Speckle contrast optical spectroscopy for cuffless blood pressure monitoring
Embargo Date
2026-08-04
OA Version
Citation
Abstract
Hypertension (elevated blood pressure (BP)), is the leading cause of cardiovascular disease (CVD), affecting nearly half of adults in the Unites States (US) and over 1 billion adults globally. Hypertension poses a major clinical and economic burden to the health care system and increases the risk of multiple adverse outcomes, including stroke, coronary artery disease, heart failure, peripheral vascular disease, and kidney disease. It is estimated that at least half of hypertensive individuals remain undiagnosed and thus untreated, increasing their risk for future CVD. There is a large body of evidence indicating that frequent BP measurements outside of the clinic provide a more robust assessment of a person’s “usual” BP compared with a single measurement acquired in the clinician’s office. Additionally, the difference between daytime and nighttime BP is strongly correlated with cardiovascular risk prediction. Currently, these measurements can only be captured by ambulatory blood pressure monitoring (ABPM) in which a person wears a BP cuff for 24 hours and the cuff inflates automatically every 30–60 minutes. ABPM has not seen widespread adoption due to the discomfort of frequent cuff measurements, especially during important nighttime BP readings. There is a large desire for a BP monitor that could provide clinicians with frequent BP readings outside of the clinic, without the need for disruptive cuff measurements.
Speckle contrast optical spectroscopy (SCOS) enables simultaneous measurement of blood flow and volume changes in the tissue. When SCOS images are acquired at a sufficient frame rate, changes in blood flow and volume can be resolved within each cardiac pulse. Previous work indicated that the morphology and timing characteristics of these blood flow waveforms were related to cardiovascular health. In this work, we developed a high speed SCOS system that acquired blood flow and volume waveforms on the wrist and finger. We extracted a wide array of temporal, shape-based, and frequency-domain features from each high-resolution waveform, as well as features that characterize the temporal relationships between these features. These features and their inter-relationships are determined by the dynamic biomechanical properties of peripheral microvasculature, including vascular compliance and resistance, which are key determinants of dynamic changes in systemic blood pressure (BP). We assessed correlations between features extracted from SCOS waveforms and BP. Then, we used features extracted from SCOS waveforms to estimate BP and investigated errors. Lastly, we explored the differences in SCOS measurements and BP estimation between healthy and hypertensive subject groups.
Description
2026
License
Attribution 4.0 International