ArticlePloS one2014
iPhone 4s photoplethysmography: which light color yields the most accurate heart rate and normalized pulse volume using the iPhysioMeter Application in the presence of motion artifact?
Article in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
22 citing papers in PubMed.
- Smartphone-based Assessment of Vasomotor Function via Fingertip Arteriolar Elasticity Using the Volume-Oscillometric Method with Green Light Photoplethysmography.Annals of biomedical engineering · 2026Article
- A comprehensive review of heart rate measurement using remote photoplethysmography and deep learning.Biomedical engineering online · 2025Review
- Arteriolar Elasticity Measurement in the Fingertip Based on Photoplethysmographic Volume-Oscillometry: A New Approach to the Assessment of Vasomotor Functions in the Microvasculature.Cardiovascular engineering and technology · 2025Article
- Raw Photoplethysmography as an Enhancement for Research-Grade Wearable Activity Monitors.JMIR mHealth and uHealth · 2024Article
- Validity of resting heart rate derived from contact-based smartphone photoplethysmography compared with electrocardiography: a scoping review and checklist for optimal acquisition and reporting.Frontiers in digital health · 2024Article
- Feasibility Study of Remote Contactless Perfusion Imaging with Consumer-Grade Mobile Camera.Advances in experimental medicine and biology · 2022Article
- Blue as an Underrated Alternative to Green: Photoplethysmographic Heartbeat Intervals Estimation under Two Temperature Conditions.Sensors (Basel, Switzerland) · 2021Article
- Cuffless blood pressure estimation based on haemodynamic principles: progress towards mobile healthcare.PeerJ · 2021Article
- Smartphone-assisted experimentation as a didactic strategy to maintain practical lessons in remote education: alternatives for physiology education during the COVID-19 pandemic.Advances in physiology education · 2020Article
- MW-PPG Sensor: An on-Chip Spectrometer Approach.Sensors (Basel, Switzerland) · 2019Article
- Smartphone Sensors for Health Monitoring and Diagnosis.Sensors (Basel, Switzerland) · 2019Review
- Reviewing Mobile Apps to Control Heart Rate in Literature and Virtual Stores.Journal of medical systems · 2019Review
- Motion Artifact Reduction for Wrist-Worn Photoplethysmograph Sensors Based on Different Wavelengths.Sensors (Basel, Switzerland) · 2019Article
- Current progress of photoplethysmography and SPOBiomedical engineering letters · 2019Review
- Cuffless blood pressure estimation using only a smartphone.Scientific reports · 2018Article
- Analysis of a Pulse Rate Variability Measurement Using a Smartphone Camera.Journal of healthcare engineering · 2018Article
- Non-contact, synchronous dynamic measurement of respiratory rate and heart rate based on dual sensitive regions.Biomedical engineering online · 2017Article
- Photoplethysmography Revisited: From Contact to Noncontact, From Point to Imaging.IEEE transactions on bio-medical engineering · 2016Review
- Toward a Smartphone Application for Estimation of Pulse Transit Time.Sensors (Basel, Switzerland) · 2015Article
- A novel method based on two cameras for accurate estimation of arterial oxygen saturation.Biomedical engineering online · 2015Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Recent progress in information and communication technologies has made it possible to measure heart rate (HR) and normalized pulse volume (NPV), which are important physiological indices, using only a smartphone. This has been achieved with reflection mode photoplethysmography (PPG), by using a smartphone's embedded flash as a light source and the camera as a light sensor. Despite its widespread use, the method of PPG is susceptible to motion artifacts as physical displacements influence photon propagation phenomena and, thereby, the effective optical path length. Further, it is known that the wavelength of light used for PPG influences the photon penetration depth and we therefore hypothesized that influences of motion artifact could be wavelength-dependant. To test this hypothesis, we made measurements in 12 healthy volunteers of HR and NPV derived from reflection mode plethysmograms recorded simultaneously at three different spectral regions (red, green and blue) at the same physical location with a smartphone. We then assessed the accuracy of the HR and NPV measurements under the influence of motion artifacts. The analyses revealed that the accuracy of HR was acceptably high with all three wavelengths (all rs > 0.996, fixed biases: -0.12 to 0.10 beats per minute, proportional biases: r = -0.29 to 0.03), but that of NPV was the best with green light (r = 0.791, fixed biases: -0.01 arbitrary units, proportional bias: r = 0.11). Moreover, the signal-to-noise ratio obtained with green and blue light PPG was higher than that of red light PPG. These findings suggest that green is the most suitable color for measuring HR and NPV from the reflection mode photoplethysmogram under motion artifact conditions. We conclude that the use of green light PPG could be of particular benefit in ambulatory monitoring where motion artifacts are a significant issue.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.