{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T16:33:09Z","timestamp":1785429189537,"version":"3.56.0"},"reference-count":32,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T00:00:00Z","timestamp":1777680000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["62361013"],"award-info":[{"award-number":["62361013"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["62361013"],"award-info":[{"award-number":["62361013"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Guangxi Key Research and Development Program Project","award":["GuikeFN2600640136"],"award-info":[{"award-number":["GuikeFN2600640136"]}]},{"DOI":"10.13039\/501100004829","name":"Science and Technology Department of Sichuan Province","doi-asserted-by":"publisher","award":["2025ZNSFSC0457"],"award-info":[{"award-number":["2025ZNSFSC0457"]}],"id":[{"id":"10.13039\/501100004829","id-type":"DOI","asserted-by":"publisher"}]},{"award":["2025ZNSFSC0457"],"award-info":[{"award-number":["2025ZNSFSC0457"]}],"id":[{"id":"https:\/\/ror.org\/04323m874","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Hypertension is a major risk factor for cardiovascular disease and requires effective long-term monitoring. Photoplethysmography (PPG), acquired from wearable optical sensors, offers a convenient and non-invasive signal source for cuffless blood pressure (BP) estimation, but existing studies have mainly emphasized model architecture optimization, with limited systematic investigation of signal representation. This study systematically compares seven one-dimensional-to-two-dimensional signal transformation methods and evaluates multiple architectural variants for PPG-based cuffless BP estimation under a unified framework. Experiments were conducted using PPG and arterial BP signals from the UCI Open Blood Pressure Database. The best-performing configuration, based on continuous wavelet transform (CWT), achieved estimation errors of 3.80 \u00b1 5.02 mmHg for systolic BP and 1.65 \u00b1 2.70 mmHg for diastolic BP. Further real-world validation on 26 participants using an Omron cuff-based monitor as the reference showed good consistency, with correlation coefficients of R = 0.96 for SBP and R = 0.74 for DBP. The results demonstrate that appropriate signal representation, particularly CWT, plays a critical role in improving estimation accuracy and robustness, and may facilitate the development of wearable cuffless BP monitoring systems.<\/jats:p>","DOI":"10.3390\/s26092847","type":"journal-article","created":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T01:12:09Z","timestamp":1777857129000},"page":"2847","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Comparative Study of Signal Representations Methods and Deep Learning Architectures for PPG-Based Cuffless Blood Pressure Estimation"],"prefix":"10.3390","volume":"26","author":[{"given":"Han","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China"},{"name":"School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xudong","family":"Hu","sequence":"additional","affiliation":[{"name":"School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, China"},{"name":"Ningbo Ming Sing Optical R&D Co., Ltd., Ningbo 315104, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xizhuang","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhencheng","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, China"},{"name":"Guangxi Key Laboratory of Metabolic Reprogramming and Intelligent Medical Engineering for Chronic Diseases, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8337-6147","authenticated-orcid":false,"given":"Yongbo","family":"Liang","sequence":"additional","affiliation":[{"name":"School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, China"},{"name":"Guangxi Key Laboratory of Metabolic Reprogramming and Intelligent Medical Engineering for Chronic Diseases, Guilin 541004, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gang","family":"Wang","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Health and Rehabilitation Science, School of Life Science and Technology, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1038\/s41581-019-0244-2","article-title":"The Global Epidemiology of Hypertension","volume":"16","author":"Mills","year":"2020","journal-title":"Nat. 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