Reflection-type photoplethysmography (PPG) pulse sensors are widely used in consumer markets to measure cardiovascular signals. Different from off-chip package solutions in which the light-emitting diode (LED) and photodetector (PD) are in separate chips, a GaN integrated optoelectronic chip with a novel ring structure is proposed to realize a PPG pulse sensor. The integrated optoelectronic chip consists of two multiple-quantum well (MQW) diodes. For higher sensitivities, the central and peripheral MQW diodes are suitable as the LED and PD, respectively. The results indicate that the integrated optoelectronic chip based on a blue LED epitaxial wafer is more suitable for the integrated PPG sensor based on device performance. Moreover, the amplitude of the PPG pulse signal collected from fingertips is higher than that from a wrist. The feasibility of the reflection-type PPG pulse sensor based on a GaN integrated optoelectronic chip is fully verified with the advantages of smaller sizes and lower costs.

中文翻译：

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基于环形结构集成光电芯片的反射型光电容积脉搏传感器

反射型光电容积脉搏波 (PPG) 脉冲传感器广泛用于消费市场以测量心血管信号。与发光二极管（LED）和光电探测器（PD）在单独芯片中的片外封装解决方案不同，提出了一种具有新颖环形结构的GaN集成光电芯片来实现PPG脉冲传感器。集成光电芯片由两个多量子阱 (MQW) 二极管组成。对于更高的灵敏度，中央和外围 MQW 二极管分别适合作为 LED 和 PD。结果表明基于蓝光LED外延片的集成光电芯片更适合基于器件性能的集成PPG传感器。此外，从指尖采集的 PPG 脉冲信号的幅度高于从手腕采集的脉冲信号。