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Photoplethysmography

Photoplethysmography is a non-invasive optical technique used to detect volumetric changes in blood in peripheral tissues.
It measures the variations in light absorption, which are related to changes in the blood volume.
This technique has a wide range of applications in medical and physiological monitoring, including the assessment of cardiovascular function, respiratory rate, and blood oxygen saturation.
Photoplethysmography provides a simple and cost-effective way to obtain information about the cardiovascular system and can be used in both clinical and research settings.
The descrition of this techinque may be found in the literature, preprints, and patents.

Most cited protocols related to «Photoplethysmography»

1
Comparative Analysis of Blood Pressure Measurement Methods
Several BP measurement methods are now available. The main methods include catheterization, auscultation, oscillometry, volume clamping, and tonometry.
Catheterization is the gold standard method [6 (link)]. This method measures instantaneous BP by placing a strain gauge in fluid contact with blood at any arterial site (e.g., radial artery, aorta). However, the method is invasive.
Auscultation, oscillometry, and volume clamping are noninvasive methods. These methods employ an inflatable cuff.
Auscultation is the standard clinical method [7 (link)]. This method measures systolic and diastolic BP by occluding an artery with a cuff and detecting the Korotkoff sounds using a stethoscope and manometer during cuff deflation. The first sound indicates the initiation of turbulent flow and thus systolic BP, while the fifth sound is silent and indicates the renewal of laminar flow and thus diastolic BP.
Oscillometry is the most popular non-invasive, automatic method [8 (link), 9 (link)]. This method measures mean, diastolic, and systolic BP by also using a cuff but with a pressure sensor inside it. The measured cuff pressure not only rises and falls with cuff inflation and deflation but also shows tiny oscillations indicating the pulsatile blood volume in the artery. The amplitude of these oscillations varies with the applied cuff pressure, as the arterial elasticity is nonlinear. The BP values are estimated from the varying oscillation amplitudes using the empirical fixed-ratios principle. When evaluated against auscultation using an Association for the Advancement of Medical Instrumentation (AAMI) protocol, some oscillometric devices achieve BP errors within the AAMI limits of 5 mmHg bias and 8 mmHg precision [10 ]. However, oscillometry is unreliable in subjects with certain conditions such as atrial fibrillation, stiff arteries, and pre-eclampsia [11 ].
Volume clamping is a non-invasive, automatic method used in research [12 (link), 13 ]. This method measures instantaneous (finger) BP by using a cuff and a photoplethysmography (PPG) sensor to measure the blood volume (see Section V.A). The blood volume at zero transmural pressure is estimated via oscillometry. The cuff pressure is then continually varied to maintain this blood volume throughout the cardiac cycle via a fast servo-control system. The applied cuff pressure may thus equal BP. Volume clamping devices also achieve BP errors within AAMI limits when evaluated against auscultation and near AAMI limits when evaluated against radial artery catheterization [14 (link)].
However, cuff use has several drawbacks. In particular, cuffs are cumbersome and time consuming to use, disruptive during ambulatory monitoring, especially while sleeping, and do not readily extend to low resources settings.
Tonometry is another non-invasive method used in research that, in theory, does not require an inflatable cuff [15 , 16 ]. This method measures instantaneous BP by pressing a manometer-tipped probe on an artery. The probe must flatten or applanate the artery so that its wall tension is perpendicular to the probe. However, manual and automatic applanation have proven difficult. As a result, in practice, the measured waveform has been routinely calibrated with cuff BP whenever a BP change is anticipated [17 (link)].
In sum, the existing BP measurement methods are invasive, manual, or require a cuff. So, none are suitable for ubiquitous (i.e., ultra-convenient, unobtrusive, and low cost) monitoring.
Mukkamala R., Hahn J.O., Inan O.T., Mestha L.K., Kim C.S., Töreyin H, & Kyal S. (2015). Towards Ubiquitous Blood Pressure Monitoring via Pulse Transit Time: Theory and Practice. IEEE transactions on bio-medical engineering, 62(8), 1879-1901.
Publication 2015
Aorta Arteries Arteries, Radial Atrial Fibrillation Auscultation BLOOD Blood Pressure Blood Volume Cardiac Volume Catheterization Clinical Protocols Diastole Elasticity Fingers Gold Manometry Medical Devices Oscillometry Photoplethysmography Pre-Eclampsia Pressure Pressure, Diastolic Sound Stethoscopes Strains Systole Systolic Pressure Tonometry
2
Cuffless Continuous Blood Pressure Monitoring
Somnotouch-NIBP (Somnomedics GmbH, Randersacker, Germany) is an ambulatory cuffless device for continuous (beat-to-beat), noninvasive BP monitoring. The system consists of a finger photoplethysmograph (providing additional oxygen saturation measurement) and three ECG leads, connected to a watch-like control unit placed at the wrist level and equipped with a screen where beat-to-beat pulse waveform, ECG, and PTT changes are displayed. The principle of BP estimation is based on the beat-to-beat determination of PTT, calculated as the interval between R-wave on ECG and the arrival of the corresponding pulse wave (determined from finger photoplethysmography signal) at the peripheral site. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels are calculated on the basis of the relationship between BP levels and PTT, where the increase in BP increases arterial wall tension, thus increasing its stiffness. Consequently, pulse wave propagation velocity increases, leading to a reduction in PTT. A nonlinear model describing this relationship and based on experimental data has been published 4 (link). Combining this model with a single initial BP measurement (performed using the traditional technique at the level of the brachial artery) used for device calibration allows to derive beat-to-beat BP values corresponding to changing PTT.
Bilo G., Zorzi C., Ochoa Munera J.E., Torlasco C., Giuli V, & Parati G. (2015). Validation of the Somnotouch-NIBP noninvasive continuous blood pressure monitor according to the European Society of Hypertension International Protocol revision 2010. Blood Pressure Monitoring, 20(5), 291-294.
Publication 2015
Brachial Artery Fingers Medical Devices Oximetry Photoplethysmography Pressure, Diastolic Pulse Rate Systolic Pressure Wrist
3
Multi-Echo fMRI Resting-State Protocol

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Publication 2011
Acceleration ECHO protocol Electricity Eye Hair Head Human Body Photoplethysmography Pulse Rate Radionuclide Imaging Respiration Respiratory Rate Transmission, Communicable Disease
4
Empatica E4 Wristband Sensor Evaluation
The Empatica E4 wristband contains four sensors: (1) an electrode for Electrodermal activity (EDA), (2) 3-axis accelerometer, (3) a temperature sensor, and (4) a photoplethysmography (PPG) to measure blood volume pulse (BVP) from which it derives HR and the inter beat interval (IBI) ([29 ]; see Fig. 1). Using the Empatica Manager, data were uploaded to Empatica Connect and raw CSV data were downloaded and analyzed using Kubios HRV 3.0 [30 (link)]. Kubios offers five artefact correction options based on very low to very high thresholds. We compared Empatica E4 recordings with all five Kubios artefact correction levels to the VU-AMS recordings and without any Kubios artefact correction. Recordings without post-hoc artefact correction showed the highest correlation, so no Kubios artefact correction was used for the analyses. This is not surprising, since the Empatica E4 already uses an algorithm that removes wrong IBIs [31 ].

Block diagram for the Empatica E4 wristband. Note. BVP = blood volume pulse, EDA = electrodermal activity, HF = high frequency, HR = heart rate, IBI = inter beat interval, LF = low frequency, LF/HF = ratio between low and high frequency, RMSSD = root mean squared differences of successive difference of intervals, SDNN = standard deviation of the normal to normal interval

Schuurmans A.A., de Looff P., Nijhof K.S., Rosada C., Scholte R.H., Popma A, & Otten R. (2020). Validity of the Empatica E4 Wristband to Measure Heart Rate Variability (HRV) Parameters: a Comparison to Electrocardiography (ECG). Journal of Medical Systems, 44(11), 190.
Publication 2020
3-acetonylidene-2-oxindole Blood Volume Photoplethysmography Plant Roots Pulse Rate Rate, Heart
5
Reflective PPG Wearable for Continuous Blood Pressure Monitoring
The BB-613WP is a wrist-worn or skin attached device indicated for use in measuring and displaying functional oxygen saturation of arterial hemoglobin (%SpO2) and pulse rate using photoplethysmography (PPG) technology. Most commercially available devices transmit light in specific red (~ 650 nm) and infrared (~ 880 nm) wavelengths through the tested tissue, and a detector on the other side absorbs the transmitted light. These wavelengths have a unique absorbance pattern upon interaction with oxy- and deoxyhemoglobin. The detector measures the changing absorbance at each of the wavelengths allowing it to determine the absorbance resulting from the pulsating arterial blood alone excluding venous blood, skin, bone, muscle, and fat. The BB-613WP uses a unique reflective PPG technology, where, unlike most devices, the light source (Light Emitting Diodes, LEDs) and sensor array are placed on the same side (backside) of the device. As the LEDs transmit light into the subject’s skin, part of this light is reflected from the tissue and is detected by a photodiode detector. The high temporal and quantitative resolution of the device allows it to capture minute changes in tissue reflectance, calculating numerous vital signs derived from pulse contours, including advanced hemodynamic parameters such as tracking changes in blood pressure. This is based on Pulse Wave Transit Time (PWTT) which is obtained utilizing pulse measurements from the integrated SpO2 sensor, following a calibration process using an oscillometric blood pressure monitor. Once a calibration measurement is taken using the cuff-based BP device, the values are entered into a user’s application. The calibration is valid for three months, after which a new calibration measurement should be taken and introduced into the application using the same method.
The results are displayed on the LCD screen of the wristwatch device as well as on the mobile application installed on the user’s smartphone. From there, the data is transmitted in real-time to a web application used by health care providers.
Nachman D., Gepner Y., Goldstein N., Kabakov E., Ishay A.B., Littman R., Azmon Y., Jaffe E, & Eisenkraft A. (2020). Comparing blood pressure measurements between a photoplethysmography-based and a standard cuff-based manometry device. Scientific Reports, 10, 16116.
Publication 2020
Arteries BLOOD Blood Pressure Bones Continuous Sphygmomanometers deoxyhemoglobin Enzyme Multiplied Immunoassay Technique Hemodynamics Hemoglobin Medical Devices Muscle Tissue Oscillometry Oximetry Oxygen Oxygen Saturation Photoplethysmography Pulse Rate Saturation of Peripheral Oxygen Signs, Vital Skin Tissues Veins Wrist

Most recents protocols related to «Photoplethysmography»

1
Wearable Monitoring of Sleep, Stress, and Cardiac Function
Participants wore a photoplethysmography WHOOP wristband67 (link) for the whole study period (Week 1 through Week 7) to assess changes in sleep hours and sleep-derived HRV. WHOOP algorithms have been validated as having a 95% sensitivity for sleep, 68% sensitivity for deep sleep and 70% for REM sleep68 (link). Participants were instructed to wear the waterproof wristband as much as possible and especially during sleep.
Saliva samples for cortisol awakening response were collected only for younger adults to reduce participant burden for older adults. We instructed younger participants to collect saliva samples using oral swabs both upon awakening and 30 min later. Saliva was collected in the morning on Week 2 and 7 and brought to the lab in a thermos with ice packs. Samples were stored at −20 °C until they were sent to Salimetrics (CA, USA) for cortisol assays.
During Weeks 2 and 7 visits, we obtained resting heart rate data by having participants sit in a chair for five minutes. Using HeartMath emWave Pro software and its infrared pulse plethysmograph (PPG) ear sensor, the heartbeat was sampled at 370 Hz and its inter-beat interval data was recorded after removing artifacts. The data for each participant was analyzed with Kubios HRV Premium Version 3.1 to obtain a mean heart rate and root mean squared successive difference.
Min J., Rouanet J., Martini A.C., Nashiro K., Yoo H.J., Porat S., Cho C., Wan J., Cole S.W., Head E., Nation D.A., Thayer J.F, & Mather M. (2023). Modulating heart rate oscillation affects plasma amyloid beta and tau levels in younger and older adults. Scientific Reports, 13, 3967.
Publication 2023
Aged Biological Assay Hydrocortisone Hypersensitivity Photoplethysmography Plant Roots Plethysmography Pulse Rate Rate, Heart Saliva Sleep Sleep, Slow-Wave Young Adult Youth
2
Measurement of Toe Blood Pressure
Participants rested in a supine position for at least 10 min prior to measurements, and their toes were heated to a temperature above 27 °C using heating overlays prior to testing. Systolic blood pressures were measured in the brachial arteries, and the highest systolic blood pressure measured identified the reference arm (Omron M6® AC, Omron Healthcare Co., Ltd., Kyoto, Japan). The brachial pressure was thereafter measured in the reference arm simultaneously with the measurements of the toe blood pressure. Toe blood pressures were measured with an automated photoplethysmography device (SysToe®, Atys Medical, Soucieu-en-Jarrest, France) [14 (link)]. Toe pressures were measured consecutively and for each hallux. The measurements of toe pressures were performed until obtaining a difference of 10 mmHg or less between the measured values with a maximum of five measurements of toe pressure for each hallux.
Jørgensen L.R., Hegtmann C.L., Straszek S.P., Høyer C., Polcwiartek C., Petersen L.J., Dalgaard M.K., Jensen S.E, & Nielsen R.E. (2023). Peripheral artery disease in patients with schizophrenia as compared to controls. BMC Cardiovascular Disorders, 23, 126.
Publication 2023
Brachial Artery Determination, Blood Pressure Hallux Medical Devices Photoplethysmography Pressure Systolic Pressure
3
Measuring Heart Rate Variability Using Wearables
The assessment of heart rate in rest and HRV will be performed by the Polar H10 chest strap and by photoplethysmography (PPG) with the validated mobile app of HRV4training [50 (link), 66 ]. The participants will remain in the supine position for 8 min to obtain 5 min of a stable signal. After removal of artifacts, by employing the Kubios® clinical software the temporal variables of standard deviation time domains of all RR intervals (SDNN), rMSSD, Average of all NN intervals (AVNN) and percentage of differences between adjacent NN intervals that are greater than 50 ms (pNN50) will be calculated [67 (link)]. Moreover, by also utilizing Kubios software the frequency measurements of low frequency (LF, 0.04–0.15 Hz), high frequency (HF, 0.15–0.4 Hz) and the LF/HF ratio will be obtained [67 (link)]. The HRV4Training app directly calculates the HRV outcomes.
On the other hand, daily heart rate variability (HRV) is measured using the HRV4Training application, a validated mobile application [50 (link), 66 ] that allows HRV values to be obtained by PPG (rMSSD, LF, HF, SDNN, SDNN, AVNN, pNN50 heart rate and recovery points). The morning measurement will be performed every day, in the supine decubitus position upon awakening, for 1 min. During the basal week before starting the intervention, participants will measure their HRV, to establish the reference values for each participant of the GHRV group. In the intervention weeks, the participants will measure their HRV every morning, therefore, collecting morning HRV data (rMSSD, heart rate and recovery points). The value that will be taken into consideration to establish the GHRV training intensity will be the rMSSD as it represents the parasympathetic activation of the central nervous system. The detailed information of its utilization to exercise prescription is explained in the exercise program intervention part. To eliminate the placebo effect of the use of the application, the participants of the three physical exercise groups will perform this protocol. In this way, the HRV data of all the participants will be collected to analyze their evolution with the different interventions. To reduce measurement error, the application functioning is explained to all participants, mentioned to repeat the measurement if a message saying that the sign was not optimal or poor the need to repeat it. Moreover, the exercise professional will check the quality of the sign before its analysis.
Lavín-Pérez A.M., Collado-Mateo D., Hinojo González C., de Juan Ferré A., Ruisánchez Villar C., Mayo X, & Jiménez A. (2023). High-intensity exercise prescription guided by heart rate variability in breast cancer patients: a study protocol for a randomized controlled trial. BMC Sports Science, Medicine and Rehabilitation, 15, 28.
Publication 2023
Biological Evolution Central Nervous System Chest Photoplethysmography Rate, Heart
4
Heart Rate Variability-Guided Exercise Intensity
Although all participants will daily measure their HRV, only in this intervention group each day's results will influence their exercise intensity. From the outcomes reported with smartphone photoplethysmography, explained the measurement process in the outcomes part, the root means squared differences of successive RR intervals (rMSSD) will be chosen as a reflection of vagal activity to prescribe the workout intensity [50 (link)]. In this regard, the natural logarithm of rMSSD will be calculated to make parametric statistical comparisons assuming a normal distribution. For establishing the training intensity and load, a 7-day rolling average measure (LrRMSSD7day-roll-avg) will be utilized. Subsequently, the scoring obtained will be contrasted in the smallest worthwhile change (SWC) to analyze if the daily result is inside SWC upper and lower limits, calculated as LnrMSSD reference week mean ± 0.5 × SD [51 (link), 52 (link)]. The reference week of the first 4 training weeks will take the limits created in the baseline week, and in the rest of the program, an updated measure will be carried out every 4 weeks with the SWC for the past 4 weeks, because of the influence of exercise in participants cardiac autonomic modulation [53 (link)].
In this regard, when the daily LnrMSSD fell inside the limits created by the SWC patients will perform high-intensity training characterized by a cardiovascular intensity from 80 to 95% of their reserve HR (increasing a 5% every four weeks) and a weighting load from 70 to 85% of their RM (increasing the load 5% ever mesocycle, four weeks). Whereas if any day patients’ scoring fell out of the SWC, they will train at the same intensity as the PEG (Fig. 2).

Intensity progression and intensity decision making process for the high-intensity exercise guide by HRV group

Lavín-Pérez A.M., Collado-Mateo D., Hinojo González C., de Juan Ferré A., Ruisánchez Villar C., Mayo X, & Jiménez A. (2023). High-intensity exercise prescription guided by heart rate variability in breast cancer patients: a study protocol for a randomized controlled trial. BMC Sports Science, Medicine and Rehabilitation, 15, 28.
Publication 2023
Cardiovascular System Disease Progression Heart Nervous System, Autonomic Patients Photoplethysmography Plant Roots Pneumogastric Nerve Reflex
5
Contactless Vital Signs Monitoring in Primary Care
The Home-based Healthcare Project, underway since August 2018, is a telemedicine feasibility project funded by the European Regional Development Fund and the Free State of Saxony (grant number: 100278533). The overarching project goal is the development of an innovative system to be used in primary care as a means of monitoring in chronic disease patients with elevated cardiovascular risks (e.g., heart failure). This innovative system is based on a new generation of medical technology, namely a camera-based contactless measuring technology. This project focuses on the feasibility and evaluation of the measuring technology.
The core technical component is imaging photoplethysmography (iPPG), which has been undergoing development since 2012 at the Institute for Biomedical Engineering, as well as at other locations [16 –19 ]. It enables the measurement of cardiovascular signals such as heart rate and respiration rate, as well as the estimation of oxygen saturation and blood pressure, with the cameras in standard tablets or smartphones [20 (link)].
In one extensive work package of the Home-based Healthcare Project, the use of this camera-based contactless measuring technology was investigated by an evaluation study in the ambulant primary care setting. This entailed a) the development of an appropriate measuring station, b) the application of extant algorithms to extract the vital parameters from the camera data, and c) the evaluation of the contactlessly measured vital parameters.
The acceptance survey focused on the further development of this measuring technology into a TMA and was conducted as part of the evaluation study using the participating study patients.
This project, including the evaluation study and acceptance survey, was reviewed by the Ethics Commission at the Technische Universität Dresden and approved (reference number: EK 412092019). All participants received written study informations and were informed about the study verbally by their primary care physician. All participants gave their written informed consent. The study was carried out in accordance with the Declaration of Helsinki.
Borchers P., Pfisterer D., Scherpf M., Voigt K, & Bergmann A. (2023). Needs- and user-oriented development of contactless camera-based telemonitoring in heart disease–Results of an acceptance survey from the Home-based Healthcare Project (feasibility project). PLOS ONE, 18(3), e0282527.
Publication 2023
Blood Pressure Cardiovascular System Congestive Heart Failure Disease, Chronic Europeans Oxygen Saturation Patients Photoplethysmography Primary Care Physicians Primary Health Care Rate, Heart Respiratory Rate Technology Assessment Telemedicine

Top products related to «Photoplethysmography»

1
Finometer by Finapres Medical Systems
Sourced in Netherlands, United States
The Finometer is a non-invasive cardiovascular monitoring device produced by Finapres Medical Systems. It continuously measures beat-to-beat blood pressure and related cardiovascular parameters using the volume-clamp method.
2
Finometer pro by Finapres Medical Systems
Sourced in Netherlands
The Finometer Pro is a non-invasive, continuous hemodynamic monitoring device. It measures beat-to-beat blood pressure and related cardiovascular parameters. The system uses the vascular unloading technique to provide real-time data on blood pressure and other physiological measurements.
3
Pulsetrace pca2 by BD
Sourced in United States
The PulseTrace PCA2 is a lab equipment product manufactured by BD. It is a pulse oximeter device used to measure and monitor a person's oxygen saturation levels and pulse rate.
4
Finometer midi by Finapres Medical Systems
Sourced in Netherlands
The Finometer MIDI is a non-invasive hemodynamic monitoring device designed for laboratory use. It provides continuous, beat-by-beat measurements of blood pressure and other cardiovascular parameters. The device uses the Finapres method, which relies on the volume-clamp principle, to estimate arterial blood pressure waveforms.
5
Mp150 by Biopac
Sourced in United States, Canada, United Kingdom, Germany
The MP150 is a data acquisition system designed for recording physiological signals. It offers high-resolution data capture and features multiple input channels to accommodate a variety of sensor types. The MP150 is capable of acquiring and analyzing data from various biological and physical measurements.
6
Ml206 by ADInstruments
Sourced in United States, United Kingdom
The ML206 is a high-performance data acquisition module designed for laboratory applications. It features multiple analog input channels, digital input/output channels, and signal conditioning capabilities to support a wide range of sensor and transducer measurements. The ML206 is a compact and versatile device suitable for a variety of data logging and analysis tasks.
7
Portapres by Finapres Medical Systems
Sourced in Netherlands
Portapres is a noninvasive, wearable device designed for continuous blood pressure monitoring. It is capable of measuring beat-to-beat blood pressure and related cardiovascular parameters. The Portapres device uses the volume-clamp method to obtain these measurements.
8
Powerlab by ADInstruments
Sourced in Australia, United States, United Kingdom, New Zealand, Germany, Japan, Spain, Italy, China
PowerLab is a data acquisition system designed for recording and analyzing physiological signals. It provides a platform for connecting various sensors and transducers to a computer, allowing researchers and clinicians to capture and analyze biological data.
9
Physiological monitoring unit by Siemens
The Physiological Monitoring Unit is a laboratory equipment designed to measure and record various physiological parameters of an individual. It is capable of monitoring vital signs such as heart rate, respiration rate, and blood pressure. The device is intended for use in controlled research and clinical settings to gather data for analysis and evaluation.
10
Bp 2000 blood pressure analysis system by Visitech
Sourced in United States, United Kingdom, Cameroon
The BP-2000 Blood Pressure Analysis System is a laboratory equipment device designed to measure and analyze blood pressure. It provides accurate and reliable readings of systolic and diastolic blood pressure, as well as heart rate.

More about "Photoplethysmography"

Photoplethysmography (PPG) is a non-invasive optical technique used to detect volumetric changes in blood in peripheral tissues.
It measures the variations in light absorption, which are related to changes in the blood volume.
This technique has a wide range of applications in medical and physiological monitoring, including the assessment of cardiovascular function, respiratory rate, and blood oxygen saturation.
PPG provides a simple and cost-effective way to obtain information about the cardiovascular system and can be used in both clinical and research settings.
Photoplethysmography can be used with various devices, such as the Finometer, Finometer Pro, PulseTrace PCA2, Finometer MIDI, MP150, ML206, Portapres, PowerLab, Physiological Monitoring Unit, and BP-2000 Blood Pressure Analysis System.
These devices utilize PPG to measure parameters like blood pressure, heart rate, and blood oxygen levels, which are crucial for monitoring cardiovascular health.
The PPG signal is generated by the changes in the volume of blood in the tissue, which is influenced by the cardiac cycle.
The technique is based on the principle that the absorption of light by the tissue varies with the changes in blood volume.
By analyzing the PPG signal, researchers and clinicians can gain insights into the cardiovascular system, respiratory function, and other physiological processes.
The use of PPG in medical and research settings has grown significantly due to its non-invasive nature, ease of use, and cost-effectiveness.
Researchers can leverage the power of data-driven decision making by utilizing AI-driven platforms like PubCompare.ai to optimize their PPG studies, locate the best protocols from literature, preprints, and patents, and improve the reproducibility and accuracy of their findings.