Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:7485-7488. doi: 10.1109/EMBC46164.2021.9629936.
Pulse transit time (PTT) and pulse arrival time (PAT) are promising measures for cuffless arterial blood pressure (BP) estimation given the intrinsic arterial stiffness-BP relationship. However, arterial stiffness (and PTT) is altered by autonomically-driven smooth muscle tension changes, potentially independent of BP. This would limit PTT or PAT as accurate BP correlates, more so in resistance vessels than conductance arteries.
To quantify if there is a measurable neurogenic effect on PAT measured using photoplethysmography (PPG) (path includes resistance vessels) and radial artery tonometry (path includes only conductance vessels) during physiologically induced BP changes.
PATs were measured continuously in participants (n=15, 35±15 years, 9 male) using an electrocardiogram and, simultaneously, a Finometer PRO finger sensor, a finger PPG sensor and radial artery tonometer during seated rest, cold pressor test, cycling and isometric handgrip (IHG) exercise. ΔBP/ΔPAT was calculated for each sensor and each condition.
All interventions significantly increased BP. A significant difference was observed in ΔBP/ΔPAT between cycling and both the cold pressor test and IHG exercise (p<0.05). ΔBP/ΔPAT did not differ whether measured via PPG or tonometry.
Under the conditions tested, autonomic function does not have a BP-independent effect on PAT where the path includes resistance vessels (PPG signal), likely due to the speed of the wave and the short path length of resistance vessels. Autonomic function therefore does not limit the ability for use of PPG as a signal for potentially estimating BP without a cuff.
鉴于动脉僵硬度与血压之间的内在关系，脉搏传输时间（PTT）和脉搏到达时间（PAT）是无袖带动脉血压（BP）估计的有前途的指标。然而，动脉僵硬度（和 PTT）会因自主驱动的平滑肌张力变化而改变，这种变化可能与血压无关。这将限制 PTT 或 PAT 作为准确的血压相关指标，在阻力血管中比在传导血管中更为明显。
定量测量在生理诱导的血压变化期间，使用光体积描记法（PPG）（路径包括阻力血管）和桡动脉张力测量（路径仅包括传导血管）测量的 PAT 是否存在可测量的神经效应。
在参与者（n=15，35±15 岁，9 名男性）静息、冷加压试验、骑自行车和等长握力（IHG）运动期间，使用心电图和同时使用 Finometer PRO 手指传感器、手指 PPG 传感器和桡动脉张力计连续测量 PAT。为每个传感器和每个条件计算 ΔBP/ΔPAT。
所有干预措施均显著增加血压。在骑自行车和冷加压试验和 IHG 运动之间观察到 ΔBP/ΔPAT 之间存在显著差异（p<0.05）。通过 PPG 或张力测量测量的 ΔBP/ΔPAT 没有差异。
在测试的条件下，自主功能对包括阻力血管（PPG 信号）的 PAT 没有独立于血压的影响，这可能是由于波的速度和阻力血管的短路径长度。因此，自主功能不会限制 PPG 作为无袖带估计 BP 的潜在信号的使用能力。
