Type

Journal Article

Authors

Charles Markham
Tomas Ward
Kenneth Humphreys

Subjects

Engineering

Topics
wavelength heart rate photoplethysmography pulse oximetry environmental conditions electronic engineering complementary metal oxide semiconductor calibration procedure

Noncontact simultaneous dual wavelength photoplethysmography: a further step toward noncontact pulse oximetry (2007)

Abstract We present a camera-based device capable of capturing two photoplethysmographic (PPG) signals at two different wavelengths simultaneously, in a remote noncontact manner. The system comprises a complementary metal-oxide semiconductor camera and dual wavelength array of light emitting diodes (760 and 880 nm). By alternately illuminating a region of tissue with each wavelength of light, and detecting the backscattered photons with the camera at a rate of 16 frames/wavelength s, two multiplexed PPG wave forms are simultaneously captured. This process is the basis of pulse oximetry, and we describe how, with the inclusion of a calibration procedure, this system could be used as a noncontact pulse oximeter to measure arterial oxygen saturation (S(p)O(2)) remotely. Results from an experiment on ten subjects, exhibiting normal S(p)O(2) readings, that demonstrate the instrument's ability to capture signals from a range of subjects under realistic lighting and environmental conditions are presented. We compare the signals captured by the noncontact system to a conventional PPG signal captured concurrently from a finger, and show by means of a J. Bland and D. Altman [Lancet 327, 307 (1986); Statistician 32, 307 (1983)] test, the noncontact device to be comparable to a contact device as a monitor of heart rate. We highlight some considerations that should be made when using camera-based "integrative" sampling methods and demonstrate through simulation, the suitability of the captured PPG signals for application of existing pulse oximetry calibration procedures.
Collections Ireland -> Maynooth University -> Subject = Science & Engineering: Electronic Engineering
Ireland -> Maynooth University -> Subject = Science & Engineering
Ireland -> Maynooth University -> Type = Article
Ireland -> Maynooth University -> Academic Unit = Faculty of Science and Engineering
Ireland -> Maynooth University -> Academic Unit = Faculty of Science and Engineering: Electronic Engineering
Ireland -> Maynooth University -> Status = Published
Ireland -> Maynooth University -> Open Access DRIVERset

Full list of authors on original publication

Charles Markham, Tomas Ward, Kenneth Humphreys

Experts in our system

1
Charles Markham
Maynooth University
Total Publications: 64
 
2
Tomas Ward
Maynooth University
Total Publications: 189