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Goyal K, Shah D, Day SW. Day-to-Day Variability in Measurements of Respiration Using Bioimpedance from a Non-Standard Location. SENSORS (BASEL, SWITZERLAND) 2024; 24:4612. [PMID: 39066010 PMCID: PMC11280867 DOI: 10.3390/s24144612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/09/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024]
Abstract
Non-invasive monitoring of pulmonary health may be useful for tracking several conditions such as COVID-19 recovery and the progression of pulmonary edema. Some proposed methods use impedance-based technologies to non-invasively measure the thorax impedance as a function of respiration but face challenges that limit the feasibility, accuracy, and practicality of tracking daily changes. In our prior work, we demonstrated a novel approach to monitor respiration by measuring changes in impedance from the back of the thigh. We reported the concept of using thigh-thigh bioimpedance measurements for measuring the respiration rate and demonstrated a linear relationship between the thigh-thigh bioimpedance and lung tidal volume. Here, we investigate the variability in thigh-thigh impedance measurements to further understand the feasibility of the technique for detecting a change in the respiratory status due to disease onset or recovery if used for long-term in-home monitoring. Multiple within-session and day-to-day impedance measurements were collected at 80 kHz using dry electrodes (thigh) and wet electrodes (thorax) across the five healthy subjects, along with simultaneous gold standard spirometer measurements for three consecutive days. The peak-peak bioimpedance measurements were found to be highly correlated (0.94 ± 0.03 for dry electrodes across thigh; 0.92 ± 0.07 for wet electrodes across thorax) with the peak-peak spirometer tidal volume. The data across five subjects indicate that the day-to-day variability in the relationship between impedance and volume for thigh-thigh measurements is smaller (average of 14%) than for the thorax (40%). However, it is affected by food and water and might limit the accuracy of the respiratory tidal volume.
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Affiliation(s)
- Krittika Goyal
- Department of Manufacturing and Mechanical Engineering Technology, Rochester Institute of Technology, Rochester, NY 14623, USA; (K.G.); (D.S.)
| | - Dishant Shah
- Department of Manufacturing and Mechanical Engineering Technology, Rochester Institute of Technology, Rochester, NY 14623, USA; (K.G.); (D.S.)
| | - Steven W. Day
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY 14623, USA
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2
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Fitzgerald L, Lopez Ruiz L, Zhu J, Lach J, Quinn D. Towards breath sensors that are self-powered by design. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220895. [PMID: 36147941 PMCID: PMC9490333 DOI: 10.1098/rsos.220895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/26/2022] [Indexed: 06/16/2023]
Abstract
Piezoelectric materials are widely used to generate electric charge from mechanical deformation or vice versa. These strategies are increasingly common in implantable medical devices, where sensing must be done on small scales. In the case of a flow rate sensor, a sensor's energy harvesting rate could be mapped to that flow rate, making it 'self-powered by design (SPD)'. Prior fluids-based SPD work has focused on turbulence-driven resonance and has been largely empirical. Here, we explore the possibility of sub-resonant SPD flow sensing in a human airway. We present a physical model of piezoelectric sensing/harvesting in the airway, which we validated with a benchtop experiment. Our work offers a model-based roadmap for implantable SPD sensing solutions. We also use the model to theorize a new form of SPD sensing that can detect broadband flow information.
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Affiliation(s)
- Lucy Fitzgerald
- Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA
| | - Luis Lopez Ruiz
- Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
| | - Joe Zhu
- Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA
| | - John Lach
- Electrical and Computer Engineering, George Washington University, Washington, DC, USA
| | - Daniel Quinn
- Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA
- Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA
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3
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Hayward N, Shaban M, Badger J, Jones I, Wei Y, Spencer D, Isichei S, Knight M, Otto J, Rayat G, Levett D, Grocott M, Akerman H, White N. A capaciflector provides continuous and accurate respiratory rate monitoring for patients at rest and during exercise. J Clin Monit Comput 2022; 36:1535-1546. [PMID: 35040037 PMCID: PMC8763619 DOI: 10.1007/s10877-021-00798-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/23/2021] [Indexed: 10/27/2022]
Abstract
Respiratory rate (RR) is a marker of critical illness, but during hospital care, RR is often inaccurately measured. The capaciflector is a novel sensor that is small, inexpensive, and flexible, thus it has the potential to provide a single-use, real-time RR monitoring device. We evaluated the accuracy of continuous RR measurements by capaciflector hardware both at rest and during exercise. Continuous RR measurements were made with capaciflectors at four chest locations. In healthy subjects (n = 20), RR was compared with strain gauge chest belt recordings during timed breathing and two different body positions at rest. In patients undertaking routine cardiopulmonary exercise testing (CPET, n = 50), RR was compared with pneumotachometer recordings. Comparative RR measurement bias and limits of agreement were calculated and presented in Bland-Altman plots. The capaciflector was shown to provide continuous RR measurements with a bias less than 1 breath per minute (BPM) across four chest locations. Accuracy and continuity of monitoring were upheld even during vigorous CPET exercise, often with narrower limits of agreement than those reported for comparable technologies. We provide a unique clinical demonstration of the capaciflector as an accurate breathing monitor, which may have the potential to become a simple and affordable medical device.Clinical trial number: NCT03832205 https://clinicaltrials.gov/ct2/show/NCT03832205 registered February 6th, 2019.
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Affiliation(s)
- Nick Hayward
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK.
| | - Mahdi Shaban
- School of Electronics and Computer Science, University of Southampton, Southampton, UK
| | - James Badger
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK
| | - Isobel Jones
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK.,School of Electronics and Computer Science, University of Southampton, Southampton, UK
| | - Yang Wei
- School of Electronics and Computer Science, University of Southampton, Southampton, UK.,Department of Engineering, Nottingham Trent University, Nottingham, UK
| | - Daniel Spencer
- School of Electronics and Computer Science, University of Southampton, Southampton, UK
| | - Stefania Isichei
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK
| | - Martin Knight
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK
| | - James Otto
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK
| | - Gurinder Rayat
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK
| | - Denny Levett
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK
| | - Michael Grocott
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK.,Department of Anesthesiology, Duke University School of Medicine, Durham, NC, USA
| | - Harry Akerman
- Perioperative & Critical Care Theme, Southampton NIHR Biomedical Research Centre, University Hospital Southampton / University of Southampton, Southampton, UK.,School of Electronics and Computer Science, University of Southampton, Southampton, UK
| | - Neil White
- School of Electronics and Computer Science, University of Southampton, Southampton, UK
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4
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A wearable eddy current based pulmonary function sensor for continuous non-contact point-of-care monitoring during the COVID-19 pandemic. Sci Rep 2021; 11:20144. [PMID: 34635738 PMCID: PMC8505507 DOI: 10.1038/s41598-021-99682-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 09/29/2021] [Indexed: 11/10/2022] Open
Abstract
Pulmonary function testing (PFT) allows for quantitative analysis of lung function. However, as a result of the coronavirus disease 2019 (COVID-19) pandemic, a majority of international medical societies have postponed PFTs in an effort to mitigate disease transmission, complicating the continuity of care in high-risk patients diagnosed with COVID-19 or preexisting lung pathologies. Here, we describe the development of a non-contact wearable pulmonary sensor for pulmonary waveform analysis, pulmonary volume quantification, and crude thoracic imaging using the eddy current (EC) phenomenon. Statistical regression analysis is performed to confirm the predictive validity of the sensor, and all data are continuously and digitally stored with a sampling rate of 6,660 samples/second. Wearable pulmonary function sensors may facilitate rapid point-of-care monitoring for high-risk individuals, especially during the COVID-19 pandemic, and easily interface with patient hospital records or telehealth services.
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Groenendaal W, Lee S, van Hoof C. Wearable Bioimpedance Monitoring: Viewpoint for Application in Chronic Conditions. JMIR BIOMEDICAL ENGINEERING 2021; 6:e22911. [PMID: 38907374 PMCID: PMC11041432 DOI: 10.2196/22911] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 03/01/2021] [Accepted: 04/06/2021] [Indexed: 01/20/2023] Open
Abstract
Currently, nearly 6 in 10 US adults are suffering from at least one chronic condition. Wearable technology could help in controlling the health care costs by remote monitoring and early detection of disease worsening. However, in recent years, there have been disappointments in wearable technology with respect to reliability, lack of feedback, or lack of user comfort. One of the promising sensor techniques for wearable monitoring of chronic disease is bioimpedance, which is a noninvasive, versatile sensing method that can be applied in different ways to extract a wide range of health care parameters. Due to the changes in impedance caused by either breathing or blood flow, time-varying signals such as respiration and cardiac output can be obtained with bioimpedance. A second application area is related to body composition and fluid status (eg, pulmonary congestion monitoring in patients with heart failure). Finally, bioimpedance can be used for continuous and real-time imaging (eg, during mechanical ventilation). In this viewpoint, we evaluate the use of wearable bioimpedance monitoring for application in chronic conditions, focusing on the current status, recent improvements, and challenges that still need to be tackled.
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Affiliation(s)
| | - Seulki Lee
- Imec the Netherlands / Holst Centre, Eindhoven, Netherlands
| | - Chris van Hoof
- Imec, Leuven, Belgium
- One Planet Research Center, Wageningen, Netherlands
- Department of Engineering Science, KU Leuven, Leuven, Belgium
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6
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Blanco-Almazan D, Groenendaal W, Lozano-Garcia M, Estrada-Petrocelli L, Lijnen L, Smeets C, Ruttens D, Catthoor F, Jane R. Combining Bioimpedance and Myographic Signals for the Assessment of COPD During Loaded Breathing. IEEE Trans Biomed Eng 2020; 68:298-307. [PMID: 32746014 DOI: 10.1109/tbme.2020.2998009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic conditions. The current assessment of COPD requires a maximal maneuver during a spirometry test to quantify airflow limitations of patients. Other less invasive measurements such as thoracic bioimpedance and myographic signals have been studied as an alternative to classical methods as they provide information about respiration. Particularly, strong correlations have been shown between thoracic bioimpedance and respiratory volume. The main objective of this study is to investigate bioimpedance and its combination with myographic parameters in COPD patients to assess the applicability in respiratory disease monitoring. We measured bioimpedance, surface electromyography and surface mechanomyography in forty-three COPD patients during an incremental inspiratory threshold loading protocol. We introduced two novel features that can be used to assess COPD condition derived from the variation of bioimpedance and the electrical and mechanical activity during each respiratory cycle. These features demonstrate significant differences between mild and severe patients, indicating a lower inspiratory contribution of the inspiratory muscles to global respiratory ventilation in the severest COPD patients. In conclusion, the combination of bioimpedance and myographic signals provides useful indices to noninvasively assess the breathing of COPD patients.
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Schrumpf F, Monch C, Bausch G, Fuchs M. Exploiting Weak Head Movements for Camera-based Respiration Detection. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:6059-6062. [PMID: 31947227 DOI: 10.1109/embc.2019.8856387] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In recent years, considerable progress has been made in the non-contact based detection of the respiration rate from video sequences. Common techniques either directly assess the movement of the chest due to breathing or are based on analyzing subtle color changes that occur as a result of hemodynamic properties of the skin tissue by means of remote photoplethysmography (rPPG). However, extracting hemodynamic parameters from rPPG is often difficult especially if the skin is not visible to the camera. In contrast, extracting respiratory signals from chest movements turned out to be a robust method. However, the detectability of chest regions cannot be guaranteed in any application scenario, for instance if the camera setting is optimized to provide close-up images of the head. In such a case an alternative method for respiration detection is required.It is reasonable to assume that the mechanical coupling between chest and head induces minor movements of the head which, like in rPPG, can be detected from subtle color changes as well. Although the strength of these movements is expected to be much smaller in scale, sensing these intensity variations could provide a reasonably suited respiration signal for subsequent respiratory rate analysis.In order to investigate this coupling we conducted an experimental study with 12 subjects and applied motion-and rPPG-based methods to estimate the respiratory frequency from both head regions and chest. Our results show that it is possible to derive signals correlated to chest movement from facial regions. The method is a feasible alternative to rPPG-based respiratory rate estimations when rPPG-signals cannot be derived reliably and chest movement detection cannot be applied as well.
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8
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Blanco-Almazan D, Groenendaal W, Catthoor F, Jane R. Analysis of Time Delay between Bioimpedance and Respiratory Volume Signals under Inspiratory Loaded Breathing. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:2365-2368. [PMID: 31946375 DOI: 10.1109/embc.2019.8857705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Bioimpedance is known for its linear relation with volume during normal breathing. For that reason, bioimpedance can be used as a noninvasive and comfortable technique for measuring respiration. The goal of this study is to analyze the temporal behavior of bioimpedance measured in four different electrode configurations during inspiratory loaded breathing. We measured four bioimpedance channels and airflow simultaneously in 10 healthy subjects while incremental inspiratory loads were imposed. Inspiratory loading threshold protocols are associated with breathing pattern changes and were used in respiratory mechanics studies. Consequently, this respiratory protocol allowed us to induce breathing pattern changes and evaluate the temporal relationship of bioimpedance with volume. We estimated the temporal delay between bioimpedance and volume respiratory cycles to evaluate the differences in their temporal behavior. The delays were computed as the lag which maximize the cross-correlation of the signals cycle by cycle. Six of the ten subjects showed delays in at least two different inspiratory loads. The delays were dependent on electrode configuration, hence the appearance of the delays between bioimpedance and volume were conditioned to the location and geometry of the electrode configuration. In conclusion, the delays between these signals could provide information about breathing pattern when breathing conditions change.
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9
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Blanco-Almazán D, Groenendaal W, Catthoor F, Jané R. Chest Movement and Respiratory Volume both Contribute to Thoracic Bioimpedance during Loaded Breathing. Sci Rep 2019; 9:20232. [PMID: 31882841 PMCID: PMC6934864 DOI: 10.1038/s41598-019-56588-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/10/2019] [Indexed: 11/22/2022] Open
Abstract
Bioimpedance has been widely studied as alternative to respiratory monitoring methods because of its linear relationship with respiratory volume during normal breathing. However, other body tissues and fluids contribute to the bioimpedance measurement. The objective of this study is to investigate the relevance of chest movement in thoracic bioimpedance contributions to evaluate the applicability of bioimpedance for respiratory monitoring. We measured airflow, bioimpedance at four electrode configurations and thoracic accelerometer data in 10 healthy subjects during inspiratory loading. This protocol permitted us to study the contributions during different levels of inspiratory muscle activity. We used chest movement and volume signals to characterize the bioimpedance signal using linear mixed-effect models and neural networks for each subject and level of muscle activity. The performance was evaluated using the Mean Average Percentage Errors for each respiratory cycle. The lowest errors corresponded to the combination of chest movement and volume for both linear models and neural networks. Particularly, neural networks presented lower errors (median below 4.29%). At high levels of muscle activity, the differences in model performance indicated an increased contribution of chest movement to the bioimpedance signal. Accordingly, chest movement contributed substantially to bioimpedance measurement and more notably at high muscle activity levels.
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Affiliation(s)
- Dolores Blanco-Almazán
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, 08028, Barcelona, Spain.
- Universitat Politècnica de Catalunya · BarcelonaTech (UPC), Barcelona, Spain.
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.
| | - Willemijn Groenendaal
- imec the Netherlands/Holst Centre, High tech campus 31, 5656AE, Eindhoven, The Netherlands
| | | | - Raimon Jané
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, 08028, Barcelona, Spain
- Universitat Politècnica de Catalunya · BarcelonaTech (UPC), Barcelona, Spain
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
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10
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Mosesso VN. Ventilation during cardiopulmonary resuscitation-Only mostly dead! Resuscitation 2019; 141:200-201. [PMID: 31238035 DOI: 10.1016/j.resuscitation.2019.06.274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 06/15/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Vincent N Mosesso
- Department of Emergency Medicine, University of Pittsburgh, Pittsburgh, PA 15213, United States.
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11
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Chang MP, Lu Y, Leroux B, Aramendi Ecenarro E, Owens P, Wang HE, Idris AH. Association of ventilation with outcomes from out-of-hospital cardiac arrest. Resuscitation 2019; 141:174-181. [PMID: 31112744 DOI: 10.1016/j.resuscitation.2019.05.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/04/2019] [Accepted: 05/08/2019] [Indexed: 12/29/2022]
Abstract
AIM OF STUDY To determine the association between bioimpedence-detected ventilation and out-of-hospital cardiac arrest (OHCA) outcomes. METHODS This is a retrospective, observational study of 560 OHCA patients from the Dallas-Fort Worth site enrolled in the Resuscitation Outcomes Consortium Trial of Continuous or Interrupted Chest Compressions During CPR from 4/2012 to 7/2015. We measured bioimpedance ventilation (lung inflation) waveforms in the pause between chest compression segments (Physio-Control LIFEPAK 12 and 15, Redmond, WA) recorded through defibrillation pads. We included cases ≥18 years with presumed cardiac cause of arrest assigned to interrupted 30:2 chest compressions with bag-valve-mask ventilation and ≥2 min of recorded cardiopulmonary resuscitation. We compared outcomes in two a priori pre-specified groups: patients with ventilation waveforms in <50% of pauses (Group 1) versus those with waveforms in ≥50% of pauses (Group 2). RESULTS Mean duration of 30:2 CPR was 13 ± 7 min with a total of 7762 pauses in chest compressions. Group 1 (N = 424) had a median 11 pauses and 3 ventilations per patient vs. Group 2 (N = 136) with a median 12 pauses and 8 ventilations per patient, which was associated with improved return of spontaneous circulation (ROSC) at any time (35% vs. 23%, p < 0.005), prehospital ROSC (19.8% vs. 8.7%, p < 0.0009), emergency department ROSC (33% vs. 21%, p < 0.005), and survival to hospital discharge (10.3% vs. 4.0%, p = 0.008). CONCLUSIONS This novel study shows that ventilation with lung inflation occurs infrequently during 30:2 CPR. Ventilation in ≥50% of pauses was associated with significantly improved rates of ROSC and survival.
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Affiliation(s)
- Mary P Chang
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8579, United States
| | - Yuanzheng Lu
- Emergency and Disaster Medicine Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Brian Leroux
- Department of Biostatistics and Oral Health Sciences, University of Washington, Seattle, WA, United States
| | | | - Pamela Owens
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8579, United States
| | - Henry E Wang
- University of Texas Health Science Center at Houston, Department of Emergency Medicine, Houston, TX, United States
| | - Ahamed H Idris
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8579, United States.
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12
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Aramendi E, Lu Y, Chang MP, Elola A, Irusta U, Owens P, Idris AH. A novel technique to assess the quality of ventilation during pre-hospital cardiopulmonary resuscitation. Resuscitation 2018; 132:41-46. [DOI: 10.1016/j.resuscitation.2018.08.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/19/2018] [Accepted: 08/13/2018] [Indexed: 10/28/2022]
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13
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Wearable Contactless Respiration Sensor Based on Multi-Material Fibers Integrated into Textile. SENSORS 2017; 17:s17051050. [PMID: 28481252 PMCID: PMC5469655 DOI: 10.3390/s17051050] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/21/2017] [Accepted: 05/02/2017] [Indexed: 12/03/2022]
Abstract
In this paper, we report on a novel sensor for the contactless monitoring of the respiration rate, made from multi-material fibers arranged in the form of spiral antenna (2.45 GHz central frequency). High flexibility of the used composite metal-glass-polymer fibers permits their integration into a cotton t-shirt without compromising comfort or restricting movement of the user. At the same time, change of the antenna geometry, due to the chest expansion and the displacement of the air volume in the lungs, is found to cause a significant shift of the antenna operational frequency, thus allowing respiration detection. In contrast with many current solutions, respiration is detected without attachment of the electrodes of any kind to the user’s body, neither direct contact of the fiber with the skin is required. Respiration patterns for two male volunteers were recorded with the help of a sensor prototype integrated into standard cotton t-shirt in sitting, standing, and lying scenarios. The typical measured frequency shift for the deep and shallow breathing was found to be in the range 120–200 MHz and 10–15 MHz, respectively. The same spiral fiber antenna is also shown to be suitable for short-range wireless communication, thus allowing respiration data transmission, for example, via the Bluetooth protocol, to mobile handheld devices.
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14
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Schrumpf F, Sturm M, Bausch G, Fuchs M. Derivation of the respiratory rate from directly and indirectly measured respiratory signals using autocorrelation. CURRENT DIRECTIONS IN BIOMEDICAL ENGINEERING 2016. [DOI: 10.1515/cdbme-2016-0054] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
The estimation of respiratory rates from contineous respiratory signals is commonly done using either fourier transformation or the zero-crossing method. This paper introduces another method which is based on the autocorrelation function of the respiratory signal. The respiratory signals can be measured either directly using a flow sensor or chest strap or indirectly on the basis of the electrocardiogram (ECG). We compare our method against other established methods on the basis of real-world ECG signals and use a respiration-based breathing frequency as a reference. Our method achieved the best agreement between respiration rates derived from directly and indirectly measured respiratory signals.
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Affiliation(s)
- Fabian Schrumpf
- Leipzig University of Applied Sciences (HTWK), Laboratory for Biosignal Processing
| | - Matthias Sturm
- Leipzig University of Applied Sciences (HTWK), Laboratory for Biosignal Processing
| | - Gerold Bausch
- Leipzig University of Applied Sciences (HTWK), Laboratory for Biosignal Processing
| | - Mirco Fuchs
- Leipzig University of Applied Sciences (HTWK), Laboratory for Biosignal Processing
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15
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Wang HB, Yen CW, Liang JT, Wang Q, Liu GZ, Song R. A robust electrode configuration for bioimpedance measurement of respiration. JOURNAL OF HEALTHCARE ENGINEERING 2015; 5:313-27. [PMID: 25193370 DOI: 10.1260/2040-2295.5.3.313] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Electrode configuration is an important issue in the continuous measurement of respiration using impedance pneumography (IP). The robust configuration is usually confirmed by comparing the amplitude of the IP signals acquired with different electrode configurations, while the relative change in waveform and the effects of body posture and respiratory pattern are ignored. In this study, the IP signals and respiratory volume are simultaneously acquired from 8 healthy subjects in supine, left lying, right lying and prone postures, and the subjects are asked to perform four respiratory patterns including free breathing, thoracic breathing, abdominal breathing and apnea. The IP signals are acquired with four different chest electrode configurations, and the volume are measured using pneumotachograph (PNT). Differences in correlation and absolute deviation between the IP-derived and PNT-derived respiratory volume are assessed. The influences of noise, respiratory pattern and body posture on the IP signals of different configurations have significant difference (p < 0.05). The robust electrode configuration is found on the axillary midline, which is suitable for long term respiration monitoring.
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Affiliation(s)
- Hong-Bin Wang
- School of Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Chen-Wen Yen
- Department of Mechanical and Electro-mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Jing-Tao Liang
- School of Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Qian Wang
- School of Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Guan-Zheng Liu
- School of Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Rong Song
- School of Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China
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16
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An ultrasonic contactless sensor for breathing monitoring. SENSORS 2014; 14:15371-86. [PMID: 25140632 PMCID: PMC4179033 DOI: 10.3390/s140815371] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/02/2014] [Accepted: 08/05/2014] [Indexed: 11/16/2022]
Abstract
The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569).
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Seppä VP, Hyttinen J, Uitto M, Chrapek W, Viik J. Novel electrode configuration for highly linear impedance pneumography. ACTA ACUST UNITED AC 2013; 58:35-8. [PMID: 23348215 DOI: 10.1515/bmt-2012-0068] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 01/02/2013] [Indexed: 11/15/2022]
Abstract
Impedance pneumography (IP) is a non-invasive respiration measurement technique. Emerging applications of IP in respiratory medicine use the measured signal to monitor pulmonary flow and volume parameters related to airway obstruction during tidal breathing (TB). This requires a high impedance change (ΔZ)-to-lung volume change (ΔV) linearity. Four potential electrode configurations were tested on 10 healthy subjects. Only the novel configuration where the electrodes were placed in both the thorax and the arms yielded a highly linear ΔZ/ΔV in all subjects. The presented electrode configuration may expand the clinical use of IP from the conventional tidal volume estimation to flow measurement.
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Affiliation(s)
- Ville-Pekka Seppä
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland.
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Scharf C, Cho YK, Bloch KE, Brunckhorst C, Duru F, Balaban K, Foldvary N, Liu L, Burgess RC, Candinas R, Wilkoff BL. Diagnosis of sleep-related breathing disorders by visual analysis of transthoracic impedance signals in pacemakers. Circulation 2004; 110:2562-7. [PMID: 15492313 DOI: 10.1161/01.cir.0000145540.36097.eb] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Minute ventilation sensors of cardiac pacemakers measure ventilation by means of transthoracic impedance changes between the pacemaker case and the electrode tip. We investigated whether this technique might detect sleep-related breathing disorders. METHODS AND RESULTS In 22 patients, analog waveforms of the transthoracic impedance signal measured by the pacemaker minute ventilation sensor over the course of a night were visualized, scored for apnea/hypopnea events, and compared with simultaneous polysomnography. Analysis of transthoracic impedance signals correctly identified the presence or absence of moderate to severe sleep apnea (apnea/hypopnea index, AHI >20 h(-1)) in all patients (receiver operating characteristics, ROC=1.0). The ROC for AHI scores of > or =5 h(-1) and > or =10 h(-1) showed an area under the curve of 0.95, P<0.005, and 0.97, P<0.0001, respectively. Accuracy over time assessed by comparing events per 5-minute epochs was high (Cronbach alpha reliability coefficient, 0.85; intraclass correlation, 0.73). Event-by-event comparison within +/-15 seconds revealed agreement in 81% (kappa, 0.77; P<0.001). CONCLUSIONS Detection of apnea/hypopnea events by pacemaker minute ventilation sensors is feasible and accurate compared with laboratory polysomnography. This technique might be useful to screen and monitor sleep-related breathing disorders in pacemaker patients.
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Affiliation(s)
- Christoph Scharf
- Cardiovascular Center, University Hospital Zurich, Department of Internal Medicine, Division of Cardiology and Pneumology, Rämistrasse 100, CH-8091 Zürich, Switzerland.
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Davidson KG, Bersten AD, Nicholas TE, Ravenscroft PR, Doyle IR. Measurement of tidal volume by using transthoracic impedance variations in rats. J Appl Physiol (1985) 1999; 86:759-66. [PMID: 9931218 DOI: 10.1152/jappl.1999.86.2.759] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The application of impedance pneumography for monitoring respiration in small animals has been limited by problems with calibration. With improved instrumentation, we describe the calibration of tidal volume in anesthetized rats. The detection of changes in voltage, reflecting the electrical impedance variations associated with respiration, was optimized by using disposable adhesive silver-silver chloride electrodes, advanced circuitry, and analog-to-digital recording instrumentation. We found a linear relationship between change in impedance and tidal volume in individual rats (R2 >/= 98%), which was strongly influenced by rat weight. Consequently, a calibration equation incorporating change in impedance and rat weight was derived to predict tidal volume. Comparison of the predicted and true tidal volumes revealed a mean R2 >/= 98%, slopes of approximately 1, intercepts of approximately 0, and bias of approximately 0.07 ml. The predicted volumes were not significantly affected by either frequency of respiration or pulmonary edema. We conclude that impedance pneumography provides a valuable tool for the noninvasive measurement of tidal volume in anesthetized rats.
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Affiliation(s)
- K G Davidson
- Department of Human Physiology, School of Medicine, Flinders University of South Australia
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20
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Pelosi P, Aliverti A, Dellaca R. Chest Wall Mechanics: Methods of Measurement and Physiopathologic Insights. ACTA ACUST UNITED AC 1998. [DOI: 10.1007/978-3-642-72038-3_32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
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21
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Borganelli M, el-Atassi R, Leon A, Kalbfleisch SJ, Calkins H, Morady F, Langberg JJ. Determinants of impedance during radiofrequency catheter ablation in humans. Am J Cardiol 1992; 69:1095-7. [PMID: 1561988 DOI: 10.1016/0002-9149(92)90873-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- M Borganelli
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0022
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van den Aardweg JG, Karemaker JM. Respiratory variability and associated cardiovascular changes in adults at rest. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1991; 11:95-118. [PMID: 2040134 DOI: 10.1111/j.1475-097x.1991.tb00103.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Breathing patterns and associated circulatory fluctuations may reflect the action of various regulatory mechanisms as well as mechanical influences of breathing on the circulation. Thus, the study of such patterns can enhance our knowledge of these mechanisms, both in normal and pathological conditions. In this review, literature is evaluated that provides insight into the breath-to-breath variation of respiration in quietly breathing adults. Also when respiration is seemingly random, deterministic patterns in the respiratory variability can often be discerned. The various methods used in the recognition of such patterns and their possible interpretation are discussed. Furthermore, the question is addressed how respiratory variability can affect the circulation and how this can be studied by analysing the time relationships of respiratory and circulatory parameters. This may add to both the understanding of normal cardiovascular regulation and to insight into cardiovascular disturbances under unstable respiratory conditions. As examples of such circumstances, some common conditions are discussed that are often, though not always, associated with pathology, viz. Cheyne-Stokes respiration, snoring and the sleep apnoea syndrome.
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Affiliation(s)
- J G van den Aardweg
- Department of Internal Medicine, Academisch Medisch Centrum, Amsterdam, The Netherlands
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23
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Larsen VH, Christensen PH, Oxhøj H, Brask T. Impedance pneumography for long-term monitoring of respiration during sleep in adult males. ACTA ACUST UNITED AC 1984; 4:333-42. [PMID: 6540645 DOI: 10.1111/j.1475-097x.1984.tb00808.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Impedance pneumography is based on the relationship between respired volume (delta V) and changes of transthoracic impedance (delta/Z/) during breathing. The impedance signal, the relationship between delta V and delta/Z/ and the success rate during long-term recording was studied in 11 healthy adult males, aged 21-46, by a portable tape recorder (Oxford Medilog 4-24). The signals from the tape recorder (delta/Z/), and from a spirometer (delta V) were recorded simultaneously on a mingograph during normal breathing, apnoea, deep sighs, and coughs. The relationship between delta V and delta/Z/ was also analysed on an X-Y recorder. Delta/Z/ was delayed in relation to delta V and during one respiratory cycle the relationship was not linear. The time constant of delta/Z/ was 6 s. A significant correlation was found between peak values of delta V and delta/Z/ for 0 less than delta V less than 2.5 litres. Long-term recording of delta/Z/ during one night's sleep resulted in a success rate of 63-100%, mean 90%. Invalidation of the impedance signal was caused by overloading (81%) and interference (19%). It is concluded that the Medilog respiratory recorder enables determination of respiratory frequency, periods of apnoea and a semiquantitative estimate of volume, but artifacts may invalidate the signal.
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24
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Plonsey R, Collin R. Electrode guarding in electrical impedance measurements of physiological systems--a crituque. Med Biol Eng Comput 1977; 15:519-27. [PMID: 199806 DOI: 10.1007/bf02442279] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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25
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Freundlich JJ, Erickson JC. Electrical impedance pneumography for simple nonrestrictive continuous monitoring of respiratory rate, rhythm and tidal volume for surgical patients. Chest 1974; 65:181-4. [PMID: 4810676 DOI: 10.1378/chest.65.2.181] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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26
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Van de Water JM, Mount BE, Barela JR, Schuster R, Leacock FS. Monitoring the chest with impedance. Chest 1973; 64:597-603. [PMID: 4750331 DOI: 10.1378/chest.64.5.597] [Citation(s) in RCA: 88] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Wadhwani R, Longini RL. Analysis of quiet spontaneous breathing as measured by spirometer and electrical impedance plethysmography. COMPUTERS AND BIOMEDICAL RESEARCH, AN INTERNATIONAL JOURNAL 1973; 6:74-89. [PMID: 4695392 DOI: 10.1016/0010-4809(73)90063-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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