191:
252:, and forehead. PPG can also be configured for multi-site photoplethysmography (MPPG), e.g. by making simultaneous measurements from the right and left ear lobes, index fingers and great toes, and offering further opportunities for the assessment of patients with suspected peripheral arterial disease, autonomic dysfunction, endothelial dysfunction, and arterial stiffness. MPPG also offers significant potential for data mining, e.g. using deep learning, as well as a range of other innovative pulse wave analysis techniques.
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425:. The results are comparable to blood pulse monitored by plethysmography during an occlusion-reperfusion experiment. A major advantage of this system is that no physical contact with the studied tissue surface area is required. The two major limitations of this approach are (i) the off-axis interferometric configuration that reduces the available spatial bandwidth of the
475:. In particular, laser Doppler holography of the eye fundus, the choroid constitutes the predominant contribution to the high frequency laser Doppler signal. It is however possible to circumvent its influence by subtracting the spatially averaged baseline signal, and achieve high temporal resolution and full-field imaging capability of pulsatile blood flow.
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the heart pumps blood to the periphery. Even though this pressure pulse is somewhat damped by the time it reaches the skin, it is enough to distend the arteries and arterioles in the subcutaneous tissue. If the pulse oximeter is attached without compressing the skin, a pressure pulse can also be seen
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of digital holograms reconstructed from digitized interferograms acquired at rates beyond ~1000 frames per second reveals surface waves on the hand. This method is an efficient way of performing digital holography from on-axis interferograms, which alleviates both the spatial bandwidth reduction of
387:
While photoplethysmography commonly requires some form of contact with the human skin (e.g., ear, finger), remote photoplethysmography allows physiological processes such as blood flow to be determined without skin contact. This is achieved by using face video to analyze subtle momentary changes in
324:
Respiration affects the cardiac cycle by varying the intrapleural pressure, the pressure between the thoracic wall and the lungs. Since the heart resides in the thoracic cavity between the lungs, the partial pressure of inhaling and exhaling greatly influence the pressure on the vena cava and the
352:
Anesthesiologists must often judge subjectively whether a patient is sufficiently anesthetized for surgery. As seen in the figure, if a patient is not sufficiently anesthetized, the sympathetic nervous system response to an incision can generate an immediate response in the amplitude of the PPG.
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Because the skin is so richly perfused, it is relatively easy to detect the pulsatile component of the cardiac cycle. The DC component of the signal is attributable to the bulk absorption of the skin tissue, while the AC component is directly attributable to variation in blood volume in the skin
361:
Shamir, Eidelman, et al. studied the interaction between inspiration and removal of 10% of a patient’s blood volume for blood banking before surgery. They found that blood loss could be detected both from the photoplethysmogram from a pulse oximeter and an arterial catheter. Patients showed a
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During inspiration, intrapleural pressure decreases by up to 4 mm Hg, which distends the right atrium, allowing for faster filling from the vena cava, increasing ventricular preload, but decreasing stroke volume. Conversely during expiration, the heart is compressed, decreasing cardiac
210:(LED) and then measuring the amount of light either transmitted or reflected to a photodiode. Each cardiac cycle appears as a peak, as seen in the figure. Because blood flow to the skin can be modulated by multiple other physiological systems, the PPG can also be used to monitor breathing,
248:, etc., blood flow to the periphery can be reduced, resulting in a PPG without a discernible cardiac pulse. In this case, a PPG can be obtained from a pulse oximeter on the head, with the most common sites being the ear,
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provides a contactless alternative to conventional photoplethysmography. For instance, it can be used to monitor the heart rate of newborn babies, or analyzed with deep neural networks to quantify stress levels.
851:
McKay ND, Griffiths B, Di Maria C, Hedley S, Murray A, Allen J (October 2014). "Novel photoplethysmography cardiovascular assessments in patients with
Raynaud's phenomenon and systemic sclerosis: a pilot study".
421:, which is sensitive to the phase of light waves, and hence can reveal sub-micron out-of-plane motion. In particular, wide-field imaging of pulsatile motion induced by blood flow can be measured on the thumb by
320:(Nipride), a peripheral vasodilator, on the finger PPG of a sedated subject. As expected, the PPG amplitude increases after infusion, and additionally, the Respiratory Induced Variation (RIV) becomes enhanced.
288:
The height of AC component of the photoplethysmogram is proportional to the pulse pressure, the difference between the systolic and diastolic pressure in the arteries. As seen in the figure showing
214:, and other circulatory conditions. Additionally, the shape of the PPG waveform differs from subject to subject, and varies with the location and manner in which the pulse oximeter is attached.
217:
Although PPG sensors are in common use in a number of commercial and clinical applications, the exact mechanisms determining the shape of the PPG waveform are not yet fully understood.
1173:
Davies HJ, Bachtiger P, Williams I, Molyneaux PL, Peters NS, Mandic DP (July 2022). "Wearable In-Ear PPG: Detailed
Respiratory Variations Enable Classification of COPD".
812:"A prospective comparison of bilateral photoplethysmography versus the ankle-brachial pressure index for detecting and quantifying lower limb peripheral arterial disease"
756:"Investigation of photoplethysmography and arterial blood oxygen saturation from the ear-canal and the finger under conditions of artificially induced hypothermia"
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efficiency and increasing stroke volume. When the frequency and depth of respiration increases, the venous return increases, leading to increased cardiac output.
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and measures changes in light absorption. A conventional pulse oximeter monitors the perfusion of blood to the dermis and subcutaneous tissue of the skin.
1347:
Rouast PV, Adam MT, Chiong R, Cornforth D, Lux E (2018). "Remote heart rate measurement using low-cost RGB face video: A technical literature review".
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Puyo L, Bellonnet-Mottet L, Martin A, Te F, Paques M, Atlan M (2020). "Real-time digital holography of the retina by principal component analysis".
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the off-axis configuration and the filtering of physiological signals. A higher spatial bandwidth is crucial for larger image field of view.
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laser
Doppler imaging of pulse waves on the surface of the hand by holographic photoplethysmography from on-axis digital interferometry.
597:
Shelley K, Shelley S, Lake C (2001). "Pulse
Oximeter Waveform: Photoelectric Plethysmography". In Lake C, Hines R, Blitt C (eds.).
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decrease in the cardiac pulse amplitude caused by reduced cardiac preload during exhalation when the heart is being compressed.
889:"Quantifying the correlation between photoplethysmography and laser Doppler flowmetry microvascular low-frequency oscillations"
72:
778:
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1408:
Bencteux J, Pagnoux P, Kostas T, Bayat S, Atlan M (June 2015). "Holographic laser
Doppler imaging of pulsatile blood flow".
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that can be used to detect blood volume changes in the microvascular bed of tissue. A PPG is often obtained by using a
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Effects of an incision on a subject under general anesthesia on the photoplethysmograph (PPG) and blood pressure (BP).
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Motion artifacts are often a limiting factor preventing accurate readings during exercise and free living conditions.
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119:
86:
146:
Representative PPG taken from an ear pulse oximeter. Variation in amplitude are from
Respiratory Induced Variation.
241:. The PPG can be obtained from transmissive absorption (as at the finger tip) or reflection (as on the forehead).
68:
57:
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reportedly provided clearance to a photoplethysmography-based cuffless blood pressure monitor in August 2019.
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Premature
Ventricular Contraction (PVC) can be seen in the PPG just as in the EKG and the Blood Pressure (BP).
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The change in volume caused by the pressure pulse is detected by illuminating the skin with the light from a
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the subject's skin color which are not detectable to the human eye. Such camera-based measurement of blood
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from the photoplethysmogram, as well as more detailed respiratory measurements such as inspiratory time.
763:
2015 37th Annual
International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
534:
Allen J (March 2007). "Photoplethysmography and its application in clinical physiological measurement".
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In outpatient settings, pulse oximeters are commonly worn on the finger. However, in cases of shock,
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301:
152:
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Charlton PH, Birrenkott DA, Bonnici T, Pimentel MA, Johnson AE, Alastruey J, et al. (2018).
614:
2007 29th Annual
International Conference of the IEEE Engineering in Medicine and Biology Society
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46:
93:
1077:"What is the best site for measuring the effect of ventilation on the pulse oximeter waveform?"
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Pelaez EA, Villegas ER (2007). "LED power reduction trade-offs for ambulatory pulse oximetry".
233:, the PPG signal they record is rarely displayed and is nominally only processed to determine
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456:
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1427:
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1028:"Photoplethysmography: beyond the calculation of arterial oxygen saturation and heart rate"
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pulsatile waves on the back of a frog measured by off-axis holographic photoplethysmography
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1126:"Breathing Rate Estimation From the Electrocardiogram and Photoplethysmogram: A Review"
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Charlton PH, Kyriaco PA, Mant J, Marozas V, Chowienczyk P, Alastruey J (March 2022).
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Shelley KH, Jablonka DH, Awad AA, Stout RG, Rezkanna H, Silverman DG (August 2006).
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292:(PVCs), the PPG pulse for the cardiac cycle with the PVC results in lower amplitude
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Proceedings of the IEEE. Institute of
Electrical and Electronics Engineers
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1228:"Pulse oximetry plethysmographic waveform during changes in blood volume"
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211:
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Shamir M, Eidelman LA, Floman Y, Kaplan L, Pizov R (February 1999).
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949:"AI-enabled remote and objective quantification of stress at scale"
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Photoplethysmography: Technology, Signal Analysis and Applications
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405:
Photoplethysmography of the thumb by off-axis digital holography.
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Mizeva I, Di Maria C, Frick P, Podtaev S, Allen J (March 2015).
810:
Allen J, Overbeck K, Nath AF, Murray A, Stansby G (April 2008).
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1490:
Puyo L, Paques M, Fink M, Sahel JA, Atlan M (September 2018).
988:
Alian AA, Shelley KH (December 2014). "Photoplethysmography".
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Al-Jebrni AH, Chwyl B, Wang XY, Wong A, Saab BJ (2020-05-01).
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A refinement of holographic photoplethysmography, holographic
707:"Wearable Photoplethysmography for Cardiovascular Monitoring"
663:"Utility of the photoplethysmogram in circulatory monitoring"
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Reisner A, Shaltis PA, McCombie D, Asada HH (May 2008).
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Verkruysse W, Svaasand LO, Nelson JS (December 2008).
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Best Practice & Research. Clinical Anaesthesiology
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141:
1292:"Remote plethysmographic imaging using ambient light"
1269:"FDA Okays Biobeat's Cuffless Blood Pressure Monitor"
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Remote photoplethysmography can also be performed by
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356:
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437:) analysis that filters-off physiological signals.
285:caused by the pressure pulse of the cardiac cycle.
203:from the venous plexus, as a small secondary peak.
60:. Unsourced material may be challenged and removed.
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280:Venous pulsations can clearly be seen in this PPG.
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1496:laser Doppler holography of the human retina"
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1175:IEEE Transactions on Bio-Medical Engineering
1016:
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1384:Example of contactless monitoring in action
601:. W.B. Saunders Company. pp. 420–428.
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510:Pulse oximetry § Derived measurements
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120:Learn how and when to remove this message
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953:Biomedical Signal Processing and Control
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332:Much research has focused on estimating
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264:Monitoring heart rate and cardiac cycle
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1130:IEEE Reviews in Biomedical Engineering
765:. Vol. 2015. pp. 7954–7957.
616:. Vol. 2007. pp. 2296–2299.
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58:adding citations to reliable sources
29:
27:Chart of tissue blood volume changes
582:Kyriacou PA, Allen J, eds. (2021).
24:
1094:10.1213/01.ane.0000222477.67637.17
1045:10.1213/01.ane.0000269512.82836.c9
290:premature ventricular contractions
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357:Monitoring hypo- and hypervolemia
1397:from the original on 2021-12-11.
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1087:(2): 372–7, table of contents.
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754:Budidha K, Kyriacou PA (2015).
45:needs additional citations for
1232:British Journal of Anaesthesia
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340:Monitoring depth of anesthesia
13:
1:
1349:Frontiers of Computer Science
1267:Wendling P (28 August 2019).
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325:filling of the right atrium.
1410:Journal of Biomedical Optics
1026:Shelley KH (December 2007).
893:Journal of Biomedical Optics
680:10.1097/ALN.0b013e31816c89e1
485:Clitoral photoplethysmograph
449:Principal component analysis
431:short-time Fourier transform
7:
866:10.1093/rheumatology/keu196
816:Journal of Vascular Surgery
515:Vaginal photoplethysmograph
478:
378:Remote photoplethysmography
175:) is an optically obtained
10:
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966:10.1016/j.bspc.2020.101929
723:10.1109/JPROC.2022.3149785
622:10.1109/IEMBS.2007.4352784
548:10.1088/0967-3334/28/3/R01
435:discrete Fourier transform
1500:Biomedical Optics Express
1440:10.1117/1.JBO.20.6.066006
1361:10.1007/s11704-016-6243-6
1187:10.1109/TBME.2022.3145688
1142:10.1109/RBME.2017.2763681
1002:10.1016/j.bpa.2014.08.006
914:10.1117/1.JBO.20.3.037007
829:10.1016/j.jvs.2007.11.057
771:10.1109/EMBC.2015.7320237
536:Physiological Measurement
366:Monitoring blood pressure
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1081:Anesthesia and Analgesia
1032:Anesthesia and Analgesia
302:ventricular fibrillation
298:Ventricular tachycardia
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221:Sites for measuring PPG
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429:, and (ii) the use of
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308:Monitoring respiration
304:can also be detected.
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183:which illuminates the
500:Laser Doppler imaging
457:laser Doppler imaging
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194:Finger pulse oximeter
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1522:10.1364/BOE.9.004113
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1245:10.1093/bja/82.2.178
1038:(6 Suppl): S31–S36.
383:Conventional imaging
318:sodium nitroprusside
208:light-emitting diode
135:Photoplethysmography
69:"Photoplethysmogram"
54:improve this article
1570:Vascular procedures
1432:2015JBO....20f6006B
1308:2008OExpr..1621434V
1302:(26): 21434–21445.
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599:Clinical Monitoring
18:Photoplethysmograph
1565:Medical monitoring
490:Heart rate monitor
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423:digital holography
419:digital holography
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229:are commonly used
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860:(10): 1855–1863.
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235:blood oxygenation
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