Presentation Information
[22a-C402-7]Flexible organic photoplethysmography sensors based on large-area organic photodiodes for long-term pulse wave monitoring
〇(M2)SHUYANG GUO1, Sunghoon Lee1, Tomoyuki Yokota1, Takao Someya1 (1.The Univ. of Tokyo)
Keywords:
orgainic photodiode,photoplethysmography sensors,pulse wave
This research developed a photoplethysmogram (PPG) sensor suitable for long-term monitoring. The PPG sensor consists of an organic light-emitting diode (OLED) and an organic photodiode (OPD). OPDs offer flexibility and allow for the fabrication of OPDs with larger areas and different configurations. PPG sensors are sensitive to monitoring conditions, and even slight changes in position can lead to measurement failure, presenting a challenge for long-term monitoring.
In this study, we focus on designing a large-area OPD to fabricate a flexible PPG sensor suitable for long-term monitoring of PPG signal. The OPD of size 2×12 mm2 was successfully designed. The dark current at -2 V is increased only 2.78 times compared to the 2×2 mm2 OPD. The large-area OPD can capture signals over a wider range, enhancing the sensor's ability to collect human signals and reducing the likelihood of measurement failure due to changes in position. Red OLED is used to consist of the PPG sensor. Compared to 2×2 mm2 OPDs, when using the designed PPG sensor on the wrist, the range of areas where the signal can be successfully measured has been increased from 40% to 100%. Additionally, large-area OPDs exhibit stronger light absorption, under the condition of obtaining a signal with an amplitude of about 3 mV, the intensity of the required light source decreases from 20 mA to 10 mA. This is beneficial in reducing power consumption. Furthermore, structural optimization of the PPG sensor is conducted by investigating the effect of the distance between the OPD and the OLED on the signal-to-noise ratio.
In this study, we focus on designing a large-area OPD to fabricate a flexible PPG sensor suitable for long-term monitoring of PPG signal. The OPD of size 2×12 mm2 was successfully designed. The dark current at -2 V is increased only 2.78 times compared to the 2×2 mm2 OPD. The large-area OPD can capture signals over a wider range, enhancing the sensor's ability to collect human signals and reducing the likelihood of measurement failure due to changes in position. Red OLED is used to consist of the PPG sensor. Compared to 2×2 mm2 OPDs, when using the designed PPG sensor on the wrist, the range of areas where the signal can be successfully measured has been increased from 40% to 100%. Additionally, large-area OPDs exhibit stronger light absorption, under the condition of obtaining a signal with an amplitude of about 3 mV, the intensity of the required light source decreases from 20 mA to 10 mA. This is beneficial in reducing power consumption. Furthermore, structural optimization of the PPG sensor is conducted by investigating the effect of the distance between the OPD and the OLED on the signal-to-noise ratio.