000078897 001__ 78897 000078897 005__ 20230914083223.0 000078897 0247_ $$2doi$$a10.3389/fnins.2019.00339 000078897 0248_ $$2sideral$$a111377 000078897 037__ $$aART-2019-111377 000078897 041__ $$aeng 000078897 100__ $$0(orcid)0000-0003-1272-0550$$aLázaro, Jesús$$uUniversidad de Zaragoza 000078897 245__ $$aBaroreflex sensitivity measured by pulse photoplethysmography 000078897 260__ $$c2019 000078897 5060_ $$aAccess copy available to the general public$$fUnrestricted 000078897 5203_ $$aNovel methods for assessing baroreflex sensitivity (BRS) using only pulse photoplethysmography (PPG) signals are presented. Proposed methods were evaluated with a data set containing electrocardiogram (ECG), blood pressure (BP), and PPG signals from 17 healthy subjects during a tilt table test. The methods are based on a surrogate of a index, which is defined as the power ratio of RR interval variability (RRV) and that of systolic arterial pressure series variability (SAPV). The proposed a index surrogates use pulse-to-pulse interval series variability (PPV) as a surrogate of RRV, and different morphological features of the PPG pulse which have been hypothesized to be related to BP, as series surrogates of SAPV. A time-frequency technique was used to assess BRS, taking into account the non-stationarity of the protocol. This technique identifies two time-varying frequency bands where RRV and SAPV (or their surrogates) are expected to be coupled: the low frequency (LF, inside 0.04–0.15 Hz range), and the high frequency (HF, inside 0.15–0.4 Hz range) bands. Furthermore, time-frequency coherence is used to identify the time intervals when the RRV and SAPV (or their surrogates) are coupled. Conventional a index based on RRV and SAPV was used as Gold Standard. Spearman correlation coefficients between conventional a index and its PPG-based surrogates were computed and the paired Wilcoxon statistical test was applied in order to assess whether the indices can find significant differences (p < 0.05) between different stages of the protocol. The highest correlations with the conventional a index were obtained by the a-index-surrogate based on PPV and pulse up-slope (PUS), with 0.74 for LF band, and 0.81 for HF band. Furthermore, this index found significant differences between rest stages and tilt stage in both LF and HF bands according to the paired Wilcoxon test, as the conventional a index also did. These results suggest that BRS changes induced by the tilt test can be assessed with high correlation by only a PPG signal using PPV as RRV surrogate, and PPG morphological features as SAPV surrogates, being PUS the most convenient SAPV surrogate among the studied ones. 000078897 536__ $$9info:eu-repo/grantAgreement/ES/MINECO-FEDER/RTI2018-097723-B-I00$$9info:eu-repo/grantAgreement/ES/MINECO-FEDER/DPI2016-75458-R$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 745755-WECARMON$$9info:eu-repo/grantAgreement/EC/H2020/745755/EU/Wearable Cardiorespiratory Monitor/WECARMON$$9info:eu-repo/grantAgreement/ES/DGA-FEDER/T39-17R-BSICoS$$9info:eu-repo/grantAgreement/ES/CSIC-IMB-CNM/ICTS NANBIOSIS-SU8 Unit-CIBER-BBN 000078897 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/ 000078897 590__ $$a3.707$$b2019 000078897 592__ $$a1.554$$b2019 000078897 591__ $$aNEUROSCIENCES$$b96 / 270 = 0.356$$c2019$$dQ2$$eT2 000078897 593__ $$aNeuroscience (miscellaneous)$$c2019$$dQ1 000078897 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000078897 700__ $$0(orcid)0000-0001-7285-0715$$aGil, Eduardo$$uUniversidad de Zaragoza 000078897 700__ $$aOrini, Michele 000078897 700__ $$0(orcid)0000-0001-8742-0072$$aLaguna, Pablo$$uUniversidad de Zaragoza 000078897 700__ $$0(orcid)0000-0003-3434-9254$$aBailón, Raquel$$uUniversidad de Zaragoza 000078897 7102_ $$15007$$2520$$aUniversidad de Zaragoza$$bDpto. Informát.Ingenie.Sistms.$$cÁrea Ingen.Sistemas y Automát. 000078897 7102_ $$15008$$2800$$aUniversidad de Zaragoza$$bDpto. Ingeniería Electrón.Com.$$cÁrea Teoría Señal y Comunicac. 000078897 773__ $$g13 (2019), 1-13$$pFront. neurosci.$$tFrontiers in neuroscience$$x1662-4548 000078897 8564_ $$s3864690$$uhttps://zaguan.unizar.es/record/78897/files/texto_completo.pdf$$yVersión publicada 000078897 8564_ $$s11489$$uhttps://zaguan.unizar.es/record/78897/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000078897 909CO $$ooai:zaguan.unizar.es:78897$$particulos$$pdriver 000078897 951__ $$a2023-09-13-10:42:05 000078897 980__ $$aARTICLE