一氧化氮（nitric oxide，NO）是生物体内的信使分子，具有舒张血管、扩张支气管、抑制血小板凝聚等功能，在生物体多种生理活动中都起着重要的调控作用。吸入NO气体技术是20世纪90年代在临床上应用的一种见效快、无创伤性呼吸急救新技术。吸入NO气体的浓度一般在3~20 ppm，最高不超过80 ppm。吸入低浓度NO气体对肺动脉高压、呼吸衰竭综合征、慢性阻塞性肺疾病以及支气管哮喘等多种心肺疾病具有良好的治疗效果。

     目前临床上使用的储气式医用NO系统的气源昂贵、输送装置复杂，导致NO吸入疗法治疗价格费用高，限制了吸入NO气体在相关疾病治疗中应用和发展。小型化即时产生式医用NO系统可以随时产生NO气体，避免了NO气体的储存与稀释，具有体积小、操作简单、价格便宜等优势，可在医院、社区甚至是家庭中使用。本文设计并搭建了便携式医用NO发生器平台，并对其关键技术进行研究。

    首先，通过对空气中放电产生NO的等离子体形式分析，脉冲电弧放电产生的热平衡等离子体具有温度高、电弧稳定等优势可以快速稳定地产生NO气体。对热平衡等离子体产生NO的化学反应过程进行分析，为实验研究电弧放电反应生成NO、NO₂气体浓度影响提供理论基础。本文搭建了基于高频脉冲放电的便携式NO发生器实验平台，并对系统各模块的结构设计和功能以及工作流程进行了详细介绍。其次，通过对等离子体反应器多参数下的流场仿真模拟，分析了气流方向和气体流量对反应仓内部流场分布的影响。通过多参数的脉冲电弧放电实验，探究了气流方向、气体流量、输入电压等参数对NO、NO₂浓度以及NO₂/NO比值的影响，并结合流场仿真，找出脉冲电弧等离子体生成NO、NO₂气体的影响规律。通过实验参数的调节对系统进行改进和调优，找出便携式NO发生器的最佳工作点。便携式NO发生器在2L/min的气流条件下可稳定输出NO为32.5ppm的最高浓度，可满足NO气体吸入需求。最后对装有疏松Ca(OH)₂颗粒的NO₂去除装置的过滤效果进行验证，实验发现该去除装置可将NO₂/NO比值降低至5%左右，对NO气体中的NO₂有很好的过滤效果。通过对不同实验参数的组合，便携式NO发生器可有效输出符合临床NO吸入治疗要求的NO气体。

  Nitric oxide (NO) is a messenger molecule in the organism which has functions of relaxing blood vessels, dilating bronchi, inhibiting platelet aggregation and plays an important role in regulating various physiological activities of the organism. Inhaled NO is a new technique of quick-response, non-invasive respiratory first aid applied in clinic in the 1990s. The concentration of inhaled NO is generally 3-20ppm, the maximum concentration does not exceed 80ppm. Inhaling low concentrations of NO has a good therapeutic effect on many cardiopulmonary diseases such as pulmonary hypertension, respiratory distress syndrome, chronic obstructive pulmonary disease, and bronchial asthma.

  Cartridge operated medical NO system currently used in clinic is expensive in gas source and complicated in delivery device. Therefore, the high cost of NO inhalation therapy limits the application and development of inhaled NO in the treatment of related diseases. The portable instant-generation medical NO system can generate NO gas at any time avoiding the storage and dilution. With the advantages of small size, simple operation and low price, the portable instant-generation medical NO system can be used in hospitals, communities and even homes. This paper designs a portable medical NO generator platform and studies its key technologies.

  First of all, through the analysis of the plasma generation of NO in the air, thermal equilibrium plasma generated by arc discharge has the advantage of high temperature and stable which can quickly and stably generate NO gas. The chemical reaction process of NO produced by thermal equilibrium plasma is analyzed to provide a theoretical basis for the experimental study of the effect of NO and NO₂ concentration generated by arc discharge reaction.

  This paper introduces the structural design, function and working process of the portable NO generator experimental platform based on high-frequency pulse discharge. Secondly, the influence of the gas flow direction and gas flow on the distribution of the flow field inside the reaction chamber was analyzed through the simulation of the flow filed under the multiparameter of the plasma reactor. Multi-parameter pulse arc discharge experiment is conducted to explore the influence of gas flow direction, gas flow, input voltage and other parameters on the concentration of NO, NO₂ and the ratio of NO₂/NO. Flow filed simulation and experiment are combined to find out the influence law of NO and NO₂ generated by arc plasma. Many experimental parameters of this system are adjusted to find the best working point of the portable NO generator. The portable NO generator has a stable output capacity at the gas flow rate of 2 L/min that can production of NO up to 32.5 parts per million. Then the NO₂ removal device of the portable NO generator uses loose Ca(OH)₂ particles have a good removal effect on NO₂ from potentially toxic gases generated during the pulsed arc reaction. The filtration experiment found that the NO₂ removal device can reduce the NO₂/NO ratio to about 5%. The combination of multiple parameters in the portable NO system has finally achieved the ability to stably produce high-quality NO gas, which satisfied the demand for medical inhaled NO.