Foo Jong Yong Abdiel
Biomedical Engineering Research Centre, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, 6th Storey, Xfrontiers Block 637553, Singapore.
Cardiovasc Eng. 2007 Sep;7(3):121-6. doi: 10.1007/s10558-007-9034-8.
The human autonomic nervous system modulates blood pressure (BP) and heart rate in order to maintain homeostasis. Present techniques that monitor BP may cause discomforts to children. Pulse transit time change (DeltaPTT) is known to be inversely correlated to BP change. In this study, a mathematical model using only a few empirical parameters and the measured lower limb vascular path length is introduced to estimate DeltaPTT when a different posture is adopted. To assess the reliability of the model, 23 healthy children aged 8.4 +/- 2.3 years were recruited to adopt the sitting and supine position at discrete intervals. PTT measurements were obtained from their toe with respect to an ECG for both postures. The results showed that there was significant correlation between the model and measured DeltaPTT (P < 0.05; R(2) = 0.813). The findings herein suggest that this simple yet practical model can have the accuracy to estimate the DeltaPTT value. Moreover, it does not require the use of an ECG or pulse oximeter in its computation. Hence, it can provide a rapid prediction before a child adopts a postural change. This may be potentially useful for detection of children with vascular abnormalities at their lower limbs.
人类自主神经系统调节血压（BP）和心率以维持体内平衡。目前监测血压的技术可能会给儿童带来不适。已知脉搏传输时间变化（DeltaPTT）与血压变化呈负相关。在本研究中，引入了一个仅使用几个经验参数和测量的下肢血管路径长度的数学模型，以估计采用不同姿势时的DeltaPTT。为了评估该模型的可靠性，招募了23名年龄为8.4±2.3岁的健康儿童，让他们在不同时间间隔采用坐姿和仰卧位。针对两种姿势，从他们的脚趾相对于心电图获取PTT测量值。结果表明，模型与测量的DeltaPTT之间存在显著相关性（P < 0.05；R(2) = 0.813）。本文的研究结果表明，这个简单而实用的模型能够准确估计DeltaPTT值。此外，其计算过程不需要使用心电图或脉搏血氧仪。因此，它可以在儿童姿势改变之前提供快速预测。这对于检测下肢血管异常的儿童可能具有潜在的用途。
