Leier Mairo, Pilt Kristjan, Karai Deniss, Jervan Gert
Annu Int Conf IEEE Eng Med Biol Soc. 2015;2015:1849-52. doi: 10.1109/EMBC.2015.7318741.
The aim of this paper is to propose a smart optical sensor for cardiovascular activity monitoring at different tissue layers. Photoplethysmography (PPG) is a noninvasive optical technique for monitoring mainly blood volume changes in the examined tissue. However, different important physiological parameters, such as oxygen saturation, heart and breathing rate, dynamics of skin micro-circulation, vasomotion activity etc., can be extracted from the registered PPG signal. The developed sensor consists of 32 light emitting sources with four different wavelengths, which are located to the four different distances from four photo detectors. Compared to the existing sensors, the system enables to select the optimal LED (light emitting diode) and photo detector couple in order to obtain the pulse wave signal from the interested blood vessels with the highest possible signal to noise ratio. In this study, the designed PPG sensor was tested for the pulse wave registration from radial artery. The highest efficiency and signal to noise ratio was achieved using infrared LED (940 nm) and photo-diode pair.
本文的目的是提出一种用于监测不同组织层心血管活动的智能光学传感器。光电容积脉搏波描记法（PPG）是一种主要用于监测被检查组织中血容量变化的非侵入性光学技术。然而，诸如血氧饱和度、心率和呼吸频率、皮肤微循环动力学、血管舒缩活动等不同的重要生理参数，可以从记录的PPG信号中提取出来。所开发的传感器由32个具有四种不同波长的发光源组成，这些发光源与四个光电探测器的距离各不相同。与现有传感器相比，该系统能够选择最佳的发光二极管（LED）和光电探测器组合，以便从感兴趣的血管中获得具有尽可能高信噪比的脉搏波信号。在本研究中，对设计的PPG传感器进行了从桡动脉记录脉搏波的测试。使用红外发光二极管（940 nm）和光电二极管对实现了最高的效率和信噪比。
