Continuous cuffless blood pressure monitoring using photoplethysmography-based PPG2BP-net for high intrasubject blood pressure variations

Abstract

Continuous, comfortable, convenient (C3), and accurate blood pressure (BP) measurement and monitoring are needed for early diagnosis of various cardiovascular diseases. To supplement the limited C3 BP measurement of existing cuff-based BP technologies, though they may achieve reliable accuracy, cuffless BP measurement technologies, such as pulse transit/arrival time, pulse wave analysis, and image processing, have been studied to obtain C3 BP measurement. One of the recent cuffless BP measurement technologies, innovative machine-learning and artificial intelligence-based technologies that can estimate BP by extracting BP-related features from photoplethysmography (PPG)-based waveforms have attracted interdisciplinary attention of the medical and computer scientists owing to their handiness and effectiveness for both C3 and accurate, i.e., C3A, BP measurement. However, C3A BP measurement remains still unattainable because the accuracy of the existing PPG-based BP methods was not sufficiently justified for subject-independent and highly varying BP, which is a typical case in practice. To circumvent this issue, a novel convolutional neural network(CNN)- and calibration-based model (PPG2BP-Net) was designed by using a comparative paired one-dimensional CNN structure to estimate highly varying intrasubject BP. To this end, approximately $$70\%$$ 70 % , $$20\%$$ 20 % , and $$10\%$$ 10 % of 4185 cleaned, independent subjects from 25,779 surgical cases were used for training, validating, and testing the proposed PPG2BP-Net, respectively and exclusively (i.e., subject-independent modelling). For quantifying the intrasubject BP variation from an initial calibration BP, a novel ‘standard deviation of subject-calibration centring (SDS)’ metric is proposed wherein high SDS represents high intrasubject BP variation from the calibration BP and vice versa. PPG2BP-Net achieved accurately estimated systolic and diastolic BP values despite high intrasubject variability. In 629-subject data acquired after 20 minutes following the A-line (arterial line) insertion, low error mean and standard deviation of $$0.209\pm 7.509$$ 0.209 ± 7.509 and $$0.150\pm 4.549\;\textrm{mmHg}$$ 0.150 ± 4.549 mmHg for highly varying A-line systolic and diastolic BP values, respectively, where their SDSs are 15.375 and 8.745. This study moves one step forward in developing the C3A cuffless BP estimation devices that enable the push and agile pull services.

First-in-Human Study for Evaluating the Accuracy of Smart Ring Based Cuffless Blood Pressure Measurement

“…The BP measuring algorithm model was developed to accurately measure BP based on a 1D-CNN structure with intraoperative BP vital records from 4,185 cases. 14 In our prospective validation study, the accuracy of BP measurement using the smart ring across various BP ranges was assessed. The mean differences in BP measurements between the smart ring and standard auscultatory method were less than 1 mmHg for both SBP and DBP.…”

“…Therefore, BP can be estimated by analyzing changes in the shape of the PPG waveform using a Convolutional Neural Network (CNN) after calibration. 13 14 Collected raw PGG signals are preprocessed and filtered by algorithm on the server, and raw signals that are difficult to recognize are automatically discarded or undergo a preprocessing stage to transform them into a visually discernible form.…”

Feasibility and Effectiveness of a Ring-Type Blood Pressure Measurement Device Compared With 24-Hour Ambulatory Blood Pressure Monitoring Device

“…If deemed valid by the algorithm, they were used to estimate BP values through a BP algorithm. 17) A corresponding BP value was generated for each ABPM reading, enabling comparison with the ABPM device.…”

When and how to use ambulatory blood pressure monitoring and home blood pressure monitoring for managing hypertension

“…Moreover, conventional ABPM is not widely feasible in primary clinics, is not acceptable for frequent use, and may cause problems such as sleep disturbance, anxiety, and skin irritation during monitoring owing to cuff inflation [ 19 ]. To overcome these shortcomings, cuffless BP monitoring using a wearable device has been attempted for continuous BP estimation [ 20 ]. However, currently, cuffless devices are not recommended for use in the diagnosis or management of hypertension in clinical practice [ 4 ].…”