Doubling the Signal Quality of Smartphone Camera Pulse Oximetry Using the Display Screen as a Controllable Selective Light Source.
Doubling the Signal Quality of Smartphone Camera Pulse Oximetry Using the Display Screen as a Controllable Selective Light Source.
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DOI：
10.1109/embc.2018.8513286
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发表时间：
2018-07-01
期刊：
影响因子：
--
通讯作者：
Ofek, Eyal
中科院分区：
文献类型：
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作者：
Holz, Christian;Ofek, Eyal
最近的智能手机有可能使用其强大的传感器和实时处理测量结果的能力将摄像头血氧仪带给每个人，通过随时随地的血氧仪监测，有可能改善人们的生活。智能手机上的相机血氧测定的挑战是氧合血红蛋白和脱氧血红蛋白的反射之间的低对比度。在本文中，我们表明，这是使用相机闪光灯照明的结果，它均匀地照亮整个波段，从而导致反射的对比度降低。相反，我们建议使用前置摄像头捕获脉搏，并使用手机的显示屏（红色、绿色和蓝色波段的选择性光源）进行照明。我们评估的手机显示器的光谱特性，使用分光辐射计在一个受控的实验中，卷积它们与手机的相机的灵敏度曲线，并表明，屏幕的窄带显示照明增加了所需波段的反射之间的对比度的一个因素相比，闪光灯照明。我们的初步评估进一步支持了我们的方法和发现。
Recent smartphones have the potential to bring camera oximetry to everyone using their powerful sensors and the capability to process measurements in real-time, potentially augmenting people's lives through always-available oximetry monitoring everywhere. The challenge of camera oximetry on smartphones is the low contrast between reflections from oxyhemoglobin and deoxyhemoglobin. In this paper, we show that this is the result of using the camera flash for illumination, which illuminates evenly across bands than thus leads to the diminished contrast in reflections. Instead, we propose capturing pulse using the front-facing camera and illuminating with the phone's display, a selective illuminant in the red, green, and blue band. We evaluate the spectral characteristics of the phone display using a spectroradiometer in a controlled experiment, convolve them with the sensitivity curves of the phone's camera, and show that the screen's narrow-band display illumination increases the contrast between the reflections in the desired bands by a factor of two compared to flash illumination. Our preliminary evaluation showed further support for our approach and findings.