Cai Fuhong, Wang Dan, Zhu Min, He Sailing
Department of Electrical Engineering, Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, China.
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
Biomed Opt Express. 2017 Nov 8;8(12):5427-5436. doi: 10.1364/BOE.8.005427. eCollection 2017 Dec 1.
Spectrally-resolved imaging techniques are becoming central to the investigation of bio-samples. In this paper, we demonstrate the use of a WIFI-camera as a detection module to assemble a pencil-like imaging spectrometer, which weighs only 140 g and has a size of 3.1 cm in diameter and 15.5 cm in length. The spectrometer is standalone, and works wirelessly. A smartphone or network computer can serve as the data receiver and processor. The wavelength resolution of the spectrometer is about 17 nm, providing repeatable measurements of spatial two-dimensional images at various wavelengths for various bio-samples, including bananas, meat, and human hands. The detected spectral range is 400 nm - 675 nm and a white LED array lamp is selected as the light source. Based on the detected spectra, we can monitor the impacts of chlorophyll, myoglobin, and hemoglobin on bananas, pork, and human hands, respectively. For human hand scanning, a 3D spectral image data cube, which exhibits excellent signal to background noise ratio, can be obtained within 16 sec. We envisage that the adaptation of imaging spectrometer devices to the widely-accepted smartphone technology will help to carry out on-site studies in various applications. Besides, our pencil-like imaging spectrometer is cost-effective (<$300) and easy to assemble. This portable imaging spectrometer can facilitate the collection of large amounts of spectral image data. With the help of machine learning, we can realize object recognition based on spectral classification in the future.
光谱分辨成像技术正成为生物样本研究的核心。在本文中，我们展示了使用一台WIFI相机作为检测模块来组装一支铅笔状成像光谱仪，该光谱仪仅重140克，直径3.1厘米，长度15.5厘米。该光谱仪是独立的，并且无线工作。智能手机或网络计算机可作为数据接收器和处理器。该光谱仪的波长分辨率约为17纳米，可为包括香蕉、肉类和人手在内的各种生物样本在不同波长下提供空间二维图像的可重复测量。检测光谱范围为400纳米至675纳米，并选择白色LED阵列灯作为光源。基于检测到的光谱，我们可以分别监测叶绿素、肌红蛋白和血红蛋白对香蕉、猪肉和人手的影响。对于人手扫描，可在16秒内获得一个三维光谱图像数据立方体，其具有出色的信背比。我们设想，将成像光谱仪设备与广泛接受的智能手机技术相结合，将有助于在各种应用中开展现场研究。此外，我们的铅笔状成像光谱仪性价比高（<300美元）且易于组装。这种便携式成像光谱仪可便于收集大量光谱图像数据。借助机器学习，我们未来可以实现基于光谱分类的目标识别。
