Authors:
Yiming Zhang
1
;
Congcong Zhou
1
;
Zhongyi Huang
1
and
Xuesong Ye
1
;
2
Affiliations:
1
Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang University, Hangzhou 310027, China
;
2
Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310058, P.R. China
Keyword(s):
Blood Pressure, Non-invasive, Pulse Transit Time, Synchronization, Wearable.
Abstract:
There were many studies showing the relation between pulse transit time (PTT) and blood pressure (BP). Besides, hemodynamic covariates may also contribute to BP values. Our previous study has proposed a BP model based on PTT, HR, stiffness index (SIx) and descent time (DT), which has been validated on the Multi-parameter Intelligent Monitoring for Intensive Care (MIMIC) database. In this article, we present a prototype cuff-less monitoring device for non-invasive estimation of BP, which can obtain both electrocardiogram (ECG) and finger plethysmograph (PPG) signals synchronously. The model proposed above has been validated by using ECG and PPG records from 22 healthy subjects with no cardiovascular disease and hypertension, and the error of BP estimation was 0.002±8.544 mmHg for SBP, 0.005±6.690 mmHg for DBP. The reliability of this method in long-term BP monitoring was further verified by studying the data of one individual for 28 days, while the error was 5.204±5.462 mmHg for SBP,
2.714±4.756 mmHg for DBP without calibration. The results show that the model could estimate the BP value within the acceptable error range based on this study, which is extremely close to AAMI's standard (5±8mmHg) and consistent with the cuff-method. The proposed ultra-low power, wearable, time-synchronized prototype monitoring device with an embedded hemodynamic covariate model, can measure SBP and DBP values accurately, which is expected to estimate continuous blood pressure better.
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