Near-Infrared Spectral Study on Blood Oxygen Saturation in Multilayer Tissue
GAO Bo1，WEI Wei2，GONG Min1*，WANG Li2
1. School of Physical Science and Technology, Sichuan University, Sichuan Province Key Laboratory of Microelectronics, Chengdu 610064, China 2. Department of Anesthesiology and Critical Ill Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
Abstract：The technology of non-invasive near-infrared spectral detection of biological tissue blood oxygen saturation has great research and application prospects, and has widespread clinical applications. However, the conventional finger oximeter only reflects local oxygen saturation values, and has limitations in the application. These oxygenation readings become unreliable or cease, too. In the present paper, a new method is described that the reflectance pulse oximetry with variable incident light intensity is employed to measure biological multilayer tissue. The photoplethysmographic (PPG) signals significantly change with the change in the incident light intensity in the experiment on the fingertip. Further analysis shows that the changes of the PPG signals correspond to the multilayer structure of finger. It means that the blood oxygen saturation of different tissue level must be calculated from the PPG signals. These features show that this method must be feasible.
[1] Kurth C D, Steven J M, Swedlow D. Am. J. Anesthesiol., 1996, 23: 169. [2] ZHUANG Xin-liang, ZENG Yin-ming, CHEN Bo-luan(庄心良，曾因明，陈伯銮). Modern Anesthesiology(现代麻醉学). Beijing: People’s Medical Publishing House(北京：人民卫生出版社)，2003. [3] Wei Wei, Zhu Zhaoqiong, Liu Lunxu, et al. Anesth. Analog, 2005, 101: 440. [4] Kyriacou P A, Crerar-Gilber A, Langford R M, et al. Journal of Physics: Conference Series，2006, 45: 232. [5] Crerar-Gilbert A, Kyriacou P A, Jones D P, et al. Anaesthesia, 2002, 57：442. [6] ZHU Zhao-qiong, WEI Wei, XUE Fu-shan, et al(朱昭琼，魏 蔚，薛福善，等). Journal of Clinical Anesthesiology(临床麻醉学杂志)，2006，21(10)：670. [7] Webster J G. Design of Pulse Oximeters. Bristol: Institute of Physics Publishing, 1997. [8] Nijboer J A，Dorlas J C，Mahieu H F. Clin. Phys. Physiol. Meas., 1981, 2(3): 205. [9] Mannheimer P D, Casciani J R, Fein M E，et al. IEEE Trans. Biomed. Eng, 1997, 44：148. [10] Moyle J T B. Principles and Practice Series: Pulse Oximetry. London: BMJ Publishing Group, 1994. [11] Cormack G C，et al. The Arterial Anatomy of Skin Flaps. Churchill Livingstone, 1994. [12] Burr-Brown Corporation, DDC112 Hardware Guide, 2000. [13] Reuss James L. IEEE Transactions on Biomedical Engineering, 2005, 52(2)：153. [14] Haahr Rasmus G, Duun Sune，et al. Proceedings of the 29th Annual International Conference of the IEEE EMBS, 2007. 2350. [15] Dresher R P，Mendelson Y. IEEE Bioengineering Conference, 2006. 49.
