Allen H V, Anderson M F, Meindl J D
Am J Physiol. 1977 May;232(5):H537-44. doi: 10.1152/ajpheart.1977.232.5.H537.
A totally implantable pulsed Doppler ultrasonic blood flowmeter has recently been developed to provide information on the velocity-flow profile in a vessel as well as its diameter. Volume flow can be indirectly obtained according to the formula: Q = (phi/4)(diam)2-v. In order to determine the accuracy of this estimate, in vivo direct bleedout measurements were performed on the abdominal aorta of six dogs with an overall accuracy in 77 trials of +2.0 +/- 8.7% (mean +/- 1 SD). The best-fit mean linear regression line was found to be: flowmeter output = 1.013-true flow + 5.1 ml/min. The scatter in the flowmeter's accuracy is thought to be due to small variations in the angle of the transducer. The source of the 2% overestimation in the mean accuracy could not be directly attributed to any one condition; the error is sufficiently small that in many cases it can be neglected.
最近开发了一种完全植入式脉冲多普勒超声血流仪，用于提供血管内速度-流量剖面及其直径的信息。体积流量可根据公式间接获得：Q = (π/4)(直径)²×v。为了确定该估计值的准确性，对6只狗的腹主动脉进行了体内直接放血测量，在77次试验中的总体准确性为+2.0±8.7%（平均值±1标准差）。发现最佳拟合平均线性回归线为：流量计输出 = 1.013×真实流量 + 5.1毫升/分钟。流量计准确性的离散被认为是由于换能器角度的微小变化。平均准确性中2%高估的来源不能直接归因于任何一种情况；该误差足够小，在许多情况下可以忽略不计。
