Comparison of Visible and Infrared Video Plethysmography Captured from Different Regions of the Human Face
Comparison of Visible and Infrared Video Plethysmography Captured from Different Regions of the Human Face
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DOI：
10.1109/embc44109.2020.9176138
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发表时间：
2020-07
期刊：
影响因子：
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通讯作者：
N. Sugita;Tomoya Matsuzaki;M. Yoshizawa;K. Ichiji;Shunsuke Yamaki;N. Homma
中科院分区：
文献类型：
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作者：
N. Sugita;Tomoya Matsuzaki;M. Yoshizawa;K. Ichiji;Shunsuke Yamaki;N. Homma
最近，视频体积描记术(VPG)--一种使用摄像机估计心率的技术--得到了极大的关注。对VPG的大多数研究都使用了可见的RGB相机；只进行了有限数量的研究，研究了即使在黑暗环境中也可以使用的近红外光(波长750-2500 nm)。本研究的目的是研究用可见光(VPGVIS)和近红外光(VPGNIR)从面部四个部位(前额、右脸颊、左脸颊和鼻子)收集的VPG数据的差异。通过对人脸进行近红外和可见光交替照射，同时获得VPGVIS和VPGNIR。实验结果表明，用VPGNIR估计的心率均方根误差比用VPGVIS估计的心率的均方根误差高1次/分。然而，与我们的预期相反，VPGNIR中包含的心跳相关成分的功率并没有降低，尽管在近红外光区的吸光度是可见光范围的1/100。这一结果支持了VPG波产生的主要因素是血管压迫皮下组织和静脉床引起的光学性质改变的假说。此外，当鼻子被设置为ROI时，使用VPG估计心率的准确性往往较高。这一结果可能与鼻子的解剖结构有关。
Recently, video plethysmography (VPG) – a heart rate estimation technique using a video camera – has gained significant attention. Most studies of VPG have used a visible RGB camera; only a limited number of studies investigating near-infrared light (wavelength 750–2500 nm), which can be used even in a dark environment, have been performed. The purpose of this study was to investigate the differences between VPG data collected using visible light (VPGVIS) or near-infrared light (VPGNIR) from four facial areas (forehead, right cheek, left cheek, and nose). An experiment was conducted to obtain both VPGVIS and VPGNIR simultaneously by alternately irradiating the face with NIR and VIS lights. Experimental results showed that the root mean squared error of heart rate estimated using VPGNIR was 1 bpm higher than that of VPGVIS. However, contrary to our expectations, the power of the heartbeat-related component included in VPGNIR was not reduced despite the absorbance of hemoglobin in the NIR light range being 1/100 of that in the VIS light range. This result supports the hypothesis that a main factor in the generation of VPG waves was change in the optical properties caused by blood vessels compressing the subcutaneous tissue and the venous bed. Additionally, the accuracy of the heart rate estimation using VPG tended to be high when the nose was set as the ROI. This result was likely associated with the anatomical structure of the nose.