109\/GlobalSIP.2017.8308675"},{"key":"S2631717624000094_r21","doi-asserted-by":"publisher","DOI":"10.1126\/scirobotics.abj3487"},{"key":"S2631717624000094_r33","doi-asserted-by":"publisher","DOI":"10.1016\/S1050-6411(00)00030-4"},{"key":"S2631717624000094_r11","doi-asserted-by":"publisher","DOI":"10.1152\/japplphysiol.00162.2014"},{"key":"S2631717624000094_r17","first-page":"549","volume-title":"ICRA 2019","author":"Hamaya","year":"2019"},{"key":"S2631717624000094_r8","first-page":"7483","volume-title":"IEEE Trans. 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Human muscle synergy recruitment and variability assessment for walking speed prediction module design. IETE Journal of Research, 8829\u20138847.","DOI":"10.1080\/03772063.2022.2101555"},{"key":"S2631717624000094_r30","doi-asserted-by":"publisher","DOI":"10.1186\/s12984-019-0535-7"},{"key":"S2631717624000094_r13","doi-asserted-by":"publisher","DOI":"10.1109\/LRA.2021.3061351"},{"key":"S2631717624000094_r23","doi-asserted-by":"publisher","DOI":"10.1016\/j.cobme.2023.100487"},{"key":"S2631717624000094_r2","unstructured":"Brochu, E. , Cora, V. M. , and De Freitas, N. (2010). A tutorial on bayesian optimization of expensive cost functions, with application to active user modeling and hierarchical reinforcement learning. arXiv preprint arXiv:1012.2599."},{"key":"S2631717624000094_r22","doi-asserted-by":"publisher","DOI":"10.1109\/MRA.2019.2954108"},{"key":"S2631717624000094_r32","doi-asserted-by":"publisher","DOI":"10.3389\/fncom.2018.00003"},{"key":"S2631717624000094_r26","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0184054"},{"key":"S2631717624000094_r36","first-page":"570","volume-title":"IEEE Int. Conf. Robot. 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