1
|
Kiselev AR, Posnenkova OM, Karavaev AS, Shvartz VA, Novikov MY, Gridnev VI. Frequency-Domain Features and Low-Frequency Synchronization of Photoplethysmographic Waveform Variability and Heart Rate Variability with Increasing Severity of Cardiovascular Diseases. Biomedicines 2024; 12:2088. [PMID: 39335601 PMCID: PMC11429429 DOI: 10.3390/biomedicines12092088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2024] [Revised: 09/05/2024] [Accepted: 09/09/2024] [Indexed: 09/30/2024] Open
Abstract
Objective-Heart rate variability (HRV) and photoplethysmographic waveform variability (PPGV) are available approaches for assessing the state of cardiovascular autonomic regulation. The goal of our study was to compare the frequency-domain features and low-frequency (LF) synchronization of the PPGV and HRV with increasing severity of cardiovascular diseases. Methods-Our study included 998 electrocardiogram (ECG) and finger photoplethysmogram (PPG) recordings from subjects, classified into five categories: 53 recordings from healthy subjects, aged 28.1 ± 6.2 years, 536 recordings from patients with hypertension (HTN), 49.0 ± 8.8 years old, 185 recordings from individuals with stable coronary artery disease (CAD) (63.9 ± 9.3 years old), 104 recordings from patients with myocardial infarction (MI) that occurred three months prior to the recordings (PMI) (65.1 ± 11.0 years old), and 120 recordings from study subjects with acute myocardial infarction (AMI) (64.7 ± 11.5 years old). Spectral analyses of the HRV and PPGV were carried out, along with an assessment of the synchronization strength between LF oscillations of the HRV and of PPGV (synchronization index). Results-Changes in all frequency-domain indices and the synchronization index were observed along the following gradient: healthy subjects → patients with HTN → patients with CAD → patients with PMI → patients with AMI. Similar frequency-domain indices of the PPGV and HRV show little relationship with each other. Conclusions-The frequency-domain indices of the PPGV are highly sensitive to the development of any cardiovascular disease and, therefore, are superior to the HRV indices in this regard. The S index is an independent parameter from the frequency-domain indices.
Collapse
Affiliation(s)
- Anton R Kiselev
- Coordinating Center for Fundamental Research, National Medical Research Center for Therapy and Preventive Medicine, 10 Petroverigsky Pereulok, Bld. 3, Moscow 101990, Russia
| | - Olga M Posnenkova
- Institute of Cardiology Research, Saratov State Medical University, Saratov 410012, Russia
| | - Anatoly S Karavaev
- Department of Dynamic Modeling and Biomedical Engineering, Saratov State University, Saratov 410012, Russia
| | - Vladimir A Shvartz
- Department of Surgical Treatment for Interactive Pathology, Bakulev National Medical Research Center for Cardiovascular Surgery, Moscow 121552, Russia
| | - Mikhail Yu Novikov
- Coordinating Center for Fundamental Research, National Medical Research Center for Therapy and Preventive Medicine, 10 Petroverigsky Pereulok, Bld. 3, Moscow 101990, Russia
| | - Vladimir I Gridnev
- Institute of Cardiology Research, Saratov State Medical University, Saratov 410012, Russia
| |
Collapse
|
2
|
Li K, Sun J. Understanding the physiological transmission mechanisms of photoplethysmography signals: a comprehensive review. Physiol Meas 2024; 45:08TR02. [PMID: 39106894 DOI: 10.1088/1361-6579/ad6be4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Accepted: 08/06/2024] [Indexed: 08/09/2024]
Abstract
Objective. The widespread adoption of Photoplethysmography (PPG) as a non-invasive method for detecting blood volume variations and deriving vital physiological parameters reflecting health status has surged, primarily due to its accessibility, cost-effectiveness, and non-intrusive nature. This has led to extensive research around this technique in both daily life and clinical applications. Interestingly, despite the existence of contradictory explanations of the underlying mechanism of PPG signals across various applications, a systematic investigation into this crucial matter has not been conducted thus far. This gap in understanding hinders the full exploitation of PPG technology and undermines its accuracy and reliability in numerous applications.Approach. Building upon a comprehensive review of the fundamental principles and technological advancements in PPG, this paper initially attributes the origin of PPG signals to a combination of physical and physiological transmission processes. Furthermore, three distinct models outlining the concerned physiological transmission processes are synthesized, with each model undergoing critical examination based on theoretical underpinnings, empirical evidence, and constraints.Significance. The ultimate objective is to form a fundamental framework for a better understanding of physiological transmission processes in PPG signal generation and to facilitate the development of more reliable technologies for detecting physiological signals.
Collapse
Affiliation(s)
- Kai Li
- School of Medical Imaging, Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences, Shanghai 201318, People's Republic of China
- School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China
| | - Jiuai Sun
- School of Medical Imaging, Jiading District Central Hospital Affiliated Shanghai University of Medicine and Health Sciences, Shanghai 201318, People's Republic of China
| |
Collapse
|
3
|
Kiselev AR, Mureeva EN, Skazkina VV, Panina OS, Karavaev AS, Chernenkov YV. Full-Term and Preterm Newborns Differ More Significantly in Photoplethysmographic Waveform Variability than Heart Rate Variability. Life (Basel) 2024; 14:675. [PMID: 38929659 PMCID: PMC11204696 DOI: 10.3390/life14060675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Features of cardiovascular autonomic regulation in infants are poorly studied compared with adults. However, the clinical significance of autonomic dysfunction in infants is very high. The goal of our research was to study the temporal and frequency-dependent features, as well as low-frequency synchronization in cardiovascular autonomic regulation in full-term vs. preterm newborns, based on the analysis of their heart rate variability (HRV) and photoplethysmographic waveform variability (PPGV). METHODS The study included three groups of newborns: 64 full-term newborns (with a gestational age at birth of 37-40 weeks) with a physiological course of the neonatal adaptation; 23 full-term newborns (with a gestational age at birth of 37-40 weeks) with a pathological course of the neonatal adaptation; and 17 preterm newborns (with a postconceptional age of 34 weeks or more). We conducted spectral analysis of HRV and PPGV, along with an assessment of the synchronization strength between low-frequency oscillations in HRV and in PPGV (synchronization index). We employed several options for the boundaries of the high-frequency (HF) band: 0.15-0.40 Hz, 0.2-2 Hz, 0.15-0.8 Hz, and 0.24-1.04 Hz. RESULTS Preterm newborns had higher heart rate, RMSSD, and PNN50 values relative to both groups of full-term newborns. Values of SDNN index and synchronization index (S index) were similar in all groups of newborns. Differences in frequency domain indices of HRV between groups of newborns depended on the considered options of HF band boundaries. Values of frequency domain indices of PPGV demonstrated similar differences between groups, regardless of the boundaries of considered options of HF bands and the location of PPG signal recording (forehead or leg). An increase in sympathetic influences on peripheral blood flow and a decrease in respiratory influences were observed along the following gradient: healthy full-term newborns → preterm newborns → full-term newborns with pathology. CONCLUSIONS Differences in frequency domain indices of autonomic regulation between the studied groups of newborns depended on the boundaries of the considered options of the HF band. Frequency domain indices of PPGV revealed significantly more pronounced differences between groups of newborns than analogous HRV indicators. An increase in sympathetic influences on peripheral blood flow and a decrease in respiratory influences were observed along the following gradient: healthy full-term newborns → preterm newborns → full-term newborns with pathology.
Collapse
Affiliation(s)
- Anton R. Kiselev
- Coordinating Center for Fundamental Research, National Medical Research Center for Therapy and Preventive Medicine, 101990 Moscow, Russia
| | - Elena N. Mureeva
- Department of Pediatrics and Neonatology, Saratov State Medical University, 410012 Saratov, Russia
| | - Viktoria V. Skazkina
- Department of Dynamic Modeling and Biomedical Engineering, Saratov State University, 410012 Saratov, Russia
| | - Olga S. Panina
- Department of Pediatrics and Neonatology, Saratov State Medical University, 410012 Saratov, Russia
| | - Anatoly S. Karavaev
- Department of Dynamic Modeling and Biomedical Engineering, Saratov State University, 410012 Saratov, Russia
| | - Yuri V. Chernenkov
- Department of Pediatrics and Neonatology, Saratov State Medical University, 410012 Saratov, Russia
| |
Collapse
|
4
|
Lambert Cause J, Solé Morillo Á, da Silva B, García-Naranjo JC, Stiens J. Evaluating Vascular Depth-Dependent Changes in Multi-Wavelength PPG Signals Due to Contact Force. SENSORS (BASEL, SWITZERLAND) 2024; 24:2692. [PMID: 38732798 PMCID: PMC11085639 DOI: 10.3390/s24092692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024]
Abstract
Photoplethysmography (PPG) is a non-invasive method used for cardiovascular monitoring, with multi-wavelength PPG (MW-PPG) enhancing its efficacy by using multiple wavelengths for improved assessment. This study explores how contact force (CF) variations impact MW-PPG signals. Data from 11 healthy subjects are analyzed to investigate the still understudied specific effects of CF on PPG signals. The obtained dataset includes simultaneous recording of five PPG wavelengths (470, 525, 590, 631, and 940 nm), CF, skin temperature, and the tonometric measurement derived from CF. The evolution of raw signals and the PPG DC and AC components are analyzed in relation to the increasing and decreasing faces of the CF. Findings reveal individual variability in signal responses related to skin and vasculature properties and demonstrate hysteresis and wavelength-dependent responses to CF changes. Notably, all wavelengths except 631 nm showed that the DC component of PPG signals correlates with CF trends, suggesting the potential use of this component as an indirect CF indicator. However, further validation is needed for practical application. The study underscores the importance of biomechanical properties at the measurement site and inter-individual variability and proposes the arterial pressure wave as a key factor in PPG signal formation.
Collapse
Affiliation(s)
- Joan Lambert Cause
- Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium; (Á.S.M.); (B.d.S.); (J.S.)
- Department of Biomedical Engineering, Universidad de Oriente, Santiago de Cuba 90500, Cuba
| | - Ángel Solé Morillo
- Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium; (Á.S.M.); (B.d.S.); (J.S.)
| | - Bruno da Silva
- Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium; (Á.S.M.); (B.d.S.); (J.S.)
| | | | - Johan Stiens
- Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium; (Á.S.M.); (B.d.S.); (J.S.)
| |
Collapse
|
5
|
Zylinski M, Occhipinti E, Mandic D. Generalization Error of a Regression Model for Non-Invasive Blood Pressure Monitoring using a Single Photoplethysmography (PPG) Signal. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:i-iv. [PMID: 38083115 DOI: 10.1109/embc40787.2023.10340929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Photoplethysmography (PPG) sensors integrated in wearable devices offer the potential to monitor arterial blood pressure (ABP) in patients. Such cuffless, non-invasive, and continuous solution is suitable for remote and ambulatory monitoring. A machine learning model based on PPG signal can be used to detect hypertension, estimate beat-by-beat ABP values, and even reconstruct the shape of the ABP. Overall, models presented in literature have shown good performance, but there is a gap between research and potential real-world use cases. Usually, models are trained and tested on data from the same dataset and same subjects, which may lead to overestimating their accuracy. In this paper: we compare cross-validation, where the test data are from the same dataset as training data, and external validation, where the model is tested on samples from a new dataset, on a regression model which predicts diastolic blood pressure from PPG features. The results show that, in the cross-validation, the predicted and the real values are linearly dependent, while in the external validation, the predicted values are not related to the real ones, but probably just through an average value.
Collapse
|
6
|
Garrett A, Kim B, Sie EJ, Gurel NZ, Marsili F, Boas DA, Roblyer D. Simultaneous photoplethysmography and blood flow measurements towards the estimation of blood pressure using speckle contrast optical spectroscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:1594-1607. [PMID: 37078049 PMCID: PMC10110303 DOI: 10.1364/boe.482740] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/10/2023] [Accepted: 03/12/2023] [Indexed: 05/03/2023]
Abstract
Non-invasive continuous blood pressure monitoring remains elusive. There has been extensive research using the photoplethysmographic (PPG) waveform for blood pressure estimation, but improvements in accuracy are still needed before clinical use. Here we explored the use of an emerging technique, speckle contrast optical spectroscopy (SCOS), for blood pressure estimation. SCOS provides measurements of both blood volume changes (PPG) and blood flow index (BFi) changes during the cardiac cycle, and thus provides a richer set of parameters compared to traditional PPG. SCOS measurements were taken on the finger and wrists of 13 subjects. We investigated the correlations between features extracted from both the PPG and BFi waveforms with blood pressure. Features from the BFi waveforms were more significantly correlated with blood pressure than PPG features ( R = - 0.55, p = 1.1 × 10-4 for the top BFi feature versus R = - 0.53, p = 8.4 × 10-4 for the top PPG feature). Importantly, we also found that features combining BFi and PPG data were highly correlated with changes in blood pressure ( R = - 0.59, p = 1.7 × 10-4 ). These results suggest that the incorporation of BFi measurements should be further explored as a means to improve blood pressure estimation using non-invasive optical techniques.
Collapse
Affiliation(s)
- Ariane Garrett
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Byungchan Kim
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Edbert J. Sie
- Reality Labs, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | - Nil Z. Gurel
- Reality Labs, Meta Platforms Inc., Menlo Park, CA 94025, USA
| | | | - David A. Boas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Darren Roblyer
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| |
Collapse
|
7
|
Guler S, Ozturk O, Golparvar A, Dogan H, Yapici MK. Effects of illuminance intensity on the green channel of remote photoplethysmography (rPPG) signals. Phys Eng Sci Med 2022; 45:1317-1323. [PMID: 36036875 DOI: 10.1007/s13246-022-01175-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/16/2022] [Indexed: 12/15/2022]
Abstract
Point-of-care remote photoplethysmography (rPPG) devices that utilize low-cost RGB cameras have drawn considerable attention due to their convenience in contactless and non-invasive vital signs monitoring. In rPPG, sufficient lighting conditions are essential for obtaining accurate diagnostics by observing the complete signal morphology. The effects of illuminance intensity and light source settings play a significant role in rPPG assessment quality, and it was previously observed that different lighting schemes result in different signal quality and morphology. This study presents a quantitative empirical analysis where the quality and morphology of rPPG signals were assessed under different light settings. Participants' faces were exposed to the white LED spotlight, first when the sources were installed directly behind the video camera, and then when the sources were installed in a cross-polarized scheme. Hence, the effect of specular reflectance on rPPG signals could be observed in an increasing projection. The signal qualities were analyzed in each intensity level using a signal-to-noise (SNR) ratio metric. In 3 of 7 participants, placing the video camera on the same level as the light source led to signal quality loss of up to 3 dB for the range 30-60 Lux. In addition, two fundamental morphological features were analyzed, and the derivative-related feature was found to be increasing with illuminance intensity in 6 of 7 participants.
Collapse
Affiliation(s)
- Saygun Guler
- Department of Electronics Engineering, Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, 34956, Istanbul, Turkey.
| | - Ozberk Ozturk
- Department of Electronics Engineering, Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, 34956, Istanbul, Turkey
| | - Ata Golparvar
- Department of Electronics Engineering, Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, 34956, Istanbul, Turkey.,Integrated Circuits Laboratory (ICLAB), École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchêtel, Switzerland
| | - Huseyin Dogan
- Department of Computing and Informatics, Bournemouth University, Fern Barrow, Bournemouth, Dorset, BH12 5BB, UK
| | - Murat Kaya Yapici
- Department of Electronics Engineering, Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, 34956, Istanbul, Turkey.,Department of Electrical Engineering, University of Washington, Washington, 98195, USA
| |
Collapse
|
8
|
Prabha A, Yadav J, Rani A, Singh V. Intelligent estimation of blood glucose level using wristband PPG signal and physiological parameters. Biomed Signal Process Control 2022. [DOI: 10.1016/j.bspc.2022.103876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
9
|
Classification of emotional states via transdermal cardiovascular spatiotemporal facial patterns using multispectral face videos. Sci Rep 2022; 12:11188. [PMID: 35778591 PMCID: PMC9249872 DOI: 10.1038/s41598-022-14808-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 06/13/2022] [Indexed: 11/17/2022] Open
Abstract
We describe a new method for remote emotional state assessment using multispectral face videos, and present our findings: unique transdermal, cardiovascular and spatiotemporal facial patterns associated with different emotional states. The method does not rely on stereotypical facial expressions but utilizes different wavelength sensitivities (visible spectrum, near-infrared, and long-wave infrared) to gauge correlates of autonomic nervous system activity spatially and temporally distributed across the human face (e.g., blood flow, hemoglobin concentration, and temperature). We conducted an experiment where 110 participants viewed 150 short emotion-eliciting videos and reported their emotional experience, while three cameras recorded facial videos with multiple wavelengths. Spatiotemporal multispectral features from the multispectral videos were used as inputs to a machine learning model that was able to classify participants’ emotional state (i.e., amusement, disgust, fear, sexual arousal, or no emotion) with satisfactory results (average ROC AUC score of 0.75), while providing feature importance analysis that allows the examination of facial occurrences per emotional state. We discuss findings concerning the different spatiotemporal patterns associated with different emotional states as well as the different advantages of the current method over existing approaches to emotion detection.
Collapse
|
10
|
Bonnet S, Lubin M, Doron M, Blanquer G, Perriollat M, Prada R, Blandin P, Gerbelot R. Spatial dependency of the PPG morphology at right carotid common artery. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2022; 2022:3146-3149. [PMID: 36085811 DOI: 10.1109/embc48229.2022.9871985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
PhotoPlethysmoGraphy (PPG) is ubiquitously employed in wearable devices for health monitoring. Photodiode signal inversion is observed in rare occasions, most of the time when the sensor is pressed against the skin. We report in this article such observations made at the right common carotid artery site. Indeed we have systematically observed a photodiode signal inversion when the PPG sensor is placed where the pulse is the best felt at the carotid. In addition to be inverted, the pulse is steeper during the systolic phase. Such inversion has implications in terms of pulse arrival time (PAT) measurements In our experiments, this causes a difference of 20 ms in the carotid PAT when measured at the absolute maximum slope. The mechanical and optical properties of tissues must be better accounted to explain the PPG signal morphology. Clinical Relevance- Understanding the role of mechanical tissue properties seems relevant in order to obtain more reproducible results in PPG signal analysis.
Collapse
|
11
|
Galli A, Montree RJH, Que S, Peri E, Vullings R. An Overview of the Sensors for Heart Rate Monitoring Used in Extramural Applications. SENSORS (BASEL, SWITZERLAND) 2022; 22:4035. [PMID: 35684656 PMCID: PMC9185322 DOI: 10.3390/s22114035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 06/02/2023]
Abstract
This work presents an overview of the main strategies that have been proposed for non-invasive monitoring of heart rate (HR) in extramural and home settings. We discuss three categories of sensing according to what physiological effect is used to measure the pulsatile activity of the heart, and we focus on an illustrative sensing modality for each of them. Therefore, electrocardiography, photoplethysmography, and mechanocardiography are presented as illustrative modalities to sense electrical activity, mechanical activity, and the peripheral effect of heart activity. In this paper, we describe the physical principles underlying the three categories and the characteristics of the different types of sensors that belong to each class, and we touch upon the most used software strategies that are currently adopted to effectively and reliably extract HR. In addition, we investigate the strengths and weaknesses of each category linked to the different applications in order to provide the reader with guidelines for selecting the most suitable solution according to the requirements and constraints of the application.
Collapse
Affiliation(s)
- Alessandra Galli
- Department of Information Engineering, University of Padova, I-35131 Padova, Italy;
| | - Roel J. H. Montree
- Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (R.J.H.M.); (S.Q.); (E.P.)
| | - Shuhao Que
- Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (R.J.H.M.); (S.Q.); (E.P.)
| | - Elisabetta Peri
- Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (R.J.H.M.); (S.Q.); (E.P.)
| | - Rik Vullings
- Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (R.J.H.M.); (S.Q.); (E.P.)
| |
Collapse
|
12
|
Xu G, Dong L, Yuan J, Zhao Y, Liu M, Hui M, Zhao Y, Kong L. Rational selection of RGB channels for disease classification based on IPPG technology. BIOMEDICAL OPTICS EXPRESS 2022; 13:1820-1833. [PMID: 35519270 PMCID: PMC9045892 DOI: 10.1364/boe.451736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/17/2022] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
The green channel is usually selected as the optimal channel for vital signs monitoring in image photoplethysmography (IPPG) technology. However, some controversies arising from the different penetrability of skin tissue in visible light remain unresolved, i.e., making the optical and physiological information carried by the IPPG signals of the RGB channels inconsistent. This study clarifies that the optimal channels for different diseases are different when IPPG technology is used for disease classification. We further verified this conclusion in the classification model of heart disease and diabetes mellitus based on the random forest classification algorithm. The experimental results indicate that the green channel has a considerably excellent performance in classifying heart disease patients and the healthy with an average Accuracy value of 88.43% and an average F1score value of 93.72%. The optimal channel for classifying diabetes mellitus patients and the healthy is the red channel with an average Accuracy value of 82.12% and the average F1score value of 89.31%. Due to the limited penetration depth of the blue channel into the skin tissue, the blue channel is not as effective as the green and red channels as a disease classification channel. This investigation is of great significance to the development of IPPG technology and its application in disease classification.
Collapse
Affiliation(s)
- Ge Xu
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
| | - Liquan Dong
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
- Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314019, China
| | - Jing Yuan
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuejin Zhao
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
- Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314019, China
| | - Ming Liu
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
- Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314019, China
| | - Mei Hui
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuebin Zhao
- Taiyuan Central Hospital, Taiyuan, 030009, China
| | - Lingqin Kong
- Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China
- Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing, 314019, China
| |
Collapse
|
13
|
Barszczyk A, Zhou W, Lee K. AIM and Transdermal Optical Imaging. Artif Intell Med 2022. [DOI: 10.1007/978-3-030-64573-1_250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
14
|
Wolling F, Wasala SM, Van Laerhoven K. Optimal Preprocessing of Raw Signals from Reflective Mode Photoplethysmography in Wearable Devices. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:1157-1163. [PMID: 34891493 DOI: 10.1109/embc46164.2021.9630955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The optical measurement principle photoplethysmography has emerged in today's wearable devices as the standard to monitor the wearer's heart rate in everyday life. This cost-effective and easy-to-integrate technique has transformed from the original transmission mode pulse oximetry for clinical settings to the reflective mode of modern ambulatory, wrist-worn devices. Numerous proposed algorithms aim at the efficient heart rate measurement and accurate detection of the consecutive pulses for the derivation of secondary features from the heart rate variability. Most, however, have been evaluated either on own, closed recordings or on public datasets that often stem from clinical pulse oximeters in transmission instead of wearables' reflective mode. Signals tend furthermore to be preprocessed with filters, which are rarely documented and unintentionally fitted to the available and applied signals. We investigate the influence of preprocessing on the peak positions and present the benchmark of two cutting-edge pulse detection algorithms on actual raw measurements from reflective mode photoplethysmography. Based on 21806 pulse labels, our evaluation shows that the most suitable but still universal filter passband is located at 0.5 to 15.0Hz since it preserves the required harmonics to shape the peak positions.
Collapse
|
15
|
Lubin M, Gerbelot R, Prada R, Porcherot J, Bonnet S. Evaluation of a dual-PPG system for pulse transit time monitoring. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:1349-1352. [PMID: 34891534 DOI: 10.1109/embc46164.2021.9630814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This work presents a new dual-photoplethysmographic (PPG) system for pulse transit time (PTT) monitoring. An experiment has been set up in order to compare the PTT measurement between carotid and radial arteries from two systems: our physiological multimodal platform (PMP) and the Complior® tonometer. This work explores the comparison between such optical and mechanical modalities. The results show that the PPG device tends to overestimate the PTT (RMSE = 16 ms). Furthermore, both mechanical and optical signals have been superposed and demonstrated that pulse morphologies are quite similar.Clinical Relevance-Carotid-radial pulse wave velocity (PWV) is compared on a small cohort of subjects and significant differences are observed between optical and mechanical-based systems.
Collapse
|
16
|
Photoplethysmography in Normal and Pathological Sleep. SENSORS 2021; 21:s21092928. [PMID: 33922042 PMCID: PMC8122413 DOI: 10.3390/s21092928] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 01/20/2023]
Abstract
This article presents an overview of the advancements that have been made in the use of photoplethysmography (PPG) for unobtrusive sleep studies. PPG is included in the quickly evolving and very popular landscape of wearables but has specific interesting properties, particularly the ability to capture the modulation of the autonomic nervous system during sleep. Recent advances have been made in PPG signal acquisition and processing, including coupling it with accelerometry in order to construct hypnograms in normal and pathologic sleep and also to detect sleep-disordered breathing (SDB). The limitations of PPG (e.g., oxymetry signal failure, motion artefacts, signal processing) are reviewed as well as technical solutions to overcome these issues. The potential medical applications of PPG are numerous, including home-based detection of SDB (for triage purposes), and long-term monitoring of insomnia, circadian rhythm sleep disorders (to assess treatment effects), and treated SDB (to ensure disease control). New contact sensor combinations to improve future wearables seem promising, particularly tools that allow for the assessment of brain activity. In this way, in-ear EEG combined with PPG and actigraphy could be an interesting focus for future research.
Collapse
|
17
|
Abstract
The pandemic caused by the new coronavirus (SARS-COV-2) has led to more than two million deaths in the world by March 2021. The worldwide call to reduce transmission is enormous. Recently, there has been a rapid growth of telemedicine and the use of mobile health (mHealth) in the context of the COVID-19 pandemic. Smartphone accessories such as a flashlight, camera, microphone, and microprocessor can measure different clinical parameters such as oxygen saturation, blood pressure, heart rate, breathing rate, fever, pulmonary auscultation, and even voice analysis. All these parameters are of great clinical importance when evaluating suspected patients of COVID-19 or monitoring infected patients admitted in various hospitals or in-home isolation. In remote medical care, the results of these parameters can be sent to a call center or a health unit for interpretation by a qualified health professional. Thus, the patient can receive orientations or be immediately referred for in-patient care. The application of machine learning and other artificial intelligence strategies assume a central role in signal processing and are gaining much space in the medical field. In this work, we present different approaches for evaluating clinical parameters that are valuable in the case of COVID-19 and we hope that soon all these parameters can be measured by a single smartphone application, facilitating remote clinical assessments.
Collapse
|
18
|
De Pinho Ferreira N, Gehin C, Massot B. A Review of Methods for Non-Invasive Heart Rate Measurement on Wrist. Ing Rech Biomed 2021. [DOI: 10.1016/j.irbm.2020.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
19
|
AIM and Transdermal Optical Imaging. Artif Intell Med 2021. [DOI: 10.1007/978-3-030-58080-3_250-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
20
|
Chatterjee S, Budidha K, Kyriacou PA. Investigating the origin of photoplethysmography using a multiwavelength Monte Carlo model. Physiol Meas 2020; 41:084001. [PMID: 32585642 DOI: 10.1088/1361-6579/aba008] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Photoplethysmography (PPG) is a photometric technique used for the measurement of volumetric changes in the blood. The recent interest in new applications of PPG has invigorated more fundamental research regarding the origin of the PPG waveform, which since its discovery in 1937, remains inconclusive. A handful of studies in the recent past have explored various hypotheses for the origin of PPG. These studies relate PPG to mechanical movement, red blood cell orientation or blood volume variations. OBJECTIVE Recognising the significance and need to corroborate a theory behind PPG formation, the present work rigorously investigates the origin of PPG based on a realistic model of light-tissue interactions. APPROACH A three-dimensional comprehensive Monte Carlo model of finger-PPG was developed and explored to quantify the optical entities pertinent to PPG (e.g. absorbance, reflectance, and penetration depth) as the functions of multiple wavelengths and source-detector separations. Complementary to the simulations, a pilot in vivo investigation was conducted on eight healthy volunteers. PPG signals were recorded using a custom-made multiwavelength sensor with an adjustable source-detector separation. MAIN RESULTS Simulated results illustrate the distribution of photon-tissue interactions in the reflectance PPG geometry. The depth-selective analysis quantifies the contributions of the dermal and subdermal tissue layers in the PPG wave formation. A strong negative correlation (r = -0.96) is found between the ratios of the simulated absorbances and measured PPG amplitudes. SIGNIFICANCE This work quantified for the first time the contributions of different tissue layers and sublayers in the formation of the PPG signal.
Collapse
Affiliation(s)
- Subhasri Chatterjee
- Research Centre for Biomedical Engineering, City, University of London, United Kingdom
| | | | | |
Collapse
|
21
|
Nomoni M, May JM, Kyriacou PA. Novel Polydimethylsiloxane (PDMS) Pulsatile Vascular Tissue Phantoms for the In-Vitro Investigation of Light Tissue Interaction in Photoplethysmography. SENSORS (BASEL, SWITZERLAND) 2020; 20:E4246. [PMID: 32751541 PMCID: PMC7435705 DOI: 10.3390/s20154246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022]
Abstract
Currently there exists little knowledge or work in phantoms for the in-vitro evaluation of photoplethysmography (PPG), and its' relationship with vascular mechanics. Such phantoms are needed to provide robust, basic scientific knowledge, which will underpin the current efforts in developing new PPG technologies for measuring or estimating blood pressure, blood flow and arterial stiffness, to name but a few. This work describes the design, fabrication and evaluation of finger tissue-simulating pulsatile phantoms with integrated custom vessels. A novel technique has been developed to produce custom polydimethylsiloxane (PDMS) vessels by a continuous dip-coating process. This process can accommodate the production of different sized vessel diameters (1400-2500 µm) and wall thicknesses (56-80 µm). These vessels were embedded into a mould with a solution of PDMS and India ink surrounding them. A pulsatile pump experimental rig was set up to test the phantoms, where flow rate (1-12 L·min-1), heart rate (40-120 bpm), and total resistance (0-100% resistance clamps) could be controlled on demand. The resulting flow profiles approximates human blood flow, and the detected contact PPG signal (red and infrared) from the phantom closely resembles the morphology of in-vivo PPG waveforms with signal-to-noise ratios of 38.16 and 40.59 dB, for the red and infrared wavelengths, respectively. The progress made by this phantom development will help in obtaining new knowledge in the behaviour of PPG's under differing flow conditions, optical tissue properties and differing vessel stiffness.
Collapse
Affiliation(s)
- Michelle Nomoni
- Research Centre for Biomedical Engineering, City, University of London, London EC1V 0HB, UK; (J.M.M.); (P.A.K.)
| | | | | |
Collapse
|
22
|
Contactless Monitoring of Microcirculation Reaction on Local Temperature Changes. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9224947] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Assessment of skin blood flow is an important clinical task which is required to study mechanisms of microcirculation regulation including thermoregulation. Contactless assessment of vasomotor reactivity in response to thermal exposure is currently not available. The aim of this study is to show the applicability of the imaging photoplethysmography (IPPG) method to measure quantitatively the vasomotor response to local thermal exposure. Seventeen healthy subjects aged 23 ± 7 years participated in the study. A warm transparent compress applied to subject’s forehead served as a thermal impact. A custom-made IPPG system operating at green polarized light was used to monitor the subject’s face continuously and simultaneously with skin temperature and electrocardiogram (ECG) recordings. We found that the thermal impact leads to an increase in the amplitude of blood pulsations (BPA) simultaneously with the skin temperature increase. However, a multiple increase in BPA remained after the compress was removed, whereas the skin temperature returned to the baseline. Moreover, the BPA increase and duration of the vasomotor response was associated with the degree of external heating. Therefore, the IPPG method allows us to quantify the parameters of capillary blood flow during local thermal exposure to the skin. This proposed technique of assessing the thermal reactivity of microcirculation can be applied for both clinical use and for biomedical research.
Collapse
|
23
|
3D Convolutional Neural Networks for Remote Pulse Rate Measurement and Mapping from Facial Video. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9204364] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Remote pulse rate measurement from facial video has gained particular attention over the last few years. Research exhibits significant advancements and demonstrates that common video cameras correspond to reliable devices that can be employed to measure a large set of biomedical parameters without any contact with the subject. A new framework for measuring and mapping pulse rate from video is presented in this pilot study. The method, which relies on convolutional 3D networks, is fully automatic and does not require any special image preprocessing. In addition, the network ensures concurrent mapping by producing a prediction for each local group of pixels. A particular training procedure that employs only synthetic data is proposed. Preliminary results demonstrate that this convolutional 3D network can effectively extract pulse rate from video without the need for any processing of frames. The trained model was compared with other state-of-the-art methods on public data. Results exhibit significant agreement between estimated and ground-truth measurements: the root mean square error computed from pulse rate values assessed with the convolutional 3D network is equal to 8.64 bpm, which is superior to 10 bpm for the other state-of-the-art methods. The robustness of the method to natural motion and increases in performance correspond to the two main avenues that will be considered in future works.
Collapse
|
24
|
|
25
|
Luo H, Yang D, Barszczyk A, Vempala N, Wei J, Wu SJ, Zheng PP, Fu G, Lee K, Feng ZP. Smartphone-Based Blood Pressure Measurement Using Transdermal Optical Imaging Technology. Circ Cardiovasc Imaging 2019; 12:e008857. [PMID: 31382766 DOI: 10.1161/circimaging.119.008857] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cuff-based blood pressure measurement lacks comfort and convenience. Here, we examined whether blood pressure can be determined in a contactless manner using a novel smartphone-based technology called transdermal optical imaging. This technology processes imperceptible facial blood flow changes from videos captured with a smartphone camera and uses advanced machine learning to determine blood pressure from the captured signal. METHODS We enrolled 1328 normotensive adults in our study. We used an advanced machine learning algorithm to create computational models that predict reference systolic, diastolic, and pulse pressure from facial blood flow data. We used 70% of our data set to train these models and 15% of our data set to test them. The remaining 15% of the sample was used to validate model performance. RESULTS We found that our models predicted blood pressure with a measurement bias±SD of 0.39±7.30 mm Hg for systolic pressure, -0.20±6.00 mm Hg for diastolic pressure, and 0.52±6.42 mm Hg for pulse pressure, respectively. CONCLUSIONS Our results in normotensive adults fall within 5±8 mm Hg of reference measurements. Future work will determine whether these models meet the clinically accepted accuracy threshold of 5±8 mm Hg when tested on a full range of blood pressures according to international accuracy standards.
Collapse
Affiliation(s)
- Hong Luo
- The Affiliated Hospital of Hangzhou Normal University (H.L., D.Y., J.W.), Hangzhou Normal University, Zhejiang, China
| | - Deye Yang
- The Affiliated Hospital of Hangzhou Normal University (H.L., D.Y., J.W.), Hangzhou Normal University, Zhejiang, China
| | - Andrew Barszczyk
- Department of Physiology (A.B., Z.-P.F.), University of Toronto, ON, Canada
| | - Naresh Vempala
- Dr Eric Jackman Institute of Child Study (N.V., S.J.W., P.P.Z., K.L.), University of Toronto, ON, Canada
| | - Jing Wei
- The Affiliated Hospital of Hangzhou Normal University (H.L., D.Y., J.W.), Hangzhou Normal University, Zhejiang, China
| | - Si Jia Wu
- Dr Eric Jackman Institute of Child Study (N.V., S.J.W., P.P.Z., K.L.), University of Toronto, ON, Canada
| | - Paul Pu Zheng
- Dr Eric Jackman Institute of Child Study (N.V., S.J.W., P.P.Z., K.L.), University of Toronto, ON, Canada
| | - Genyue Fu
- Department of Psychology (G.F.), Hangzhou Normal University, Zhejiang, China
| | - Kang Lee
- Dr Eric Jackman Institute of Child Study (N.V., S.J.W., P.P.Z., K.L.), University of Toronto, ON, Canada.,Department of Psychology, Zhejiang Normal University, Jinhua, China (K.L.)
| | - Zhong-Ping Feng
- Department of Physiology (A.B., Z.-P.F.), University of Toronto, ON, Canada
| |
Collapse
|
26
|
Zaunseder S, Trumpp A, Wedekind D, Malberg H. Cardiovascular assessment by imaging photoplethysmography - a review. ACTA ACUST UNITED AC 2019; 63:617-634. [PMID: 29897880 DOI: 10.1515/bmt-2017-0119] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 05/04/2018] [Indexed: 12/12/2022]
Abstract
Over the last few years, the contactless acquisition of cardiovascular parameters using cameras has gained immense attention. The technique provides an optical means to acquire cardiovascular information in a very convenient way. This review provides an overview on the technique's background and current realizations. Besides giving detailed information on the most widespread application of the technique, namely the contactless acquisition of heart rate, we outline further concepts and we critically discuss the current state.
Collapse
Affiliation(s)
- Sebastian Zaunseder
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| | - Alexander Trumpp
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| | - Daniel Wedekind
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| | - Hagen Malberg
- TU Dresden, Institute of Biomedical Engineering, Helmholtzstraße 18, Dresden, 01069 Saxony, Germany
| |
Collapse
|
27
|
Miyaji T, Sviridova N, Aihara K, Zhao T, Nakano A. Human photoplethysmogram through the Morse graph: Searching for the saddle point in experimental data. CHAOS (WOODBURY, N.Y.) 2019; 29:043121. [PMID: 31042948 DOI: 10.1063/1.5088989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/29/2019] [Indexed: 06/09/2023]
Abstract
Photoplethysmogram (PPG) is one of the noninvasive biological signals widely used for the estimation of physiological parameters, such as heart rates in human health monitoring. Methods of its processing, its applications, and dynamics have been extensively investigated over the last several decades. However, there is still lack of the knowledge related to the fundamental structure of the PPG dynamics such as saddle equilibrium points, which have crucial importance to achieve the full understanding of the PPG dynamics and might provide useful information for establishing a mathematical model of the PPG. In this study, Morse graph theory was applied to the experimental PPG data in an attempt to verify the existence of saddle equilibrium and estimate its location with respect to the time-delay-reconstructed PPG attractor. The results demonstrated evidence that a saddle equilibrium point can be found in a neighborhood of the reconstructed PPG trajectory; moreover, it was found to be in the same reconstructed attractor's region for healthy subjects from different age groups that points toward fundamental importance of the found saddle equilibrium for a general understanding of the PPG dynamics.
Collapse
Affiliation(s)
- Tomoyuki Miyaji
- Meiji Institute for Advanced Study of Mathematical Sciences, Meiji University, Tokyo 164-8525, Japan
| | - Nina Sviridova
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan
| | - Kazuyuki Aihara
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan
| | - Tiejun Zhao
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-8519, Japan
| | - Akimasa Nakano
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-8519, Japan
| |
Collapse
|
28
|
Dunn CE, Lertsakdadet B, Crouzet C, Bahani A, Choi B. Comparison of speckleplethysmographic (SPG) and photoplethysmographic (PPG) imaging by Monte Carlo simulations and in vivo measurements. BIOMEDICAL OPTICS EXPRESS 2018; 9:4306-4316. [PMID: 30615714 PMCID: PMC6157764 DOI: 10.1364/boe.9.004306] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/11/2018] [Accepted: 07/20/2018] [Indexed: 05/02/2023]
Abstract
Noncontact photoplethysmography (PPG) is limited by a poor signal-to-noise ratio (SNR). A solution to this limitation is the use of alternate sources of optical contrast to generate a complementary pulsatile waveform. One such source is laser speckle contrast, which is modulated in biological tissues by the flow rate of red blood cells. Averaging a region of interest from a speckle contrast image over time allows for the calculation of a speckleplethysmogram (SPG). Similar to PPG, SPG enables monitoring of heart rate and respiratory rate. A gap in the knowledge base exists as to the precise spatiotemporal relationship between PPG and SPG signals. We have developed an eight-layer tissue model to simulate both PPG and SPG signals in a reflectance geometry via Monte Carlo methods. We modeled PPG by compression of the upper and lower blood nets due to expansion of the larger arterial layer below. The in silico PPG peak-to-peak amplitude percent was greater at 532 nm than at 860 nm (5.6% vs. 3.0%, respectively), which matches trends from the literature. We modeled SPG by changing flow speeds of red blood cells in both the capillaries and arterioles over the cardiac cycle. The in silico SPG peak-to-peak amplitude percent was 24% at 532 nm and 40% at 860 nm. In silico results are similar to in vivo results measured with a two-camera set up for simultaneous imaging of PPG and SPG. Both in silico and in vivo data suggest SPG has a much larger SNR than PPG, which may prove beneficial for noncontact, wide-field optical monitoring of cardiovascular health.
Collapse
Affiliation(s)
- Cody E. Dunn
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
- Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, 2400 Engineering Hall, Irvine, CA 92697, USA
| | - Ben Lertsakdadet
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Christian Crouzet
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Adrian Bahani
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
| | - Bernard Choi
- Beckman Laser Institute and Medical Clinic, University of California-Irvine, 1002 Health Sciences Road East, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, 3120 Natural Sciences II, Irvine, CA 92697, USA
- Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California, Irvine, 2400 Engineering Hall, Irvine, CA 92697, USA
- Department of Surgery, University of California, Irvine, 333 City Boulevard West, Suite 1600, Orange, CA 92868, USA
| |
Collapse
|
29
|
Silva H, Ferreira HA, da Silva HP, Monteiro Rodrigues L. The Venoarteriolar Reflex Significantly Reduces Contralateral Perfusion as Part of the Lower Limb Circulatory Homeostasis in vivo. Front Physiol 2018; 9:1123. [PMID: 30174614 PMCID: PMC6107688 DOI: 10.3389/fphys.2018.01123] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 07/27/2018] [Indexed: 12/31/2022] Open
Abstract
Perfusion at microvascular level involves the contribution of both local and central regulators, under a complex vascular signaling frame. The venoarteriolar reflex (VAR) is one of such regulatory responses, of particular relevance in the lower limb to prevent edema. Although known for quite some time, many of the complex interactions involving all of these regulatory mechanisms still need clarification. Our objective was to look deeper into VAR through modern photoplethymography (PPG). Twelve healthy subjects (both sexes, 26.0 ± 5.0 y.o.) were enrolled in this study after informed written consent. Subjects were submitted to a leg lowering maneuver while lying supine to evoke the VAR, involving three phases-10 min baseline register, both legs extended, 10 min challenge, with one randomly chosen leg (test) pending 50 cm below heart level, while the contralateral (control) remained in place, and 10 minutes recovery, resuming the initial position. PPG signals were collected from both feet and treated by the wavelet transform (WT) revealing six spectral bands in frequency intervals comprising the cardiac [1.6-0.7 Hz], respiratory [0.4-0.26 Hz], myogenic [0.26-0.1 Hz], neurogenic/sympathetic [0.1-0.045 Hz], endothelial NO-dependent (NOd) [0.045-0.015 Hz], and NO-independent (NOi) [0.015-0.007 Hz] activities. For the first time, this approach revealed that, with VAR, perfusion significantly decreased in both limbs, although the change was more pronounced in the test foot. Here, a significant decrease in myogenic, neurogenic and NOd, were noted, while the control foot recorded a decrease in neurogenic and an increase in NOd. These results confirm the utility of WT spectral analysis for flowmotion. Further, it strongly suggests that VAR results from a complex cooperation between local myogenic-endothelial responses, where a central neurogenic reflex might also be involved.
Collapse
Affiliation(s)
- Henrique Silva
- Research Center for Biosciences and Health Technologies, Universidade Lusófona's CBiOS, Lisbon, Portugal
- Pharmacological Sciences Department, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Hugo A. Ferreira
- Faculty of Sciences, Institute of Biophysics and Biomedical Engineering, Universidade de Lisboa, Lisbon, Portugal
| | - Hugo P. da Silva
- IT - Instituto de Telecomunicações, Lisbon, Portugal
- School of Technology, Polytechnic Institute of Setúbal, Setúbal, Portugal
| | - L. Monteiro Rodrigues
- Research Center for Biosciences and Health Technologies, Universidade Lusófona's CBiOS, Lisbon, Portugal
- Pharmacological Sciences Department, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| |
Collapse
|
30
|
Robinson MB, Wisniowiecki AM, Butcher RJ, Wilson MA, Nance Ericson M, Cote GL. In vivo performance of a visible wavelength optical sensor for monitoring intestinal perfusion and oxygenation. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-12. [PMID: 29777581 PMCID: PMC5981030 DOI: 10.1117/1.jbo.23.5.055004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/26/2018] [Indexed: 06/08/2023]
Abstract
Traumatic injury resulting in hemorrhage is a prevalent cause of death worldwide. The current standard of care for trauma patients is to restore hemostasis by controlling bleeding and administering intravenous volume resuscitation. Adequate resuscitation to restore tissue blood flow and oxygenation is critical within the first hours following admission to assess severity and avoid complications. However, current clinical methods for guiding resuscitation are not sensitive or specific enough to adequately understand the patient condition. To better address the shortcomings of the current methods, an approach to monitor intestinal perfusion and oxygenation using a multiwavelength (470, 560, and 630 nm) optical sensor has been developed based on photoplethysmography and reflectance spectroscopy. Specifically, two sensors were developed using three wavelengths to measure relative changes in the small intestine. Using vessel occlusion, systemic changes in oxygenation input, and induction of hemorrhagic shock, the capabilities and sensitivity of the sensor were explored in vivo. Pulsatile and nonpulsatile components of the red, blue, and green wavelength signals were analyzed for all three protocols (occlusion, systemic oxygenation changes, and shock) and were shown to differentiate perfusion and oxygenation changes in the jejunum. The blue and green signals produced better correlation to perfusion changes during occlusion and shock, while the red and blue signals, using a new correlation algorithm, produced better data for assessing changes in oxygenation induced both systemically and locally during shock. The conventional modulation ratio method was found to be an ineffective measure of oxygenation in the intestine due to noise and an algorithm was developed based on the Pearson correlation coefficient. The method utilized the difference in phase between two different wavelength signals to assess oxygen content. A combination of measures from the three wavelengths provided verification of oxygenation and perfusion states, and showed promise for the development of a clinical monitor.
Collapse
Affiliation(s)
- Mitchell B. Robinson
- Texas A&M University, Optical Biosensing Laboratory, Department of Biomedical Engineering, College Station, Texas, United States
| | - Anna M. Wisniowiecki
- Texas A&M University, Optical Biosensing Laboratory, Department of Biomedical Engineering, College Station, Texas, United States
| | - Ryan J. Butcher
- Texas A&M University, Optical Biosensing Laboratory, Department of Biomedical Engineering, College Station, Texas, United States
| | - Mark A. Wilson
- VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, United States
- University of Pittsburgh, Department of Surgery, Pittsburgh, Pennsylvania, United States
| | | | - Gerard L. Cote
- Texas A&M University, Optical Biosensing Laboratory, Department of Biomedical Engineering, College Station, Texas, United States
- TEES Center for Remote Healthcare Technologies and Systems, College Station, Texas, United States
| |
Collapse
|