Isabey D, Delpuech C
Bull Eur Physiopathol Respir. 1986 Sep-Oct;22(5):483-8.
Recent systems proposed in the literature to accurately measure flow rates at high frequency, such as the wave tube technique or the loudspeaker technique, are not adequate for large amplitude oscillations. Other standard pneumotachometer systems require analytical or numerical correction procedures. In this study, we propose a low cost, rapid response flowmeter for high and low flow rates, made up of a standard screen pneumotachometer coupled with a piezoresistive differential pressure transducer of recent conception. By reference to a gas capacitance, the frequency response of this device is compared to the frequency response obtained with the same screen pneumotachometer coupled with a standard low range medical pressure transducer. Contrary to the standard device, the new device has a flat amplitude response up to 70 Hz and introduces a minimal phase delay up to 90 Hz (9 degrees), both with a 1.51.s-1 constant peak flow and a peak flow rate two times greater. The authors suggest that this improved flowmeter can be advantageously used in physiological studies requiring accurate high frequency flow measurements over short periods of time.
文献中最近提出的用于精确测量高频流速的系统，如波管技术或扬声器技术，对于大幅度振荡并不适用。其他标准的呼吸流速计系统需要分析或数值校正程序。在本研究中，我们提出了一种用于高低流速测量的低成本、快速响应的流量计，它由一个标准的筛孔式呼吸流速计与一个最新设计的压阻式差压传感器组成。通过与气体电容进行比较，将该装置的频率响应与使用相同的筛孔式呼吸流速计和标准低量程医用压力传感器获得的频率响应进行对比。与标准装置不同，新装置在高达70Hz时具有平坦的幅度响应，在高达90Hz（9度）时引入的相位延迟最小，无论是在1.51.s-1的恒定峰值流速还是峰值流速两倍更高的情况下。作者认为，这种改进的流量计可有利地用于需要在短时间内进行精确高频流量测量的生理研究中。
