{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T16:15:26Z","timestamp":1772554526897,"version":"3.50.1"},"reference-count":46,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,2,25]],"date-time":"2021-02-25T00:00:00Z","timestamp":1614211200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005799","name":"National Chiao Tung University","doi-asserted-by":"publisher","award":["109A159"],"award-info":[{"award-number":["109A159"]}],"id":[{"id":"10.13039\/501100005799","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Continuous hemodynamic monitoring is important for long-term cardiovascular healthcare, especially in hypertension. The impedance plethysmography (IPG) based carotid pulse sensing is a non-invasive diagnosis technique for measuring pulse signals and further evaluating the arterial conditions of the patient such as continuous blood pressure (BP) monitoring. To reach the high-resolution IPG-based carotid pulse detection for cardiovascular applications, this study provides an optimized measurement parameter in response to obvious pulsation from the carotid artery. The influence of the frequency of excitation current, electrode cross-sectional area, electrode arrangements, and physiological site of carotid arteries on IPG measurement resolution was thoroughly investigated for optimized parameters. In this study, the IPG system was implemented and installed on the subject\u2019s neck above the carotid artery to evaluate the measurement parameters. The measurement results within 6 subjects obtained the arterial impedance variation of 2137 m\u03a9 using the optimized measurement conditions, including excitation frequency of 50 kHz, a smaller area of 2 cm2, electrode spacing of 4 cm and 1.7 cm for excitation and sensing functions, and location on the left side of the neck. The significance of this study demonstrates an optimized measurement methodology of IPG-based carotid pulse sensing that greatly improves the measurement quality in cardiovascular monitoring.<\/jats:p>","DOI":"10.3390\/s21051600","type":"journal-article","created":{"date-parts":[[2021,2,26]],"date-time":"2021-02-26T04:36:24Z","timestamp":1614314184000},"page":"1600","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Bio-Impedance Measurement Optimization for High-Resolution Carotid Pulse Sensing"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3463-643X","authenticated-orcid":false,"given":"Ting-Wei","family":"Wang","sequence":"first","affiliation":[{"name":"Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"given":"Hsiao-Wei","family":"Chu","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"given":"Lin","family":"Chou","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5191-334X","authenticated-orcid":false,"given":"Yen-Ling","family":"Sung","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan"}]},{"given":"Yuan-Ta","family":"Shih","sequence":"additional","affiliation":[{"name":"Research and Development Department VI, Smart Healthcare BU, Leadtek Research Inc., New Taipei 23511, Taiwan"}]},{"given":"Po-Chun","family":"Hsu","sequence":"additional","affiliation":[{"name":"Research and Development Department VI, Smart Healthcare BU, Leadtek Research Inc., New Taipei 23511, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3885-6600","authenticated-orcid":false,"given":"Hao-Min","family":"Cheng","sequence":"additional","affiliation":[{"name":"Center for Evidence-Based Medicine, Department of Medical Education, Taipei Veterans General Hospital, Taipei 11217, Taiwan"},{"name":"Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei 112304, Taiwan"},{"name":"Institute of Public Health and Community Medicine Research Center, National Yang-Ming University, Taipei 112304, Taiwan"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1270-3961","authenticated-orcid":false,"given":"Shien-Fong","family":"Lin","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Maarman, G.J., Chakafana, G., and Sliwa, K. (2020). World Heart Day: A World Heart Federation Communiqu\u00e9 on the Future of Basic Sciences and Translational Medicine in Global Cardiovascular Research, American Physiological Society.","DOI":"10.1152\/ajplung.00339.2020"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1016\/S0031-3955(16)32486-5","article-title":"Catheterization of umbilical vessels in newborn infants","volume":"17","author":"Kitterman","year":"1970","journal-title":"Pediatr. Clin. N. Am."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1719","DOI":"10.1093\/eurheartj\/eht565","article-title":"Central blood pressure: Current evidence and clinical importance","volume":"35","author":"McEniery","year":"2014","journal-title":"Eur. Heart J."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Dias, D., and Paulo Silva Cunha, J. (2018). Wearable Health Devices-Vital Sign Monitoring, Systems and Technologies. Sensors, 18.","DOI":"10.3390\/s18082414"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1455","DOI":"10.1109\/JBHI.2016.2620995","article-title":"Continuous Blood Pressure Measurement From Invasive to Unobtrusive: Celebration of 200th Birth Anniversary of Carl Ludwig","volume":"20","author":"Ding","year":"2016","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1538","DOI":"10.1109\/TBME.2014.2309951","article-title":"Unobtrusive sensing and wearable devices for health informatics","volume":"61","author":"Zheng","year":"2014","journal-title":"IEEE Trans. Bio-Med. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"128114","DOI":"10.1109\/ACCESS.2019.2939798","article-title":"Organic Multi-Channel Optoelectronic Sensors for Wearable Health Monitoring","volume":"7","author":"Khan","year":"2019","journal-title":"IEEE Access"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5745","DOI":"10.1038\/ncomms6745","article-title":"All-organic optoelectronic sensor for pulse oximetry","volume":"5","author":"Lochner","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_9","first-page":"678","article-title":"Validation of a Standalone Smartphone Application for Measuring Heart Rate Using Imaging Photoplethysmography","volume":"23","author":"Poh","year":"2017","journal-title":"Telemed. J. e-Health Off. J. Am. Telemed. Assoc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"11534","DOI":"10.1109\/ACCESS.2020.2965082","article-title":"Cuff-Less Blood Pressure Monitoring System Using Smartphones","volume":"8","author":"Tabei","year":"2020","journal-title":"IEEE Access"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TIM.2020.3011784","article-title":"Electrode Placement Strategies for the Measurement of Radial Artery Bioimpedance: Simulations and Experiments","volume":"70","author":"Pesti","year":"2020","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_12","first-page":"1112","article-title":"Design of an Optical Blood Pressure Sensor for Noninvasive Monitoring of Blood Pressure","volume":"3","author":"Raghunath","year":"2015","journal-title":"Int. J. Sci. Eng. Adv. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Yang, X., Wang, Y., and Qing, X. (2018). A Flexible Capacitive Pressure Sensor Based on Ionic Liquid. Sensors, 18.","DOI":"10.3390\/s18072395"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2371","DOI":"10.1007\/s00542-020-04777-x","article-title":"Design and sensitivity analysis of capacitive MEMS pressure sensor for blood pressure measurement","volume":"26","author":"Rao","year":"2020","journal-title":"Microsyst. Technol."},{"key":"ref_15","first-page":"321","article-title":"Highly sensitive flexible capacitive pressure sensor with a broad linear response range and finite element analysis of micro-array electrode","volume":"6","author":"Ma","year":"2020","journal-title":"J. Mater."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e1900109","DOI":"10.1002\/adhm.201900109","article-title":"Soft Wearable Pressure Sensors for Beat-to-Beat Blood Pressure Monitoring","volume":"8","author":"Kim","year":"2019","journal-title":"Adv. Healthc. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Liu, Z.D., Liu, J.K., Wen, B., He, Q.Y., Li, Y., and Miao, F. (2018). Cuffless Blood Pressure Estimation Using Pressure Pulse Wave Signals. Sensors, 18.","DOI":"10.3390\/s18124227"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1088\/0967-3334\/24\/3\/306","article-title":"Piezoelectric sensor determination of arterial pulse wave velocity","volume":"24","author":"McLaughlin","year":"2003","journal-title":"Physiol. Meas."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Wang, T.W., and Lin, S.F. (2020). Wearable Piezoelectric-Based System for Continuous Beat-to-Beat Blood Pressure Measurement. Sensors, 20.","DOI":"10.3390\/s20030851"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Liu, S.H., Cheng, D.C., and Su, C.H. (2017). A Cuffless Blood Pressure Measurement Based on the Impedance Plethysmography Technique. Sensors, 17.","DOI":"10.3390\/s17051176"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Huynh, T.H., Jafari, R., and Chung, W.-Y. (2018). An Accurate Bioimpedance Measurement System for Blood Pressure Monitoring. Sensors, 18.","DOI":"10.3390\/s18072095"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Wang, T.W., Chen, W.X., Chu, H.W., and Lin, S.F. (2020). Single-channel Bio-impedance Measurement for Wearable Continuous Blood Pressure Monitoring. IEEE Trans. Instrum. Meas., 1.","DOI":"10.1109\/TIM.2020.3035578"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1723","DOI":"10.1109\/TBCAS.2019.2946661","article-title":"Cuffless Blood Pressure Monitoring from an Array of Wrist Bio-Impedance Sensors Using Subject-Specific Regression Models: Proof of Concept","volume":"13","author":"Ibrahim","year":"2019","journal-title":"IEEE Trans. Biomed. Circuits Syst."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2","DOI":"10.5617\/jeb.953","article-title":"Development of a real-time, semi-capacitive impedance phlebography device","volume":"6","author":"Weyer","year":"2015","journal-title":"J. Electr. Bioimpedance"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"184909","DOI":"10.1109\/ACCESS.2020.3029604","article-title":"Single-Channel Impedance Plethysmography Neck Patch Device for Unobtrusive Wearable Cardiovascular Monitoring","volume":"8","author":"Wang","year":"2020","journal-title":"IEEE Access"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"144","DOI":"10.14366\/usg.16019","article-title":"Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method","volume":"36","author":"Soleimani","year":"2017","journal-title":"Ultrasonography"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1109\/RBME.2010.2084078","article-title":"Dry-Contact and Noncontact Biopotential Electrodes: Methodological Review","volume":"3","author":"Chi","year":"2010","journal-title":"Biomed. Eng. IEEE Rev."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Fu, Y., Zhao, J., Dong, Y., and Wang, X. (2020). Dry Electrodes for Human Bioelectrical Signal Monitoring. Sensors, 20.","DOI":"10.3390\/s20133651"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"20","DOI":"10.5617\/jeb.2657","article-title":"Simulation of impedance measurements at human forearm within 1 kHz to 2 MHz","volume":"7","author":"Anand","year":"2016","journal-title":"J. Electr. Bioimpedance"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Preedy, V.R. (2012). Use of Bioelectrical Impedance: General Principles and Overview. Handbook of Anthropometry: Physical Measures of Human Form in Health and Disease, Springer.","DOI":"10.1007\/978-1-4419-1788-1"},{"key":"ref_31","first-page":"9210258","article-title":"Fundamentals, Recent Advances, and Future Challenges in Bioimpedance Devices for Healthcare Applications","volume":"2019","author":"Min","year":"2019","journal-title":"J. Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"122","DOI":"10.4236\/jbise.2011.42018","article-title":"Development of forearm impedance plethysmography for the minimally invasive monitoring of cardiac pumping function","volume":"4","author":"Wang","year":"2011","journal-title":"J. Biomed. Sci. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Min, M., K\u00f5iv, H., Priidel, E., Pesti, K., and Annus, P. (2019). Noninvasive Acquisition of the Aortic Blood Pressure Waveform. Wearable Devices-The Big Wave of Innovation, IntechOpen.","DOI":"10.5772\/intechopen.86065"},{"key":"ref_34","first-page":"100","article-title":"I Luso-Brazilian positioning on central arterial pressure","volume":"108","author":"Amodeo","year":"2017","journal-title":"Arquivos brasileiros de cardiologia"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1349","DOI":"10.1016\/j.medengphy.2013.03.006","article-title":"Novel approach of processing electrical bioimpedance data using differential impedance analysis","volume":"35","author":"Sanchez","year":"2013","journal-title":"Med. Eng. Phys."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"09nt01","DOI":"10.1088\/1361-6579\/ab3666","article-title":"Numerical estimation of Fricke-Morse impedance model parameters using single-frequency sinusoidal excitation","volume":"40","author":"Zhang","year":"2019","journal-title":"Physiol. Meas."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"381251","DOI":"10.1155\/2014\/381251","article-title":"Bioelectrical Impedance Methods for Noninvasive Health Monitoring: A Review","volume":"2014","author":"Bera","year":"2014","journal-title":"J. Med. Eng."},{"key":"ref_38","first-page":"2414","article-title":"The effect of vascular diseases on bioimpedance measurements: Mathematical modeling","volume":"5","author":"Hassan","year":"2018","journal-title":"Biomed. Res. Ther."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"66","DOI":"10.5617\/jeb.3350","article-title":"Spatial resolution in electrical impedance tomography: A topical review","volume":"8","author":"Chitturi","year":"2017","journal-title":"J. Electr. Bioimpedance"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"967","DOI":"10.1109\/TBME.2018.2865751","article-title":"Noninvasive Cuffless Blood Pressure Estimation Using Pulse Transit Time and Impedance Plethysmography","volume":"66","author":"Huynh","year":"2019","journal-title":"IEEE Trans. Bio-Med. Eng."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Grimnes, S., and Martinsen, \u00d8.G. (2015). Chapter 6\u2014Geometrical Analysis. Bioimpedance and Bioelectricity Basics, Academic Press. [3rd ed.].","DOI":"10.1016\/B978-0-12-411470-8.00006-4"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Jacob, S. (2008). Chapter 7\u2014Head and neck. Human Anatomy, Churchill Livingstone.","DOI":"10.1016\/B978-0-443-10373-5.50010-5"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1561","DOI":"10.1148\/rg.256045013","article-title":"Sonographic Examination of the Carotid Arteries","volume":"25","author":"Tahmasebpour","year":"2005","journal-title":"Radiographics"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Cho, M., Kim, J., and Cho, S.H. (2009, January 24\u201327). A bio-impedance measurement system for portable monitoring of heart rate and pulse wave velocity using small body area. Proceedings of the 2009 IEEE International Symposium on Circuits and Systems (ISCAS), Taipei, Taiwan.","DOI":"10.1109\/ISCAS.2009.5118460"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1016\/0002-9149(79)90220-0","article-title":"Control of blood pressure by carotid sinus baroreceptors in human beings","volume":"44","author":"Mancia","year":"1979","journal-title":"Am. J. Cardiol."},{"key":"ref_46","unstructured":"Dyck, P.J., and Thomas, P.K. (2005). Chapter 52\u2014Diseases of the Ninth, Tenth, Eleventh, and Twelfth Cranial Nerves. Peripheral Neuropathy, W.B. Saunders. [4th ed.]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/5\/1600\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:28:19Z","timestamp":1760160499000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/5\/1600"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,25]]},"references-count":46,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2021,3]]}},"alternative-id":["s21051600"],"URL":"https:\/\/doi.org\/10.3390\/s21051600","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,25]]}}}