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Sensors (Basel, Switzerland) Jun 2014Bioimpedance analysis is a noninvasive, low cost and a commonly used approach for body composition measurements and assessment of clinical condition. There are a variety... (Review)
Review
Bioimpedance analysis is a noninvasive, low cost and a commonly used approach for body composition measurements and assessment of clinical condition. There are a variety of methods applied for interpretation of measured bioimpedance data and a wide range of utilizations of bioimpedance in body composition estimation and evaluation of clinical status. This paper reviews the main concepts of bioimpedance measurement techniques including the frequency based, the allocation based, bioimpedance vector analysis and the real time bioimpedance analysis systems. Commonly used prediction equations for body composition assessment and influence of anthropometric measurements, gender, ethnic groups, postures, measurements protocols and electrode artifacts in estimated values are also discussed. In addition, this paper also contributes to the deliberations of bioimpedance analysis assessment of abnormal loss in lean body mass and unbalanced shift in body fluids and to the summary of diagnostic usage in different kinds of conditions such as cardiac, pulmonary, renal, and neural and infection diseases.
Topics: Biosensing Techniques; Body Composition; Diagnosis, Computer-Assisted; Equipment Design; Equipment Failure Analysis; Humans; Models, Biological; Monitoring, Physiologic; Plethysmography, Impedance
PubMed: 24949644
DOI: 10.3390/s140610895 -
Sensors (Basel, Switzerland) Dec 2022Depth-based plethysmography (DPG) for the measurement of respiratory parameters is a mobile and cost-effective alternative to spirometry and body plethysmography. In... (Review)
Review
Depth-based plethysmography (DPG) for the measurement of respiratory parameters is a mobile and cost-effective alternative to spirometry and body plethysmography. In addition, natural breathing can be measured without a mouthpiece, and breathing mechanics can be visualized. This paper aims at showing further improvements for DPG by analyzing recent developments regarding the individual components of a DPG measurement. Starting from the advantages and application scenarios, measurement scenarios and recording devices, selection algorithms and location of a region of interest (ROI) on the upper body, signal processing steps, models for error minimization with a reference measurement device, and final evaluation procedures are presented and discussed. It is shown that ROI selection has an impact on signal quality. Adaptive methods and dynamic referencing of body points to select the ROI can allow more accurate placement and thus lead to better signal quality. Multiple different ROIs can be used to assess breathing mechanics and distinguish patient groups. Signal acquisition can be performed quickly using arithmetic calculations and is not inferior to complex 3D reconstruction algorithms. It is shown that linear models provide a good approximation of the signal. However, further dependencies, such as personal characteristics, may lead to non-linear models in the future. Finally, it is pointed out to focus developments with respect to single-camera systems and to focus on independence from an individual calibration in the evaluation.
Topics: Humans; Plethysmography; Spirometry; Respiratory Mechanics; Respiratory Rate; Linear Models; Respiration
PubMed: 36560048
DOI: 10.3390/s22249680 -
Nutrients Oct 2022Energy expenditure is a key parameter in quantifying physical activity. Traditional methods are limited because they are expensive and cumbersome. Additional portable...
PURPOSE
Energy expenditure is a key parameter in quantifying physical activity. Traditional methods are limited because they are expensive and cumbersome. Additional portable and cheaper devices are developed to estimate energy expenditure to overcome this problem. It is essential to verify the accuracy of these devices. This study aims to validate the accuracy of energy expenditure estimation by a respiratory magnetometer plethysmography system in children, adolescents and adults using a deep learning model.
METHODS
Twenty-three healthy subjects in three groups (nine adults (A), eight post-pubertal (PP) males and six pubertal (P) females) first sat or stood for six minutes and then performed a maximal graded test on a bicycle ergometer until exhaustion. We measured energy expenditure, oxygen uptake, ventilatory thresholds 1 and 2 and maximal oxygen uptake. The respiratory magnetometer plethysmography system measured four chest and abdomen distances using magnetometers sensors. We trained the models to predict energy expenditure based on the temporal convolutional networks model.
RESULTS
The respiratory magnetometer plethysmography system provided accurate energy expenditure estimation in groups A (R = 0.98), PP (R = 0.98) and P (R = 0.97). The temporal convolutional networks model efficiently estimates energy expenditure under sitting, standing and high levels of exercise intensities.
CONCLUSION
Our results proved the respiratory magnetometer plethysmography system's effectiveness in estimating energy expenditure for different age populations across various intensities of physical activity.
Topics: Adolescent; Adult; Child; Deep Learning; Energy Metabolism; Exercise; Female; Humans; Male; Oxygen; Oxygen Consumption; Plethysmography
PubMed: 36235842
DOI: 10.3390/nu14194190 -
Journal of Applied Physiology... Jul 2022Mice are a valuable model for elegant studies of complex, system-dependent diseases, including pulmonary diseases. Current tools to assess lung function in mice are...
Mice are a valuable model for elegant studies of complex, system-dependent diseases, including pulmonary diseases. Current tools to assess lung function in mice are either terminal or lack accuracy. We set out to develop a low-cost, accurate, head-out variable-pressure plethysmography system to allow for repeated, nonterminal measurements of lung function in mice. Current head-out plethysmography systems are limited by air leaks that prevent accurate measures of volume and flow. We designed an inflatable cuff that encompasses the mouse's neck preventing air leak. We wrote corresponding software to collect and analyze the data, remove movement artifacts, and automatically calibrate each dataset. This software calculates volume, inspiratory/expiratory time, breaths per minute, mid-expiratory flow, and end-inspiratory pause. To validate the use, we established that our plethysmography system accurately measured tidal breathing, the bronchoconstrictive response to methacholine, sex- and age-associated changes in breathing, and breathing changes associated with house dust mite sensitization. Our estimates of volume, flow, and timing of breaths are in line with published estimates, we observed dose-dependent decreases in volume and flow in response to methacholine ( < 0.05), increased lung volume, and decreased breathing rate with aging ( < 0.05), and that house dust mite sensitization decreased volume and flow ( < 0.05) while exacerbating the methacholine-induced increase in inspiratory time ( < 0.05). We describe an accurate, sensitive, low-cost, head-out plethysmography system that allows for longitudinal studies of pulmonary disease in mice. We describe a low-cost, variable-pressure head-out plethysmography system that can be used to assess lung function in mice. A balloon cuff is inflated around the mouse's neck to prevent air leak, allowing for accurate measurements of lung volume and air flow. Custom software facilitates system calibration, removes movement artifacts, and eases data analysis. The system was validated by measuring tidal breathing, responses to methacholine, and changes associated with house dust mite sensitization, sex, and aging.
Topics: Animals; Bronchoconstriction; Lung; Lung Volume Measurements; Methacholine Chloride; Mice; Plethysmography; Tidal Volume
PubMed: 35608203
DOI: 10.1152/japplphysiol.00835.2021 -
Journal of Applied Physiology... May 2021Work of breathing ([Formula: see text]) derived from a single lung volume and pleural pressure is limited and does not fully characterize the mechanical work done by the...
Work of breathing ([Formula: see text]) derived from a single lung volume and pleural pressure is limited and does not fully characterize the mechanical work done by the respiratory musculature. It has long been known that abdominal activation increases with increasing exercise intensity, yet the mechanical work done by these muscles is not reflected in [Formula: see text]. Using optoelectronic plethysmography (OEP), we sought to show first that the volumes obtained from OEP (V) were comparable to volumes obtained from flow integration (V) during cycling and running, and second, to show that partitioned volume from OEP could be utilized to quantify the mechanical work done by the rib cage ([Formula: see text]) and abdomen ([Formula: see text]) during exercise. We fit 11 subjects (6 males/5 females) with reflective markers and balloon catheters. Subjects completed an incremental ramp cycling test to exhaustion and a series of submaximal running trials. We found good agreement between V versus V during cycling (bias = 0.002; > 0.05) and running (bias = 0.016; > 0.05). From rest to maximal exercise,[Formula: see text] increased by 84% (range: 30%-99%; [Formula: see text]: 1 ± 1 J/min to 61 ± 52 J/min). The relative contribution of the abdomen increased from 17 ± 9% at rest to 26 ± 16% during maximal exercise. Our study highlights and provides a quantitative measure of the role of the abdominal muscles during exercise. Incorporating the work done by the abdomen allows for a greater understanding of the mechanical tasks required by the respiratory muscles and could provide further insight into how the respiratory system functions during disease and injury. We demonstrated that optoelectronic plethysmography (OEP) is a reliable tool to determine ventilatory volume changes during cycling and running, without restricting natural upper arm movements. Second, using OEP volumes coupled with pressure-derived measures, we calculated the work done by the rib cage and abdomen, respectively, during exercise. Collectively, our findings indicate that pulmonary mechanics can be accurately quantified using OEP, and abdominal work performed during ventilation contributes substantially to the overall work of the respiratory musculature.
Topics: Female; Humans; Lung Volume Measurements; Male; Plethysmography; Respiration; Running; Work of Breathing
PubMed: 33703946
DOI: 10.1152/japplphysiol.00945.2020 -
Journal of Applied Physiology... Feb 2005Venous occlusion plethysmography is a simple but elegant technique that has contributed to almost every major area of vascular biology in humans. The general principles...
Venous occlusion plethysmography is a simple but elegant technique that has contributed to almost every major area of vascular biology in humans. The general principles of plethysmography were appreciated by the late 1800s, and the application of these principles to measure limb blood flow occurred in the early 1900s. Plethysmography has been instrumental in studying the role of the autonomic nervous system in regulating limb blood flow in humans and important in studying the vasodilator responses to exercise, reactive hyperemia, body heating, and mental stress. It has also been the technique of choice to study how human blood vessels respond to a variety of exogenously administered vasodilators and vasoconstrictors, especially those that act on various autonomic and adrenergic receptors. In recent years, plethysmography has been exploited to study the role of the vascular endothelium in health and disease. Venous occlusion plethysmography is likely to continue to play an important role as investigators seek to understand the physiological significance of newly identified vasoactive factors and how genetic polymorphisms affect the cardiovascular system in humans.
Topics: Cardiovascular Diseases; Exercise; Extremities; History, 19th Century; History, 20th Century; Humans; Hyperemia; Plethysmography; Raynaud Disease; Regional Blood Flow
PubMed: 15649884
DOI: 10.1152/japplphysiol.00773.2004 -
Respiratory Research Mar 2020The mechanism for symptomatic improvement after bronchial thermoplasty (BT) is unclear, since spirometry reveals little or no change. In this study, the effects of BT on...
BACKGROUND
The mechanism for symptomatic improvement after bronchial thermoplasty (BT) is unclear, since spirometry reveals little or no change. In this study, the effects of BT on airway resistance were examined using two independent techniques.
METHODS
Eighteen consecutive patients, with severe asthma (57.6 ± 14.2 years) were evaluated by spirometry and plethysmography at three time points: (i) baseline, (ii) left lung treated but right lung untreated and (iii) 6 weeks after both lungs were treated with BT. At each assessment, total and specific airway resistance (Raw, sRaw) were measured. High resolution CT scans were undertaken at the first two assessments, and measurements of lobar volume, airway volume and airway resistance were made. The Asthma Control Questionnaire (ACQ) was administered at each assessment.
RESULTS
The baseline ACQ score was 3.5 ± 0.9, and improved progressively to 1.8 ± 1.2 (p < 0.01). At baseline, severe airflow obstruction was observed, FEV1 44.8 ± 13.7% predicted, together with gas trapping, and elevated Raw at 342 ± 173%predicted. Following BT, significant improvements in Raw and sRaw were observed, as well as a reduction in Residual Volume, increase in Vital Capacity and no change in FEV1. The change in Raw correlated with the change in ACQ (r = 0.56, p < 0.05). CT scans demonstrated reduced airway volume at baseline, which correlated with the increased Raw determined by plethysmography (p = - 0.536, p = < 0.05). Following BT, the airway volume increased in the treated lung, and this was accompanied by a significant reduction in CT-determined local airway resistance.
CONCLUSION
Symptomatic improvement after BT is mediated by increased airway volume and reduced airway resistance.
Topics: Adult; Aged; Airway Resistance; Asthma; Bronchial Thermoplasty; Female; Humans; Male; Middle Aged; Plethysmography; Respiratory Function Tests
PubMed: 32228586
DOI: 10.1186/s12931-020-1330-5 -
Respiratory Medicine Mar 2019The exercise challenge is the gold standard for diagnosing exercise-induced bronchoconstriction (EIB). Airway obstructions appear up to 30 min after the challenge,... (Comparative Study)
Comparative Study
BACKGROUND
The exercise challenge is the gold standard for diagnosing exercise-induced bronchoconstriction (EIB). Airway obstructions appear up to 30 min after the challenge, with a maximum decrease in spirometry and a maximum increase in airway resistance. There is evidence that changes in body plethysmography parameters are more sensitive to the exercise challenge and precede those in spirometry.
PURPOSE
To compare changes in body plethysmography and spirometry parameters after exercise challenges and to verify the cut-off values of sReff in EIB.
PROCEDURES
In 82 subjects with suspected EIB, a total of 473 lung function tests were measured at baseline and at 5, 10, 15, and 30 min after exercise challenges at different stages of bronchial obstruction.
FINDINGS
The maximum changes in the body plethysmography parameter sReff significantly preceded the maximum changes in the spirometry parameter FEV (sReff: 12.2 min ±8.8, FEV: 15.2 min ±9.3, p < 0.005). The parameters of sReff and FEV had a strong negative correlation (r = -0.63, p < 0.0001) with a nonlinear, polynomial relationship. Furthermore, sReff and Reff had a strong linear correlation (r = 0.86, p < 0.001), and Reff and Rtot had a perfect linear correlation (r = 0.99, p < 0.001). Based on baseline values and on quantile regression, an increase of 0.25 kPa s in sReff was defined as significant. Using this cut-off value, FEV and sReff almost equally detected EIB.
CONCLUSION
The changes in sReff were more sensitive and better indicated lung impairment than did the changes in FEV, which underestimated the degree of hyperinflation.
Topics: Adolescent; Adult; Airway Obstruction; Airway Resistance; Asthma, Exercise-Induced; Bronchial Provocation Tests; Child; Female; Forced Expiratory Volume; Humans; Male; Plethysmography, Whole Body; Spirometry; Young Adult
PubMed: 30827475
DOI: 10.1016/j.rmed.2019.01.011 -
Scientific Reports Nov 2022Measuring breathing rates without a mouthpiece is of interest in clinical settings. Electrocardiogram devices and, more recently, optoelectronic plethysmography (OEP)...
Measuring breathing rates without a mouthpiece is of interest in clinical settings. Electrocardiogram devices and, more recently, optoelectronic plethysmography (OEP) methods can estimate breathing rates with only a few electrodes or motion-capture markers placed on the patient. This study estimated and compared the accuracy and reliability of three non-invasive devices: an OEP system with 12 markers, an electrocardiogram device and the conventional spirometer. Using the three devices simultaneously, we recorded 72 six-minute epochs on supine subjects. Our results show that the OEP system has a very low limit of agreement and a bias lower than 0.4% compared with the spirometer, indicating that these devices can be used interchangeably. We observed comparable results for electrocardiogram devices. The OEP system facilitates breathing rate measurements and offers a more complete chest-lung volume analysis that can be easily associated with heart rate analysis without any synchronisation process, for useful features for clinical applications and intensive care.
Topics: Humans; Heart Rate; Reproducibility of Results; Plethysmography; Lung Volume Measurements; Spirometry; Respiration
PubMed: 36357452
DOI: 10.1038/s41598-022-23915-1 -
British Heart Journal Jan 1960
Topics: Cardiovascular Diseases; Diagnostic Techniques, Cardiovascular; Humans; Plethysmography, Impedance
PubMed: 14433931
DOI: No ID Found