Panerai R B, Coughtrey H, Rennie J M, Evans D H
Division of Medical Physics, Faculty of Medicine, University of Leicester, UK.
Physiol Meas. 1993 Nov;14(4):411-8. doi: 10.1088/0967-3334/14/4/002.
The instantaneous relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), measured with Doppler ultrasound in the anterior cerebral artery, is represented by a vascular waterfall model comprising vascular resistance, compliance, and critical closing pressure. One min recordings obtained from 61 low birth weight newborns were fitted to the model using a least-squares procedures with correction for the time delay between the BP and CBFV signals. A sensitivity analysis was performed to study the effects of low-pass filtering (LPF), cutoff frequency, and noise on the estimated parameters of the model. Results indicate excellent fitting of the model (F-test, p < 0.0001) when the BP and CBFV signals are LPF at 7.5 Hz. Reconstructed CBFV waveforms using the BP signal and the model parameters have a mean correlation coefficient of 0.94 with the measured flow velocity tracing (N = 232 epochs). The model developed can be useful for interpreting clinical findings and as a framework for research into cerebral autoregulation.
通过多普勒超声在前脑动脉测量的动脉血压（BP）与脑血流速度（CBFV）之间的瞬时关系，由一个包含血管阻力、顺应性和临界关闭压的血管瀑布模型表示。使用最小二乘法对61例低出生体重新生儿进行1分钟记录，并对BP和CBFV信号之间的时间延迟进行校正，使其符合该模型。进行敏感性分析以研究低通滤波（LPF）、截止频率和噪声对模型估计参数的影响。结果表明，当BP和CBFV信号在7.5Hz进行低通滤波时，模型拟合良好（F检验，p<0.0001）。使用BP信号和模型参数重建的CBFV波形与测量的流速描记图的平均相关系数为0.94（N = 232个时段）。所开发的模型可用于解释临床发现，并作为脑自动调节研究的框架。
