{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T17:28:26Z","timestamp":1770139706078,"version":"3.49.0"},"reference-count":43,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2023,3,16]],"date-time":"2023-03-16T00:00:00Z","timestamp":1678924800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004606","name":"Chang Gung Memorial Hospital","doi-asserted-by":"publisher","award":["CMRPD2I0033"],"award-info":[{"award-number":["CMRPD2I0033"]}],"id":[{"id":"10.13039\/501100004606","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004606","name":"Chang Gung Memorial Hospital","doi-asserted-by":"publisher","award":["107-2221-E-182-008-MY3"],"award-info":[{"award-number":["107-2221-E-182-008-MY3"]}],"id":[{"id":"10.13039\/501100004606","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Science and Technology Council","award":["CMRPD2I0033"],"award-info":[{"award-number":["CMRPD2I0033"]}]},{"name":"National Science and Technology Council","award":["107-2221-E-182-008-MY3"],"award-info":[{"award-number":["107-2221-E-182-008-MY3"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Electrocardiogram (ECG) biometric provides an authentication to identify an individual on the basis of specific cardiac potential measured from a living body. Convolutional neural networks (CNN) outperform traditional ECG biometrics because convolutions can produce discernible features from ECG through machine learning. Phase space reconstruction (PSR), using a time delay technique, is one of the transformations from ECG to a feature map, without the need of exact R-peak alignment. However, the effects of time delay and grid partition on identification performance have not been investigated. In this study, we developed a PSR-based CNN for ECG biometric authentication and examined the aforementioned effects. Based on a population of 115 subjects selected from the PTB Diagnostic ECG Database, a higher identification accuracy was achieved when the time delay was set from 20 to 28 ms, since it produced a well phase-space expansion of P, QRS, and T waves. A higher accuracy was also achieved when a high-density grid partition was used, since it produced a fine-detail phase-space trajectory. The use of a scaled-down network for PSR over a low-density grid with 32 \u00d7 32 partitions achieved a comparable accuracy with using a large-scale network for PSR over 256 \u00d7 256 partitions, but it had the benefit of reductions in network size and training time by 10 and 5 folds, respectively.<\/jats:p>","DOI":"10.3390\/s23063164","type":"journal-article","created":{"date-parts":[[2023,3,16]],"date-time":"2023-03-16T03:14:35Z","timestamp":1678936475000},"page":"3164","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Convolutional Neural Network for Individual Identification Using Phase Space Reconstruction of Electrocardiogram"],"prefix":"10.3390","volume":"23","author":[{"given":"Hsiao-Lung","family":"Chan","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, Taoyuan 333, Taiwan"},{"name":"Biomedical Engineering Research Center, Chang Gung University, Taoyuan 333, Taiwan"},{"name":"Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan 333, Taiwan"}]},{"given":"Hung-Wei","family":"Chang","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, Taoyuan 333, Taiwan"}]},{"given":"Wen-Yen","family":"Hsu","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, Taoyuan 333, Taiwan"}]},{"given":"Po-Jung","family":"Huang","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Chang Gung University, Taoyuan 333, Taiwan"}]},{"given":"Shih-Chin","family":"Fang","sequence":"additional","affiliation":[{"name":"Department of Neurology, Cardinal Tien Hospital Yung Ho Branch, New Taipei City 234, Taiwan"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9200","DOI":"10.1109\/JIOT.2019.2929087","article-title":"Practical privacy-preserving ECG-based authentication for IoT-based healthcare","volume":"6","author":"Huang","year":"2019","journal-title":"IEEE Internet Things J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"808","DOI":"10.1109\/19.930458","article-title":"ECG analysis: A new approach in human identification","volume":"50","author":"Biel","year":"2001","journal-title":"IEEE Trans. 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