A study on visualization of nitriic oxide in humans

为了测量人体一氧化氮（NO），我们开发了一种专门用于测量人体呼出一氧化氮的实时监测系统。该系统不仅可以在计算机显示器上显示呼出的NO （ppb）和CO2的痕迹，还可以显示空气流量，VCO2和VNO。我们可以实时监测呼出一氧化氮的变化。因此，NO的可视化在计算机屏幕上执行。该系统由化学发光NO分析仪、O2-CO2分析仪、气体流量计、AD/DA转换装置、信号延时软磨损、DA/AD转换装置和信号采集装置（MacLab）组成。在人体呼出一氧化氮和鼻腔一氧化氮的测量中对整个系统进行了测试，结果表明该系统对人体呼出一氧化氮和鼻腔一氧化氮的估计是有用的。我们试图用这个装置来阐明人体下气道呼出一氧化氮的来源。结果表明呼出的一氧化氮可能产生于周围气道，可能是终末细支气管。因为呼气时间和/或屏气时间延长，肺泡通气量增加，呼出NO增加。过度通气几乎不可能冲洗掉气道中的NO，提示NO在气道上皮内产生，并通过其自身在上皮内的高分压不断向气道腔扩散。结果表明，体育锻炼可降低鼻NO的含量，同时降低鼻气道阻力。在临床研究中，弥漫性泛细支气管炎患者呼出的一氧化氮含量很低。这些患者也表现出低鼻NO。通过使用我们的设备，可以准确、快速地测量呼出的一氧化氮。

In order to measure nitric oxide (NO) in human subjects, we have developed a realtime monitoring system especially design for a measurement of human exhaled NO.The system can exhibit not only the traces of exhaled NO (ppb) and CO2 but also air flow, VCO2, and VNO on the computer display. We can monitor the changes of exhlaed NO in a real time fashion. Visualization of NO is thus performed on the computer screen. This system consists of a chemiluminescence NO analyzer, an O2-CO2 analyzer, a gas flow meter, an AD/DA converting apparatus, signal delaying soft wear, a DA/AD converting apparatus, and the signal acquisition device (MacLab). The whole system was tested in the measurements of human exhaled NO and human nasal NO and turned out to be useful for the estimation of exhaled NO as well as nasal NO.We attempted to clarify the origin of exhaled NO in the human lower airway by using this device. The results demonstrated that the exhaled NO is likely to be produced in the peripheral airway, probably, terminal bronchioles. Because the exhaled NO increases when the expiration time and/or breath-hold time prolong and the alveolar ventilation increases. It was almost impossible to wash out NO in the airway by hyperventilation, suggesting that the NO is produced in the airway epithelia and continuously diffuses toward the airway cavity by its own high partial pressure within the epilthelia. Nasal NO was found to decrease by physical exercise along with a decrease in nasal airway resistance. In the clinical study, the exhaled NO from the patients with diffuse panbronchiolitis was measured to be very low. These patients exhibited low nasal NO as well. By using our device, accurate and quick measurement of exhaled NO was possible.