Does multi-wavelength PPG-based pulse transit time accurately track systolic blood pressure changes compared to traditional ECG-PPG pulse transit time in healthy adults?
Multi-wavelength PPG measured at a single site (fingertip) shows strong potential for cuffless blood pressure monitoring, outperforming traditional multi-site ECG-PPG methods in tracking systolic blood pressure changes.
Pulse transit time (PTT) has been widely studied as an index of blood pressure (BP) changes. In recent years, some prototypes of PTT-based wearable BP measurement devices have been developed, which can relieve users from the discomfort caused by the inflating cuff used in auscultatory and oscillometric BP measurement techniques. However, in the common practice for PTT detection, multi-site sensor implementation on human body is required, making it difficult for the integration of wearable devices. Since multi-wavelength (MW) photoplethysmogram (PPG) signals carry blood pulsation information of different blood vessels embedded in different skin depths, the time difference between different wavelength PPG signals collected at the same body site can be treated as a special PTT on a short length of blood vessels beneath the skin. In this work, the time difference between MW PPG, denoted as PTTMW, was explored to track BP changes as a substitute of infrared (IR) PTTEP. (PTTEP is the time interval between electrocardiogram (ECG) and IR PPG. ) Ten healthy adult subjects participated in the experiment, and their continuous BP, ECG and fingertip MW PPG signals generated from blue, green, yellow and IR light were recorded after 2-minute static handgrip exercise at 33% maximal voluntary contraction. The results showed that the correlation between Systolic BP (SBP) and IR-Blue PTTMW (|r|= 0. 52) was comparable to the correlation between SBP and IR PTTEP (|r|= 0. 59). Moreover, we optimized the wavelength combination of PTTMWs for each subject and found the average value of optimal correlation between SBP and PTTMW reached 0. 76, which was significantly (p<;0. 01) higher than the correlation between IR PTTEP and SBP. This study reveals that the time difference between MW PPG can be potentially used as PTT for cuffless BP measurement with its unique advantage in simple sensor implementation at only one body site.
Liu et al. (Mon,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: