PMID- 38430568
OWN - NLM
STAT- MEDLINE
DCOM- 20240321
LR  - 20240321
IS  - 1361-6579 (Electronic)
IS  - 0967-3334 (Linking)
VI  - 45
IP  - 3
DP  - 2024 Mar 20
TI  - Remote photoplethysmography based on reflected light angle estimation.
LID - 10.1088/1361-6579/ad2f5d [doi]
AB  - Objective. In previous studies, the factors affecting the accuracy of imaging 
      photoplethysmography (iPPG) heart rate (HR) measurement have been focused on the 
      light intensity, facial reflection angle, and motion artifacts. However, the 
      factor of specularly reflected light has not been studied in detail. We explored 
      the effect of specularly reflected light on the accuracy of HR estimation and 
      proposed an estimation method for the direction of specularly radiated 
      light.Approach. To study the HR measurement accuracy influenced by specularly 
      reflected light, we control the component of specularly reflected light by 
      controlling its angle. A total of 100 videos from four different reflected light 
      angles were collected, and 25 subjects participated in the dataset collection. We 
      extracted angles and illuminations for 71 facial regions, fitting sample points 
      through interpolation, and selecting the angle corresponding to the maximum 
      weight in the fitted curve as the estimated reflected angle.Main results. The 
      experimental results show that higher specularly reflected light compromises HR 
      estimation accuracy under the same value of light intensity. Notably, at a 60 degrees  
      angle, the HR accuracy (ACC) increased by 0.7%, while the signal-to-noise ratio 
      and Pearson correlation coefficient increased by 0.8 dB and 0.035, respectively, 
      compared to 0 degrees . The overall root mean squared error, standard deviation, and mean 
      error of our proposed reflected light angle estimation method on the illumination 
      multi-angle incidence (IMAI) dataset are 1.173 degrees , 0.978 degrees , and 0.773 degrees . The average 
      Pearson value is 0.8 in the PURE rotation dataset. In addition, the average ACC 
      of HR measurements in the PURE dataset is improved by 1.73% in our method 
      compared to the state-of-the-art traditional methods.Significance. Our method has 
      great potential for clinical applications, especially in bright light 
      environments such as during surgery, to improve accuracy and monitor blood volume 
      changes in blood vessels.
CI  - (c) 2024 Institute of Physics and Engineering in Medicine.
FAU - Fan, Xuanhe
AU  - Fan X
AUID- ORCID: 0009-0000-6400-9109
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
FAU - Liu, Fangwu
AU  - Liu F
AD  - Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 
      People's Republic of China.
FAU - Zhang, Jinjin
AU  - Zhang J
AUID- ORCID: 0009-0007-9418-4523
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
FAU - Gao, Tong
AU  - Gao T
AUID- ORCID: 0009-0009-6286-2283
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
FAU - Fan, Ziyang
AU  - Fan Z
AUID- ORCID: 0009-0003-7373-7441
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
FAU - Huang, Zhijie
AU  - Huang Z
AUID- ORCID: 0009-0006-0826-810X
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
FAU - Xue, Wei
AU  - Xue W
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
FAU - Zhang, JingJing
AU  - Zhang J
AUID- ORCID: 0000-0003-0408-374X
AD  - China University of Geosciences, Wuhan, China, School of Automation, Hubei Key 
      Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 
      People's Republic of China.
LA  - eng
PT  - Journal Article
DEP - 20240320
PL  - England
TA  - Physiol Meas
JT  - Physiological measurement
JID - 9306921
SB  - IM
MH  - Humans
MH  - Heart Rate/physiology
MH  - *Signal Processing, Computer-Assisted
MH  - *Photoplethysmography/methods
MH  - Rotation
MH  - Artifacts
MH  - Algorithms
OTO - NOTNLM
OT  - angle estimation
OT  - reflected light
OT  - remote heart rate measurement
OT  - remote photoplethysmography
OT  - uneven illumination
EDAT- 2024/03/03 08:42
MHDA- 2024/03/21 12:43
CRDT- 2024/03/02 17:33
PHST- 2023/08/08 00:00 [received]
PHST- 2024/03/01 00:00 [accepted]
PHST- 2024/03/21 12:43 [medline]
PHST- 2024/03/03 08:42 [pubmed]
PHST- 2024/03/02 17:33 [entrez]
AID - 10.1088/1361-6579/ad2f5d [doi]
PST - epublish
SO  - Physiol Meas. 2024 Mar 20;45(3). doi: 10.1088/1361-6579/ad2f5d.