{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T11:20:29Z","timestamp":1772104829147,"version":"3.50.1"},"reference-count":39,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T00:00:00Z","timestamp":1772064000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000065","name":"NINDS","doi-asserted-by":"publisher","award":["UH3NS103468"],"award-info":[{"award-number":["UH3NS103468"]}],"id":[{"id":"10.13039\/100000065","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000065","name":"NINDS","doi-asserted-by":"publisher","award":["UH3NS129898"],"award-info":[{"award-number":["UH3NS129898"]}],"id":[{"id":"10.13039\/100000065","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"National Science Foundation","doi-asserted-by":"publisher","award":["HRD-2112554"],"award-info":[{"award-number":["HRD-2112554"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>As a step towards advancing adaptive DBS control for Parkinson\u2019s disease, we have developed an automated algorithm that detects tremor continuously on a seconds-resolution time scale from a wearable accelerometer and present the feasibility study test results. Triaxial acceleration data were wirelessly streamed from an Apple Watch as well as acquired from an internal accelerometer in the implanted DBS device itself. The algorithm first determines if there is any high-power voluntary activity, such as walking, using the arm, or transitioning from sitting to standing; then, it identifies peaks in the 4\u20137 Hz Parkinsonian tremor frequency band. Peak detection for tremor activity was more accurate using the Apple Watch than the IPG. Peak and harmonic detection were also more accurate using continuous wavelet transforms than short-time Fourier transform. According to the repeated measures correlation, our detection algorithm correlated strongly with DBS intensity (Subject RZCH: r = \u22120.93, p = 3.6 \u00d7 10\u22125; 6KOZ: r = \u22120.97, p = 1.6 \u00d7 10\u22125, NU5U: r = \u22120.94, p = 0.057). Pearson\u2019s correlation coefficient between our tremor detection algorithm and the currently accepted industry metric was found to be 0.57 (t-value = 8.5, dof = 148, p &lt; 1 \u00d7 10\u22126). Our algorithm is distinctive in the capability to detect Parkinsonian tremor, with a high degree of clinical relevance, during daily living activities and is able to discriminate tremor from walking, using a convenient, commercial wrist-worn accelerometer.<\/jats:p>","DOI":"10.3390\/s26051459","type":"journal-article","created":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T10:33:02Z","timestamp":1772101982000},"page":"1459","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Continuous Accelerometry-Based Tremor Detection During Daily Living"],"prefix":"10.3390","volume":"26","author":[{"given":"Luis","family":"Martinez","sequence":"first","affiliation":[{"name":"Department of Electrical and Computer Engineering, California State University, Los Angeles, Los Angeles, CA 90032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Orlando","family":"Martinez","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, California State University, Los Angeles, Los Angeles, CA 90032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stephen L.","family":"Schmidt","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rocio","family":"Rodriguez Capilla","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hector","family":"Gardea","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, California State University, Los Angeles, Los Angeles, CA 90032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arabo","family":"Gholian","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, California State University, Los Angeles, Los Angeles, CA 90032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dennis A.","family":"Turner","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA"},{"name":"Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8426-3526","authenticated-orcid":false,"given":"Deborah Soonmee","family":"Won","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, California State University, Los Angeles, Los Angeles, CA 90032, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1111\/jnc.13691","article-title":"The clinical symptoms of Parkinson\u2019s disease","volume":"139","author":"Sveinbjornsdottir","year":"2016","journal-title":"J. Neurochem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"120196","DOI":"10.1016\/j.jns.2022.120196","article-title":"The pathophysiology of Parkinson\u2019s disease tremor","volume":"435","author":"Dirkx","year":"2022","journal-title":"J. Neurol. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.neuint.2013.06.005","article-title":"Biomarkers in Parkinson\u2019s disease (recent update)","volume":"63","author":"Sharma","year":"2013","journal-title":"Neurochem. Int."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.parkreldis.2006.03.001","article-title":"Deep brain stimulation in neurologic disorders","volume":"13","author":"Halpern","year":"2007","journal-title":"Park. Relat. Disord."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"723","DOI":"10.2147\/NDT.S113998","article-title":"The role of deep brain stimulation in Parkinson\u2019s disease: An overview and update on new developments","volume":"13","author":"Fang","year":"2017","journal-title":"Neuropsychiatr. Dis. Treat."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1097\/00004691-200401000-00003","article-title":"Deep brain stimulation for the treatment of Parkinson\u2019s disease","volume":"21","author":"Volkmann","year":"2004","journal-title":"J. Clin. Neurophysiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1056\/NEJMoa060281","article-title":"A randomized trial of deep-brain stimulation for Parkinson\u2019s disease","volume":"355","author":"Deuschl","year":"2006","journal-title":"N. Engl. J. Med."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"764","DOI":"10.1111\/joim.13541","article-title":"Deep brain stimulation for Parkinson\u2019s disease","volume":"292","author":"Hariz","year":"2022","journal-title":"J. Intern. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1756286419838096","DOI":"10.1177\/1756286419838096","article-title":"An update on best practice of deep brain stimulation in Parkinson\u2019s disease","volume":"12","author":"Hartmann","year":"2019","journal-title":"Ther. Adv. Neurol. Disord."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1001\/archneurol.2010.260","article-title":"Deep brain stimulation for Parkinson disease: An expert consensus and review of key issues","volume":"68","author":"Bronstein","year":"2011","journal-title":"Arch. Neurol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1834","DOI":"10.1002\/mds.115","article-title":"An update on adaptive deep brain stimulation in Parkinson\u2019s disease","volume":"33","author":"Habets","year":"2018","journal-title":"Mov. Disord."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Hoang, K.B., Cassar, I.R., Grill, W.M., and Turner, D.A. (2017). Biomarkers and stimulation algorithms for adaptive brain stimulation. Front. Neurosci., 11.","DOI":"10.3389\/fnins.2017.00564"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"911","DOI":"10.1093\/brain\/awad429","article-title":"At home adaptive dual target deep brain stimulation in Parkinson\u2019s disease with proportional control","volume":"147","author":"Schmidt","year":"2024","journal-title":"Brain"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2660","DOI":"10.1093\/brain\/awl190","article-title":"Tremor amplitude is logarithmically related to 4- and 5-point tremor rating scales","volume":"129","author":"Elble","year":"2006","journal-title":"Brain"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"van der Linden, C., Berger, T., Brandt, G.A., Strelow, J.N., Jergas, H., Baldermann, J.C., Visser-Vandewalle, V., Fink, G.R., Barbe, M.T., and Petry-Schmelzer, J.N. (2023). Accelerometric classification of resting and postural tremor amplitude. Sensors, 23.","DOI":"10.3390\/s23208621"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2129","DOI":"10.1002\/mds.22340","article-title":"Movement Disorder Society-sponsored revision of the Unified Parkinson\u2019s Disease Rating Scale (MDS-UPDRS): Scale presentation and clinimetric testing results","volume":"23","author":"Goetz","year":"2008","journal-title":"Mov. Disord."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2824","DOI":"10.1212\/WNL.0000000000204762","article-title":"Chronic adaptive DBS provides similar \u201con\u201d time with trend of improvement compared to continuous DBS in Parkinson\u2019s disease and 98% of participants chose to remain on aDBS (S2.008)","volume":"Volume 102","author":"Martijn","year":"2024","journal-title":"Neurology"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Louie, K.H., Balakid, J.P., Bath, J.E., Song, S., Azgomi, H.F., Marks, J.H., Choi, J.T., Starr, P.A., and Wang, D.D. (2025). Adaptive deep brain stimulation timed to gait phase improves walking in Parkinson\u2019s disease. medRxiv.","DOI":"10.1101\/2025.08.19.25333759"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1479","DOI":"10.1016\/j.brs.2025.08.006","article-title":"Analyses of biomarkers for tremor using local field potentials recorded from deep brain stimulation electrodes in the thalamus","volume":"18","author":"Kumaravelu","year":"2025","journal-title":"Brain Stimul."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"863","DOI":"10.1002\/mds.28513","article-title":"Closed-loop deep brain stimulation for essential tremor based on thalamic local field potentials","volume":"36","author":"He","year":"2021","journal-title":"Mov. Disord."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1261","DOI":"10.1136\/jnnp-2020-323141","article-title":"Biomarkers in functional movement disorders: A systematic review","volume":"91","author":"Thomsen","year":"2020","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.parkreldis.2016.06.008","article-title":"How typical are \u201ctypical\u201d tremor characteristics? Sensitivity and specificity of five tremor phenomena","volume":"30","author":"Elting","year":"2016","journal-title":"Park. Relat. Disord."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1543","DOI":"10.1002\/mds.20634","article-title":"Psychogenic tremor disorders identified using tree-based statistical algorithms and quantitative tremor analysis","volume":"20","author":"Piboolnurak","year":"2005","journal-title":"Mov. Disord."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Yao, L., Brown, P., and Shoaran, M. (2018, January 17\u201319). Resting Tremor Detection in Parkinson\u2019s Disease with Machine Learning and Kalman Filtering. Proceedings of the 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS), Cleveland, OH, USA.","DOI":"10.1109\/BIOCAS.2018.8584721"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"127","DOI":"10.3109\/03091902.2016.1148792","article-title":"Parkinson\u2019s disease hand tremor detection system for mobile application","volume":"40","author":"Fraiwan","year":"2016","journal-title":"J. Med. Eng. Technol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1002\/ana.26612","article-title":"An apple a day to keep the Parkinson\u2019s disease doctor away?","volume":"93","author":"Bloem","year":"2023","journal-title":"Ann. Neurol."},{"key":"ref_27","unstructured":"MATLAB Hep Center (2025, November 01). Islocalmax Documentation. Available online: https:\/\/www.mathworks.com\/help\/matlab\/ref\/islocalmax.html."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"eabd7865","DOI":"10.1126\/scitranslmed.abd7865","article-title":"Smartwatch inertial sensors continuously monitor real-world motor fluctuations in Parkinson\u2019s disease","volume":"13","author":"Powers","year":"2021","journal-title":"Sci. Transl. Med."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1083","DOI":"10.4103\/neuroindia.NI_880_16","article-title":"Review of tremor in Parkinson\u2019s disease and atypical parkinsonian disorders","volume":"65","author":"Mailankody","year":"2017","journal-title":"Neurol. India"},{"key":"ref_30","unstructured":"Boby, F.Y. (2023). Unsupervised Classification of Physical Activity From Implanted Accelerometer in Deep Brain Stimulation Patients. [Master\u2019s Thesis, California State University]."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Bakdash, J.Z., and Marusich, L.R. (2017). Repeated Measures Correlation. Front. Psychol., 8.","DOI":"10.3389\/fpsyg.2017.00456"},{"key":"ref_32","first-page":"471","article-title":"The clinical evaluation of Parkinson\u2019s tremor","volume":"5","author":"Zach","year":"2015","journal-title":"J. Park. Dis."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1224","DOI":"10.1016\/j.jocn.2010.12.053","article-title":"Tremor is attenuated during walking in essential tremor with resting tremor but not parkinsonian tremor","volume":"18","author":"Uchida","year":"2011","journal-title":"J. Clin. Neurosci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1097\/WNP.0000000000000250","article-title":"The Texting Rhythm: A Novel EEG Waveform Using Smartphones","volume":"33","author":"Tatum","year":"2016","journal-title":"J. Clin. Neurophysiol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"e3454","DOI":"10.1212\/WNL.0000000000010757","article-title":"Teaching NeuroImages: Texting rhythm","volume":"95","author":"Hanrahan","year":"2020","journal-title":"Neurology"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1038\/s41531-021-00223-5","article-title":"Subthalamic and pallidal deep brain stimulation for Parkinson\u2019s disease\u2014Meta-analysis of outcomes","volume":"7","author":"Lachenmayer","year":"2021","journal-title":"npj Park. Dis."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"e245","DOI":"10.1016\/j.wneu.2022.04.084","article-title":"Differential effects of subthalamic nucleus and Globus pallidus internus deep brain stimulation on motor subtypes in Parkinson\u2019s disease","volume":"164","author":"Fan","year":"2022","journal-title":"World Neurosurg."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"106450","DOI":"10.1016\/j.clineuro.2020.106450","article-title":"STN versus GPi deep brain stimulation for dyskinesia improvement in advanced Parkinson\u2019s disease: A meta-analysis of randomized controlled trials","volume":"201","author":"Zhang","year":"2021","journal-title":"Clin. Neurol. Neurosurg."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1002\/mdc3.12329","article-title":"How Do I Examine for Re-Emergent Tremor?","volume":"3","author":"Jankovic","year":"2016","journal-title":"Mov. Disord. Clin. Pract."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/5\/1459\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T10:36:36Z","timestamp":1772102196000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/5\/1459"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,26]]},"references-count":39,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["s26051459"],"URL":"https:\/\/doi.org\/10.3390\/s26051459","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,26]]}}}