一、引言 Machella(1936)是第一个把热膜风速计用于测量动物血速的人。对于人类的血速测量,热膜风速计在某些限定的条件下已得到应用。血速的测量原理是使一很小的薄金属片保持高于周围血液温度的恒定温度,然后测量保持上述恒温所需要的能量。由于热膜风速计具有探头尺寸小,频率响应高的特点。优于其它技术手段,所以我们决定把 I. INTRODUCTION Machella (1936) is the first person to use a hot film anemometer to measure animal blood velocity. For human blood velocity measurements, hot film anemometers have been used under certain defined conditions. Blood velocity is measured by keeping a small piece of thin metal at a constant temperature above the temperature of the surrounding blood and measuring the amount of energy required to maintain the constant temperature. As the hot film anemometer has a small probe size, high frequency response characteristics. Better than other technical means, so we decided to put it