Kwon Junhwan, Kwon Oyun, Oh Kyeong Taek, Kim Jeongmin, Yoo Sun K
Department of Medical EngineeringYonsei University College of Medicine Seoul 03722 South Korea.
Department of Anesthesiology and Pain MedicineSeverance HospitalCollege of Medicine Seoul 03722 South Korea.
IEEE J Transl Eng Health Med. 2023 Jul 17;11:505-514. doi: 10.1109/JTEHM.2023.3295775. eCollection 2023.
Breathing can be measured in a non-contact method using a thermal camera. The objective of this study investigates non-contact breathing measurements using thermal cameras, which have previously been limited to measuring the nostril only from the front where it is clearly visible. The previous method is challenging to use for other angles and frontal views, where the nostril is not well-represented. In this paper, we defined a new region called the breathing-associated-facial-region (BAFR) that reflects the physiological characteristics of breathing, and extract breathing signals from views of 45 and 90 degrees, including the frontal view where the nostril is not clearly visible. Experiments were conducted on fifteen healthy subjects in different views, including frontal with and without nostril, 45-degree, and 90-degree views. A thermal camera (A655sc model, FLIR systems) was used for non-contact measurement, and biopac (MP150, Biopac-systems-Inc) was used as a chest breathing reference. The results showed that the proposed algorithm could extract stable breathing signals at various angles and views, achieving an average breathing cycle accuracy of 90.9% when applied compared to 65.6% without proposed algorithm. The average correlation value increases from 0.587 to 0.885. The proposed algorithm can be monitored in a variety of environments and extract the BAFR at diverse angles and views.
呼吸可以通过热成像仪以非接触方式进行测量。本研究的目的是调查使用热成像仪进行非接触式呼吸测量，此前这种方法仅限于从鼻孔清晰可见的正面进行测量。之前的方法在其他角度和正面视图中使用具有挑战性，因为在这些视图中鼻孔的呈现效果不佳。在本文中，我们定义了一个名为呼吸相关面部区域（BAFR）的新区域，该区域反映了呼吸的生理特征，并从45度和90度视角（包括鼻孔不清晰可见的正面视角）提取呼吸信号。对15名健康受试者在不同视角下进行了实验，包括有鼻孔和无鼻孔的正面、45度和90度视角。使用热成像仪（A655sc型号，FLIR系统）进行非接触测量，并使用生物信号采集仪（MP150，Biopac系统公司）作为胸部呼吸参考。结果表明，所提出的算法能够在各种角度和视图下提取稳定的呼吸信号，应用该算法时平均呼吸周期准确率达到90.9%，而未使用该算法时为65.6%。平均相关值从0.587增加到0.885。所提出的算法可以在各种环境中进行监测，并在不同角度和视图下提取BAFR。
