Garrett Ariane, Kim Byungchan, Gurel Nil Z, Sie Edbert J, Wilson Benjamin K, Marsili Francesco, Forman John P, Hamburg Naomi M, Boas David A, Roblyer Darren
Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
Reality Labs, Meta Platforms Inc., Menlo Park, CA 94025, USA.
Biomed Opt Express. 2025 Jul 2;16(8):3004-3016. doi: 10.1364/BOE.560022. eCollection 2025 Aug 1.
This work introduces high-speed (390 Hz) speckle contrast optical spectroscopy (SCOS) to enable simultaneous measurements of multi-anatomic site microvascular blood volume and flow oscillations. Simultaneous blood flow and volume waveforms were extracted at two wavelengths on the wrist and finger, in reflectance and transmission mode, respectively. Blood volume changes (also known as photoplethysmography, or PPG) were determined based on intensity oscillations. Blood flow information was determined based on dynamic light scattering information encoded in the 2D spatial speckle pattern after removal of stochastic and instrument noise. 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). In comparison to PPG alone, SCOS demonstrated a notable 31% improvement (p = 3.45 * 10) in systolic BP estimation when integrated into subject-specific machine-learning models. The resulting errors were remarkably low (systolic BP: 0.06+/- 2.88 mmHg, diastolic BP: 0.09 +/-2.14 mmHg) across a wide range of BP variations (range SBP: 89-284 mmHg). This improvement was sustained several weeks later within a re-measured cohort, indicating highly robust BP predictions. Looking ahead, high-speed SCOS holds the potential to substantially enhance the non-invasive characterization of the cardiovascular system, including continuous and non-invasive BP measurements, which are a long-sought-after goal of the biomedical community.
这项工作引入了高速（390赫兹）散斑对比光学光谱法（SCOS），以实现对多个解剖部位微血管血容量和血流振荡的同步测量。分别在手腕和手指处以反射和透射模式，在两个波长下提取了同步的血流和血容量波形。基于强度振荡确定血容量变化（也称为光电容积脉搏波描记法，或PPG）。血流信息是在去除随机噪声和仪器噪声后，基于二维空间散斑图案中编码的动态光散射信息确定的。我们从每个高分辨率波形中提取了大量的时间、基于形状和频域特征，以及表征这些特征之间时间关系的特征。这些特征及其相互关系由外周微血管的动态生物力学特性决定，包括血管顺应性和阻力，它们是全身血压（BP）动态变化的关键决定因素。与单独的PPG相比，当SCOS集成到特定受试者的机器学习模型中时，收缩压估计有显著的31%的改善（p = 3.45 * 10）。在广泛的血压变化范围内（收缩压范围：89 - 284 mmHg），所得误差非常低（收缩压：0.06 +/- 2.88 mmHg，舒张压：0.09 +/- 2.14 mmHg）。几周后，在重新测量的队列中这种改善仍然存在，表明血压预测具有高度稳健性。展望未来，高速SCOS有潜力大幅增强心血管系统的非侵入性表征，包括连续和非侵入性血压测量，这是生物医学界长期追求的目标。
