Comparison between red, green and blue light reflection photoplethysmography for heart rate monitoring during motion

Abstract

Abstract-Reflection photoplethysmography (PPG) using 530 nm (green) wavelength light has the potential to be a superior method for monitoring heart rate (HR) during normal daily life due to its relative freedom from artifacts. However, little is known about the accuracy of pulse rate (PR) measured by 530 nm light PPG during motion. Therefore, we compared the HR measured by electrocadiography (ECG) as a reference with PR measured by 530, 645 (red), and 470 nm (blue) wavelength light PPG during baseline and while performing hand waving in 12 participants. In addition, we examined the change of signal-to-noise ratio (SNR) by motion for each of the three wavelengths used for the PPG. The results showed that the limit of agreement in Bland-Altman plots between the HR measured by ECG and PR measured by 530 nm light PPG (±0.61 bpm) was smaller than that achieved when using 645 and 470 nm light PPG (±3.20 bpm and ±2.23 bpm, respectively). The ΔSNR (the difference between baseline and task values) of 530 and 470nm light PPG was significantly smaller than ΔSNR for red light PPG. In conclusion, 530 nm light PPG could be a more suitable method than 645 and 470nm light PPG for monitoring HR in normal daily life. I. INTRODUCTIONPhotoplethysmography (PPG) is a popular optical technology for the monitoring heart rate (HR) in normal daily life due to its simplicity and convenience, in its simplest form only requiring the attachment of a light emitting diode (LED) and a photodetector (PD) [1,2]. However, the reliability of PPG signals measured during normal daily life can be reduced by motion artifacts [3,4]. Thus, various techniques for the Jihyoung Lee is with Graduate

Photoplethysmography Revisited: From Contact to Noncontact, From Point to Imaging

“…Therefore, red and near IR light are typically utilized as light sources in PPG sensors (for a review, see [18]). Recently, green-wavelength PPG devices are becoming increasingly popular for their large intensity variations in modulation that are observed during the cardiac cycle [19]–[21]. Compared to red/IR light, green LED has much greater absorptivity for both oxyhemoglobin and deoxyhaemoglobin [22], thus resulting in a better signal-to-noise ratio (SNR).…”

“…Compared to red/IR light, green LED has much greater absorptivity for both oxyhemoglobin and deoxyhaemoglobin [22], thus resulting in a better signal-to-noise ratio (SNR). Several studies have compared the performance of IR and green light PPG and found that the green light achieved higher accuracy of pulse rate detection than did the IR light [20], [21]. …”

“…In June 2015, using the keywords “Photoplethysmography/photoplethysmographic & camera”, we found 51 relevant studies in the Web of Science™ database. The main part of this topic review was based on 69 IPPG-related studies [9], [21], [37], [59], [60], [62]–[125]. A summary of several recent representative IPPG studies is presented in Table II.…”

Wearable heart rate monitor using photoplethysmography for motion

“…This PPG system was designed using APDS-9007 low powered light photo sensor that received reflectance light sourced from green light at user's finger. Green led produced 530 nm wavelength turn to be most suitable wavelength to react with blood melanin inside microvascular bed of tissue which provides better waveform [7].…”

“…Blood volume inside the microvascular bed tissue changes according to the time heart pump blood to the whole body which also known as a heart beat. This process makes PPG signal connected to any changes in human cardiovascular system [6,7].…”