Wolf M, Brun N, Greisen G, Keel M, von Siebenthal K, Bucher H
Clinic for Neonatology, University Hospital, Zurich, Switzerland.
Med Biol Eng Comput. 1996 May;34(3):221-6. doi: 10.1007/BF02520077.
Cerebral blood flow can be measured in neonates by near infra-red spectrophotometry. The tracer is oxyhaemoglobin. The purpose of the study is to compare the test-retest variability of two previously proposed methods (UCH and COP) of analysis, and to investigate the influence of sampling rates, smoothing and integration periods. Under clinical conditions good measurements are often difficult to obtain. Therefore, a second goal is to find ways of determining the quality of individual measurements. 380 cerebral blood flow measurements from 69 infants are analysed. The data set is optimised statistically for the lowest test-retest variability and the following results are obtained. The test-retest variability of measurements at 2 s sampling time data is considerably worse than at 0.5 s sampling time. Smoothing does not change the test retest variability. A 6 s integration period gives higher values and higher test-retest variability than an 8 s integration period. By applying the suggested criteria, a test-retest variability of 17% is achieved, if 50% of the measurements are rejected. The mean cerebral blood flow is 12.2 ml (100 g)-1 min-1 for the UCH method and 9.7 ml [corrected] (100 g)-1 min-1 for the COP method. The test-retest variability of both methods is comparable for 0.5 s sampling time. For 2 s sampling time the method proposed by Skov et al. is significantly better. These test retest variabilities represent maximum values, part of the observed variability may be due to physiological changes of unknown magnitude.
可通过近红外分光光度法测量新生儿的脑血流量。示踪剂是氧合血红蛋白。本研究的目的是比较两种先前提出的分析方法（UCH和COP）的重测变异性，并研究采样率、平滑处理和积分周期的影响。在临床条件下，通常很难获得良好的测量结果。因此，第二个目标是找到确定个体测量质量的方法。对69名婴儿的380次脑血流量测量进行了分析。对数据集进行了统计优化，以实现最低的重测变异性，并获得了以下结果。2秒采样时间数据测量的重测变异性明显比0.5秒采样时间差。平滑处理不会改变重测变异性。与8秒积分周期相比，6秒积分周期给出的值更高，重测变异性也更高。通过应用建议的标准，如果剔除50%的测量值，重测变异性可达到17%。UCH方法的平均脑血流量为12.2 ml（100 g）-1 min-1，COP方法的平均脑血流量为9.7 ml [校正后]（100 g）-1 min-1。对于0.5秒采样时间，两种方法的重测变异性相当。对于2秒采样时间，Skov等人提出的方法明显更好。这些重测变异性代表最大值，观察到的部分变异性可能归因于未知大小的生理变化。
