1
|
Wang L, Tian S, Zhu R. A new method of continuous blood pressure monitoring using multichannel sensing signals on the wrist. MICROSYSTEMS & NANOENGINEERING 2023; 9:117. [PMID: 37744263 PMCID: PMC10511443 DOI: 10.1038/s41378-023-00590-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/06/2023] [Accepted: 07/31/2023] [Indexed: 09/26/2023]
Abstract
Hypertension is a worldwide health problem and a primary risk factor for cardiovascular disease. Continuous monitoring of blood pressure has important clinical value for the early diagnosis and prevention of cardiovascular disease. However, existing technologies for wearable continuous blood pressure monitoring are usually inaccurate, rely on subject-specific calibration and have poor generalization across individuals, which limit their practical applications. Here, we report a new blood pressure measurement method and develop an associated wearable device to implement continuous blood pressure monitoring for new subjects. The wearable device detects cardiac output and pulse waveform features through dual photoplethysmography (PPG) sensors worn on the palmar and dorsal sides of the wrist, incorporating custom-made interface sensors to detect the wearing contact pressure and skin temperature. The detected multichannel signals are fused using a machine-learning algorithm to estimate continuous blood pressure in real time. This dual PPG sensing method effectively eliminates the personal differences in PPG signals caused by different people and different wearing conditions. The proposed wearable device enables continuous blood pressure monitoring with good generalizability across individuals and demonstrates promising potential in personal health care applications.
Collapse
Affiliation(s)
- Liangqi Wang
- State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, 100084 Beijing, China
| | - Shuo Tian
- State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, 100084 Beijing, China
| | - Rong Zhu
- State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, 100084 Beijing, China
| |
Collapse
|
2
|
Abushouk A, Kansara T, Abdelfattah O, Badwan O, Hariri E, Chaudhury P, Kapadia SR. The Dicrotic Notch: Mechanisms, Characteristics, and Clinical Correlations. Curr Cardiol Rep 2023; 25:807-816. [PMID: 37493873 DOI: 10.1007/s11886-023-01901-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/05/2023] [Indexed: 07/27/2023]
Abstract
PURPOSE OF REVIEW The dicrotic notch (DN) has long been considered a marker of arterial stiffness and compliance. Herein, we explored the recent developments in vascular medicine research in an attempt to assess the DN utility in clinical cardiovascular medicine. RECENT FINDINGS Since its discovery, several studies have attempted to measure the changes in different parameters of the DN in physiological and pathological states. Despite the significance of their findings, the clinical role of the DN remained limited. This may have been related to the difficulty of measuring the DN via indwelling arterial catheters in the past. However, over the past two decades, several non-invasive methods have been developed, which may re-ignite interest in DN research. The DN may have broader applications in clinical cardiovascular medicine. Further research is needed to establish the accuracy of DN non-invasive measurement methods and compare its prognostic value to other circulatory parameters.
Collapse
Affiliation(s)
- Abdelrahman Abushouk
- Department of Cardiovascular Medicine, Heart, Vascular, and Thoracic Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, USA
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Tikal Kansara
- Department of Hospital Medicine, Union Hospital, Cleveland Clinic Foundation, Dover, OH, USA
| | - Omar Abdelfattah
- Division of Cardiovascular Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Osamah Badwan
- Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Essa Hariri
- Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
- Division of Cardiovascular Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Pulkit Chaudhury
- Department of Cardiovascular Medicine, Heart, Vascular, and Thoracic Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, USA
| | - Samir R Kapadia
- Department of Cardiovascular Medicine, Heart, Vascular, and Thoracic Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, USA.
| |
Collapse
|
3
|
Azudin K, Gan KB, Jaafar R, Ja'afar MH. The Principles of Hearable Photoplethysmography Analysis and Applications in Physiological Monitoring-A Review. SENSORS (BASEL, SWITZERLAND) 2023; 23:6484. [PMID: 37514778 PMCID: PMC10384007 DOI: 10.3390/s23146484] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/29/2023] [Accepted: 06/04/2023] [Indexed: 07/30/2023]
Abstract
Not long ago, hearables paved the way for biosensing, fitness, and healthcare monitoring. Smart earbuds today are not only producing sound but also monitoring vital signs. Reliable determination of cardiovascular and pulmonary system information can explore the use of hearables for physiological monitoring. Recent research shows that photoplethysmography (PPG) signals not only contain details on oxygen saturation level (SPO2) but also carry more physiological information including pulse rate, respiration rate, blood pressure, and arterial-related information. The analysis of the PPG signal from the ear has proven to be reliable and accurate in the research setting. (1) Background: The present integrative review explores the existing literature on an in-ear PPG signal and its application. This review aims to identify the current technology and usage of in-ear PPG and existing evidence on in-ear PPG in physiological monitoring. This review also analyzes in-ear (PPG) measurement configuration and principle, waveform characteristics, processing technology, and feature extraction characteristics. (2) Methods: We performed a comprehensive search to discover relevant in-ear PPG articles published until December 2022. The following electronic databases: Institute of Electrical and Electronics Engineers (IEEE), ScienceDirect, Scopus, Web of Science, and PubMed were utilized to conduct the studies addressing the evidence of in-ear PPG in physiological monitoring. (3) Results: Fourteen studies were identified but nine studies were finalized. Eight studies were on different principles and configurations of hearable PPG, and eight studies were on processing technology and feature extraction and its evidence in in-ear physiological monitoring. We also highlighted the limitations and challenges of using in-ear PPG in physiological monitoring. (4) Conclusions: The available evidence has revealed the future of in-ear PPG in physiological monitoring. We have also analyzed the potential limitation and challenges that in-ear PPG will face in processing the signal.
Collapse
Affiliation(s)
- Khalida Azudin
- Department of Electrical, Electronic & Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
| | - Kok Beng Gan
- Department of Electrical, Electronic & Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
| | - Rosmina Jaafar
- Department of Electrical, Electronic & Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
| | - Mohd Hasni Ja'afar
- Department of Community Health, Faculty of Medicine, UKM Medical Centre, Universiti Kebangsaan Malaysia, Cheras 56000, Kuala Lumpur, Malaysia
| |
Collapse
|
4
|
Advances in Cuffless Continuous Blood Pressure Monitoring Technology Based on PPG Signals. BIOMED RESEARCH INTERNATIONAL 2022; 2022:8094351. [PMID: 36217389 PMCID: PMC9547685 DOI: 10.1155/2022/8094351] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/30/2022] [Indexed: 11/17/2022]
Abstract
Objective. To review the progress of research on photoplethysmography- (PPG-) based cuffless continuous blood pressure monitoring technologies and prospect the challenges that need to be addressed in the future. Methods. Using Web of Science and PubMed as search engines, the literature on cuffless continuous blood pressure studies using PPG signals in the recent five years were searched. Results. Based on the retrieved literature, this paper describes the available open datasets, commonly used signal preprocessing methods, and model evaluation criteria. Early researches employed multisite PPG signals to calculate pulse wave velocity or time and predicted blood pressure by a simple linear equation. Later, extensive researches were dedicated to mine the features of PPG signals related to blood pressure and regressed blood pressure by machine learning models. Most recently, many researches have emerged to experiment with complex deep learning models for blood pressure prediction with the raw PPG signal as input. Conclusion. This paper summarized the methods in the retrieved literature, provided insight into the artificial intelligence algorithms employed in the literature, and concluded with a discussion of the challenges and opportunities for the development of cuffless continuous blood pressure monitoring technologies.
Collapse
|
5
|
Williamson S, Daniel-Watanabe L, Finnemann J, Powell C, Teed A, Allen M, Paulus M, Khalsa SS, Fletcher PC. The Hybrid Excess and Decay (HED) model: an automated approach to characterising changes in the photoplethysmography pulse waveform. Wellcome Open Res 2022. [DOI: 10.12688/wellcomeopenres.17855.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Photoplethysmography offers a widely used, convenient and non-invasive approach to monitoring basic indices of cardiovascular function, such as heart rate and blood oxygenation. Systematic analysis of the shape of the waveform generated by photoplethysmography might be useful to extract estimates of several physiological and psychological factors influencing the waveform. Here, we developed a robust and automated method for such a systematic analysis across individuals and across different physiological and psychological contexts. We describe a psychophysiologically-relevant model, the Hybrid Excess and Decay (HED) model, which characterises pulse wave morphology in terms of three underlying pressure waves and a decay function. We present the theoretical and practical basis for the model and demonstrate its performance when applied to a pharmacological dataset of 105 participants receiving intravenous administrations of the sympathomimetic drug isoproterenol (isoprenaline). We show that these parameters capture photoplethysmography data with a high degree of precision and, moreover, are sensitive to experimentally-induced changes in interoceptive arousal within individuals. We conclude by discussing the possible value in using the HED model as a complement to standard measures of photoplethysmography signals.
Collapse
|
6
|
Pulse oximetry for the diagnosis of vascular injury following limb trauma. J Plast Reconstr Aesthet Surg 2022; 75:3182-3189. [DOI: 10.1016/j.bjps.2022.04.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 03/06/2022] [Accepted: 04/12/2022] [Indexed: 11/22/2022]
|
7
|
A new variant position of head-up CPR may be associated with improvement in the measurements of cranial near-infrared spectroscopy suggestive of an increase in cerebral blood flow in non-traumatic out-of-hospital cardiac arrest patients: A prospective interventional pilot study. Resuscitation 2022; 175:159-166. [PMID: 35395338 DOI: 10.1016/j.resuscitation.2022.03.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/18/2022] [Accepted: 03/29/2022] [Indexed: 11/21/2022]
Abstract
AIM OF THE STUDY This study aimed to investigate the effect of the head-up position implemented during cardiopulmonary resuscitation (CPR) on cerebral blood flow (CBF) using near-infrared spectroscopy in out-of-hospital cardiac arrest patients. METHODS Baseline characteristics (age, sex, cerebral performance category before cardiac arrest, witnessed cardiac arrest, bystander CPR, first monitored rhythm, no-flow time, prehospital low-flow time, CPR duration in the emergency department (ED), and reason for stopping CPR in the ED) were recorded. The changes of CBF were derived from the optical oscillation waveform measured by near-infrared spectroscopy in adult patients with out-of-hospital cardiac arrest by alternating head-up and supine positions at 4-minute intervals while performing CPR. The CBF velocity according to the head position was also evaluated using the time derivative of the oscillation waveform. RESULTS During the study period, 28 patients were enrolled. The median increase in CBF in the prefrontal area in the head-up position was 14.6% (Interquartile range, 8.8-65.0), more than that in the supine position. An increase in CBF was observed in the head-up position compared with the supine position in 83.3% of the patients included in the analysis. CONCLUSION CBF increased when the head-up position was used during CPR in non-traumatic out-of-hospital cardiac arrest patients. abberivation OHCA: out-of-hospital cardiac arrest, ROSC: return of spontaneous circulation, CBF: cerebral blood flow, CPR: cardiopulmonary resuscitation, EMT: emergency medical technician, ACD: active chest compression-decompression, ITD: impedance threshold device, HUP: head-up position, ICP: intracranial pressure, CePP: cerebral perfusion pressure, NIRS: Near-infrared spectroscopy, ED: emergency department, ALS: advanced life support, HbO2: oxy-haemoglobin, HbR: deoxy-haemoglobin, RMS: root-mean-square, IQR: interquartile rage, TCD: transcranial doppler, CVR: cerebrovascular resistance, MAP: mean arterial pressure.
Collapse
|
8
|
Park J, Seok HS, Kim SS, Shin H. Photoplethysmogram Analysis and Applications: An Integrative Review. Front Physiol 2022; 12:808451. [PMID: 35300400 PMCID: PMC8920970 DOI: 10.3389/fphys.2021.808451] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/21/2021] [Indexed: 12/03/2022] Open
Abstract
Beyond its use in a clinical environment, photoplethysmogram (PPG) is increasingly used for measuring the physiological state of an individual in daily life. This review aims to examine existing research on photoplethysmogram concerning its generation mechanisms, measurement principles, clinical applications, noise definition, pre-processing techniques, feature detection techniques, and post-processing techniques for photoplethysmogram processing, especially from an engineering point of view. We performed an extensive search with the PubMed, Google Scholar, Institute of Electrical and Electronics Engineers (IEEE), ScienceDirect, and Web of Science databases. Exclusion conditions did not include the year of publication, but articles not published in English were excluded. Based on 118 articles, we identified four main topics of enabling PPG: (A) PPG waveform, (B) PPG features and clinical applications including basic features based on the original PPG waveform, combined features of PPG, and derivative features of PPG, (C) PPG noise including motion artifact baseline wandering and hypoperfusion, and (D) PPG signal processing including PPG preprocessing, PPG peak detection, and signal quality index. The application field of photoplethysmogram has been extending from the clinical to the mobile environment. Although there is no standardized pre-processing pipeline for PPG signal processing, as PPG data are acquired and accumulated in various ways, the recently proposed machine learning-based method is expected to offer a promising solution.
Collapse
Affiliation(s)
- Junyung Park
- Department of Biomedical Engineering, Chonnam National University, Yeosu, South Korea
| | - Hyeon Seok Seok
- Department of Biomedical Engineering, Chonnam National University, Yeosu, South Korea
| | - Sang-Su Kim
- Department of Biomedical Engineering, Chonnam National University, Yeosu, South Korea
| | - Hangsik Shin
- Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea
| |
Collapse
|
9
|
Chen KH, Brown CL, Wells JL, Rothwell ES, Otero M, Levenson RW, Fredrickson BL. Physiological linkage during shared positive and shared negative emotion. J Pers Soc Psychol 2021; 121:1029-1056. [PMID: 32897091 PMCID: PMC8261768 DOI: 10.1037/pspi0000337] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Physiological linkage refers to the degree to which peoples' physiological responses change in coordinated ways. Here, we examine whether and how physiological linkage relates to incidents of shared emotion, distinguished by valence. Past research has used an "overall average" approach and characterized how physiological linkage over relatively long time periods (e.g., 10-15 min) reflects psychological and social processes (e.g., marital satisfaction, empathy). Here, we used a "momentary" approach and characterized whether physiological linkage over relatively short time periods (i.e., 15 s) reflects shared positive emotion, shared negative emotion, or both, and whether linkage during shared emotions relates to relational functioning. Married couples (156 dyads) had a 15-min conflict conversation in the laboratory. Using behavioral coding, each second of conversation was classified into 1 of 4 emotion categories: shared positive emotion, shared negative emotion, shared neutral emotion, or unshared emotion. Using a composite of 3 peripheral physiological measures (i.e., heart rate, skin conductance, finger pulse amplitude), we computed momentary in-phase and antiphase linkage to represent coordinated changes in the same or opposite direction, respectively. We found that shared positive emotion was associated with higher in-phase and lower antiphase linkage, relative to the other 3 emotion categories. Greater in-phase physiological linkage during shared positive emotion was also consistently associated with higher-quality interactions and relationships, both concurrently and longitudinally (i.e., 5 to 6 years later). These findings advance our understanding of the nature of physiological linkage, the emotional conditions under which it occurs, and its possible associations with relational functioning. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Collapse
Affiliation(s)
- Kuan-Hua Chen
- Institute of Personality and Social Research, University of California, Berkeley
- Department of Psychology, University of California, Berkeley
| | - Casey L. Brown
- Department of Psychology, University of California, Berkeley
| | - Jenna L. Wells
- Department of Psychology, University of California, Berkeley
| | - Emily S. Rothwell
- Department of Psychology, University of California, Davis
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst
| | - Marcela Otero
- Department of Psychology, University of California, Berkeley
- Sierra Pacific Mental Illness Research Education and Clinical Centers, VA Palo Alto Health Care System
- Department of Psychiatry and Behavioral Sciences, Stanford University
| | - Robert W. Levenson
- Institute of Personality and Social Research, University of California, Berkeley
- Department of Psychology, University of California, Berkeley
| | | |
Collapse
|
10
|
Coutrot M, Dudoignon E, Joachim J, Gayat E, Vallée F, Dépret F. Perfusion index: Physical principles, physiological meanings and clinical implications in anaesthesia and critical care. Anaesth Crit Care Pain Med 2021; 40:100964. [PMID: 34687923 DOI: 10.1016/j.accpm.2021.100964] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 10/20/2022]
Abstract
Photoplethysmography (PPG) has been extensively used for pulse oximetry monitoring in anaesthesia, perioperative and intensive care. However, some components of PPG signal have been employed for other purposes, such as non-invasive haemodynamic monitoring. Perfusion index (PI) is derived from PPG signal and represents the ratio of pulsatile on non-pulsatile light absorbance or reflectance of the PPG signal. PI determinants are complex and interlinked, involving and reflecting the interaction between peripheral and central haemodynamic characteristics, such as vascular tone and stroke volume. Recently, several studies have shed light on the interesting performances of this variable, especially assessing regional or neuraxial block success, and haemodynamic monitoring in anaesthesia, perioperative and intensive care. Nevertheless, no review has yet been published concerning the interest of PI in these fields. In this narrative review will be exposed first the physiological and pathophysiological determinants of PI, and then the mean to measure this value as well as its potential limitations. In the second part, the existing data concerning usefulness of PI in different clinical settings such as operating theatres, intensive care units and emergency departments will be presented and discussed. Finally, the perspectives concerning the use of PI and mentioned aspects that should be explored regarding this tool will be underlined.
Collapse
Affiliation(s)
- Maxime Coutrot
- AP-HP, GH St-Louis-Lariboisière, Department of Anaesthesiology and Critical Care and Burn Unit, Paris, France; FHU PROMICE, Paris, France.
| | - Emmanuel Dudoignon
- AP-HP, GH St-Louis-Lariboisière, Department of Anaesthesiology and Critical Care and Burn Unit, Paris, France; University Paris Diderot, France.
| | - Jona Joachim
- AP-HP, GH St-Louis-Lariboisière, Department of Anaesthesiology and Critical Care and Burn Unit, Paris, France
| | - Etienne Gayat
- AP-HP, GH St-Louis-Lariboisière, Department of Anaesthesiology and Critical Care and Burn Unit, Paris, France; University Paris Diderot, France; UMR INSERM 942, Institut National de la Santé et de la Recherche Médicale (INSERM), France; FHU PROMICE, Paris, France
| | - Fabrice Vallée
- AP-HP, GH St-Louis-Lariboisière, Department of Anaesthesiology and Critical Care and Burn Unit, Paris, France; University Paris Diderot, France; UMR INSERM 942, Institut National de la Santé et de la Recherche Médicale (INSERM), France; FHU PROMICE, Paris, France; Inria, France; LMS, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, France
| | - François Dépret
- AP-HP, GH St-Louis-Lariboisière, Department of Anaesthesiology and Critical Care and Burn Unit, Paris, France; University Paris Diderot, France; UMR INSERM 942, Institut National de la Santé et de la Recherche Médicale (INSERM), France; FHU PROMICE, Paris, France; F-CRIN INICRCT network, Paris, France
| |
Collapse
|
11
|
Shimoda Y, Sonobe S, Niizuma K, Endo T, Endo H, Otomo M, Tominaga T. Digital intravascular pressure wave recording during endovascular treatment reveals abnormal shunting flow in vertebral venous fistula of the vertebral artery: illustrative case. JOURNAL OF NEUROSURGERY: CASE LESSONS 2021; 2:CASE21172. [PMID: 35854859 PMCID: PMC9265175 DOI: 10.3171/case21172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 04/20/2021] [Indexed: 12/02/2022]
Abstract
BACKGROUND An arteriovenous fistula is an abnormal arteriovenous shunt between an artery and a vein, which often leads to venous congestion in the central nervous system. The blood flow near the fistula is different from normal artery flow. A novel method to detect the abnormal shunting flow or pressure near the fistula is needed. OBSERVATIONS A 76-year-old woman presented to the authors’ institute with progressive right upper limb weakness. Right vertebral angiography showed a fistula between the right extracranial vertebral artery (VA) and the right vertebral venous plexus at the C7 level. The patient underwent endovascular treatment for shunt flow reduction. Before the procedure, blood pressures were measured at the proximal VA, distal VA near the fistula, and just at the fistula and drainer using a microcatheter. The blood pressure waveforms were characteristically different in terms of resistance index, half-decay time, and appearance of dicrotic notch. The fistula was embolized with coils and N-butyl cyanoacrylate solution. LESSONS During endovascular treatment, the authors were able to digitally record the vascular pressure waveform from the tip of the microcatheter and succeeded in calculating several parameters that characterize the shunting flow. Furthermore, these parameters could help recognize the abnormal blood flow, allowing a safer endovascular surgery.
Collapse
Affiliation(s)
| | | | - Kuniyasu Niizuma
- Departments of Neurosurgery and
- Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan; and
- Department of Neurosurgical Engineering and Translational Neuroscience, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Japan
| | - Toshiki Endo
- Departments of Neurosurgery and
- Neurosurgical Engineering and Translational Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan; and
| | | | | | | |
Collapse
|
12
|
The slope of cerebral oxyhemoglobin oscillation is associated with vascular reserve capacity in large artery steno-occlusion. Sci Rep 2021; 11:8568. [PMID: 33883666 PMCID: PMC8060335 DOI: 10.1038/s41598-021-88198-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/05/2021] [Indexed: 11/08/2022] Open
Abstract
Inadequate cerebral perfusion is a risk factor for cerebral ischemia in patients with large artery steno-occlusion. We investigated whether prefrontal oxyhemoglobin oscillation (ΔHbO2, 0.6-2 Hz) was associated with decreased vascular reserve in patients with steno-occlusion in the large anterior circulation arteries. Thirty-six patients with steno-occlusion in the anterior circulation arteries (anterior cerebral artery, middle cerebral artery, and internal carotid artery) were included and compared to thirty-six control subjects. Patients were categorized into two groups (deteriorated vascular reserve vs. preserved vascular reserve) based on the results of Diamox single- photon emission computed tomography imaging. HbO2 data were collected using functional near-infrared spectroscopy. The slope of ΔHbO2 and the ipsilateral/contralateral slope ratio of ΔHbO2 were analyzed. Among the included patients (n = 36), 25 (69.4%) had deteriorated vascular reserve. Patients with deteriorated vascular reserve had a significantly higher average slope of ΔHbO2 on the ipsilateral side (5.01 ± 2.14) and a higher ipsilateral/contralateral ratio (1.44 ± 0.62) compared to those with preserved vascular reserve (3.17 ± 1.36, P = 0.014; 0.93 ± 0.33, P = 0.016, respectively) or the controls (3.82 ± 1.69, P = 0.019; 0.94 ± 0.29, P = 0.001). The ipsilateral/contralateral ΔHbO2 ratio could be used as a surrogate for vascular reserve in patients with severe steno-occlusion in the anterior circulation arteries.
Collapse
|
13
|
Bourdillon N, Jeanneret F, Nilchian M, Albertoni P, Ha P, Millet GP. Sleep Deprivation Deteriorates Heart Rate Variability and Photoplethysmography. Front Neurosci 2021; 15:642548. [PMID: 33897355 PMCID: PMC8060636 DOI: 10.3389/fnins.2021.642548] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/03/2021] [Indexed: 12/21/2022] Open
Abstract
Introduction Sleep deprivation has deleterious effects on cardiovascular health. Using wearable health trackers, non-invasive physiological signals, such as heart rate variability (HRV), photoplethysmography (PPG), and baroreflex sensitivity (BRS) can be analyzed for detection of the effects of partial sleep deprivation on cardiovascular responses. Methods Fifteen participants underwent 1 week of baseline recording (BSL, usual day activity and sleep) followed by 3 days with 3 h of sleep per night (SDP), followed by 1 week of recovery with sleep ad lib (RCV). HRV was recorded using an orthostatic test every morning [root mean square of the successive differences (RMSSD), power in the low-frequency (LF) and high-frequency (HF) bands, and normalized power nLF and nHF were computed]; PPG and polysomnography (PSG) were recorded overnight. Continuous blood pressure and psychomotor vigilance task were also recorded. A questionnaire of subjective fatigue, sleepiness, and mood states was filled regularly. Results RMSSD and HF decreased while nLF increased during SDP, indicating a decrease in parasympathetic activity and a potential increase in sympathetic activity. PPG parameters indicated a decrease in amplitude and duration of the waveforms of the systolic and diastolic periods, which is compatible with increases in sympathetic activity and vascular tone. PSG showed a rebound of sleep duration, efficiency, and deep sleep in RCV compared to BSL. BRS remained unchanged while vigilance decreased during SDP. Questionnaires showed an increased subjective fatigue and sleepiness during SDP. Conclusion HRV and PPG are two markers easily measured with wearable devices and modified by partial sleep deprivation, contradictory to BRS. Both markers showed a decrease in parasympathetic activity, known as detrimental to cardiovascular health.
Collapse
Affiliation(s)
- Nicolas Bourdillon
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.,be.care SA, Renens, Switzerland
| | | | | | - Patrick Albertoni
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Pascal Ha
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
14
|
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]
|
15
|
Giosa L, Busana M, Payen D. Pitfalls in the assessment of ventriculo-arterial coupling from peripheral waveform analysis in septic shock. Comment on Br J Anaesth 2020; 125: 1018-1024. Br J Anaesth 2021; 126:e101-e102. [PMID: 33422286 DOI: 10.1016/j.bja.2020.12.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 11/30/2022] Open
Affiliation(s)
- Lorenzo Giosa
- Department of Surgical Sciences, University of Turin, Turin, Italy.
| | - Mattia Busana
- Department of Anesthesiology, University Medical Center of Göttingen, Göttingen, Germany
| | - Didier Payen
- University of Paris 7, Denis Diderot, Paris, France
| |
Collapse
|
16
|
Shin H, Park J, Seok HS, Kim SS. Photoplethysmogram analysis and applications: An Integrative Review (Preprint). JMIR BIOMEDICAL ENGINEERING 2020. [DOI: 10.2196/25567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
17
|
Aarotale PN, Blaber AP, Tavakolian K. Effect of Blood Volume Shift Simulated via Head-up Tilt on Photoplethysmography Morphology. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2695-269. [PMID: 33018562 DOI: 10.1109/embc44109.2020.9176555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
PPG can provide information on cardiovascular responses to fluid shifts from upper to lower part of body under the condition of orthostatic stress. The current study investigated ability of PPG derived LVET and other PPG derived features to identify progressive central hypovolemia induced by head up tilt (HUT) and evaluated potential use of LVET as early noninvasive indicator of blood loss. Continuous finger PPG, blood pressure, and electrocardiography were recorded simultaneously during 5-minutes of baseline and HUT of 20°, 40°, and 60° from 15 participants (age: 26.5 ± 3 years; height: 177 ± 8 cm; weight: 72 ± 10 kg, mean ± SD). Beat-by-beat pulse rate (PR), systolic amplitude (SA), systolic time (ST), diastolic time (DT), and PP Interval (PPI) and Ratio of pulse rate over systolic amplitude (PR/SA) were derived for each stage. LVET was derived from each stage. Friedman test followed by post-hoc analysis using Tukey-HSD was conducted to highlight the significance of changes induced by HUT. Application of 60° HUT (i.e. moderate category simulated hypovolemia) resulted in a significant change in PR (80±3 bpm vs 68±3 bpm, p=0.0008), DT (264±7 ms vs 303±4 ms, p=0.0008), ST (110±6 ms vs 117±7 ms, p=0.02), PP interval (764±39 ms vs 869±25 ms, p=0.0045), PR/SA (112±16 vs 82±21, p=0.012) , SA (0.875± 0.2 vs 1.69±0.6, p=0.012) and LVET(292 vs 351ms,p=0.0008) compared to baseline. LVET has a strong association with the change in central blood volume and may be used as a sensitive early marker of progressive hypovolemia. The findings of the study support the hypothesis of differentiating simulated hypovolemia based on PPG alone. Keywords: Hypovolemia, HUT, LVET.
Collapse
|
18
|
Assessing cognitive load in adolescent and adult students using photoplethysmogram morphometrics. Cogn Neurodyn 2020; 14:709-721. [PMID: 33014183 DOI: 10.1007/s11571-020-09617-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 06/11/2020] [Accepted: 07/07/2020] [Indexed: 10/23/2022] Open
Abstract
Compared to cardiac parameters and skin conductivities, the photoplethysmogram (PPG) recorded at fingertips and other parts near to peripheral nerve ends have been recently revealed to be yet another sensitive measure for cognitive load assessment. However, there is so far no research on measuring adolescents' cognitive load using physiological signals. A comprehensive study on the effects of PPG morphometrics over a cohort covering both adolescent and adult students is also absent. In this study, we analyze the morphological features of PPG on cognitive load assessment and compare them between adolescent and adult students. Experiments on two-level arithmetic tasks show that the PPG morphometrics reached the same level of significance on the effect of task difficulty/period as heart rate, and different morphological behaviors were also shown between adolescent and adult students during the cognitive task effects, which may imply their physiological differences across age. Physiological signals recorded by wearable devices are also found to be effective in measuring cognitive load.
Collapse
|
19
|
Allen J, O'Sullivan J, Stansby G, Murray A. Age-related changes in pulse risetime measured by multi-site photoplethysmography. Physiol Meas 2020; 41:074001. [PMID: 32784270 DOI: 10.1088/1361-6579/ab9b67] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE It is accepted that changes in the peripheral pulse waveform characteristics occur with ageing. Pulse risetime is one important feature which has clinical value. However, it is unclear how it varies across the full age spectrum from child to senior and for different peripheral measurement sites. The objectives of this study were to determine the association between age and pulse risetime characteristics over an 8-decade age range at the ears, fingers, and toes, and to consider effects arising from differences in systolic blood pressure (SBP), height and heart rate. APPROACH Multi-site photoplethysmography (MPPG) pulse waveforms were recorded non-invasively from the right and left ears, fingers, and toes of 304 normal healthy human subjects (range 6-87 years; 156 male and 148 female). SBP, height, and heart rate were also measured. Multi-site PPG pulse risetimes, and their site differences, were determined. MAIN RESULTS Univariate regression analysis showed positive correlations with risetime for age (ears, fingers and toes: + 0.8, + 1.9, and + 1.1 ms/year, respectively), SBP (+0.5, + 1.3, and + 0.9 ms/mmHg) and height (+0.5, + 1.2, and + 1.0 ms/cm), but with a clear inverse association with heart rate (-1.8, - 2.5, and - 1.6 ms min) (P < 0.0001). No significant differences between male and female subjects were found for pulse risetime. SIGNIFICANCE Normative multi-site PPG risetime characteristics have been defined in over 300 subjects and are shown to increase with age linearly up to the 8th decade. In contrast, we have shown that heart rate has a clear inverse relationship with risetime for all measurement sites.
Collapse
Affiliation(s)
- John Allen
- Centre for Intelligent Healthcare, Coventry University, Coventry, CV1 5FB, United Kingdom. Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | | | | | | |
Collapse
|
20
|
Hardware Prototype for Wrist-Worn Simultaneous Monitoring of Environmental, Behavioral, and Physiological Parameters. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10165470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We designed a low-cost wrist-worn prototype for simultaneously measuring environmental, behavioral, and physiological domains of influencing factors in healthcare. Our prototype continuously monitors ambient elements (sound level, toxic gases, ultraviolet radiation, air pressure, temperature, and humidity), personal activity (motion tracking and body positioning using gyroscope, magnetometer, and accelerometer), and vital signs (skin temperature and heart rate). An innovative three-dimensional hardware, based on the multi-physical-layer approach is introduced. Using board-to-board connectors, several physical hardware layers are stacked on top of each other. All of these layers consist of integrated and/or add-on sensors to measure certain domain (environmental, behavioral, or physiological). The prototype includes centralized data processing, transmission, and visualization. Bi-directional communication is based on Bluetooth Low Energy (BLE) and can connect to smartphones as well as smart cars and smart homes for data analytic and adverse-event alerts. This study aims to develop a prototype for simultaneous monitoring of the all three areas for monitoring of workplaces and chronic obstructive pulmonary disease (COPD) patients with a concentration on technical development and validation rather than clinical investigation. We have implemented 6 prototypes which have been tested by 5 volunteers. We have asked the subjects to test the prototype in a daily routine in both indoor (workplaces and laboratories) and outdoor. We have not imposed any specific conditions for the tests. All presented data in this work are from the same prototype. Eleven sensors measure fifteen parameters from three domains. The prototype delivers the resolutions of 0.1 part per million (PPM) for air quality parameters, 1 dB, 1 index, and 1 °C for sound pressure level, UV, and skin temperature, respectively. The battery operates for 12.5 h under the maximum sampling rates of sensors without recharging. The final expense does not exceed 133€. We validated all layers and tested the entire device with a 75 min recording. The results show the appropriate functionalities of the prototype for further development and investigations.
Collapse
|
21
|
El Atrache R, Tamilia E, Mohammadpour Touserkani F, Hammond S, Papadelis C, Kapur K, Jackson M, Bucciarelli B, Tsuboyama M, Sarkis RA, Loddenkemper T. Photoplethysmography: A measure for the function of the autonomic nervous system in focal impaired awareness seizures. Epilepsia 2020; 61:1617-1626. [DOI: 10.1111/epi.16621] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 11/26/2022]
Affiliation(s)
- Rima El Atrache
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Eleonora Tamilia
- Children's Brain Dynamics Division of Newborn Medicine Department of Medicine Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
- Fetal‐Neonatal Neuroimaging and Developmental Science Center Boston Children's Hospital Boston Massachusetts USA
| | - Fatemeh Mohammadpour Touserkani
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
- Department of Neurology SUNY Downstate Medical Center Brooklyn New York USA
| | - Sarah Hammond
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Christos Papadelis
- Children's Brain Dynamics Division of Newborn Medicine Department of Medicine Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
- Jane and John Justin Neurosciences Center Cook Children's Health Care System Fort Worth Texas USA
- Department of Bioengineering University of Texas at Arlington Arlington Texas USA
| | - Kush Kapur
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Michele Jackson
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Bethany Bucciarelli
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Melissa Tsuboyama
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| | - Rani A. Sarkis
- Department of Neurology Brigham and Women's HospitalHarvard Medical School Boston Massachusetts USA
| | - Tobias Loddenkemper
- Division of Epilepsy and Clinical Neurophysiology Department of Neurology Boston Children's HospitalHarvard Medical School Boston Massachusetts USA
| |
Collapse
|
22
|
Mohammadpour Touserkani F, Tamilia E, Coughlin F, Hammond S, El Atrache R, Jackson M, Bendsen-Jensen M, Kim B, Connolly J, Manganaro S, Papadelis C, Kapur K, Loddenkemper T. Photoplethysmographic evaluation of generalized tonic-clonic seizures. Epilepsia 2020; 61:1606-1616. [PMID: 32652564 DOI: 10.1111/epi.16590] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Photoplethysmography (PPG) is an optical technique measuring variations of blood perfusion in peripheral tissues. We evaluated alterations in PPG signals in relationship to the occurrence of generalized tonic-clonic seizures (GTCSs) in patients with epilepsy to evaluate the feasibility of seizure detection. METHODS During electroencephalographic (EEG) long-term monitoring, patients wore portable wristband sensor(s) on their wrists or ankles recording PPG signals. We analyzed PPG signals during three time periods, which were defined with respect to seizures detected on EEG: (1) baseline (>30 minutes prior to seizure), (2) preseizure period, and (3) postseizure period. Furthermore, we selected five random control segments during seizure-free periods. PPG features, including frequency, amplitude, duration, slope, smoothness, and area under the curve, were automatically calculated. We used a linear mixed-effect model to evaluate changes in PPG features between different time periods in an attempt to identify signal changes that detect seizures. RESULTS We prospectively enrolled 174 patients from the epilepsy monitoring unit at Boston Children's Hospital. Twenty-five GTCSs were recorded from 13 patients. Data from the first recorded GTCS of each patient were included in the analysis. We observed an increase in PPG frequency during pre- and postseizure periods that was higher than the changes during seizure-free periods (frequency increase: preseizure = 0.22 Hz, postseizure = 0.58 Hz vs changes during seizure-free period = 0.05 Hz). The PPG slope decreased significantly by 56.71 nW/s during preseizure periods compared to seizure-free periods. Additionally, the smoothness increased significantly by 0.22 nW/s during the postseizure period compared to seizure-free periods. SIGNIFICANCE Monitoring of PPG signals may assist in the detection of GTCSs in patients with epilepsy. PPG may serve as a promising biomarker for future seizure detection systems and may contribute to future seizure prediction systems.
Collapse
Affiliation(s)
- Fatemeh Mohammadpour Touserkani
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Department of Neurology, SUNY Downstate Medical Center, Brooklyn, New York
| | - Eleonora Tamilia
- Division of Newborn Medicine, Department of Medicine, Children's Brain Dynamics, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts.,Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, Massachusetts
| | - Francesca Coughlin
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sarah Hammond
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rima El Atrache
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Michele Jackson
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Megan Bendsen-Jensen
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Boram Kim
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jack Connolly
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Department of Neurology, SUNY Downstate Medical Center, Brooklyn, New York
| | - Sheryl Manganaro
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Christos Papadelis
- Division of Newborn Medicine, Department of Medicine, Children's Brain Dynamics, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts.,Cook Children's Health Care System, Jane and John Justin Neurosciences Center, Fort Worth, Texas.,Department of Bioengineering, University of Texas at Arlington, Arlington, Texas
| | - Kush Kapur
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tobias Loddenkemper
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
23
|
Xie Z, Wang G, Cheng Y, Zhang Q, Le MN, Wang RK. Optical coherence tomography angiography measures blood pulsatile waveforms at variable tissue depths. Quant Imaging Med Surg 2020; 11:907-917. [PMID: 33654664 DOI: 10.21037/qims-20-778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background Photoplethysmography (PPG) is routinely used to detect the blood pulse signal from skin tissue beds in clinics. However, the origin of the PPG signal remains controversial. The purpose of this study is to explore optical coherence tomography angiography (OCTA) to indicate pulsatile waveforms in the papillary plexus and dermal plexus separately under different hand elevations. Method Optical microangiography (OMAG) algorithm was used to obtain a 3D OCTA signals, from which the depth-resolved pulsatile blood flow signals were extracted from different skin vascular plexus. The systolic amplitude, crest time, and delta T were measured from the OCTA pulsatile signals when the hand was placed at the positions of 50 cm below, 0 cm, and 50 cm above the heart level. Results The pulse signal integrated from all the depths has a similar waveform to that of the PPG and showed the same morphological change at different hand elevations. The pulsatile patterns from the papillary plexus and dermal plexus showed distinct morphological changes at different local blood pressure. Less amplitude difference was found from papillary plexus comparing to that of the dermal plexus. Crest time was found in an increasing trend in the OCTA pulsatile waveform from both plexuses when the arm was raised from the position below to above the heart level. In contrast, a decreasing trend of Delta T was detected in the dermal pulsatile but was not observed from that of the papillary plexus, indicating that vascular resistance associated with the arm elevations does not necessarily have the same effect on the two plexuses. Conclusions OCTA can provide depth-resolved pulsatile waveforms within different microvascular plexus within tissue skin beds. This technique could open doors to understanding the mechanisms of how blood flow changes at different skin circulatory plexus.
Collapse
Affiliation(s)
- Zhiying Xie
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Geng Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Yuxuan Cheng
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Minh Nhan Le
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| |
Collapse
|
24
|
Bourdillon N, Nilchian M, Millet GP. Photoplethysmography Detection of Overreaching. Med Sci Sports Exerc 2019; 51:701-707. [PMID: 30407274 DOI: 10.1249/mss.0000000000001836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Detecting the onset of functional overreaching (FOR) or nonfunctional overreaching in endurance athletes is of prior importance to ensure reactive amendment of the scheduled training program. The objective of this study was to assess photoplethysmography (PPG) in overloaded athletes and test whether 1) it would be affected differently in functional overreached (FOR) or nonoverreached acutely fatigued (AF) athletes and 2) specific PPG characteristics would allow for timely distinction of FOR and AF. METHODS Fifteen athletes performed 2-wk baseline training followed by 3-wk overload (+45%; OVL) and 2-wk recovery (-20%). Three-thousand-meter time-trial running was used to assess performance at the end of baseline, OVL, and recovery and distinguish FOR and AF. PPG was recorded overnight using a wearable sensor, every third night. Overnight means and variances of systolic, diastolic, and dicrotic amplitudes and times as well as systolic and diastolic slopes were used to discriminate FOR and AF athletes. RESULTS Performance was decreased in FOR and improved in AF at the end of OVL. Diastolic time was greater in AF than FOR, whereas systolic slope was smaller in AF than in FOR during OVL. The variances of systolic, diastolic, dicrotic amplitudes, systolic, diastolic slopes, and pulse areas were smaller in AF compared with FOR in the last week of OVL. CONCLUSION PPG is an efficient tool for the detection of overreaching because it distinguished FOR and AF athletes during OVL (prior performance decrement). This fast-responding method would therefore allow for adjusting the daily training content to prevent nonfunctional overreaching.
Collapse
Affiliation(s)
- Nicolas Bourdillon
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, SWITZERLAND
| | | | - Grégoire P Millet
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, SWITZERLAND
| |
Collapse
|
25
|
Ghijsen M, Rice TB, Yang B, White SM, Tromberg BJ. Wearable speckle plethysmography (SPG) for characterizing microvascular flow and resistance. BIOMEDICAL OPTICS EXPRESS 2018; 9:3937-3952. [PMID: 30338166 PMCID: PMC6191642 DOI: 10.1364/boe.9.003937] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/11/2018] [Accepted: 07/18/2018] [Indexed: 05/04/2023]
Abstract
In this work we introduce a modified form of laser speckle imaging (LSI) referred to as affixed transmission speckle analysis (ATSA) that uses a single coherent light source to probe two physiological signals: one related to pulsatile vascular expansion (classically known as the photoplethysmographic (PPG) waveform) and one related to pulsatile vascular blood flow (named here the speckle plethysmographic (SPG) waveform). The PPG signal is determined by recording intensity fluctuations, and the SPG signal is determined via the LSI dynamic light scattering technique. These two co-registered signals are obtained by transilluminating a single digit (e.g. finger) which produces quasi-periodic waveforms derived from the cardiac cycle. Because PPG and SPG waveforms probe vascular expansion and flow, respectively, in cm-thick tissue, these complementary phenomena are offset in time and have rich dynamic features. We characterize the timing offset and harmonic content of the waveforms in 16 human subjects and demonstrate physiologic relevance for assessing microvascular flow and resistance.
Collapse
Affiliation(s)
- Michael Ghijsen
- Laser Microbeam and Medical Program, Beckman Laser Institute, 1002 Health Sciences Road, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
| | - Tyler B. Rice
- Laser Associated Sciences Inc., 16 Foxglove Way, Irvine, CA 92612, USA
| | - Bruce Yang
- Laser Associated Sciences Inc., 16 Foxglove Way, Irvine, CA 92612, USA
| | - Sean M. White
- Laser Associated Sciences Inc., 16 Foxglove Way, Irvine, CA 92612, USA
| | - Bruce J. Tromberg
- Laser Microbeam and Medical Program, Beckman Laser Institute, 1002 Health Sciences Road, Irvine, CA 92612, USA
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
- Department of Surgery, University of California, Irvine Medical Center, Orange, CA 92868, USA
| |
Collapse
|
26
|
The value of dynamic preload variables during spontaneous ventilation. Curr Opin Crit Care 2018; 23:310-317. [PMID: 28614095 DOI: 10.1097/mcc.0000000000000430] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW To discuss the physiological significance and clinical value of dynamic preload variables in spontaneously breathing patients. RECENT FINDINGS Dynamic preload variables reflect the response of the cardiac output to a modification of preload and can therefore be used to assess fluid responsiveness. Continuous dynamic parameters that are calculated from the variations in the arterial and plethysmographic waveforms following a mechanical breath have been shown to predict fluid responsiveness much better than static preload parameters. These parameters are displayed on many patient monitors though their use is limited to mechanically ventilated patients. However, spontaneous breathing may also induce significant hemodynamic changes because of the repetitive negative swings in the pleural pressure. By better understanding the physiological basis of these changes, the same 'dynamic parameters' can be used to gain unique physiological insights during spontaneous breathing. These include the ability to identify and/or monitor respiratory rate, respiratory effort (e.g., patient-ventilator asynchrony), fluid responsiveness (to some degree), pulsus paradoxus (e.g. asthma, cardiac tamponade), and, importantly, upper airway obstruction. SUMMARY Although originally intended to be used only during mechanical ventilation, 'dynamic parameters' may offer valuable clinical information in spontaneously breathing patients.
Collapse
|
27
|
Perel A. Non-invasive multi-parametric cardiorespiratory assessment of the hemodynamically unstable patient. ACTA ACUST UNITED AC 2017; 65:69-73. [PMID: 29246396 DOI: 10.1016/j.redar.2017.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 11/17/2022]
Affiliation(s)
- A Perel
- Department of Anesthesiology and Intensive Care, Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel.
| |
Collapse
|
28
|
BHAT SHREYA, ADAM MUHAMMAD, HAGIWARA YUKI, NG EDDIEY. THE BIOPHYSICAL PARAMETER MEASUREMENTS FROM PPG SIGNAL. J MECH MED BIOL 2017. [DOI: 10.1142/s021951941740005x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Early investigation on blood circulation by Hertzman (1937) leads to the observation of vital body signs such as respiration rate, heart rate (HR), blood oxygenation and vascular assessment using photoplethysmographic (PPG) device. PPG is a noninvasive, painless optical technique used to monitor the pulsations linked to alteration in the blood volume. The PPG waveform is a summation of pulsatile and nonpulsatile components and contains useful information about the physiological systems. With the breakthrough in technology and development of powerful analytical tools, PPG devices are constantly being used in advanced medical equipments such as smart-watches and smart-wristbands for HR monitoring, pulse oximeters for measuring respiratory rate and noncontact PPG device for blood oxygen saturation measurement. This paper presents description on PPG and its characteristic waveform and working principle. It also includes brief explanation on nonlinear analysis of PPG signals and salient applications of PPG followed by its advantages and limitations.
Collapse
Affiliation(s)
- SHREYA BHAT
- Department of Psychiatry, St John’s Research Institute, Bangalore, India
| | - MUHAMMAD ADAM
- Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore
| | - YUKI HAGIWARA
- Department of Electronics and Computer Engineering, Ngee Ann Polytechnic, Singapore
| | - EDDIE Y. K. NG
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| |
Collapse
|
29
|
Hwang CS, Yang SP, Jang KW, Park JW, Jeong KH. Angle-selective optical filter for highly sensitive reflection photoplethysmogram. BIOMEDICAL OPTICS EXPRESS 2017; 8:4361-4368. [PMID: 29082070 PMCID: PMC5654785 DOI: 10.1364/boe.8.004361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 06/07/2023]
Abstract
We report an angle-selective optical filter (ASOF) for highly sensitive reflection photoplethysmography (PPG) sensors. The ASOF features slanted aluminum (Al) micromirror arrays embedded in transparent polymer resin, which effectively block scattered light under human tissue. The device microfabrication was done by using geometry-guided resist reflow of polymer micropatterns, polydimethylsiloxane replica molding, and oblique angle deposition of thin Al film. The angular transmittance through the ASOF is precisely controlled by the angle of micromirrors. For the mirror angle of 30 degrees, the ASOF accepts an incident light between - 90 to + 50 degrees and the maximum transmittance at - 55 degrees. The ASOF exhibits the substantial reduction of both the in-band noise of PPG signals over a factor of two and the low-frequency noise by three times. Consequently, this filter allows distinguishing the diastolic peak that allows miscellaneous parameters with diverse vascular information. This optical filter provides a new opportunity for highly sensitive PPG monitoring or miscellaneous optical tomography.
Collapse
|
30
|
Lu T, Markvicka EJ, Jin Y, Majidi C. Soft-Matter Printed Circuit Board with UV Laser Micropatterning. ACS APPLIED MATERIALS & INTERFACES 2017; 9:22055-22062. [PMID: 28605185 DOI: 10.1021/acsami.7b05522] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
When encapsulated in elastomer, micropatterned traces of Ga-based liquid metal (LM) can function as elastically deformable circuit wiring that provides mechanically robust electrical connectivity between solid-state elements (e.g., transistors, processors, and sensor nodes). However, LM-microelectronics integration is currently limited by challenges in rapid fabrication of LM circuits and the creation of vias between circuit terminals and the I/O pins of packaged electronics. In this study, we address both with a unique layup for soft-matter electronics in which traces of liquid-phase Ga-In eutectic (EGaIn) are patterned with UV laser micromachining (UVLM). The terminals of the elastomer-sealed LM circuit connect to the surface mounted chips through vertically aligned columns of EGaIn-coated Ag-Fe2O3 microparticles that are embedded within an interfacial elastomer layer. The processing technique is compatible with conventional UVLM printed circuit board (PCB) prototyping and exploits the photophysical ablation of EGaIn on an elastomer substrate. Potential applications to wearable computing and biosensing are demonstrated with functional implementations in which soft-matter PCBs are populated with surface-mounted microelectronics.
Collapse
Affiliation(s)
- Tong Lu
- Department of Mechanical Engineering and ‡Robotics Institute, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Eric J Markvicka
- Department of Mechanical Engineering and ‡Robotics Institute, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Yichu Jin
- Department of Mechanical Engineering and ‡Robotics Institute, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Carmel Majidi
- Department of Mechanical Engineering and ‡Robotics Institute, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| |
Collapse
|
31
|
Wang L, Xu L, Zhou S, Wang H, Yao Y, Hao L, Li BN, Qi L. Design and implementation of a pulse wave generator based on Windkessel model using field programmable gate array technology. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2017.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
32
|
Alteration of Arterial Mechanical Impedance Greater than that of Photoplethysmogram and Laser Doppler Flowmetry during Endoscopic Thoracic Sympathectomy. J Med Biol Eng 2017. [DOI: 10.1007/s40846-017-0246-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
33
|
Tusman G, Bohm SH, Suarez-Sipmann F. Advanced Uses of Pulse Oximetry for Monitoring Mechanically Ventilated Patients. Anesth Analg 2017; 124:62-71. [DOI: 10.1213/ane.0000000000001283] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
34
|
|
35
|
Analysing the effects of cold, normal, and warm digits on transmittance pulse oximetry. Biomed Signal Process Control 2016. [DOI: 10.1016/j.bspc.2015.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
36
|
Weyer S, Weishaupt F, Kleeberg C, Leonhardt S, Teichmann D. RheoStim: Development of an Adaptive Multi-Sensor to Prevent Venous Stasis. SENSORS 2016; 16:428. [PMID: 27023544 PMCID: PMC4850942 DOI: 10.3390/s16040428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/17/2016] [Accepted: 03/18/2016] [Indexed: 11/24/2022]
Abstract
Chronic venous insufficiency of the lower limbs is often underestimated and, in the absence of therapy, results in increasingly severe complications, including therapy-resistant tissue defects. Therefore, early diagnosis and adequate therapy is of particular importance. External counter pulsation (ECP) therapy is a method used to assist the venous system. The main principle of ECP is to squeeze the inner leg vessels by muscle contractions, which are evoked by functional electrical stimulation. A new adaptive trigger method is proposed, which improves and supplements the current therapeutic options by means of pulse synchronous electro-stimulation of the muscle pump. For this purpose, blood flow is determined by multi-sensor plethysmography. The hardware design and signal processing of this novel multi-sensor plethysmography device are introduced. The merged signal is used to determine the phase of the cardiac cycle, to ensure stimulation of the muscle pump during the filling phase of the heart. The pulse detection of the system is validated against a gold standard and provides a sensitivity of 98% and a false-negative rate of 2% after physical exertion. Furthermore, flow enhancement of the system has been validated by duplex ultrasonography. The results show a highly increased blood flow in the popliteal vein at the knee.
Collapse
Affiliation(s)
- Sören Weyer
- Chair for Medical Information Technology, Helmholtz Institute, RWTH Aachen University, Pauwelsstr. 20, Aachen 52074, Germany.
| | - Fabio Weishaupt
- Chair for Medical Information Technology, Helmholtz Institute, RWTH Aachen University, Pauwelsstr. 20, Aachen 52074, Germany.
| | - Christian Kleeberg
- tic Medizintechnik GmbH & Co. KG, Endelner Feld 9, Dorsten 46286, Germany.
| | - Steffen Leonhardt
- Chair for Medical Information Technology, Helmholtz Institute, RWTH Aachen University, Pauwelsstr. 20, Aachen 52074, Germany.
| | - Daniel Teichmann
- Chair for Medical Information Technology, Helmholtz Institute, RWTH Aachen University, Pauwelsstr. 20, Aachen 52074, Germany.
| |
Collapse
|
37
|
Fischer C, Domer B, Wibmer T, Penzel T. An Algorithm for Real-Time Pulse Waveform Segmentation and Artifact Detection in Photoplethysmograms. IEEE J Biomed Health Inform 2016; 21:372-381. [PMID: 26780821 DOI: 10.1109/jbhi.2016.2518202] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Photoplethysmography has been used in a wide range of medical devices for measuring oxygen saturation, cardiac output, assessing autonomic function, and detecting peripheral vascular disease. Artifacts can render the photoplethysmogram (PPG) useless. Thus, algorithms capable of identifying artifacts are critically important. However, the published PPG algorithms are limited in algorithm and study design. Therefore, the authors developed a novel embedded algorithm for real-time pulse waveform (PWF) segmentation and artifact detection based on a contour analysis in the time domain. This paper provides an overview about PWF and artifact classifications, presents the developed PWF analysis, and demonstrates the implementation on a 32-bit ARM core microcontroller. The PWF analysis was validated with data records from 63 subjects acquired in a sleep laboratory, ergometry laboratory, and intensive care unit in equal parts. The output of the algorithm was compared with harmonized experts' annotations of the PPG with a total duration of 31.5 h. The algorithm achieved a beat-to-beat comparison sensitivity of 99.6%, specificity of 90.5%, precision of 98.5%, and accuracy of 98.3%. The interrater agreement expressed as Cohen's kappa coefficient was 0.927 and as F-measure was 0.990. In conclusion, the PWF analysis seems to be a suitable method for PPG signal quality determination, real-time annotation, data compression, and calculation of additional pulse wave metrics such as amplitude, duration, and rise time.
Collapse
|
38
|
Liu C, Zheng D, Murray A. Arteries Stiffen With Age, but Can Retain an Ability to Become More Elastic With Applied External Cuff Pressure. Medicine (Baltimore) 2015; 94:e1831. [PMID: 26469929 PMCID: PMC4616803 DOI: 10.1097/md.0000000000001831] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
It is accepted that arterial compliance decreases with age, with changes in the arterial pulse shape measured at the periphery. The aim of this study was to determine the relationship between arterial transmural pressure changes and changes in peripheral finger pulse shape characteristics for both older and younger subjects.Finger photoplethysmographic pulses were recorded noninvasively from the right index fingers of 100 healthy normotensive subjects. Their median age was 43 years (range 20-71 years) allowing two distinct age groups to be compared (older group ≥45 and younger group < 45 years). Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30, and 40 mmHg. Pulse maximum amplitude and rise time were calculated for each age group, and for each cuff pressure level.Gradual and significant decreases in both pulse maximum amplitude and rise time were found with increasing cuff pressure for both age groups. With an external cuff pressure of 40 mmHg, there was an average maximum amplitude and rise time decrease of 27.1% (P < 0.001) and 7.5% (P < 0.001) respectively. The changes in the older group were significantly greater than those in the younger group for maximum amplitude (30.3% vs 24.4%, P = 0.006), but not for rise time (8.0% vs 6.7%, P = 0.23).Our results show that arterial compliance of the arm artery increases with reduced transmural pressure for both older and younger groups, and demonstrate that the aged arm artery can become more elastic with applied external cuff pressure.
Collapse
Affiliation(s)
- Chengyu Liu
- From the Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, NE1 4LP, UK (CL, DZ, AM); School of Control Science and Engineering, Shandong University, Jinan, 250061, China (CL); and Health and Well Being Academy, Faculty of Medical Science, Anglia Ruskin University, Chelmsford, CM1 1SQ, UK (DZ)
| | | | | |
Collapse
|
39
|
von Wowern E, Östling G, Nilsson PM, Olofsson P. Digital Photoplethysmography for Assessment of Arterial Stiffness: Repeatability and Comparison with Applanation Tonometry. PLoS One 2015; 10:e0135659. [PMID: 26291079 PMCID: PMC4546304 DOI: 10.1371/journal.pone.0135659] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/23/2015] [Indexed: 12/02/2022] Open
Abstract
Introduction Arterial stiffness is an independent risk factor for cardiovascular morbidity and can be assessed by applanation tonometry by measuring pulse wave velocity (PWV) and augmentation index (AIX) by pressure pulse wave analysis (PWA). As an inexpensive and operator independent alternative, photoelectric plethysmography (PPG) has been introduced with analysis of the digital volume pulse wave (DPA) and its second derivatives of wave reflections. Objective The objective was to investigate the repeatability of arterial stiffness parameters measured by digital pulse wave analysis (DPA) and the associations to applanation tonometry parameters. Methods and Results 112 pregnant and non-pregnant individuals of different ages and genders were examined with SphygmoCor arterial wall tonometry and Meridian DPA finger photoplethysmography. Coefficients of repeatability, Bland-Altman plots, intraclass correlation coefficients and correlations to heart rate (HR) and body height were calculated for DPA variables, and the DPA variables were compared to tonometry variables left ventricular ejection time (LVET), PWV and AIX. No DPA variable showed any systematic measurement error or excellent repeatability, but dicrotic index (DI), dicrotic dilatation index (DDI), cardiac ejection elasticity index (EEI), aging index (AI) and second derivatives of the crude pulse wave curve, b/a and e/a, showed good repeatability. Overall, the correlations to AIX were better than to PWV, with correlations coefficients >0.70 for EEI, AI and b/a. Considering the level of repeatability and the correlations to tonometry, the overall best DPA parameters were EEI, AI and b/a. The two pansystolic time parameters, ejection time compensated (ETc) by DPA and LVET by tonometry, showed a significant but weak correlation. Conclusion For estimation of the LV function, ETc, EEI and b/a are suitable, for large artery stiffness EEI, and for small arteries DI and DDI. The only global parameter, AI, showed a high repeatability and the overall best correlations with AIX and PWV.
Collapse
Affiliation(s)
- Emma von Wowern
- Department of Obstetrics and Gynecology, Institution of Clinical Sciences, Skåne University Hospital, Lund University, Malmö, Sweden
- * E-mail:
| | - Gerd Östling
- Medical Research Unit, Department of Internal Medicine, Institution of Clinical Sciences, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Peter M. Nilsson
- Medical Research Unit, Department of Internal Medicine, Institution of Clinical Sciences, Skåne University Hospital, Lund University, Malmö, Sweden
| | - Per Olofsson
- Department of Obstetrics and Gynecology, Institution of Clinical Sciences, Skåne University Hospital, Lund University, Malmö, Sweden
| |
Collapse
|
40
|
Effects of thoracic pressure changes on MRI signals in the brain. J Cereb Blood Flow Metab 2015; 35:1024-32. [PMID: 25712496 PMCID: PMC4640249 DOI: 10.1038/jcbfm.2015.20] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 12/11/2014] [Accepted: 01/09/2015] [Indexed: 11/09/2022]
Abstract
Cerebrovascular stressors, such as breath holding or CO2 inhalation, cause global magnetic resonance imaging (MRI) signal changes. In this study, we show that intrathoracic pressure changes cause rapid MRI signal alterations that have similar spatial patterns to the changes associated with breath holding or CO2 inhalation. Nine subjects performed the Valsalva maneuver during functional MRI data collection. Expiratory pressures ranged from 10 to 40 mm Hg. Breath holds ending on either inhalation or exhalation were also collected. The maximal and minimal functional MRI (fMRI) signal scaled with thoracic pressure load, and the overall amplitude of responses to the Valsalva varied, depending on brain tissue. Additionally, a Valsalva effort as short as 5 seconds yielded signal changes similar in spatial distribution and magnitude to a 20-second breath hold, suggesting potential applications of the Valsalva maneuver for calibrated fMRI experiments.
Collapse
|
41
|
FPGA-based design and implementation of arterial pulse wave generator using piecewise Gaussian–cosine fitting. Comput Biol Med 2015; 59:142-151. [DOI: 10.1016/j.compbiomed.2015.02.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 02/07/2015] [Accepted: 02/09/2015] [Indexed: 11/19/2022]
|
42
|
Perel A. Excessive variations in the plethysmographic waveform during spontaneous ventilation: an important sign of upper airway obstruction. Anesth Analg 2015; 119:1288-92. [PMID: 25405690 DOI: 10.1213/ane.0000000000000378] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The respiratory variations in the plethysmographic (PLET) waveform of the pulse oximeter during mechanical ventilation can be automatically quantified as the PLET variation index (PVI(®)). Like other dynamic variables, the PVI may provide useful information about fluid responsiveness but only when the patient is receiving fully controlled mechanical ventilation with no spontaneous breathing activity. However, a growing number of monitors that automatically measure and display the values of the PVI and other dynamic variables are being introduced into clinical practice. Using these monitors in spontaneously breathing patients may cause inadequately trained personnel to make erroneous decisions or may eventually lead to a total disregard of dynamic parameters altogether. The aim of this study is to call attention to the fact that excessive variations in the PVI during spontaneous ventilation, termed sPVI, should not be regarded as artifactual since they may be an early important sign of upper airway obstruction (UAO). Among the monitor screen shots that were stored for educational purposes, I have identified 4 screen shots of patients who were clinically diagnosed as having significant UAO. In all instances, UAO was associated with prominent variations in the PLET waveform. These variations were calculated as the difference between the maximal and minimal amplitudes of the PLET signal divided by either the maximal amplitude (sPVI) or by the mean of the 2 values (ΔPOP). The ranges of the measured ΔPOP and sPVI values during UAO were 28% to 42% and 25% to 39%, respectively. These values are 2 to 3 times higher than the range of 9.5% to 15% that was repeatedly found as the best threshold for the identification of fluid responsiveness in mechanically ventilated patients. In 2 of these cases, simultaneously measured values of the pulse pressure variation were high as well (19% and 34%), while the calculated pulsus paradoxus was 28 and 40 mm Hg. In 2 cases, the analog signals of impedance plethysmography and capnography persisted, despite the presence of clinically significant UAO. It is, therefore, suggested that monitoring the sPVI may be of great clinical importance in spontaneously breathing patients who are susceptible to develop UAO.
Collapse
Affiliation(s)
- Azriel Perel
- From the Department of Anesthesiology and Critical Care, Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
43
|
Khan M, Pretty CG, Amies AC, Elliott R, Shaw GM, Chase JG. Investigating the Effects of Temperature on Photoplethysmography. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.ifacol.2015.10.166] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
44
|
Using the multi-parameter variability of photoplethysmographic signals to evaluate short-term cardiovascular regulation. J Clin Monit Comput 2014; 29:605-12. [DOI: 10.1007/s10877-014-9641-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 11/12/2014] [Indexed: 11/25/2022]
|
45
|
Alian AA, Shelley KH. Photoplethysmography. Best Pract Res Clin Anaesthesiol 2014; 28:395-406. [PMID: 25480769 DOI: 10.1016/j.bpa.2014.08.006] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/15/2014] [Accepted: 08/27/2014] [Indexed: 11/29/2022]
Abstract
The photoplethysmographic (PPG) waveform, also known as the pulse oximeter waveform, is one of the most commonly displayed clinical waveforms. First described in the 1930s, the technology behind the waveform is simple. The waveform, as displayed on the modern pulse oximeter, is an amplified and highly filtered measurement of light absorption by the local tissue over time. It is optimized by medical device manufacturers to accentuate its pulsatile components. Physiologically, it is the result of a complex, and not well understood, interaction between the cardiovascular, respiratory, and autonomic systems. All modern pulse oximeters extract and display the heart rate and oxygen saturation derived from the PPG measurements at multiple wavelengths. "As is," the PPG is an excellent monitor for cardiac arrhythmia, particularly when used in conjunction with the electrocardiogram (ECG). With slight modifications in the display of the PPG (either to a strip chart recorder or slowed down on the monitor screen), the PPG can be used to measure the ventilator-induced modulations which have been associated with hypovolemia. Research efforts are under way to analyze the PPG using improved digital signal processing methods to develop new physiologic parameters. It is hoped that when these new physiologic parameters are combined with a more modern understanding of cardiovascular physiology (functional hemodynamics) the potential utility of the PPG will be expanded. The clinical researcher's objective is the use of the PPG to guide early goal-directed therapeutic interventions (fluid, vasopressors, and inotropes), in effect to extract from the simple PPG the information and therapeutic guidance that was previously only obtainable from an arterial pressure line and the pulmonary artery catheter.
Collapse
Affiliation(s)
- Aymen A Alian
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA.
| | - Kirk H Shelley
- Department of Anesthesiology, Yale University School of Medicine, New Haven, CT, USA.
| |
Collapse
|
46
|
Synchronizing chaotification with support vector machine and wolf pack search algorithm for estimation of peripheral vascular occlusion in diabetes mellitus. Biomed Signal Process Control 2014. [DOI: 10.1016/j.bspc.2013.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
47
|
Impact of changes in systemic vascular resistance on a novel non-invasive continuous cardiac output measurement system based on pulse wave transit time: a report of two cases. J Clin Monit Comput 2013; 28:423-7. [PMID: 24197827 PMCID: PMC4119244 DOI: 10.1007/s10877-013-9529-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 10/31/2013] [Indexed: 11/20/2022]
Abstract
The inaccuracy of arterial waveform analysis for measuring continuos cardiac output (CCO) associated with changes in systemic vascular resistance (SVR) has been well documented. A new non-invasive continuous cardiac output monitoring system (esCCO) mainly utilizing pulse wave transit time (PWTT) in place of arterial waveform analysis has been developed. However, the trending ability of esCCO to measure cardiac output during changes in SVR remains unclear. After a previous multicenter study on esCCO measurement, we retrospectively identified two cases in which apparent changes in SVR developed in a short period during data collection. In each case, the trending ability of esCCO to measure cardiac output and time component of PWTT were analyzed. Recorded data suggest that the time component of PWTT may have a significant impact on the accuracy of estimating stroke volume during changes in SVR. However, further prospective clinical studies are required to test this hypothesis.
Collapse
|
48
|
|
49
|
|
50
|
Mousa WF. Effect of hypercapnia on pleth variability index during stable propofol: Remifentanil anesthesia. Saudi J Anaesth 2013; 7:234-7. [PMID: 24015122 PMCID: PMC3757792 DOI: 10.4103/1658-354x.115317] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The pleth variability index (PVI), which is calculated from respiratory variations in the perfusion index (PI), has been shown to predict fluid responsiveness in mechanically ventilated patients; however, vasomotor tone changes induced by hypercapnia can affect PI and hence may slim down the accuracy of PVI. This study was designed to find out the impact of mild hypercapnia on PVI. METHODS A total of 30 patients were randomized after induction of general anesthesia with target controlled infusion propofol and remifentanil to either hypercapnia, (etCO2 =45 mmHg), (group 1, 15 patients) or normocapnia (etCO2 =35 mmHg) (group 2, 15 patients). After a stabilization period of 10 min, patients were crossed over to the other intentional level of etCO2. Heart rate (HR), mean arterial pressure (MAP), PI, PVI were collected at the end of each stabilization period. RESULTS Patient characteristics and baseline values of HR, MAP, PI and PVI were comparable between the groups. Carryover effect was statistically excluded. Hypercapnia significantly increased PI and decreased PVI with significant negative correlation. CONCLUSION Hypercapnia retracts back PVI values compared with normocapnia. Precise judgment of fluid responsiveness as indicated by PVI necessitates its comparison against similar etCO2 levels.
Collapse
Affiliation(s)
- Wesam Farid Mousa
- Department of Anesthesia and Surgical ICU, College of Medicine, University of Dammam, Al-Khobar, Saudi Arabia
| |
Collapse
|