ArticleScientific reports2017
Video capillaroscopy clarifies mechanism of the photoplethysmographic waveform appearance.
Article in Scientific reports, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 26 papers, 1 of them a synthesis that pooled it.
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
26 citing papers in PubMed, 1 synthesis or guideline pooled it, 61 citations in OpenAlex.
- Noninvasive hemoglobin sensing and imaging: optical tools for disease diagnosis.Journal of biomedical optics · 2022Pooled it
- Differential sensitivity of impedance plethysmography and photoplethysmography sensors to temperature-induced peripheral vasoconstriction.Scientific reports · 2026Article
- Development of a Rotation-Robust PPG Sensor for a Smart Ring.Sensors (Basel, Switzerland) · 2025Article
- Panoramic Nailfold Flow Velocity Measurement Method Based on Enhanced Plasma Gap Information.Journal of imaging informatics in medicine · 2025Article
- Enhancing the quantification of post-occlusive reactive hyperemia: a multimodal optical approach.Pflugers Archiv : European journal of physiology · 2025Article
- Revisiting the Venoarteriolar Reflex-Further Insights from Upper Limb Dependency in Healthy Subjects.Biology · 2024Article
- Red Blood Cells' Area Deformation as the Origin of the Photoplethysmography Signal.Sensors (Basel, Switzerland) · 2023Article
- Miniaturized microscope for non-invasive imaging of leukocyte-endothelial interaction in human microcirculation.Scientific reports · 2023Article
- On the development of low power wearable devices for assessment of physiological vital parameters: a systematic review.Zeitschrift fur Gesundheitswissenschaften = Journal of public health · 2023Review
- Multispectral imaging of nailfold capillaries using light-emitting diode illumination.Journal of biomedical optics · 2022Article
- Assessing pulse transit time to the skeletal muscle microcirculation using near-infrared spectroscopy.Journal of applied physiology (Bethesda, Md. : 1985) · 2022Article
- Comparative study of photoplethysmographic waveforms with application of antihypertensive medication in hypertensive patients.Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc · 2022Article
- Rational selection of RGB channels for disease classification based on IPPG technology.Biomedical optics express · 2022Article
- Pulse Oximetry: The Working Principle, Signal Formation, and Applications.Advances in experimental medicine and biology · 2022Article
- Remote Photoplethysmography for Evaluation of Cutaneous Sensory Nerve Fiber Function.Sensors (Basel, Switzerland) · 2021Article
- Laser Doppler Spectrum Analysis Based on Calculation of Cumulative Sums Detects Changes in Skin Capillary Blood Flow in Type 2 Diabetes Melitus.Diagnostics (Basel, Switzerland) · 2021Article
- Blood Vessel Imaging at Pre-Larval Stages of Zebrafish Embryonic Development.Diagnostics (Basel, Switzerland) · 2020Article
- Association of remote imaging photoplethysmography and cutaneous perfusion in volunteers.Scientific reports · 2020Article
- Visualization of skin capillaries with moving red blood cells in arbitrary area of the body.Biomedical optics express · 2019Article
- Contactless monitoring of the blood-flow changes in upper limbs.Biomedical optics express · 2018Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Photoplethysmography (PPG) devices are widely used in clinical practice but the origin of PPG signal is still under debating. The classical theory assumes that the PPG waveform stems from variations of blood volume in pulsating arteries. In this research we analysed high-speed video recordings of capillaries in a fingernail bed. It was found that speed of erythrocytes in capillaries has pronounced modulation in time, which follows variations of instantaneous blood pressure in arteries. However, the mean speed significantly differs even for neighbour capillaries whereas change of the speed occurs in phase for the most of capillaries. Moreover, the light intensity remitted from the papillary dermis is also modulated at the heartbeat frequency displaying significant correlation with waveforms of the RBC speed. Obtained results can hardly be explained by the classical theory of PPG signal formation. Shallow penetrating visible light acquires modulation of erythrocytes density in the capillary bed without interacting with deeper situated pulsating arteries. Therefore, the capillary bed could serve as a distributed sensor for monitor the status of deep vessels. Better understanding of the photoplethysmography basis will result in a wider range of applications of this fast growing technology in both medical and research practice.
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.