Feng Liyang, Liu Yanxiang, Wang Yi, Zhou Hong, Lu Zhongming, Li Tie
State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
University of Chinese Academy of Sciences (UCAS), Beijing, 100049, China.
Microsyst Nanoeng. 2024 Oct 21;10(1):151. doi: 10.1038/s41378-024-00782-6.
Expiratory CO concentrations can directly reflect human physiological conditions, and their detection is highly important in the treatment and rehabilitation of critically ill patients. Existing respiratory gas analyzers suffer from large sizes and high power consumption due to the limitations of the internal CO sensors, which prevent them from being wearable to track active people. The internal and external interference and sensitivity limitations must be overcome to realize wearable respiratory monitoring applications for CO sensors. In this work, an ultra-compact CO sensor was developed by integrating a microelectromechanical system emitter and thermopile detectors with an optical gas chamber; the power consumption of the light source and ambient temperature of the thermally sensitive devices were reduced by heat transfer control; the time to reach stabilization of the sensor was shortened; the humidity resistance of the sensor was improved by a dual-channel design; the light loss of the sensor was compensated by improving the optical coupling efficiency, which was combined with the amplitude trimming network to equivalently improve the sensitivity of the sensor. The minimum size of the developed sensor was 12 mm × 6 mm × 4 mm, and the reading error was <4% of the reading from -20 °C to 50 °C. The minimum power consumption of the sensor was ~33 mW, and the response time and recovery time were 10 s (@1 Hz), and the sensor had good humidity resistance, stability, and repeatability. These results indicate that the CO sensor developed using this strategy has great potential for wearable respiratory monitoring applications.
呼气中一氧化碳（CO）浓度能够直接反映人体生理状况，其检测在危重症患者的治疗与康复中具有重要意义。由于内部CO传感器的限制，现有的呼吸气体分析仪体积大、功耗高，无法实现可穿戴以跟踪活动人群。要实现用于CO传感器的可穿戴呼吸监测应用，必须克服内部和外部干扰以及灵敏度限制。在这项工作中，通过将微机电系统发射器和热电堆探测器与光学气室集成，开发了一种超紧凑型CO传感器；通过热传递控制降低了光源的功耗和热敏器件的环境温度；缩短了传感器达到稳定的时间；通过双通道设计提高了传感器的耐湿性；通过提高光耦合效率补偿了传感器的光损失，并结合幅度微调网络等效地提高了传感器的灵敏度。所开发传感器的最小尺寸为12 mm × 6 mm × 4 mm，在-20 °C至50 °C范围内读数误差小于读数的4%。传感器的最小功耗约为33 mW，响应时间和恢复时间为10 s（@1 Hz），并且该传感器具有良好的耐湿性、稳定性和重复性。这些结果表明，采用该策略开发的CO传感器在可穿戴呼吸监测应用方面具有巨大潜力。
