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Klop M, Claassen JAHR, Floor-Westerdijk MJ, van Wezel RJA, Maier AB, Meskers CGM. Home-based monitoring of cerebral oxygenation in response to postural changes using near-infrared spectroscopy. GeroScience 2024:10.1007/s11357-024-01241-w. [PMID: 38890204 DOI: 10.1007/s11357-024-01241-w] [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: 05/07/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024] Open
Abstract
Orthostatic hypotension (OH) is prevalent in older adults and can cause falls and hospitalization. Diagnostic intermittent blood pressure (BP) measurements are only a proxy for cerebral perfusion and do not reflect daily-life BP fluctuations. Near-infrared spectroscopy (NIRS)-measured cerebral oxygenation potentially overcomes these drawbacks. This study aimed to determine feasibility, face validity, and reliability of NIRS in the home environment. Ten participants with OH (2 female, mean age 77, SD 3.7) and 11 without OH (5 female, mean age 78, SD 6.7) wore a NIRS sensor at home on two different days for 10-11 h per day. Preceded by a laboratory-situated test, cerebral oxygenation was measured during three standardized supine-stand tests per day and during unsupervised daily life activities. Data availability, quality, and user experience were assessed (feasibility), as well as differences in posture-related oxygenation responses between participants with and without OH and between symptomatic (dizziness, light-headedness, blurred vision) and asymptomatic postural changes (face validity). Reliability was assessed through repetitive supine-stand tests. Up to 80% of the standardized home-based supine-stand tests could be analyzed. Oxygenation recovery values were lower for participants with OH (p = 0 .03-0.15); in those with OH, oxygenation showed a deeper maximum drop for symptomatic than asymptomatic postural changes (p = 0.04). Intra-class correlation coefficients varied from 0.07 to 0.40, with no consistent differences over measurements. This proof-of-concept study shows feasibility and face validity of at-home oxygenation monitoring using NIRS, confirming its potential value for diagnosis and monitoring in OH and OH-related symptoms. Further data are needed for conclusions about reliability.
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Affiliation(s)
- Marjolein Klop
- Department of Neurobiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Jurgen A H R Claassen
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | | | - Richard J A van Wezel
- Department of Neurobiology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
- OnePlanet Research Center, Radboud University, Nijmegen, The Netherlands
- Department of Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, The Netherlands
| | - Andrea B Maier
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Centre for Healthy Longevity, @AgeSingapore, National University Health System, Singapore, Singapore
- Department of Human Movement Sciences, @AgeAmsterdam, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Carel G M Meskers
- Department of Rehabilitation Medicine, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
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2
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Azarbarzin A, Labarca G, Kwon Y, Wellman A. Physiologic Consequences of Upper Airway Obstruction in Sleep Apnea. Chest 2024:S0012-3692(24)00708-6. [PMID: 38885898 DOI: 10.1016/j.chest.2024.05.028] [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: 01/10/2023] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 06/20/2024] Open
Abstract
OSA is diagnosed and managed by a metric called the apnea-hypopnea index (AHI). The AHI quantifies the number of respiratory events (apnea or hypopnea), disregarding important information on the characteristics and physiologic consequences of respiratory events, including degrees of ventilatory deficit and associated hypoxemia, cardiac autonomic response, and cortical activity. The oversimplification of the disorder by the AHI is considered one of the reasons for divergent findings on the associations of OSA and cardiovascular disease (CVD) in observational and randomized controlled trial studies. Prospective observational cohort studies have demonstrated strong associations of OSA with several cardiovascular diseases, and randomized controlled trials of CPAP intervention have not been able to detect a benefit of CPAP to reduce the risk of CVD. Over the last several years, novel methodologies have been proposed to better quantify the magnitude of OSA-related breathing disturbance and its physiologic consequences. As a result, stronger associations with cardiovascular and neurocognitive outcomes have been observed. In this review, we focus on the methods that capture polysomnographic heterogeneity of OSA.
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Affiliation(s)
- Ali Azarbarzin
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
| | - Gonzalo Labarca
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; Department of Respiratory Diseases, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Younghoon Kwon
- Department of Medicine, University of Washington, Seattle, WA
| | - Andrew Wellman
- Division of Sleep and Circadian Disorders, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
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3
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Christierson L, Frieberg P, Lala T, Töger J, Liuba P, Revstedt J, Isaksson H, Hakacova N. Multi-Modal in Vitro Experiments Mimicking the Flow Through a Mitral Heart Valve Phantom. Cardiovasc Eng Technol 2024:10.1007/s13239-024-00732-3. [PMID: 38782878 DOI: 10.1007/s13239-024-00732-3] [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] [Received: 06/29/2023] [Accepted: 04/29/2024] [Indexed: 05/25/2024]
Abstract
PURPOSE Fluid-structure interaction (FSI) models are more commonly applied in medical research as computational power is increasing. However, understanding the accuracy of FSI models is crucial, especially in the context of heart valve disease in patient-specific models. Therefore, this study aimed to create a multi-modal benchmarking data set for cardiac-inspired FSI models, based on clinically important parameters, such as the pressure, velocity, and valve opening, with an in vitro phantom setup. METHOD An in vitro setup was developed with a 3D-printed phantom mimicking the left heart, including a deforming mitral valve. A range of pulsatile flows were created with a computer-controlled motor-and-pump setup. Catheter pressure measurements, magnetic resonance imaging (MRI), and echocardiography (Echo) imaging were used to measure pressure and velocity in the domain. Furthermore, the valve opening was quantified based on cine MRI and Echo images. RESULT The experimental setup, with 0.5% cycle-to-cycle variation, was successfully built and six different flow cases were investigated. Higher velocity through the mitral valve was observed for increased cardiac output. The pressure difference across the valve also followed this trend. The flow in the phantom was qualitatively assessed by the velocity profile in the ventricle and by streamlines obtained from 4D phase-contrast MRI. CONCLUSION A multi-modal set of data for validation of FSI models has been created, based on parameters relevant for diagnosis of heart valve disease. All data is publicly available for future development of computational heart valve models.
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Affiliation(s)
- Lea Christierson
- Department of Clinical Sciences Lund, Pediatric Heart Center, Skåne University Hospital, Lund University, Lund, Sweden.
- Department of Biomedical Engineering, Lund University, Lund, Sweden.
| | - Petter Frieberg
- Department of Clinical Sciences Lund, Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Tania Lala
- Department of Biomedical Engineering, Lund University, Lund, Sweden
- Department of Clinical Sciences Lund, Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Johannes Töger
- Department of Clinical Sciences Lund, Clinical Physiology, Skåne University Hospital, Lund University, Lund, Sweden
| | - Petru Liuba
- Department of Clinical Sciences Lund, Pediatric Heart Center, Skåne University Hospital, Lund University, Lund, Sweden
| | - Johan Revstedt
- Department of Energy Science, Lund University, Lund, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Nina Hakacova
- Department of Clinical Sciences Lund, Pediatric Heart Center, Skåne University Hospital, Lund University, Lund, Sweden
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4
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Li J, Jia H, Zhou J, Huang X, Xu L, Jia S, Gao Z, Yao K, Li D, Zhang B, Liu Y, Huang Y, Hu Y, Zhao G, Xu Z, Li J, Yiu CK, Gao Y, Wu M, Jiao Y, Zhang Q, Tai X, Chan RH, Zhang Y, Ma X, Yu X. Thin, soft, wearable system for continuous wireless monitoring of artery blood pressure. Nat Commun 2023; 14:5009. [PMID: 37591881 PMCID: PMC10435523 DOI: 10.1038/s41467-023-40763-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
Continuous monitoring of arterial blood pressure (BP) outside of a clinical setting is crucial for preventing and diagnosing hypertension related diseases. However, current continuous BP monitoring instruments suffer from either bulky systems or poor user-device interfacial performance, hampering their applications in continuous BP monitoring. Here, we report a thin, soft, miniaturized system (TSMS) that combines a conformal piezoelectric sensor array, an active pressure adaptation unit, a signal processing module, and an advanced machine learning method, to allow real wearable, continuous wireless monitoring of ambulatory artery BP. By optimizing the materials selection, control/sampling strategy, and system integration, the TSMS exhibits improved interfacial performance while maintaining Grade A level measurement accuracy. Initial trials on 87 volunteers and clinical tracking of two hypertension individuals prove the capability of the TSMS as a reliable BP measurement product, and its feasibility and practical usability in precise BP control and personalized diagnosis schemes development.
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Affiliation(s)
- Jian Li
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Huiling Jia
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Jingkun Zhou
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Xingcan Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Long Xu
- School of Mechanical and Aerospace Engineering, Jilin University, 130012, Changchun, China
| | - Shengxin Jia
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Zhan Gao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Kuanming Yao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Dengfeng Li
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Binbin Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Yiming Liu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Ya Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Yue Hu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Guangyao Zhao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Zitong Xu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Jiyu Li
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Chun Ki Yiu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Yuyu Gao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Mengge Wu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), 610054, Chengdu, China
| | - Yanli Jiao
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Qiang Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Xuecheng Tai
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
- Department of Mathematics, Hong Kong Baptist University, Hong Kong, China
| | - Raymond H Chan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Yuanting Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China
| | - Xiaohui Ma
- Department of vascular and endovascular surgery, The first medical center of Chinese PLA General Hospital, 100853, Beijing, China.
| | - Xinge Yu
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China.
- Hong Kong Centre for Cerebro-Cardiovascular Health Engineering (COCHE), Hong Kong, China.
- City University of Hong Kong Shenzhen Research Institute, 518057, Shenzhen, China.
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5
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Marmo AC, Grunlan MA. Biomedical Silicones: Leveraging Additive Strategies to Propel Modern Utility. ACS Macro Lett 2023; 12:172-182. [PMID: 36669481 PMCID: PMC10848296 DOI: 10.1021/acsmacrolett.2c00701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/18/2023] [Indexed: 01/21/2023]
Abstract
Silicones have a long history of use in biomedical devices, with unique properties stemming from the siloxane (Si-O-Si) backbone that feature a high degree of flexibility and chemical stability. However, surface, rheological, mechanical, and electrical properties of silicones can limit their utility. Successful modification of silicones to address these limitations could lead to superior and new biomedical devices. Toward improving such properties, recent additive strategies have been leveraged to modify biomedical silicones and are highlighted herein.
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Affiliation(s)
- Alec C. Marmo
- Department
of Materials Science and Engineering Texas
A&M University, College
Station, Texas 77843-3003, United States
| | - Melissa A. Grunlan
- Department
of Biomedical Engineering, Department of Materials Science and Engineering,
Department of Chemistry Texas A&M University, College Station, Texas 77843-3003, United
States
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6
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Chen C, Zheng N, Wu W, Tang M, Feng W, Zhang W, Li X, Jiang Y, Pang J, Min D, Fu L. Self-Adhesive and Conductive Dual-Network Polyacrylamide Hydrogels Reinforced by Aminated Lignin, Dopamine, and Biomass Carbon Aerogel for Ultrasensitive Pressure Sensor. ACS APPLIED MATERIALS & INTERFACES 2022; 14:54127-54140. [PMID: 36413754 DOI: 10.1021/acsami.2c12914] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Conductive hydrogels have attracted extensive interest owing to its potential in soft robotics, electronic skin, and human monitoring. However, insufficient mechanical properties, lower adhesivity, and unsatisfactory conductivity seriously hinder potential applications in this emerging field. Herein, a highly elastic conductive hydrogel with a combination of favorable mechanical properties, self-adhesiveness, and excellent electrical performance was achieved by the synergistic effect of aminated lignin (AL), polydopamine (PDA), polyacrylamide (PAM) chains, and biomass carbon aerogel (C-SPF). In detail, AL was applied to induce slow oxidative polymerization of DA for preparing the sticky hydrogel containing PDA. Then, C-SPF carbon aerogel was used as a matrix to construct a dual-network structured composite hydrogel by combining with the hydrogels derived from PDA, AL, and PAM. The as-prepared conductive hydrogel displayed excellent mechanical performance, strong adhesive strength, and repeatable adhesivity. The prepared hydrogel-based pressure sensor possessed fast response (0.6 s loading and 0.8 s unloading stress time), high response (maximum RCR = 1.8 × 104), wide working pressure range (from 0 to 240.0 kPa), and excellent durability (stable 500 compression cycles with 30% deformation). In addition, the prepared sensor also displayed ultrahigh sensitivity (170 kPa-1), which was near 4 orders of magnitude higher than the conventional lignin-modified PAM hydrogels. The multiple interactions between hydrogel components and the mechanical properties of hydrogel were also verified by molecular dynamics investigation. Moreover, the excellent cytocompatibility and antibacterial activity of this composite hydrogel ensured high potential in various applications such as human/machine interaction, artificial intelligence, personal healthcare, and wearable devices.
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Affiliation(s)
- Changzhou Chen
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Na Zheng
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Weixin Wu
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Mengqi Tang
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Wenyao Feng
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Wei Zhang
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Xiangyu Li
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Yan Jiang
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Jinhui Pang
- State Key Laboratory Base of Eco-chemical Engineering, Qingdao University of Science & Technology, Qingdao266042, China
| | - Douyong Min
- College of Light Industry and Food Engineering, Guangxi University, Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning530004, China
| | - Lianhua Fu
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Health Science Center, Shenzhen University, Shenzhen518060, China
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7
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Athaya T, Choi S. A Review of Noninvasive Methodologies to Estimate the Blood Pressure Waveform. SENSORS (BASEL, SWITZERLAND) 2022; 22:3953. [PMID: 35632360 PMCID: PMC9145242 DOI: 10.3390/s22103953] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/19/2022] [Accepted: 05/21/2022] [Indexed: 05/06/2023]
Abstract
Accurate estimation of blood pressure (BP) waveforms is critical for ensuring the safety and proper care of patients in intensive care units (ICUs) and for intraoperative hemodynamic monitoring. Normal cuff-based BP measurements can only provide systolic blood pressure (SBP) and diastolic blood pressure (DBP). Alternatively, the BP waveform can be used to estimate a variety of other physiological parameters and provides additional information about the patient's health. As a result, various techniques are being proposed for accurately estimating the BP waveforms. The purpose of this review is to summarize the current state of knowledge regarding the BP waveform, three methodologies (pressure-based, ultrasound-based, and deep-learning-based) used in noninvasive BP waveform estimation research and the feasibility of employing these strategies at home as well as in ICUs. Additionally, this article will discuss the physical concepts underlying both invasive and noninvasive BP waveform measurements. We will review historical BP waveform measurements, standard clinical procedures, and more recent innovations in noninvasive BP waveform monitoring. Although the technique has not been validated, it is expected that precise, noninvasive BP waveform estimation will be available in the near future due to its enormous potential.
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Affiliation(s)
| | - Sunwoong Choi
- School of Electrical Engineering, Kookmin University, Seoul 02707, Korea;
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8
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Jiang H, Zou L, Huang D, Feng Q. Continuous Blood Pressure Estimation Based on Multi-Scale Feature Extraction by the Neural Network With Multi-Task Learning. Front Neurosci 2022; 16:883693. [PMID: 35600611 PMCID: PMC9120547 DOI: 10.3389/fnins.2022.883693] [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: 02/25/2022] [Accepted: 04/15/2022] [Indexed: 11/15/2022] Open
Abstract
In this article, a novel method for continuous blood pressure (BP) estimation based on multi-scale feature extraction by the neural network with multi-task learning (MST-net) has been proposed and evaluated. First, we preprocess the target (Electrocardiograph; Photoplethysmography) and label signals (arterial blood pressure), especially using peak-to-peak time limits of signals to eliminate the interference of the false peak. Then, we design a MST-net to extract multi-scale features related to BP, fully excavate and learn the relationship between multi-scale features and BP, and then estimate three BP values simultaneously. Finally, the performance of the developed neural network is verified by using a public multi-parameter intelligent monitoring waveform database. The results show that the mean absolute error ± standard deviation for systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) with the proposed method against reference are 4.04 ± 5.81, 2.29 ± 3.55, and 2.46 ± 3.58 mmHg, respectively; the correlation coefficients of SBP, DBP, and MAP are 0.96, 0.92, and 0.94, respectively, which meet the Association for the Advancement of Medical Instrumentation standard and reach A level of the British Hypertension Society standard. This study provides insights into the improvement of accuracy and efficiency of a continuous BP estimation method with a simple structure and without calibration. The proposed algorithm for BP estimation could potentially enable continuous BP monitoring by mobile health devices.
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Affiliation(s)
- Hengbing Jiang
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Institute of Biological and Medical Engineering, Guangdong Academy of Sciences & National Engineering Research Center for Healthcare Devices, Guangzhou, China
- Guangdong Engineering Technology Research Center for Diagnosis and Rehabilitation of Dementia, Guangzhou, China
| | - Lili Zou
- Institute of Biological and Medical Engineering, Guangdong Academy of Sciences & National Engineering Research Center for Healthcare Devices, Guangzhou, China
- Guangdong Engineering Technology Research Center for Diagnosis and Rehabilitation of Dementia, Guangzhou, China
- *Correspondence: Lili Zou,
| | - Dequn Huang
- Institute of Biological and Medical Engineering, Guangdong Academy of Sciences & National Engineering Research Center for Healthcare Devices, Guangzhou, China
- Guangdong Engineering Technology Research Center for Diagnosis and Rehabilitation of Dementia, Guangzhou, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Qianjin Feng,
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9
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Molinaro N, Schena E, Silvestri S, Bonotti F, Aguzzi D, Viola E, Buccolini F, Massaroni C. Contactless Vital Signs Monitoring From Videos Recorded With Digital Cameras: An Overview. Front Physiol 2022; 13:801709. [PMID: 35250612 PMCID: PMC8895203 DOI: 10.3389/fphys.2022.801709] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/20/2022] [Indexed: 01/26/2023] Open
Abstract
The measurement of physiological parameters is fundamental to assess the health status of an individual. The contactless monitoring of vital signs may provide benefits in various fields of application, from healthcare and clinical setting to occupational and sports scenarios. Recent research has been focused on the potentiality of camera-based systems working in the visible range (380-750 nm) for estimating vital signs by capturing subtle color changes or motions caused by physiological activities but invisible to human eyes. These quantities are typically extracted from videos framing some exposed body areas (e.g., face, torso, and hands) with adequate post-processing algorithms. In this review, we provided an overview of the physiological and technical aspects behind the estimation of vital signs like respiratory rate, heart rate, blood oxygen saturation, and blood pressure from digital images as well as the potential fields of application of these technologies. Per each vital sign, we provided the rationale for the measurement, a classification of the different techniques implemented for post-processing the original videos, and the main results obtained during various applications or in validation studies. The available evidence supports the premise of digital cameras as an unobtrusive and easy-to-use technology for physiological signs monitoring. Further research is needed to promote the advancements of the technology, allowing its application in a wide range of population and everyday life, fostering a biometrical holistic of the human body (BHOHB) approach.
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Affiliation(s)
- Nunzia Molinaro
- Unit of Measurements and Biomedical Instrumentation, Departmental Faculty of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Emiliano Schena
- Unit of Measurements and Biomedical Instrumentation, Departmental Faculty of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Sergio Silvestri
- Unit of Measurements and Biomedical Instrumentation, Departmental Faculty of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | | | - Damiano Aguzzi
- BHOHB – Biometrical Holistic of Human Body S.r.l., Rome, Italy
| | - Erika Viola
- BHOHB – Biometrical Holistic of Human Body S.r.l., Rome, Italy
| | - Fabio Buccolini
- BHOHB – Biometrical Holistic of Human Body S.r.l., Rome, Italy
| | - Carlo Massaroni
- Unit of Measurements and Biomedical Instrumentation, Departmental Faculty of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
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10
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Marzorati D, Dorizza A, Bovio D, Salito C, Mainardi L, Cerveri P. Hybrid Convolutional Networks for End-to-End Event Detection in Concurrent PPG and PCG Signals Affected by Motion Artifacts. IEEE Trans Biomed Eng 2022; 69:2512-2523. [PMID: 35119997 DOI: 10.1109/tbme.2022.3148171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The accurate detection of physiologically-related events in photopletismographic (PPG) and phocardiographic (PCG) signals, recorded by wearable sensors, is mandatory to perform the estimation of relevant cardiovascular parameters like the heart rate and the blood pressure. However, the measurement performed in uncontrolled conditions without clinical supervision leaves the detection quality particularly susceptible to noise and motion artifacts. The performed work proposed a new fully-automatic computational framework, based on convolutional networks, to identify and localize fiducial points in time as the foot, maximum slope and peak in PPG signal and the S1 sound in the PCG signal, both acquired by a custom chest sensor, described recently in the literature by our group. The novelty entailing a custom neural architecture to process sequentially the PPG and PCG signals. Tests were performed analysing four different acquisition conditions (rest, cycling, rest recovery and walking). Cross-validation results for the three PPG fiducial points showed identification accuracy greater than 93 % and localization error (RMSE) less than 10 ms. As expected, cycling and walking conditions provided worse results than rest and recovery, however reaching an accuracy greater than 90 % and a localization error lower than 15 ms. Likewise, the identification and localization error for S1 sound were greater than 90 % and lower than 25 ms. Overall, this study showcased the ability of the proposed technique to detect events with high accuracy not only for steady acquisitions but also during subject movements. We also showed that the proposed network outperformed traditional Shannon-energy-envelope method in the detection of S1 sound. Therefore, we argue that coupling chest sensors and deep learning processing techniques may disclose wearable devices to unobtrusively acquire health information, being less affected by noise and motion artifacts.
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Farki A, Baradaran Kazemzadeh R, Akhondzadeh Noughabi E. A Novel Clustering-Based Algorithm for Continuous and Noninvasive Cuff-Less Blood Pressure Estimation. JOURNAL OF HEALTHCARE ENGINEERING 2022; 2022:3549238. [PMID: 35075386 PMCID: PMC8783699 DOI: 10.1155/2022/3549238] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 12/18/2021] [Accepted: 12/24/2021] [Indexed: 11/29/2022]
Abstract
Extensive research has been performed on continuous and noninvasive cuff-less blood pressure (BP) measurement using artificial intelligence algorithms. This approach involves extracting certain features from physiological signals, such as ECG, PPG, ICG, and BCG, as independent variables and extracting features from arterial blood pressure (ABP) signals as dependent variables and then using machine-learning algorithms to develop a blood pressure estimation model based on these data. The greatest challenge of this field is the insufficient accuracy of estimation models. This paper proposes a novel blood pressure estimation method with a clustering step for accuracy improvement. The proposed method involves extracting pulse transit time (PTT), PPG intensity ratio (PIR), and heart rate (HR) features from electrocardiogram (ECG) and photoplethysmogram (PPG) signals as the inputs of clustering and regression, extracting systolic blood pressure (SBP) and diastolic blood pressure (DBP) features from ABP signals as dependent variables, and finally developing regression models by applying gradient boosting regression (GBR), random forest regression (RFR), and multilayer perceptron regression (MLP) on each cluster. The method was implemented using the MIMIC-II data set with the silhouette criterion used to determine the optimal number of clusters. The results showed that because of the inconsistency, high dispersion, and multitrend behavior of the extracted features vectors, the accuracy can be significantly improved by running a clustering algorithm and then developing a regression model on each cluster and finally weighted averaging of the results based on the error of each cluster. When implemented with 5 clusters and GBR, this approach yielded an MAE of 2.56 for SBP estimates and 2.23 for DBP estimates, which were significantly better than the best results without clustering (DBP: 6.27, SBP: 6.36).
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Affiliation(s)
- Ali Farki
- Department of Information Technology Engineering Industrial and Systems Engineering Faculty, Tarbiat Modares University, Tehran, Iran
| | - Reza Baradaran Kazemzadeh
- Department of Information Technology Engineering Industrial and Systems Engineering Faculty, Tarbiat Modares University, Tehran, Iran
| | - Elham Akhondzadeh Noughabi
- Department of Information Technology Engineering Industrial and Systems Engineering Faculty, Tarbiat Modares University, Tehran, Iran
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12
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Al-harosh M, Yangirov M, Kolesnikov D, Shchukin S. Bio-Impedance Sensor for Real-Time Artery Diameter Waveform Assessment. SENSORS 2021; 21:s21248438. [PMID: 34960542 PMCID: PMC8709432 DOI: 10.3390/s21248438] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/08/2021] [Accepted: 12/15/2021] [Indexed: 01/21/2023]
Abstract
The real-time artery diameter waveform assessment during cardio cycle can allow the measurement of beat-to-beat pressure change and the long-term blood pressure monitoring. The aim of this study is to develop a self-calibrated bio-impedance-based sensor, which can provide regular measurement of the blood-pressure-dependence time variable parameters such as the artery diameter waveform and the elasticity. This paper proposes an algorithm based on analytical models which need prior geometrical and physiological patient parameters for more appropriate electrode system selection and hence location to provide accurate blood pressure measurement. As a result of this study, the red cell orientation effect contribution was estimated and removed from the bio-impedance signal obtained from the artery to keep monitoring the diameter waveform correspondence to the change of blood pressure.
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13
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Ignácz A, Földi S, Sótonyi P, Cserey G. NB-SQI: A novel non-binary signal quality index for continuous blood pressure waveforms. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2021.103035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Apkarian MR. Blood Pressure Characteristics and Responses During Resistance Exercise. Strength Cond J 2021. [DOI: 10.1519/ssc.0000000000000607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Quan X, Liu J, Roxlo T, Siddharth S, Leong W, Muir A, Cheong SM, Rao A. Advances in Non-Invasive Blood Pressure Monitoring. SENSORS (BASEL, SWITZERLAND) 2021; 21:s21134273. [PMID: 34206457 PMCID: PMC8271585 DOI: 10.3390/s21134273] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/18/2021] [Accepted: 06/18/2021] [Indexed: 01/30/2023]
Abstract
This paper reviews recent advances in non-invasive blood pressure monitoring and highlights the added value of a novel algorithm-based blood pressure sensor which uses machine-learning techniques to extract blood pressure values from the shape of the pulse waveform. We report results from preliminary studies on a range of patient populations and discuss the accuracy and limitations of this capacitive-based technology and its potential application in hospitals and communities.
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Affiliation(s)
- Xina Quan
- PyrAmes Inc., Cupertino, CA 95014, USA; (J.L.); (T.R.); (S.S.); (W.L.); (A.M.)
- Correspondence: ; Tel.: +1-408-216-0099
| | - Junjun Liu
- PyrAmes Inc., Cupertino, CA 95014, USA; (J.L.); (T.R.); (S.S.); (W.L.); (A.M.)
| | - Thomas Roxlo
- PyrAmes Inc., Cupertino, CA 95014, USA; (J.L.); (T.R.); (S.S.); (W.L.); (A.M.)
| | - Siddharth Siddharth
- PyrAmes Inc., Cupertino, CA 95014, USA; (J.L.); (T.R.); (S.S.); (W.L.); (A.M.)
| | - Weyland Leong
- PyrAmes Inc., Cupertino, CA 95014, USA; (J.L.); (T.R.); (S.S.); (W.L.); (A.M.)
| | - Arthur Muir
- PyrAmes Inc., Cupertino, CA 95014, USA; (J.L.); (T.R.); (S.S.); (W.L.); (A.M.)
| | - So-Min Cheong
- Department of Geography & Atmospheric Science, University of Kansas, Lawrence, KS 66045, USA;
| | - Anoop Rao
- Department of Pediatrics, Neonatology, Stanford University, Palo Alto, CA 94304, USA;
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Beutel F, Van Hoof C, Rottenberg X, Reesink K, Hermeling E. Pulse Arrival Time Segmentation Into Cardiac and Vascular Intervals - Implications for Pulse Wave Velocity and Blood Pressure Estimation. IEEE Trans Biomed Eng 2021; 68:2810-2820. [PMID: 33513094 DOI: 10.1109/tbme.2021.3055154] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE This study demonstrates a novel method for pulse arrival time (PAT) segmentation into cardiac isovolumic contraction (IVC) and vascular pulse transit time to approximate central pulse wave velocity (PWV). METHODS 10 subjects (38 ± 10 years, 121 ± 12 mmHg SBP) ranging from normotension to hypertension were repeatedly measured at rest and with induced changes in blood pressure (BP), and thus PWV. ECG was recorded simultaneously with ultrasound-based carotid distension waveforms, a photoplethysmography-based peripheral waveform, noninvasive continuous and intermittent cuff BP. Central PAT was segmented into cardiac and vascular time intervals using a fiducial point in the carotid distension waveform that reflects the IVC onset. Central and peripheral PWVs were computed from (segmented) intervals and estimated arterial path lengths. Correlations with Bramwell-Hill PWV, systolic and diastolic BP (SBP/DBP) were analyzed by linear regression. RESULTS Central PWV explained more than twice the variability (R2) in Bramwell-Hill PWV compared to peripheral PWV (0.56 vs. 0.27). SBP estimated from central PWV undercuts the IEEE mean absolute deviation threshold of 5 mmHg, significantly lower than peripheral PWV or PAT (4.2 vs. 7.1 vs. 10.1 mmHg). CONCLUSION Cardiac IVC onset signaled in carotid distension waveforms enables PAT segmentation to obtain unbiased vascular pulse transit time. Corresponding PWV estimates provide the basis for single-site assessment of central arterial stiffness, confirmed by significant correlations with Bramwell-Hill PWV and SBP. SIGNIFICANCE In a small-scale cohort, we present proof-of-concept for a novel method to estimate central PWV and BP, bearing potential to improve the practicality of cardiovascular risk assessment in clinical routines.
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17
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Lin WH, Chen F, Geng Y, Ji N, Fang P, Li G. Towards accurate estimation of cuffless and continuous blood pressure using multi-order derivative and multivariate photoplethysmogram features. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2020.102198] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Zheng N, Chen C, Tang M, Wu W, Jiang Y, Min D. Ultrahigh compressibility and superior elasticity carbon framework derived from shaddock peel for high-performance pressure sensing. RSC Adv 2021; 11:28621-28631. [PMID: 35478543 PMCID: PMC9038115 DOI: 10.1039/d1ra02978a] [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: 04/16/2021] [Accepted: 08/15/2021] [Indexed: 11/21/2022] Open
Abstract
Shaddock peel, a crop by-product mainly composed of cellulose, hemicellulose, lignin, and pectin, was developed as a flexible sensitive material for detecting environmental external pressure. Firstly, a natural carbon framework (C-SPF) with high conductivity was prepared using hydrothermal treatment followed by carbonization. Then, the PDMS elastomer was coated on the C-SPF instead of dense filling to convert the brittle C-SPF into elastic porous materials (M-SPF). Benefiting from the large deformation space of the porous framework and the stable interactions between PDMS and C-SPF, M-SPF exhibited ultrahigh coercibility (up to 99.0% strain) and high elasticity (99.4% height retention for 10 000 cycles at 50.0% strain). The M-SPF-based pressure sensor also exhibited a quick response (loading and unloading times were 20 ms and 30 ms), high sensitivity (63.4 kPa−1), wide working range (from 0 to 800 kPa), and stable stress-electric current response (10 000 cycles). These advantages open a door to a variety of applications, such as flexible wearable devices, which demonstrated human physiological signal monitoring. The low cost, simple design and portable use of piezoresistive sensors highlight the potential application of the crop by-product shaddock peel as a high-value material. The piezoresistive sensor constructed by a PDMS modified Shaddock peel 3D carbon skeleton has an excellent sensing performance, which has promising potential in the field of human health detection.![]()
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Affiliation(s)
- Na Zheng
- Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control, Nanning, 530004, People's Republic of China
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, People's Republic of China
| | - Changzhou Chen
- Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control, Nanning, 530004, People's Republic of China
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, People's Republic of China
| | - Mengqi Tang
- Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control, Nanning, 530004, People's Republic of China
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, People's Republic of China
| | - Weixin Wu
- Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control, Nanning, 530004, People's Republic of China
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, People's Republic of China
| | - Yan Jiang
- Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control, Nanning, 530004, People's Republic of China
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, People's Republic of China
| | - Douyong Min
- Guangxi Key Laboratory of Clean Pulp and Papermaking and Pollution Control, Nanning, 530004, People's Republic of China
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, People's Republic of China
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19
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Non-invasive continuous blood pressure monitoring (ClearSight™ system) during shoulder surgery in the beach chair position: a prospective self-controlled study. BMC Anesthesiol 2020; 20:271. [PMID: 33099306 PMCID: PMC7585229 DOI: 10.1186/s12871-020-01185-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 10/13/2020] [Indexed: 02/02/2023] Open
Abstract
Background The beach chair position that is commonly used in shoulder surgery is associated with relative hypovolemia, which leads to a reduction in arterial blood pressure. The effects of patient positioning on the accuracy of non-invasive continuous blood pressure monitoring with the ClearSight™ system (CS-BP; Edwards Lifesciences, Irvine CA, USA) have not been studied extensively. Our research aim was to assess agreement levels between CS-BP measurements with traditional blood pressure monitoring techniques. Methods For this prospective self-controlled study, we included 20 consecutively treated adult patients undergoing elective shoulder surgery in the beach chair position. We performed Bland-Altman analyses to determine agreement levels between blood pressure values from CS-BP and standard non-invasive (NIBP) methods. Perioperative measurements were done in both the supine (as reference) and beach chair surgical positions. Additionally, we compared invasive blood pressure (IBP) measurements with both the non-invasive methods (CS-BP and NIBP) in a sub-group of patients (n = 10) who required arterial blood pressure monitoring. Results We analyzed 229 data points (116 supine, 113 beach chair) from the entire cohort; per patient measurements were based on surgical length (range 3–9 supine, 2–10 beach chair). The mean difference (±SD; 95% limits of agreement) in the mean arterial pressure (MAP) between CS-BP and NIBP was − 0.9 (±11.0; − 24.0–22.2) in the beach chair position and − 4.9 mmHg (±11.8; − 28.0–18.2) when supine. In the sub-group, the difference between CS-BP and IBP in the beach chair position was − 1.6 mmHg (±16.0; − 32.9–29.7) and − 2.8 mmHg (±15.3; − 32.8–27.1) in the supine position. Between NIBP and IBP, we detected a difference of 3.0 mmHg (±9.1; − 20.8–14.7) in the beach chair position, and 4.6 mmHg (±13.3; − 21.4–30.6) in the supine position. Conclusions We found clinically acceptable mean differences in MAP measurements between the ClearSight™ and non-invasive oscillometric blood pressure systems when patients were in either the supine or beach chair position. For all comparisons of the monitoring systems and surgical positions, the standard deviations and limits of agreement were wide. Trial registration This study was prospectively registered at the German Clinical Trial Register (www.DRKS.de; DRKS00013773). Registered 26/01/2018.
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20
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Abstract
Hypertension is a highly common condition with well-established adverse consequences. Ambulatory blood pressure monitoring has repeatedly been shown to better predict cardiovascular outcomes and mortality, compared to single office visit blood pressure. Non-dipping of sleep-time blood pressure is an independent marker for increased cardiovascular risk. We review blood pressure variability and the challenges of blood pressure monitoring during sleep. Although pathological sleep such as obstructive sleep apnea has been associated with non-dipping of sleep-time blood pressure, blood pressure is not routinely measured during sleep due to lack of unobtrusive blood pressure monitoring technology. Second, we review existing noninvasive continuous blood pressure monitoring technologies. Lastly, we propose including sleep-time blood pressure monitoring during sleep studies and including sleep studies in patients undergoing ambulatory blood pressure monitoring.
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21
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Ramakrishna P, P M N, Kiran V R, Joseph J, Sivaprakasam M. Cuffless Blood Pressure Estimation Using Features Extracted from Carotid Dual-Diameter Waveforms. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2719-2722. [PMID: 33018568 DOI: 10.1109/embc44109.2020.9176739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The major challenges in deep learning approaches to cuffless blood pressure estimation is selecting the most appropriate representative of the blood pulse waveform and extraction of relevant features for data collection. This paper performs an analysis of a novel dataset consisting of 71 features from the carotid dual-diameter waveforms and 4 blood pressure parameters. In particular, the analysis uses gradient boosting and graph-theoretic algorithms to determine (1) features with high predictive power and (2) potential to be pruned. Identifying such features and understanding their physiological significance is important for building blood pressure estimation models using machine learning that is robust across diverse clinical environments and patient sets.
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22
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Liu Z, Zhou B, Li Y, Tang M, Miao F. Continuous Blood Pressure Estimation From Electrocardiogram and Photoplethysmogram During Arrhythmias. Front Physiol 2020; 11:575407. [PMID: 33013491 PMCID: PMC7509183 DOI: 10.3389/fphys.2020.575407] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/13/2020] [Indexed: 12/02/2022] Open
Abstract
Objective Continuous blood pressure (BP) provides valuable information for the disease management of patients with arrhythmias. The traditional intra-arterial method is too invasive for routine healthcare settings, whereas cuff-based devices are inferior in reliability and comfortable for long-term BP monitoring during arrhythmias. The study aimed to investigate an indirect method for continuous and cuff-less BP estimation based on electrocardiogram (ECG) and photoplethysmogram (PPG) signals during arrhythmias and to test its reliability for the determination of BP using invasive BP (IBP) as reference. Methods Thirty-five clinically stable patients (15 with ventricular arrhythmias and 20 with supraventricular arrhythmias) who had undergone radiofrequency ablation were enrolled in this study. Their ECG, PPG, and femoral arterial IBP signals were simultaneously recorded with a multi-parameter monitoring system. Fifteen features that have the potential ability in indicating beat-to-beat BP changes during arrhythmias were extracted from the ECG and PPG signals. Four machine learning algorithms, decision tree regression (DTR), support vector machine regression (SVR), adaptive boosting regression (AdaboostR), and random forest regression (RFR), were then implemented to develop the BP models. Results The results showed that the mean value ± standard deviation of root mean square error for the estimated systolic BP (SBP), diastolic BP (DBP) with the RFR model against the reference in all patients were 5.87 ± 3.13 and 3.52 ± 1.38 mmHg, respectively, which achieved the best performance among all the models. Furthermore, the mean error ± standard deviation of error between the estimated SBP and DBP with the RFR model against the reference in all patients were −0.04 ± 6.11 and 0.11 ± 3.62 mmHg, respectively, which complied with the Association for the Advancement of Medical Instrumentation and the British Hypertension Society (Grade A) standards. Conclusion The results indicated that the utilization of ECG and PPG signals has the potential to enable cuff-less and continuous BP estimation in an indirect way for patients with arrhythmias.
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Affiliation(s)
- ZengDing Liu
- Chinese Academy of Sciences Key Laboratory for Health Informatics, Shenzhen Institutes of Advanced Technology, Shenzhen, China.,Joint Engineering Research Center for Health Big Data Intelligent Analysis Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Bin Zhou
- State Key Lab of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ye Li
- Chinese Academy of Sciences Key Laboratory for Health Informatics, Shenzhen Institutes of Advanced Technology, Shenzhen, China.,Joint Engineering Research Center for Health Big Data Intelligent Analysis Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Min Tang
- State Key Lab of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fen Miao
- Chinese Academy of Sciences Key Laboratory for Health Informatics, Shenzhen Institutes of Advanced Technology, Shenzhen, China.,Joint Engineering Research Center for Health Big Data Intelligent Analysis Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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23
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Angelucci A, Aliverti A. Telemonitoring systems for respiratory patients: technological aspects. Pulmonology 2020; 26:221-232. [DOI: 10.1016/j.pulmoe.2019.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 12/29/2022] Open
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24
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Investigation on the effect of Womersley number, ECG and PPG features for cuff less blood pressure estimation using machine learning. Biomed Signal Process Control 2020. [DOI: 10.1016/j.bspc.2020.101942] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Comparison of a noninvasive 3D force sensor-based method and the invasive arterial cannula in postsurgery intensive care patients: a pilot study. Blood Press Monit 2020; 24:310-314. [PMID: 31633517 DOI: 10.1097/mbp.0000000000000407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Improvement in sensing technologies is leading to new, accurate noninvasive monitoring devices. However, noninvasive continuous blood pressure (BP) monitoring still faces many challenges, such as: patient's movement, device accuracy and consistency. In this study, the accuracy of a novel noninvasive BP measuring system based on a three-axis force sensor is compared with the invasive arterial cannula taking 21 simultaneous measurements mostly on elderly, postsurgical participants. For the simultaneously recorded invasive and noninvasive signals, the similarity was high, the average correlation was 0.9001 ± 0.0588. The average differences (±SD) for simultaneously recorded systolic, diastolic and mean arterial pressures were: -9.53 ± 4.69, -0.26 ± 3.06 and 1.25 ± 2.26 mmHg, respectively. The results of diastolic and mean arterial pressure satisfy the criteria set by the Association for the Advancement of Medical Instrumentation. These results suggest that this noninvasive system could be a useful tool in continuous noninvasive BP monitoring, but still requires development.
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26
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Yu N, Liu Y, Ji B, Wang S, Chen Y, Sun T, Zhang J, Yang B. High-sensitivity microliter blood pressure sensors based on patterned micro-nanostructure arrays. LAB ON A CHIP 2020; 20:1554-1561. [PMID: 32334425 DOI: 10.1039/d0lc00063a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Herein we present a micro-nanostructure integrated liquid pressure sensor, which features an ultra-high sensitivity of 16.71 mbar-1, a low-pressure regime of 2 mbar, a trace sample volume of less than 1.3 μL and a visible display element. The measurable pressure ranges of the sensors include not only from micro-scale fluids to bulk liquids but also from hydraulic pressures to blood pressures, opening a window for liquid pressure sensing in lab-on-chip platforms, point-of-care diagnostics, and even robotics.
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Affiliation(s)
- Nianzuo Yu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, P. R. China.
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27
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Chan PY, McNeil J, Nguyen T, Ryan N, Hopper I. Novel wearable and contactless monitoring devices to identify deteriorating patients in the clinical setting: a systematic review protocol. Syst Rev 2020; 9:104. [PMID: 32375867 PMCID: PMC7201723 DOI: 10.1186/s13643-020-01370-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/27/2020] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND With technological advances, there has been increasing interest in developing contactless and/or non-invasive wearable technologies that continuously monitor vital signs in the clinical setting, and in particular in the deteriorating patient. These devices as of yet have not been well validated in the clinical setting in the clinical ranges observed in a critically unwell patient. We will perform a systematic review of all novel wearable and contactless devices in the clinical setting with focus on degree of novelty and the range of vital signs captured. METHODS Ovid MEDLINE including Epub Ahead of Print and In-Process & Other Non-Indexed Citations, Ovid Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL) Health Technology Assessment (HTA) database (Ovid), CINAHL with Full Text, searches of the grey literature, cited references of eligible studies through Web of Science, and reference lists of eligible studies will be searched. Outcomes of interest will include the quality of studies in relation to reporting guidelines, limitations of non-invasive technology, and application in different clinical populations. We will perform a qualitative assessment of the novelty of the device and discuss its validation in deteriorating patients. DISCUSSION While novel monitoring devices are often proposed as a solution to problems with infection, discomfort, and frequency of monitoring in the clinical setting it has not yet been established which devices have been validated in clinical settings in the pathological ranges of vital signs that reflect patient deterioration. It is equally unclear what additional value these devices might provide. This systematic review will synthesize published data regarding devices that have been tested and validated in patients AND in a clinical setting AND in reference ranges that reflect severe illness. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42019130091.
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Affiliation(s)
- Peter Y Chan
- Department of Intensive Care Medicine, Box Hill Hospital, 8 Arnold Street, Box Hill, Victoria, 3128, Australia. .,School of Public Health and Prevention Medicine, Monash University, Melbourne, Australia.
| | - John McNeil
- School of Public Health and Prevention Medicine, Monash University, Melbourne, Australia
| | - Tam Nguyen
- School of Public Health and Prevention Medicine, Monash University, Melbourne, Australia.,St Vincent's Hospital, Melbourne, Victoria, Australia
| | - Nicholas Ryan
- Department of Intensive Care Medicine, Box Hill Hospital, 8 Arnold Street, Box Hill, Victoria, 3128, Australia
| | - Ingrid Hopper
- School of Public Health and Prevention Medicine, Monash University, Melbourne, Australia
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28
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Wiener A, Goldstein P, Alkoby O, Doenyas K, Okon‐Singer H. Blood pressure reaction to negative stimuli: Insights from continuous recording and analysis. Psychophysiology 2020; 57:e13525. [PMID: 31922263 PMCID: PMC7078923 DOI: 10.1111/psyp.13525] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 11/29/2022]
Abstract
Individuals with a tendency toward abnormally enhanced cardiovascular responses to stress are at greater risk of developing essential hypertension later in life. Accurate profiling of continuous blood pressure (BP) reactions in healthy populations is crucial for understanding normal and abnormal emotional reaction patterns. To this end, we examined the continuous time course of BP reactions to aversive pictures among healthy participants. In two experiments, we showed participants negative and neutral pictures while simultaneously measuring their continuous BP and heart rate (HR) reactions. In this study, BP reactions were analyzed continuously, in contrast to previous studies, in which BP responses were averaged across blocks. To compare time points along a temporal continuum, we applied a multi-level B-spline model, which is innovative in the context of BP analysis. Additionally, HR was similarly analyzed in order to examine its correlation with BP. Both experiments revealed a similar pattern of BP reactivity and association with HR. In line with previous studies, a decline in BP and HR levels was found in response to negative pictures compared to neutral pictures. In addition, in both conditions, we found an unexpected elevation of BP toward the end of the stimuli exposure period. These findings may be explained by the recruitment of attention resources in the presence of negative stimuli, which is alleviated toward the end of the stimulation. This study highlights the importance of continuous measurement and analysis for characterizing the time course of BP reactivity to emotional stimuli.
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Affiliation(s)
- Avigail Wiener
- Department of PsychologyUniversity of HaifaHaifaIsrael
- The Integrated Brain and Behavior Research Center (IBBR)University of HaifaHaifaIsrael
| | - Pavel Goldstein
- Department of Psychology and Neuroscience and the Institute for Cognitive ScienceUniversity of Colorado BoulderBoulderColorado USA
- School of Public HealthUniversity of HaifaHaifaIsrael
| | - Oren Alkoby
- Department of PsychologyUniversity of HaifaHaifaIsrael
- The Integrated Brain and Behavior Research Center (IBBR)University of HaifaHaifaIsrael
| | - Keren Doenyas
- Department of Nephrology and HypertensionAssaf Harofeh Medical Center, Sackler School of MedicineTel‐Aviv UniversityTel‐AvivIsrael
- Sagol Center for Hyperbaric Medicine and ResearchAssaf Harofeh Medical CenterTel‐Aviv UniversityTel‐AvivIsrael
| | - Hadas Okon‐Singer
- Department of PsychologyUniversity of HaifaHaifaIsrael
- The Integrated Brain and Behavior Research Center (IBBR)University of HaifaHaifaIsrael
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Estimation of cerebral blood flow velocity during breath-hold challenge using artificial neural networks. Comput Biol Med 2019; 115:103508. [DOI: 10.1016/j.compbiomed.2019.103508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 10/13/2019] [Accepted: 10/13/2019] [Indexed: 12/30/2022]
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Rastegar S, GholamHosseini H, Lowe A. Non-invasive continuous blood pressure monitoring systems: current and proposed technology issues and challenges. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2019; 43:10.1007/s13246-019-00813-x. [PMID: 31677058 DOI: 10.1007/s13246-019-00813-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/25/2019] [Indexed: 01/03/2023]
Abstract
High blood pressure (BP) or hypertension is the single most crucial adjustable risk factor for cardiovascular diseases (CVDs) and monitoring the arterial blood pressure (ABP) is an efficient way to detect and control the prevalence of the cardiovascular health of patients. Therefore, monitoring the regulation of BP during patients' daily life plays a critical role in the ambulatory setting and the latest mobile health technology. In recent years, many studies have been conducted to explore the feasibility and performance of such techniques in the health care system. The ultimate aim of these studies is to find and develop an alternative to conventional BP monitoring by using cuff-less, easy-to-use, fast, and cost-effective devices for controlling and lowering the physical harm of CVDs to the human body. However, most of the current studies are at the prototype phase and face a range of issues and challenges to meet clinical standards. This review focuses on the description and analysis of the latest continuous and cuff-less methods along with their key challenges and barriers. Particularly, most advanced and standard technologies including pulse transit time (PTT), ultrasound, pulse arrival time (PAT), and machine learning are investigated. The accuracy, portability, and comfort of use of these technologies, and the ability to integrate to the wearable healthcare system are discussed. Finally, the future directions for further study are suggested.
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Affiliation(s)
- Solmaz Rastegar
- School of Engineering, Computer, and Mathematical Sciences, Auckland University of Technology, Private Bag 92006, Auckland, New Zealand.
| | - Hamid GholamHosseini
- School of Engineering, Computer, and Mathematical Sciences, Auckland University of Technology, Private Bag 92006, Auckland, New Zealand
| | - Andrew Lowe
- School of Engineering, Computer, and Mathematical Sciences, Auckland University of Technology, Private Bag 92006, Auckland, New Zealand
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Pour-Ghaz I, Manolukas T, Foray N, Raja J, Rawal A, Ibebuogu UN, Khouzam RN. Accuracy of non-invasive and minimally invasive hemodynamic monitoring: where do we stand? ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:421. [PMID: 31660320 DOI: 10.21037/atm.2019.07.06] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
One of the most important variables in assessing hemodynamic status in the intensive care unit (ICU) is the cardiac function and blood pressure. Invasive methods such as pulmonary artery catheter and arterial line allow monitoring of blood pressure and cardiac function accurately and reliably. However, their use is not without drawbacks, especially when the invasive nature of these procedures and complications associated with them are considered. There are several newer methods of noninvasive and minimally invasive hemodynamic monitoring available. In this manuscript, we will review these different methods of minimally invasive and non-invasive hemodynamic monitoring and will discuss their advantages, drawbacks and limitations.
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Affiliation(s)
- Issa Pour-Ghaz
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Theodore Manolukas
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Nathalie Foray
- Department of Medicine - Critical Care, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Joel Raja
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Aranyak Rawal
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Uzoma N Ibebuogu
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Rami N Khouzam
- Department of Internal Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Memphis, TN, USA
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Noninvasive Determination of Blood Pressure by Heart Sound Analysis Compared With Intra-Arterial Monitoring in Critically Ill Children-A Pilot Study of a Novel Approach. Pediatr Crit Care Med 2019; 20:809-816. [PMID: 31107377 DOI: 10.1097/pcc.0000000000001997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To develop a novel device to predict systolic and diastolic blood pressure based on measured heart sound signals and evaluate its accuracy in comparison to intra-arterial blood pressure readings. STUDY DESIGN Prospective, observational pilot study. SETTING PICU. PATIENTS Critically ill children (0-18 yr) undergoing continuous blood pressure monitoring via radial artery intra-arterial catheters were enrolled in the study after informed consent. The study included medical, cardiac, and surgical PICU patients. INTERVENTIONS Along with intra-arterial blood pressure, patient's heart sounds were recorded simultaneously by a highly sensitive sensor taped to the chest. Additional hardware included a data acquisition unit and laptop computer. Subsequently, advanced signal processing technologies were used to minimize random interfering signals and extract and separate S1 and S2 signals. A computerized model was then developed using artificial neural network systems to estimate blood pressure from the extracted heart sound analysis. MEASUREMENTS AND MAIN OUTCOMES We found a statistically significant correlation for systolic (r = 0.964; R = 0.928) and diastolic (r = 0.935; R = 0.868) blood pressure readings (n = 491) estimated by the novel heart-sound signal-based method and those recorded by intra-arterial catheters. The mean difference of the individually paired determinations of the blood pressure between the heart-sound-based method and intra-arterial catheters was 0.6 ± 7 mm Hg for systolic blood pressure and -0.06 ± 5 mm Hg for diastolic blood pressure, which was within the recommended range of 5 ± 8 mm Hg for any new blood pressure devices. CONCLUSIONS Our findings provide proof of concept that the heart-sound signal-based method can provide accurate, noninvasive blood pressure monitoring.
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Finucane C, van Wijnen VK, Fan CW, Soraghan C, Byrne L, Westerhof BE, Freeman R, Fedorowski A, Harms MPM, Wieling W, Kenny R. A practical guide to active stand testing and analysis using continuous beat-to-beat non-invasive blood pressure monitoring. Clin Auton Res 2019; 29:427-441. [PMID: 31076939 DOI: 10.1007/s10286-019-00606-y] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 04/02/2019] [Indexed: 12/19/2022]
Abstract
PURPOSE The average adult stands approximately 50-60 times per day. Cardiovascular responses evoked during the first 3 min of active standing provide a simple means to clinically assess short-term neural and cardiovascular function across the lifespan. Clinically, this response is used to identify the haemodynamic correlates of patient symptoms and attributable causes of (pre-)syncope, and to detect autonomic dysfunction, variants of orthostatic hypotension, postural orthostatic tachycardia syndrome and orthostatic hypertension. METHODS This paper provides a set of experience/expertise-based recommendations detailing current state-of-the-art measurement and analysis approaches for the active stand test, focusing on beat-to-beat BP technologies. This information is targeted at those interested in performing and interpreting the active stand test to current international standards. RESULTS This paper presents a practical step-by-step guide on (1) how to perform active stand measurements using beat-to-beat continuous blood pressure measurement technologies, (2) how to conduct an analysis of the active stand response and (3) how to identify the spectrum of abnormal blood pressure and heart rate responses which are of clinical interest. CONCLUSION Impairments in neurocardiovascular control are an attributable cause of falls and syncope across the lifespan. The simple active stand test provides the clinician with a powerful tool for assessing individuals at risk of such common disorders. However, its simplicity belies the complexity of its interpretation. Care must therefore be taken in administering and interpreting the test in order to maximise its clinical benefit and minimise its misinterpretation.
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Affiliation(s)
- Ciarán Finucane
- Department of Medical Physics and Bioengineering, Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland.
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland.
- Department of Medical Gerontology, Trinity College Dublin, The Irish Longitudinal Study on Ageing (TILDA), Dublin, Ireland.
| | - V K van Wijnen
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - C W Fan
- Department of Gerontology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - C Soraghan
- Department of Medical Physics and Bioengineering, Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
| | - L Byrne
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
| | - B E Westerhof
- Amsterdam UMC, Vrije Universiteit Amsterdam, Pulmonary Medicine, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Amsterdam UMC, University of Amsterdam, Medical Biology, Section of Systems Physiology, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - R Freeman
- Neurology Department, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, USA
| | - A Fedorowski
- Department of Clinical Sciences, Clinical Research Center, Lund University, Malmö, Sweden
- Department of Cardiology, Skåne University Hospital, Malmö, Sweden
| | - M P M Harms
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W Wieling
- Department of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - R Kenny
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dublin 8, Ireland
- Department of Medical Gerontology, Trinity College Dublin, The Irish Longitudinal Study on Ageing (TILDA), Dublin, Ireland
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Thambiraj G, Gandhi U, Devanand V, Mangalanathan U. Noninvasive cuffless blood pressure estimation using pulse transit time, Womersley number, and photoplethysmogram intensity ratio. Physiol Meas 2019; 40:075001. [DOI: 10.1088/1361-6579/ab1f17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kim J, Chou E, Le J, Wong S, Chu M, Khine M. Soft Wearable Pressure Sensors for Beat-to-Beat Blood Pressure Monitoring. Adv Healthc Mater 2019; 8:e1900109. [PMID: 31033256 DOI: 10.1002/adhm.201900109] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/01/2019] [Indexed: 01/01/2023]
Abstract
Wrinkled gold thin films on elastomeric substrates are used as robust parallel plate electrodes for soft capacitive pressure sensors. The wrinkled structures create a robust integration with the polymer, allowing repeated normal force to deform the thin film without failure. By incorporating microridged structures that support the counter electrodes to create air cavities within the elastomeric dielectric layer, pressure sensitivity is further increased to 0.148 kPa-1 over a wide dynamic range of up to 10 kPa. The wide dynamic range and pressure sensitivity of the pressure sensor allow for consistent measurements of the pressure exerted by the radial artery located on the wrist. The soft capacitive pressure sensor displays comparable results when tested against an FDA approved device (Clearsight, Edwards Lifesciences, Irvine, CA) measuring beat-to-beat blood pressure. These soft pressure sensors using wrinkled thin films, therefore, illustrate considerable potential to continuously monitor beat-to-beat blood pressure.
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Affiliation(s)
- Joshua Kim
- Department of Materials Science and EngineeringUniversity of California Irvine Irvine CA 92697 USA
| | - En‐Fan Chou
- Department of Biomedical EngineeringUniversity of California Irvine Irvine CA 92697 USA
| | - Jamie Le
- Department of Biomedical EngineeringUniversity of California Irvine Irvine CA 92697 USA
| | - Sabrina Wong
- Department of Biomedical EngineeringUniversity of California Irvine Irvine CA 92697 USA
| | - Michael Chu
- Department of Biomedical EngineeringUniversity of California Irvine Irvine CA 92697 USA
| | - Michelle Khine
- Department of Materials Science and EngineeringUniversity of California Irvine Irvine CA 92697 USA
- Department of Biomedical EngineeringUniversity of California Irvine Irvine CA 92697 USA
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Yoo SY, Ahn JE, Cserey G, Lee HY, Seo JM. Reliability and Validity of Non-invasive Blood Pressure Measurement System Using Three-Axis Tactile Force Sensor. SENSORS 2019; 19:s19071744. [PMID: 30979050 PMCID: PMC6480067 DOI: 10.3390/s19071744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/18/2019] [Accepted: 04/04/2019] [Indexed: 11/17/2022]
Abstract
Blood pressure (BP) is a physiological parameter reflecting hemodynamic factors and is crucial in evaluating cardiovascular disease and its prognosis. In the present study, the reliability of a non-invasive and continuous BP measurement using a three-axis tactile force sensor was verified. All the data were collected every 2 min for the short-term experiment, and every 10 min for the long-term experiment. In addition, the effects on the BP measurement of external physical factors such as the tension to the radial artery on applying the device and wrist circumference were evaluated. A high correlation between the measured BP with the proposed system and with the cuff-based non-invasive blood pressure, and reproducibility, were demonstrated. All data satisfied the Association for the Advancement of Medical Instrumentation criteria. The external physical factors did not affect the measurement results. In addition to previous research indicating the high reliability of the arterial pulse waveforms, the present results have demonstrated the reliability of numerical BP values, and this implies that the three-axis force sensor can be used as a patient monitoring device.
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Affiliation(s)
- Sun-Young Yoo
- Department of Electrical and Computer Engineering, Inter-University Semiconductor Research Center, Institute of Engineering Research, Seoul National University, Seoul 08826, Korea.
| | - Ji-Eun Ahn
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 03080, Korea.
| | - György Cserey
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, 1083 Budapest, Hungary.
| | - Hae-Young Lee
- Department of Internal Medicine, Seoul National University Hospital, Seoul 03080, Korea.
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea.
| | - Jong-Mo Seo
- Department of Electrical and Computer Engineering, Inter-University Semiconductor Research Center, Institute of Engineering Research, Seoul National University, Seoul 08826, Korea.
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea.
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Blood pressure measurements in research: suitability of auscultatory, beat-to-beat, and ambulatory blood pressure measurements. Blood Press Monit 2019; 24:18-23. [PMID: 30489333 PMCID: PMC6314505 DOI: 10.1097/mbp.0000000000000355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of this study was to validate the accuracy of beat-to-beat measurements with those taken with an aneroid sphygmomanometer by auscultatory method. A secondary aim was to explore differences between auscultatory and beat-to-beat blood pressure (BP) with daytime ambulatory BP measurements. PARTICIPANTS AND METHODS A total of 46 participants, comprising 21 males, aged 47±13 years, height 171±8.5 cm and weight 82±16.8 kg attended the Exercise Physiology Laboratory at the University of New England (Armidale, New South Wales, Australia). During the visit, participants had their BP - systolic BP (SBP) and diastolic BP (DBP) - measured using auscultatory methods and a Finometer. An ambulatory BP monitor was fitted during the same visit and worn for a minimum of 12 h. RESULTS Auscultatory measurements were slightly higher than beat-to-beat for both SBP and DBP. There was no difference between auscultatory and beat-to-beat SBP with a mean difference of 0.23 mmHg (P=0.87). There were disparities between auscultatory and beat-to-beat DBP, with a mean difference of 4.82 mmHg (P<0.01). Daytime ambulatory BP was higher than both auscultatory and beat-to-beat measurements for both SBP and DBP, with P less than 0.001 for all measures. CONCLUSION There was a high level of reliability in the beat-to-beat SBP with that seen by auscultatory; however, there were disparities in DBP measurements using the same devices, which raise concerns over the accuracy of beat-to-beat DBP. Ambulatory systolic and diastolic measures were higher than beat-to-beat and auscultatory; however, they may be more suitable for monitoring diurnal changes in BP, depending upon the research model.
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Huang KH, Tan F, Wang TD, Yang YJ. A Highly Sensitive Pressure-Sensing Array for Blood Pressure Estimation Assisted by Machine-Learning Techniques. SENSORS 2019; 19:s19040848. [PMID: 30791363 PMCID: PMC6412448 DOI: 10.3390/s19040848] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/07/2019] [Accepted: 02/16/2019] [Indexed: 12/26/2022]
Abstract
This work describes the development of a pressure-sensing array for noninvasive continuous blood pulse-wave monitoring. The sensing elements comprise a conductive polymer film and interdigital electrodes patterned on a flexible Parylene C substrate. The polymer film was patterned with microdome structures to enhance the acuteness of pressure sensing. The proposed device uses three pressure-sensing elements in a linear array, which greatly facilitates the blood pulse-wave measurement. The device exhibits high sensitivity (−0.533 kPa−1) and a fast dynamic response. Furthermore, various machine-learning algorithms, including random forest regression (RFR), gradient-boosting regression (GBR), and adaptive boosting regression (ABR), were employed for estimating systolic blood pressure (SBP) and diastolic blood pressure (DBP) from the measured pulse-wave signals. Among these algorithms, the RFR-based method gave the best performance, with the coefficients of determination for the reference and estimated blood pressures being R2 = 0.871 for SBP and R2 = 0.794 for DBP, respectively.
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Affiliation(s)
- Kuan-Hua Huang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Fu Tan
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Tzung-Dau Wang
- Department of Medicine, National Taiwan University, Taipei 10617, Taiwan.
- National Taiwan University Hospital, Taipei 10002, Taiwan.
| | - Yao-Joe Yang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
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Stojanova A, Koceski S, Koceska N. Continuous Blood Pressure Monitoring as a Basis for Ambient Assisted Living (AAL) - Review of Methodologies and Devices. J Med Syst 2019; 43:24. [PMID: 30603777 DOI: 10.1007/s10916-018-1138-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 12/09/2018] [Indexed: 10/27/2022]
Abstract
Blood pressure (BP) is a bio-physiological signal that can provide very useful information regarding human's general health. High or low blood pressure or its rapid fluctuations can be associated to various diseases or conditions. Nowadays, high blood pressure is considered to be an important health risk factor and major cause of various health problems worldwide. High blood pressure may precede serious heart diseases, stroke and kidney failure. Accurate blood pressure measurement and monitoring plays fundamental role in diagnosis, prevention and treatment of these diseases. Blood pressure is usually measured in the hospitals, as a part of a standard medical routine. However, there is an increasing demand for methodologies, systems as well as accurate and unobtrusive devices that will permit continuous blood pressure measurement and monitoring for a wide variety of patients, allowing them to perform their daily activities without any disturbance. Technological advancements in the last decade have created opportunities for using various devices as a part of ambient assisted living for improving quality of life for people in their natural environment. The main goal of this paper is to provide a comprehensive review of various methodologies for continuous cuff-less blood pressure measurement, as well as to evidence recently developed devices and systems for continuous blood pressure measurement that can be used in ambient assisted living applications.
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Affiliation(s)
- Aleksandra Stojanova
- Faculty of Computer Science, University Goce Delcev - Stip, Štip, Republic of Macedonia.
| | - Saso Koceski
- Faculty of Computer Science, University Goce Delcev - Stip, Štip, Republic of Macedonia
| | - Natasa Koceska
- Faculty of Computer Science, University Goce Delcev - Stip, Štip, Republic of Macedonia
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Nguyen TQ, Hansen KL, Bechsgaard T, Lönn L, Jensen JA, Nielsen MB. Non-Invasive Assessment of Intravascular Pressure Gradients: A Review of Current and Proposed Novel Methods. Diagnostics (Basel) 2018; 9:diagnostics9010005. [PMID: 30597993 PMCID: PMC6468662 DOI: 10.3390/diagnostics9010005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/21/2018] [Accepted: 12/26/2018] [Indexed: 11/16/2022] Open
Abstract
Invasive catheterization is associated with a low risk of serious complications. However, although it is the gold standard for measuring pressure gradients, it induces changes to blood flow and requires significant resources. Therefore, non-invasive alternatives are urgently needed. Pressure gradients are routinely estimated non-invasively in clinical settings using ultrasound and calculated with the simplified Bernoulli equation, a method with several limitations. A PubMed literature search on validation of non-invasive techniques was conducted, and studies were included if non-invasively estimated pressure gradients were compared with invasively measured pressure gradients in vivo. Pressure gradients were mainly estimated from velocities obtained with Doppler ultrasound or magnetic resonance imaging. Most studies used the simplified Bernoulli equation, but more recent studies have employed the expanded Bernoulli and Navier⁻Stokes equations. Overall, the studies reported good correlation between non-invasive estimation of pressure gradients and catheterization. Despite having strong correlations, several studies reported the non-invasive techniques to either overestimate or underestimate the invasive measurements, thus questioning the accuracy of the non-invasive methods. In conclusion, more advanced imaging techniques may be needed to overcome the shortcomings of current methods.
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Affiliation(s)
- Tin-Quoc Nguyen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Kristoffer Lindskov Hansen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Thor Bechsgaard
- Department of Radiology, Odense University Hospital Svendborg Hospital, Baagøes Alle 31, 5700 Svendborg, Denmark.
| | - Lars Lönn
- Department of Diagnostic Radiology, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Jørgen Arendt Jensen
- Center for Fast Ultrasound Imaging, DTU Elektro, Technical University of Denmark, Ørsteds Plads Building 349, 2800 Lyngby, Denmark.
| | - Michael Bachmann Nielsen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
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Zakrzewski AM, Huang AY, Zubajlo R, Anthony BW. Real-Time Blood Pressure Estimation From Force-Measured Ultrasound. IEEE Trans Biomed Eng 2018; 65:2405-2416. [PMID: 30281436 PMCID: PMC10615347 DOI: 10.1109/tbme.2018.2873297] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Our objective is to create a blood pressure measurement device, which may provide a way to easily acquire frequent measurements. Common techniques to measure blood pressure include an arterial catheter, an oscillometric pressure cuff, or an auscultatory pressure cuff. METHODS The approach takes as input ultrasound images of an artery and contact force between the ultrasound array and subject. A subject may perform the self-measurements. Image and force data is analyzed for its quality and used to provide guidance or reject poor measurements. Tissue motions, due to probe contact forces and pulsing blood pressure, are estimated from the ultrasound image. Tissues elasticities and blood pressure are found by optimally fitting the observed tissue motion versus applied forces to a table of predicted motion-pre-generated with a finite element tissue deformation model. The output of the optimization is an estimate of systolic and diastolic blood pressure, arterial stiffness, and surrounding tissue stiffness. RESULTS The real-time implementation of the algorithm was validated on a cohort of 21 single-visit volunteers and on four volunteers self-monitored longitudinally. The systolic and diastolic pressures were compared to oscillometric cuff readings. Regression and Bland-Altman analyses were performed. CONCLUSION Systolic pressure and diastolic pressure can be estimated in real-time and by the subject using this novel non-invasive ultrasound-based method (systolic accuracy/precision: -5.2 mmHg/10.7 mmHg; diastolic accuracy/precision: -3.9/8.0 mmHg). SIGNIFICANCE The method occupies a middle ground between the arterial catheter and cuff-based techniques. It has the potential to give calibration-free results.
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Affiliation(s)
- Aaron M. Zakrzewski
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139
| | - Athena Y. Huang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139
| | - Rebecca Zubajlo
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139
| | - Brian W. Anthony
- Department of Mechanical Engineering and the Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139 USA
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Analysis for the Influence of ABR Sensitivity on PTT-Based Cuff-Less Blood Pressure Estimation before and after Exercise. JOURNAL OF HEALTHCARE ENGINEERING 2018; 2018:5396030. [PMID: 30402213 PMCID: PMC6196888 DOI: 10.1155/2018/5396030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/23/2018] [Accepted: 09/06/2018] [Indexed: 11/18/2022]
Abstract
An accurate and continuous measurement of blood pressure (BP) is of great importance for the prognosis of some cardiovascular diseases in out-of-hospital settings. Pulse transit time (PTT) is a well-known cardiovascular parameter which is highly correlated with BP and has been widely applied in the estimation of continuous BP. However, due to the complexity of cardiovascular system, the accuracy of PTT-based BP estimation is still unsatisfactory. Recent studies indicate that, for the subjects before and after exercise, PTT can track the high-frequency BP oscillation (HF-BP) well, but is inadequate to follow the low-frequency BP variance (LF-BP). Unfortunately, the cause for this failure of PTT in LF-BP estimation is still unclear. Based on these previous researches, we investigated the cause behind this failure of PTT in LF-BP estimation. The heart rate- (HR-) related arterial baroreflex (ABR) model was introduced to analyze the failure of PTT in LF-BP estimation. Data from 42 healthy volunteers before and after exercise were collected to evaluate the correlation between the ABR sensitivity and the estimation error of PTT-based BP in LF and HF components. In the correlation plot, an obvious difference was observed between the LF and HF groups. The correlation coefficient r for the ABR sensitivity with the estimation error of systolic BP (SBP) and diastolic BP (DBP) in LF was 0.817 ± 0.038 and 0.757 ± 0.069, respectively. However, those correlation coefficient r for the ABR sensitivity with the estimation error of SBP and DBP in HF was only 0.403 ± 0.145 and 0.274 ± 0.154, respectively. These results indicated that there is an ABR-related complex LF autonomic regulation mechanism on BP, PTT, and HR, which influences the effect of PTT in LF-BP estimation.
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Tomita K, Nakada TA, Oshima T, Oami T, Aizimu T, Oda S. Non-invasive monitoring using photoplethysmography technology. J Clin Monit Comput 2018; 33:637-645. [PMID: 30284687 DOI: 10.1007/s10877-018-0205-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/26/2018] [Indexed: 12/17/2022]
Abstract
We evaluated the accuracy and precision of a novel non-invasive monitoring device in comparison with conventional monitoring methods used in intensive care units (ICU). The study device was developed to measure blood pressure, pulse rate, respiratory rate, and oxygen saturation, continuously with a single sensor using the photoplethysmographic technique. Patients who were monitored with arterial pressure lines in the ICU were enrolled. Systolic and diastolic blood pressure, pulse rate, respiratory rate, and arterial oxygen saturation were measured continuously for 30 min at 5-min intervals using the conventional methods and the study device. The primary outcome variable was blood pressure. Blood pressure measured by the study device highly correlated with the arterial pressure line values (correlation coefficients > 0.95). Percent errors for systolic, diastolic and mean blood pressures were 2.4% and 6.7% and 6.5%, respectively. Percent errors for pulse rate, respiratory rate and oxygen saturation were 3.4%, 5.6% and 1.4%, respectively. The non-invasive, continuous, multi-parameter monitoring device presented high level of agreement with the invasive arterial blood pressure monitoring, along with sufficient accuracy and precision in the measurements of pulse rate, respiratory rate, and oxygen saturation.
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Affiliation(s)
- Keisuke Tomita
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | - Taka-Aki Nakada
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan.
| | - Taku Oshima
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | - Takehiko Oami
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | - Tuerxun Aizimu
- Center for Frontier Medical Engineering, Chiba University, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
| | - Shigeto Oda
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo, Chiba, 260-8677, Japan
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Markert JE, Jasien JV, Turner DC, Huisingh C, Girkin CA, Downs JC. IOP, IOP Transient Impulse, Ocular Perfusion Pressure, and Mean Arterial Pressure Relationships in Nonhuman Primates Instrumented With Telemetry. Invest Ophthalmol Vis Sci 2018; 59:4496-4505. [PMID: 30208417 PMCID: PMC6133237 DOI: 10.1167/iovs.18-23802] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose To characterize relationships between intraocular pressure (IOP), mean arterial pressure (MAP), ocular perfusion pressure (OPP), IOP transient impulse, and IOP baseline impulse using continuous telemetry in nonhuman primates. Methods We used our validated implantable telemetry system to wirelessly record bilateral IOP and arterial BP at 500 Hz in 7 eyes of 4 male rhesus macaques, aged 4 to 5 years. IOP, MAP, OPP, IOP transient impulse, and IOP baseline impulse were averaged into 1-hour periods over 20 days for each NHP. IOP transient impulse was defined as the portion of total IOP due to transient IOP fluctuations <0.5 seconds duration alone and IOP baseline impulse as the remaining area under the IOP versus time curve. OPP was defined as arterial BP-IOP (calculated continuously), and MAP was the hourly average of the continuous BP curve. Relationships between the variables were analyzed for each 24-hour period using either multivariate linear regression or Spearman Correlation Coefficients as appropriate. Results Over twenty 24-hour periods, IOP transient impulse and OPP showed significant positive relationship in all eyes, which was driven largely by the data during waking hours. There was no significant relationship between IOP and MAP, IOP transient impulse and MAP, or IOP baseline impulse and IOP transient impulse. Conclusions There are significant positive relationships between the frequency and/or size of transient IOP fluctuations (IOP transient impulse) and OPP. A possible explanation of this finding is that higher OPP, as well as a greater number of blinks and saccades (the primary sources of IOP transients), are associated with increased activity.
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Affiliation(s)
- John E Markert
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Jessica V Jasien
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Daniel C Turner
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Carrie Huisingh
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Christopher A Girkin
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - J Crawford Downs
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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Zakrzewski AM, Anthony BW. Noninvasive Blood Pressure Estimation Using Ultrasound and Simple Finite Element Models. IEEE Trans Biomed Eng 2018; 65:2011-2022. [PMID: 28613159 PMCID: PMC10615346 DOI: 10.1109/tbme.2017.2714666] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Many commercially available arterial blood pressure measurement devices suffer from a range of weaknesses. For example, common weaknesses include being inaccurate, invasive, and ad hoc; many also require explicit user calibration or cut off blood flow to a limb. A novel algorithmic approach is presented to accurately estimate systolic and diastolic blood pressure in a way that does not require any explicit user calibration, is noninvasive, and does not cut off blood flow. METHODS The approach uses ultrasound images of the arterial wall and corresponding contact force data to obtain blood pressure estimates. To acquire data, an ultrasound probe was placed on the patient's carotid artery and the contact force was increased from 1.5 to 12 N. The artery was then algorithmically segmented from the recorded DICOM B-Mode data. The segmentation data and the contact force were used as input into the Levenberg-Marquardt optimization method to solve for the parameters, including blood pressure, of a simple finite element model of the carotid artery. RESULTS The algorithm was validated on 24 healthy volunteers. Algorithm arterial blood pressure predictions were compared to oscillometric blood pressure cuff readings. Regression and Bland-Altman analyses were performed on the data. CONCLUSION Both systolic pressure and diastolic pressure can be estimated using this novel noninvasive ultrasound-based method (systolic accuracy/precision: $-$ 2.36 mmHg/10.21 mmHg; diastolic accuracy/precision: $-$ 0.32/8.23 mmHg). SIGNIFICANCE The method occupies a clinical middle ground between the arterial catheter and cuff-based techniques. It has the potential to give accurate results for patients with hypertension and atherosclerosis.
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Zakrzewski AM, Anthony BW. Arterial blood pressure estimation using ultrasound: Clinical results on healthy volunteers and a medicated hypertensive volunteer. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2017:2154-2157. [PMID: 29060323 DOI: 10.1109/embc.2017.8037281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study presents a non-occlusive and non-invasive ultrasound-based technique to measure blood pressure. Most popular clinically-used arterial blood pressure measurement techniques suffer from important weaknesses including being inaccurate, invasive, or occlusive. In the proposed technique, an ultrasound probe is placed on the patient's carotid artery and the contact force between the probe and the tissue is slowly increased while ultrasound images and contact force data are recorded. From this data, the artery is segmented and the segmentation data is sent into an optimization procedure; after post-processing, blood pressure is displayed to the user. This technique was applied to 24 healthy single-visit volunteers, one multi-visit healthy volunteer, and one multi-visit medicated hypertensive volunteer. Compared to the oscillometric cuff, the accuracy and precision of the algorithm-reported systolic pressure is -2.4 ± 10.2 mmHg, and for diastolic pressure is -0.3 ± 8.2 mmHg. This method has the potential to occupy a clinical middle-ground between the arterial catheter and the oscillometric cuff.
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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.
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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
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Zhang P, Qiu Q, Zhou Y. Reconstruction of continuous brachial artery pressure wave from continuous finger arterial pressure in humans. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2018; 41:1115-1125. [PMID: 29881939 DOI: 10.1007/s13246-018-0652-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/24/2018] [Indexed: 11/26/2022]
Abstract
Generalized transfer functions (GTFs) are available to compute the more relevant proximal blood pressure (BP) waveform from a more easily measured peripheral BP waveform. However, GTFs are based on the black box model. This paper presents a practical approach to reconstruct brachial artery pressure (BAP) distally from finger artery pressure (FAP). We assume that continuous BAP can be simply approximated by summing two halves of the continuous FAP shifted by the time delay. We firstly showed that the pressure wave in the finger artery can be considered twice as much as the forward/backward wave in the finger. A simplified individualized transfer function was then derived so as to estimate BAP from FAP. The effectiveness of the method was examined by experiment involving 26 healthy volunteers (26.7 ± 3.8 years old) in a resting state. By comparing with a reference BAP, we found that the proposed method can correct the FAP. The errors of the proposed method in estimating systolic and diastolic pressures are - 0.6 ± 6.0 and - 0.6 ± 3.7 mmHg, respectively. These results agree with the standard of Association for the Advancement of Medical Instrumentation (AAMI). We also found that the reconstructed BAP from FAP by terminal arterial occlusion technology (TAOT) is comparable to that of the artery occlusion technology (AOT). Our method or TAOT is promising in estimating continuous proximal blood pressure from peripheral blood pressure in practice.
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Affiliation(s)
- Pandeng Zhang
- Laboratory for Engineering and Scientific Computing, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Quanli Qiu
- Laboratory for Engineering and Scientific Computing, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Yanxia Zhou
- Department of Neurology, Shenzhen Second People's Hospital, Shenzhen, 518035, China
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Continuous noninvasive arterial blood pressure monitoring using the vascular unloading technology during complex gastrointestinal endoscopy: a prospective observational study. J Clin Monit Comput 2018; 33:25-30. [PMID: 29556885 DOI: 10.1007/s10877-018-0131-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 03/14/2018] [Indexed: 10/17/2022]
Abstract
The innovative vascular unloading technology (VUT) allows continuous noninvasive arterial blood pressure (AP) monitoring. We aimed to investigate whether the VUT enables AP changes to be detected earlier compared with intermittent AP monitoring in patients undergoing gastrointestinal endoscopy. In this prospective observational study, we recorded continuous AP measurements with the VUT (CNAP system; CNSystems Medizintechnik AG, Graz, Austria) and intermittent AP measurements with upper arm cuff oscillometry in 90 patients undergoing complex gastrointestinal endoscopy (Department of Interventional Endoscopy at the University Medical Center Hamburg-Eppendorf, Hamburg, Germany). A "hypotensive phase" was defined as a time period of at least 30 s during which ≥ 50% of the VUT-AP values were in a predefined range of hypotension, i.e., AP value a) ≥ 10% below the last oscillometric value and b) ≤ 65 mmHg for mean AP or ≤ 90 mmHg for systolic AP. In the 5-min-interval between two oscillometric measurements, one or more hypotensive phases were detected in 26 patients (29%) for mean AP and in 27 patients (30%) for systolic AP. Hypotensive phases had a mean duration of 195 ± 99 s for mean AP and 197 ± 97 s for systolic AP with a mean procedure duration of 36 (± 21) min. Continuous noninvasive AP monitoring using the VUT enables hypotensive phases to be detected earlier compared with intermittent AP monitoring during complex gastrointestinal endoscopy. These hypotensive phases may be missed or only belatedly recognized with intermittent AP monitoring. Continuous noninvasive AP measurement facilitates detecting hemodynamic instability more rapidly and therefore may improve patient safety.
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