Yang Jiachen, Wang Bin, Fan Chaowei, Wang Lei
School of Electronic Information Engineering, Tianjin University, P.R. China.
Comput Methods Biomech Biomed Engin. 2011 Dec;14(12):1033-9. doi: 10.1080/10255842.2010.504923. Epub 2011 May 24.
Most of the current mainstream respiratory devices for monitoring CO(2) concentration use the two-end structure combined with both reference-end and main testing-end. In this paper, we design a new single-end mainstream device for monitoring the carbon dioxide concentration that is breathed out of the human body. In this single end design, only the main testing-end will be involved. The mechanism is based on the low-cost digital processing method of blind source separation, which is used to separate the signal and then extract the reference signal. Meanwhile, in order to decrease the negative influence of device noise and the low sample precision caused by temperature drift, two steps are taken: one is wavelet denoising and the other is temperature drift compensation. These two steps are proved valid by clinical trials, thus improving the accuracy of devices.
目前大多数用于监测二氧化碳浓度的主流呼吸设备采用参考端和主测试端相结合的两端结构。在本文中，我们设计了一种新型的单端主流设备，用于监测人体呼出的二氧化碳浓度。在这种单端设计中，只涉及主测试端。其原理基于低成本的盲源分离数字处理方法，用于分离信号并提取参考信号。同时，为了减少设备噪声和温度漂移引起的低采样精度的负面影响，采取了两个步骤：一是小波去噪，二是温度漂移补偿。这两个步骤经临床试验证明是有效的，从而提高了设备的准确性。
